Reflections on the Voice to Parliament Referendum

This morning, I woke to the not unexpected news that the referendum on the Voice to Parliament had failed. I will hold back from expressing some of my views on the main political actors and their motivations, except to say, beware of opportunists who seek political advantage on social and justice issues as serious as this. I want to share some of my experiences with First Nations in Australia, because I’ve seen more than most and these motivate my commitment to reconciliation.

My understanding and interaction with Indigenous Australians relates mostly to my time in the outback.

I started my career in Mount Isa, which had major problems with alcoholism and homelessness in the Aboriginal community. There was one lady who was well known for urinating in public and shouting at people while carrying her flagon of McWilliams sherry. Yeah, it wasn’t nice, perhaps we need to think about the structural inequities that led her there. There was also Ian from Smelting Research, safety guru and still one of the best supervisors I’ve ever worked with. He helped save me from my inexperience more than once, when I was potentially putting myself in danger at the lead smelter.

In 1995, I did my one and only trip to Kakadu. We checked out the amazing rock art at Burrunggui. If I had my time again, I would go with an Aboriginal guide so that I could better capture the cultural meaning.

In 1997, me and my housemates took an epic drive from Mount Isa, through the red centre and on to Kalgoorlie, Bunbury, Perth then via the Pilbara, across the Kimberly and back to Isa. I was young and uninformed and climbed the sacred rock, Uluru, which I remain ashamed for to this day. It’s a reminder to me why we need to give more voice to the cultural wishes of First Nations. My ignorance was not an acceptable excuse. We stopped for petrol, I think it was at Kaltukatjara. There were padlocks on all the bowsers, as petrol sniffing was rife in outback communities. A tall, quiet, young Aboriginal man came out and looked at us. Our eyes met, no words were said. I wanted to say something empathetic. I didn’t know what. Weeks later, we traveled through Halls Creek. Things looked rough as hell there. When we stopped at Kalkarindji, the local fast food shop was overwhelmed with a crowd of Aboriginal kids trying to get fried food. A moment for me to reflect that food available in the territory at that time would not lead to good health outcomes. I left the settlement formerly known as Wave Hill with no idea about Vincent Lingiari, despite singing along to Paul Kelly’s song that trip.

In 1998, I took a drive from Mount Isa to Osborne Mine for an interview, stopping briefly at a shop in Dajarra for a snack. The white woman running the shop was saying something vicious to two Aboriginal kids there. I didn’t know the full context and I didn’t know what to say. However, I will never forget the disrespect that hung in the air, and how quickly I wanted to remove myself from that negative energy, because deep seated racism is truly oppressive when you see it.

Later when I got to Century Mine, I saw how extractive industries could work together to share economic benefits with Aboriginal communities and develop career paths for Indigenous Australians. The journey wasn’t always easy, like when the sit in occurred in 2002. I never got to meet Murrandoo, he was a bit of a controversial character, but his brother Bull and I got to talk quite a bit and I always felt we had mutual respect. For our Aboriginal workers, there were some big hurdles with literacy and numeracy and overcoming deep introversion. Some nights, before I had to leave for dinner in camp, Freddie, John, Tony and others would come and talk about their hopes, fears and aspirations. These were the most important times in my role as the manager of the plant. The highlight of my career was when I had to give a presentation in Normanton about how we would change operations at the mine site to allow more consistent delivery of water to the Aboriginal pastoral station at Moor Moor. The guy in charge made a joke before we got started about his spear that he had placed in the corner, and that he hoped he didn’t have to use it (on me). Luckily I had done my homework, we had a plan and I had worked hard to ensure that I could effectively listen to the concerns and communicate the technical and operational aspects that affected our ability to deliver water of acceptable quality to the station. They were very pleased and we delivered on our promises. That evening we drove down a dirt road to a remote community and had dinner together under the stars.

It’s been 15 years since I left Australia, and these days I feel a little more removed from First Nations issues there. However, Australia and its First Nations are in my heart and will never leave. Reconciliation is not dead, it lives in each one of us if we choose to let it.

For my Australian colleagues who voted no, I ask a few things of you. Firstly, if you have not read the Uluru Statement from the Heart, read it, I have included it below. Ask yourself, does this seem like an inherently fair statement? If not, please look at yourself in the mirror and ask if the issue is with the writers of the statement or with yourself. Secondly, given that you have decided that the Voice to Parliament is not the path forward, ask yourself what do you plan to do to advance reconciliation and address the severe inequalities in social outcomes that Indigenous Australians continue to face. If you’re devoid of ideas, I’d recommend a little education on our Australian history (yes it’s uncomfortable), listening to some music and trying to understand what the artists were saying (e.g. Midnight Oil, Yothu Yindi and Gurrumal to start). Watch the documentary on Adam Goodes and perhaps switch over to NITV sometime. Read about the Mabo decision. Find out how you can listen to more First Nations voices.

It is difficult to describe the pain I feel right now. I am not First Nations and I don’t pretend to know what it’s like to be Indigenous in Australia. But I’ve seen enough to know that what happened during this referendum wasn’t right, and many of those who championed a no vote don’t have the interests of First Nations at heart. While some First Nations people need a week of silence to reflect on what happened, I can’t be silent right now. To do so would be unconscionable. I invite you to engage with me in constructive conversation. Thanks for reading this.

https://ulurustatemdev.wpengine.com/wp-content/uploads/2022/01/UluruStatementfromtheHeartPLAINTEXT.pdf

ULURU STATEMENT FROM THE HEART

We, gathered at the 2017 National Constitutional Convention, coming from all points of the southern sky, make this statement from the heart:

Our Aboriginal and Torres Strait Islander tribes were the first sovereign Nations of the Australian continent and its adjacent islands, and possessed it under our own laws and customs. This our ancestors did, according to the reckoning of our culture, from the Creation, according to the common law from ‘time immemorial’, and according to science more than 60,000 years ago.

This sovereignty is a spiritual notion: the ancestral tie between the land, or ‘mother nature’, and the Aboriginal and Torres Strait Islander peoples who were born therefrom, remain attached thereto, and must one day return thither to be united with our ancestors. This link is the basis of the ownership of the soil, or better, of sovereignty. It has never been ceded or extinguished, and co-exists with the sovereignty of the Crown.

How could it be otherwise? That peoples possessed a land for sixty millennia and this sacred link disappears from world history in merely the last two hundred years?

With substantive constitutional change and structural reform, we believe this ancient sovereignty can shine through as a fuller expression of Australia’s nationhood.

Proportionally, we are the most incarcerated people on the planet. We are not an innately criminal people. Our children are aliened from their families at unprecedented rates. This cannot be because we have no love for them. And our youth languish in detention in obscene numbers. They should be our hope for the future.

These dimensions of our crisis tell plainly the structural nature of our problem. This is the torment of our powerlessness.

We seek constitutional reforms to empower our people and take a rightful place in our own country. When we have power over our destiny our children will flourish. They will walk in two worlds and their culture will be a gift to their country.

We call for the establishment of a First Nations Voice enshrined in the Constitution.

Makarrata is the culmination of our agenda: the coming together after a struggle. It captures our aspirations for a fair and truthful relationship with the people of Australia and a better future for our children based on justice and self-determination.

We seek a Makarrata Commission to supervise a process of agreement-making between governments and First Nations and truth-telling about our history.

In 1967 we were counted, in 2017 we seek to be heard. We leave base camp and start our trek across this vast country. We invite you to walk with us in a movement of the Australian people for a better future.

Women in Mining - Reflections from SME 2023

As I write from Denver, CO following SME MineXchange 2023, I am feeling thankful for the many outstanding, competent women in mining who I met and engaged with this week. Women who mean business and collaborate. Women with tenacity, curiosity, kindness, patience, courage, intelligence and potential. Women who are using their unique leadership styles to bring change to an industry that desperately needs it.

Tina Darakjian of WSP, one of several excellent women speakers in the Inclusion and diversity program at sme 2023

Thank you for sharing your expectations, perspectives and aspirations. Thank you for teaching me more about allyship and allowing me to advocate for you. Thank you for listening, sharing your stories and honouring my emotions. I see your beautiful diversity. There is much to do to build the broader and more inclusive professional workforce that the mining industry needs to solve its many strategic challenges. Making the industry more welcoming to women and underrepresented groups is a key part of attracting and retaining talent wherever the industry can. I look forward to working more with you to help steer us to a safer, healthier, more productive and more sustainable mining industry.

Jagersfontein tailings disaster - a reminder mining still has a credibility crisis

I woke up this morning to the devastating news of another deadly tailings dam failure, this time in Jagersfontein, Free State, South Africa. A massive mud torrent had destroyed many houses in the settlement of Charlesville. There are conflicting reports on the number of people dead and missing, with Bloomberg reporting three dead, while Mining.com has reported one dead.

Tailings innundation in Charlesville, near Jagersfontein, 11 Sep 2022 (source: https://africatimes.com/2022/09/11/sa-diamond-mine-dam-fails-fatal-deluge-hits-charlesville/)

28 years ago, there was another catastrophic tailings dam failure in Free State, in the town of Merriespruit. That event killed 17 people and lead to strengthening of residue management standards in South Africa. Merriespruit is one of a string of failures over the last 40 years, which have included Stava, Los Frailes, Mt Polly, Fundao (Samarco) and Brumadinho.

ICMM has issued a statement and reinforced the importance of the implementation of the Global Industry Standard on Tailings Management (GISTM). I, too, am dismayed and saddened, and I felt something important was missing from the ICMM press release. The Jagersfontein mine was formerly owned by De Beers, which in turn is 85% owned by Anglo American, a founding member of ICMM. The property, which had been shut down in 1971, was sold by De Beers, and in its Report to Society 2010, De Beers stated: “Where possible, the Family of Companies (i.e. De Beers) has sold late-lifecycle mines to operators optimised to generate value from late-lifecycle mines. In October 2010, we sold the mine site and tailings mineral resource at Jagersfontain Mine in South Africa. Closed as a mine for almost 40 years, the mine was sold to Superkolong Consortium, a broad based Black Economic Empowerment (BEE) holding company under terms which will deliver sustainable benefit to the Jagersfontein community.”

What was delivered to the Jagersfontein community this week is death and destruction. There are many questions. In 2010, how did De Beers assess that the new owners had the necessary competence and capacity to manage a major tailings facility, including a tailings reprocessing operation? What records and risk documentation were passed on about the facility? Was the new owner aware of and adhering to appropriate and legally required tailings management practices? Did De Beers do any follow up post transfer to ensure community interests were being addressed? Would such a requirement be fair and reasonable to expect from De Beers? Were residents of the Charleville aware of the risks in a failure event and were results of dam breach analysis shared with communities? Were response plans in place should an emergency occur?

Google Earth shows the facility as follows, which offers some clues, and I have marked on the general location of the failure and direction of the tailings flow based on early reports from Dave Petley, a geotechnical expert based in England.

Jagersfontein Tailings Facility (source: Google Earth)

It looks like there is a lot of water in the facility at the time of this photo. A 2013 environmental impact assessment report included a description of an old tailings facility and a new one adjoined to the west, constructed by the new owner, Jagersfontein Developments. Ongoing construction and modification of a tailings facility can cause problems that eventually lead to catastrophic failures. It was not clear if tailings reprocessing activities were ongoing around the time of the breach. These failures can be complex and we will need to wait for a proper investigation to be completed before causes can be identified.

2013 plans for Jagersfointain showing old and new tailings dam (Source: https://sahris.sahra.org.za/sites/default/files/additionaldocs/JD%20Report%20Impact%20Assessment%20Gys%20Hoon_0.pdf)

In the meantime, Jagersfontein reveals some yawning gaps in tailings facility safety:

1. While the GISTM has been a significant step forward in setting tailings management standards, many mining operators have not yet committed to implementing it or similar management systems such as TSM.

2. Stewardship of legacy facilities, after transfer of ownership to other companies or to communities or governments. Residual risks from tailings facilities can remain.

As an industry, there is much to do to restore our battered credibility with respect to safe tailings management. We need to renew our commitment to stop killing people. This may include a stronger leadership role for competent mining companies, investors and industry professionals to ensure that all mine operators are rising to societal expectations for safe and environmentally acceptable practice. The future of the industry depends on this.

Canada's Critical Minerals List is out. Now what?

Recently, Canada’s Minister of Natural Resources, Seamus O’Regan, announced the release of the country’s critical mineral list, consisting of 31 minerals/metals . Canada is the latest country to publish such a list, USA, EU, Japan and South Korea have previously published, as summarized in the table below.

Note that there are 9 items that appear on all lists: antimony, cobalt, gallium, indium, lithium, niobium, PGE/PGM, tungsten and vanadium.

Critical minerals list came about mainly from a geopolitical perspective to recognize the limited geographical diversity of supply of certain minerals and metals across the value chain, as well as the strategic importance of these minerals and metals for military, technology and sustainability applications. There are a few themes:

·      Minerals/metals where mine supply is limited to a few countries (e.g. cobalt from DRC, PGM and vanadium from South Africa, niobium from Brazil, REE and tungsten from China, lithium from Australia and Chile)

·      Minerals/metals that are recovered as byproducts of refining other metals, where production is limited to a few countries (largely dominated by China), such as indium and germanium from zinc refining, tellurium from copper refining, etc.

·      Minerals/metals that are key ingredients into sustainable technologies (e.g. lithium, nickel, cobalt and graphite for batteries, with resulting pathways to GHG emission reduction).

·      There are specific concerns relating to security of supply of REE from China, and the threat of withholding of supply to countries such as Japan and USA.

Criticality varies by region, and of the countries listed, Canada is unique in that it is a major net exporter of mineral and metal products, whereas the other countries are net importers. The Canadian list was selected to reflect the potential for Canadian mine and refined production, and potential integration with downstream manufacturing. While one aspect is on starting production of new critical minerals mines (e.g. for lithium, graphite and REE), another aspect is protecting the current production base. For aluminum, Canada has a world class smelting sector supported by low carbon electricity.

Canada has suffered declines in some critical metals production in the last 20 years, especially the reduction in zinc mining and zinc and copper refining. This has also led to declines in refined critical byproduct metals such as indium and bismuth. The table below shows the relationship between typical base metals production and byproduct metal production, including some critical minerals. For Canada, the continuation of plants such as Trail Smelting and Refining Complex, the Sudbury nickel smelters, Horne Smelter and CCR copper refinery are vital for production of refined critical metals in Canada.

Should the Canadian Government wish to further promote critical minerals production in Canada, it will be important to realize the intent of the Canadian Minerals and Metals Plan by providing incentives for mine development, assistance with strategic infrastructure, certainty on permitting processes, facilitating Indigenous engagement and participation in development, and support for in country smelting and refining.

Governments can sometimes help to facilitate development of, or fund, infrastructure for remote mine sites such as roads and ports.In certain cases, Canada should continue to recognize responsible supply chains for the refining of Canadian mined mineral and metal content, such as the refining of Ni-Cu-Co-PGM matte from Glencore Sudbury Nickel Operations into refined Ni, Cu, Co and PGM at Nikkelverk Refinery in Norway, and the export of copper concentrates from Western Canada to Asia.

Cooperation with trading partners and allies such as USA, UK and EU will be important to ensure that Canada is playing an effective role in supply of reliable, ethical and low-carbon critical minerals. The geography of Canada should be considered for the location of new smelting and refining capacity given transport costs and logistics. There may be good opportunities for integrated mining, smelting, refining and downstream manufacturing in Ontario and Quebec, building off existing Glencore and Vale operations. It will be harder to grow such complexes in BC due to distance from the Canadian manufacturing regions and US customers.

While the publication of the Canadian critical minerals list won’t in itself lead to immediate production increases, it signals government interest in the mining sector, and a belief that industry can contribution to supply the ingredients for sustainable technologies. This may well elevate the business case for certain mining, smelting and refining projects here in Canada. Watch this space!

References:

Humphries, M, Critical Minerals and U.S. Public Policy, Congressional Research Service, June 28, 2019.

Houses of Parliament (UK), Parliamentary Office of Science and Technology, Access to Critical Minerals, PostNote Number 609, September 2019.

Australian Government, Department of Industry, Innovation and Science, Australian Trade and Investment Commission, Australia’s Critical Minerals Strategy, 2019.

COVID-19 and Mining

By now, the COVID-19 pandemic has probably taken over most of our lives. I hope that you, your families and your colleagues are safe.

BC Provincial Health Officer and hero, Dr Bonnie Henry communicating COVID-19 daily update

"File:Bonnie Henry March 26 COVID-19 update.jpg" by ProvinceofBC is licensed under CC BY 3.0

All parts of the economy in the developed world have been affected, and natural resources have not been spared. The largest impacts have been in oil, were massive demand destruction associated with the almost complete cessation of air travel combined with much reduced vehicle use has led to sharp price reductions.

Metals have also been affected, but unlike for oil, where major producers Russia and Saudi Arabia have been increasing production, supply has typically reduced. Overall impacts on metal prices have been uneven, with gold showing strength due to the economic uncertainty, while base metals have generally weakened due to falling consumer demand for goods. In some cases, price falls have triggered production curtailment, such as Trevali’s Caribou mine in New Brunswick, after a COVID-19 related deterioration in zinc prices. The virus has directly impacted other operations. Some of the largest nickel, copper and gold mines in the Americas have suspended production, including in Canada (Voisey’s Bay), Mexico (Penasquito), Panama (Cobre de Panama) and Peru (Antamina). These shutdowns have been due to concerns of spreading infections into Indigenous communities, government mandates, or due to outbreaks amongst the workforce. Some parts of the world have seen lesser effects, for example the pandemic has now been largely suppressed in Australia, and mining production interruptions have been minimal there. Some capital and improvement projects have halted, and sadly many professionals in the industry have been forced to take unpaid time off, or have lost their jobs altogether.

The pandemic has made us acknowledge how society and the economy are interconnected, and our reconsider assumptions on freedom of movement. Mines relying on international consultants for site support suddenly need to rethink plans as many borders have been closed and flights cancelled. The Rainy River mine, located in Ontario, employs a significant portion of its workforce from towns across the nearby US border. Operations were interrupted in late March due to quarantine requirements when crossing the border. The pandemic forces us to think about system wide impacts that can occur through supply chains and services interruptions. The highly contagious nature of the virus combined with a relatively long incubation period and significant proportion of asymptomatic infections, means that outbreaks can be hard to detect until spread has already occurred. Mines in Canada have been changing practices, instituting additional sanitization measures, requiring more wearing of PPE and incorporating social distancing into the workplace. Where it is difficult to maintain social distancing, for example in the cages that bring workers down shafts in underground mines, mines have implemented rules for wearing masks. It’s a dynamic situation. A high degree of vigilance and testing are required, and careful monitoring of any relaxation in practices are needed to ensure the situation does not spin out of control.

Mining companies have a duty of care to employees and their communities to manage health and most mining companies have worked hard to set high safety and health standards in their operations. During the pandemic, it has been pleasing to see many companies proactively modifying work and travel procedures, as well as implementing screening and workplace health monitoring to avoid infections in operations. It seems most mines have avoided the levels of outbreaks that have occurred in some other sectors, such as the meat packing industry. Vigilance and mitigation measures will likely be needed for a while yet, and now is not the time to let down our guard.

Once this is all over, it will be worth reflecting on what industry did well and opportunities for improvement dealing with future health emergencies. We should also celebrate successes where mining operations were able to support their communities to navigate through the pandemic. In the meantime, I’ll continue safely working from home in downtown Vancouver, preparing for my cascade of upcoming Zoom/Skype/Teams/Webex calls, and finding ways to collaborate with colleagues through this global crisis. Take care and stay safe.

FLSmidth EcoTails ® and Filtered Tailings Forum and Demonstration of World’s Largest Filtration Plate

On June 13, 2019, I joined mining industry professionals from across North America and beyond to witness a demonstration of the world’s largest pressure filtration plate at the FLSmidth facility in Tucson, Arizona, as well as listen to presentations and a panel discussion from several industry experts on tailings management.

Over 75 leaders of some of the top companies in mining travelled to attend, a sign that tailings management is quickly becoming one of the top issues the industry faces today. Catastrophic failures of tailings dams have occurred in recent years at Mt Polley, Fundao and Brimadinho. Increasingly, miners are looking at risk management and sustainability as an investment, not just a cost, and there has been a corresponding push by mining companies to dewater tailings using available methods such as:

• Tailings filtration and paste thickening

• “Dry stack” tailing disposal

• Paste backfill (using combination of filtered and thickened tailings) in underground mines

• Co-mingling of tailings and coarser waste materials to improve geotechnical and geochemical properties.

Major filtration vendors including FLSmidth, Diemme and Outotec have been increasing scale and capacity of pressure filters in response to industry desires for reduced operating costs. The technology has been deployed on tailings for various operation flowsheets including gold leach circuits, copper and zinc flotation circuits and magnetite magnetic separation circuits. However, until now, tailings filtration has been hampered by perceptions of scale limitations (<30,000 tpd) and high operating costs ($2 - $5/t).

In recent years, Goldcorp (now Newmont-Goldcorp) partnered with FLSmidth to test and develop large scale tailings pressure filtration machines with higher reliability and faster cycle times. The demonstration unit we witnessed in Tucson has the largest pressure filtration plate ever put into service. The plate is 5 m high x 3 m wide. The available filtration area of the two sides of the plate is 25.12 m2 (total area is 30 m2 but a proportion of this is not available for filtration) and it is configured with a filtration chamber of 0.6 m3 volume. The plate used a nylon-polypropylene woven cloth as the filter media.

5 x 3 m plate with wash water sprays

Filter chamber set up with slurry feed pumping and filtrate collection

The demonstration unit was tested using a sample of tailings provided from the Newmont-Goldcorp Penasquito mine. Tailings had a size distribution of 80% passing 150 μm, typical of many industrial tailings. The chamber was filled and filtered at a pressure of 5 bar (500 kPa). This is less than full-scale unit (15 bar/1500 kPa), but filtration times can be reliably scaled up from the inverse relationship been filtration time and pressure. 

For the demonstration unit, the chamber was lowered with a wireless controlled forklift, and the top of the chamber was lifted off with a crane to reveal the cake. Eventually, FLSmidth plans to build a full-scale plate and frame filter with 5 x 3 m plates vertically mounted as per typical machines (2 x 2 m).

The cake is revealed

After sampling the cake at several points across the plate, Todd Wisdom, Director Tailings Solutions at FLSmidth handed out samples for us to see and feel. He estimated the cake moisture at 16%, which could potentially be reduced in a full-scale unit using an air blow (with a corresponding increase in the filter cycle time). The cake was then successfully released from the plate by lifting one side with the crane. 

Sample of filter cake, estimated at 16% moisture

After the demonstration, we heard from several speakers:

• Simon Hille, Group Executive, Global Technical Engineering at Newmont-Goldcorp, who led the EcoTails ® and GeoWaste ® initiative at Goldcorp explained the journey at Penasquito to assess tailings filtration and comingling of tailings and waste rock. The drivers were to reduce water consumption and tailings failure risks and improve the geochemical characteristics of mining wastes. However larger scale filtration machines and materials handling systems were necessary to reduce operating costs and support a business case.

• Dr Ward Wilson, Professor of Geotechnical and Geoenvironmental Engineering at University of Alberta spoke about the need to design waste from mining operations. Engineering suitable geotechnical and geochemical properties can help avoid catastrophic failures and issues such as acid rock drainage. He emphasized the importance of correct deposition of waste, as deposition determines the fate of the waste facility.

• Rueben Neumann, Product Manager at FLSmidth spoke about the concepts for a full-scale machine with up to 160 plates, the assessment of different materials for plate construction and why fiberglass was chosen, and the innovations of the clamped media design to reduce media damage.

• Kenny Don, Senior Applications Engineer at FLSmidth explained the importance of selecting filter feed pumps that have both the ability to deliver high volumes and high pressures at different times through the filter cycle, and the monitoring required to ensure reliable pump operation.

• Todd Wisdom, Director Tailings Solutions at FLSmidth spoke about lessons learned from large scale tailings filtration demonstration trials at Escondida, Chile using the 2 x 4 m “Colossal” filter. He emphasized the importance of weatherizing installations, completing diligent inspections and incorporating instrumentation to detect problems such as cloth failures.

• Milan Sjaus, Head of Projects and Systems Sales – North America at FLSmidth introduced us to alternative materials handling equipment and systems that can be integrated with tailings filtration. These systems, which may also include comingling tailings with waste rock, comprise of conveying, transfer and stacking systems that are configured to suit the topography of the waste disposal site at the mine. Such systems can now be designed to move > 20,000 tph of material.

Significant time and effort has already gone into the design of a full-scale filter, including finite element analysis (FEA) of the filter frame and plate design, computational fluid dynamics (CFD) of the chamber filling process, and full-scale testing of the plate and cloth washing system. A full-scale demonstration plant has been designed by Ausenco, which incorporates a full sized 5 x 3 m pressure filter with 160 chambers. Newmont-Goldcorp is actively seeking consortium partners to install the demonstration plant and prove the EcoTails ® concept at full scale. Some of the challenges that the demonstration plant will help resolve are plate handling issues with larger machines, much larger buildings, sufficient clearance to lift out plates and discharge cake and transport it away from the filter. Designs will also need to consider integration with tailings thickening, pumping and materials handling systems that may include comingling with waste rock or other materials. 

I’m sure that FLSmidth’s competitors will also continue to vigorously develop larger and more cost-effective filtration machines for a variety of mining and industrial wastes including mine tailings, bauxite residue and other refinery wastes. This healthy competition should improve viability of large-scale filtration, and help mining companies evaluate and implement filtration using technology and equipment configurations most suitable for their specific needs. 

The successful demonstration was an important milestone for the mining industry toward cost effective and large-scale tailings filtration and lower risk tailings facilities. I appreciated to opportunity to see it first-hand.

Acknowledgments:

Thank you to FLSmidth for the invitation to the forum and demonstration and for permission to publish photographs.

Can money mining and sustainability co-exist? The Whittle Consulting perspective.

In October, I attended the Whittle Consulting Money Mining and Sustainability seminar in Vancouver. Gerald Whittle, CEO and recovering management accountant, led us through two intense days. The focus – maximizing net present value (NPV) of mines.

Whittle Consulting’s mining optimization methodology, called Enterprise Optimisation, has been developed for over 30 years. It is built on multi-variable, non-linear algorithms to find the most economically attractive mining cases, subject to constraints that can be imposed by the user. The Whittle Consulting approach is integrated to consider mining, processing, financial and environmental factors.

Source: http://www.whittleconsulting.com.au/

The course centres on a fictitious but plausible copper-gold deposit called Marvin located in NSW, Australia. Marvin has a well-defined block model. Various capacity constraints are considered, such as for mining fleet, mill power, concentrate pipeline and stockpile size. The project is assumed to be generally constrained by mill power. Gerald demonstrates how an initial, credible mine design and plan can be improved by following a sequence of optimization steps that address cut-off grades, mining sequences, throughput and plant capacity trade-offs.

There are two main principles used to find the economic optima - activity based costing and the theory of constraints. Activity based costing is a method of understanding fixed and variable cost drivers, thereby relating production levels with operating costs. This is important for optimizing a mine plan, as the operating costs should be appropriately scaled for a given production level. The theory of constraints is a management philosophy developed by Eliyahu M. Goldratt and Jeff Cox in their book “The Goal”. I read it about 20 years ago and found it compelling and thought-provoking. The philosophy identifies bottlenecks, and manages the production process around them.

Enterprise Optimization can also be used to assess metrics of sustainability, including parameters such as water and energy consumption, and GHG, diesel particulate, and dust emissions. In one case, Gerald demonstrated that an optimized mining plan was also 25% more energy efficient on a per metal unit basis than a base case plan. This was primarily due to less ore tonnage treated due to higher mill feed grades, and less waste haulage due to a smaller, higher grade pit. These factors result in lower power and diesel consumptions respectively, in turn reducing GHG emissions.

More profitable mines mean there is more money for stakeholders to invest in societal improvements, and companies to invest in further exploration. There are other consequences of using the Whittle Consulting optimization approach. Increasing cut-off grade, and sending near-marginal ore to waste dumps will reduce the overall life-of-mine ore tonnes treated, resulting in shorter mine life and lower total metal production. Shorter mine life may impact on long-term employment opportunities, and lower total metal production means lower overall metal resource recovery from the deposit. These concerns can be partially alleviated by stockpiling near-marginal ore for treatment during lulls in mine production, or at the end of mine life.

Other thoughts came to mind for me. One way for a mine to improve NPV is to lower its discount rate, which can be achieved by lowering the risk profile of the project. Choosing more eco-efficient practices, and managing social license to operate are two sustainability related strategies that lower project risk, and may improve the attractiveness of the project to certain investors. This in turn may reduce the borrowing interest rate for the project.

The Whittle optimization algorithms will typically tend towards higher mill throughputs to maximize metal production, despite some recovery losses from coarser grinds, as this will maximize NPV early in the mine life.  Grind will get finer and throughput lower later in the mine life as the opportunity cost diminishes. It is important to have realistic estimates of the throughput-grind size-recovery trade-offs to ensure that recovery losses are correctly accounted for. Process engineers should work to make the separation circuit as robust as possible for coarse particle sizes and high throughput rates. Practical metallurgical improvements such as close attention to the classification circuit, and good flotation cell and reagent addition control may limit any recovery losses from higher throughput. Selection of flotation equipment that gives robust performance across a range of particle size ranges will also help. Such initiatives will improve resource recovery and further enhance financial returns.

Gerald says, “it’s not a metal mine, it’s a money mine”. Typically, the focus is on maximizing metal flow through the bottleneck to maximize profit. However, in a period of low metal prices, it may make more sense to leave ore in the ground until prices improve to improve future cash flows. Recently, Cameco took such action by placing some of its uranium operations on care and maintenance. Such actions must consider the shutdown and startup costs, and should include sensitivity analysis of future prices.

Overall, the Money Mining and Sustainability seminar was thought-provoking and informative. Case studies suggest Whittle software is a powerful, quantitative tool that can rapidly consider a wide range of mine plans and schedules within a range of physical, economic, financial, social and environmental constraints. Such a tool seems essential, in an increasingly complex world with rising stakeholder expectations despite declining metal grades and harder to process ores. I’d recommend the course to anyone interested in integrated strategic optimization of mining projects.

Social Licence to Operate: When Communities Become Advocates

Today in our Sustainability in Mining Blog, I’m introducing Isobel Alice O’Connell, a colleague from Vancouver. Isobel has over 15 years experience promoting and advising on issue management, sustainability strategy and stakeholder engagement. She is recognised for working to integrate social and sustainability performance into broader operational processes.

As Head of Social Performance at Qatar Petroleum, Isobel developed strategies and programs to mitigate human rights and stakeholder risks across the company, especially in the supply chain. She also developed and managed sustainability practices for two global consulting firms, where she designed and implemented guidelines, impact assessments/ strategies, reporting, training and assurance of non-financial performance indicators. 

Laurie: Isobel, thanks for sharing your experiences on the Social Licence to Operate (Social Licence). It is something we hear a lot about these days in North America. It was a big issue for Century Mine, where I worked at in Australia in the early 2000’s - an agreement with Aboriginal landholders was critical to allow the mine to proceed. We know that there are important challenges for resource development in Canada with respect to Indigenous and community stakeholders.

How do you understand social licence?

Isobel: I like how Pierre Lassonde, President of Newmont Mining Corporation describes social licence, ‘You don’t get your social license by going to a government ministry and making an application or simply paying a fee… It requires far more than money to truly become part of the communities in which you operate.’

In simple terms, social licence is the trust, ongoing approval and support by both a local community and affected stakeholders for an existing or to be constructed project.  It is important to point out, there is no one structure or right way to gain Social Licence, but rather it is "the duty to consult" concerned parties for broad social acceptance, and within the extractive industry the increasing interest in the social licence to grow.

Laurie: How did the term social licence come about?

Isobel: The idea of a social licence started in the mining industry some 20 years ago but has now been adopted the extractive industries dealing with a range of community concerns, fears or opposition, especially in regard to natural resource extraction and competing land use priorities. Ironically, when Canadian mining executive Jim Cooney coined the term social licence in 1997, he was talking about building support for mines in developing countries, not resource projects at home.

The term social licence draws attention to the difference between a legal permit and the social acceptance or legitimacy that is essential for a company to be able to survive, prosper and ultimately be part of communities that advocate both a company’s and industry’s interests. It is increasingly recognized by various stakeholders and communities as a prerequisite to development, or how to action a broader Corporate Social Responsibility (CSR) strategy as a platform to engage stakeholders.

Laurie: What would you say to people who say the process is just a corporate bribe?

Isobel: Ensure that the benefits of an operation outweigh the costs at the local level is the necessary first step in establishing the social licence. Then outlining and delivering legitimate benefits to the community regardless of whether it is a natural resource, or even the increasingly trendy renewable energy.

For example, over the last 4 decades, companies were generally welcomed by communities because they offered employment. While this remains true in many parts of the world, providing just jobs is increasingly regarded as not sufficient to earn a trusted place in the community. More is expected of both companies, and likely include legacy and/ or succession planning initiatives.

Laurie: In Canada, what would you say are ways social licence can be undertaken correctly?

Isobel: Some Canadian mining companies have been recognized for their commitment to social development through best business practices and CSR programs. They also participate in international initiatives such as the United Nations Global Compact, the Extractive Industries Transparency Initiative (EITI), and the Equator Principles.

Laurie: What is the best way for a resource company to approach social licence?

Isobel: To play a part in the broader “social contract”, a company will need to understand the broad socio-economic parameters of the region where a community is located and find opportunities to strengthen its operations.

Stakeholder engagement is the key to success. Getting involved in regional development forums, working effectively with other industries community development for the broader and long-term outlook of the region will be necessary. Maintaining good relationships with a wide range of well-connected stakeholders, and playing its part in the broader regional development. A company becomes part of a community. The community will advocate for a company’s interests. That’s the beauty of the often-symbiotic relationship that the social licence to operate can stimulate, but should never take it for granted. This diagram from On Common Ground Consultants summarizes it well.

Source: https://socialicense.com/definition.html

On a final note, and one that shouldn’t be overlooked, a government’s political and legal framework is vital to a company’s capacity and willingness to restrain its activities within sociably acceptable standards. Strong democratic institutions with clearly defined social and environmental regulations tend to raise the overall quality and social acceptance of private sector practices so that companies will have an incentive to exceed legal expectations and meet socially desirable standards.

Laurie: Thanks very much for sharing your knowledge on social licence Isobel. I'm on the Community and Environment Society Committee for the Australasian Institute of Mining and Metallurgy (AusIMM) and I’ll share your thoughts with my colleagues there. Perspectives from different parts of the world are always appreciated. If any readers have further questions for you, or would like to discuss how you might support them on managing social licence risks, how can they reach you?

Isobel: Thank-you for letting me be Resourceful Paths inaugural subject matter expert interviewee. I'm always keen to assist companies with manoeuvring through the numerous international sustainability guidelines and standards currently being implemented worldwide. They too can show how a company is building its awareness and executing their social license to operate. Please contact me via my LinkedIn profile.

Can mining survive in the circular economy?

There’s been much talk in the environment community about shifting from a linear “take-make-dispose” economy to a circular one. The premise is that by mimicking natural systems, and focusing on recovery, reuse and recycling of materials, we can eliminate waste and reduce extraction of virgin materials. The promise is that we can decouple growth from resource and environmental constraints. It almost sounds like a path to putting the mining industry out of business. Is this the beginning of the end of mining? I doubt it, but some things will change.

What is the circular economy?

Mainstream discussion on the circular economy is recent, however it’s reflected in various concepts from the 1970’s to 1990’s, including Industrial Ecology, Biomimicry and Natural Capital. All focus on systems design, learning from nature, eliminating wastes, and inter-disciplinary collaboration.

The Ellen MacArthur Foundation was established in 2010 to accelerate the transition to the circular economy based on three principles:

• Principal 1: Preserve and enhance natural capital...by controlling finite stocks and balancing renewable resource flows
• Principle 2: Optimise resource yields...by circulating products, components, and materials at the highest utility at all times in both technical and biological cycles
• Principle 3: Foster system effectiveness...by revealing and designing out negative externalities

Innovate UK visualizes the circular economy through material loops and interconnections.

https://connect.innovateuk.org/web/collaborations-circular-economy © Innovate UK 2017. All rights reserved.

Up till now, mining is all about scale

Over the last 50 years, the mining industry has been extracting increasing ore volumes based on a "bigger is better" paradigm. This was financially rewarding, as larger equipment with automated control brought economies of scale and low operating costs, often in the form of huge open pit mines and processing plants. However, with scale comes more water and energy use, more GHG emissions and more wastes. This heads in the very opposite direction to the circular economy. Declining ore grades and waning exploration success force miners to spend more to bring metal production to market. Miners have underestimated the complexity of executing mega-projects. Capital cost and schedule blowouts, difficult production ramp-ups and stakeholder interventions have led to big investor losses.

Only higher metal prices justify the risks and costs for such projects. But higher metal prices reflect increasing scarcity and declining productivity in mining. They stimulate innovation for substitution and more resourceful use of materials. This includes redesign of products to reduce weight of material used, refurbishing and recycling. In the long term, these factors affect the viability of the current mining business model.

Economics, consumer demands and environmental factors are driving the circular economy

Today’s customers are increasingly looking to purchase products as a service, when and where they want them. This changes the relationship between materials ownership and standard of living. Citizens in many parts of the world are becoming more aware and increasingly concerned about the health consequences of pollution, and risks from spills and failures of mine tailings facilities. This is driving regulatory constraints on the mining industry, and incentivizing investment in recycling and renewable resources. Many consumers, particularly in Europe, now demand more transparency on the environmental performance of products, this is reported through the EU Ecolabel scheme.

There is also momentum towards a circular economy through product stewardship and extended producer responsibility, which places responsibility on manufacturers to account for and minimize safety and environment impacts from their products.

How can the mining industry adapt to the circular economy?

The circular economy can be an opportunity for the mining industry to adapt. Mining companies are starting to use renewable energy and increase water recycling, strategies which reduce overall emissions, risk and long term costs. Underground mines that selectively mine higher value ores and return paste backfill minimize waste. Some vertically integrated mining and smelting companies, such as the European base metals producer, Boliden, have business models based on both raw materials extraction and recycling. This allows them to find synergies in materials sourcing, resource recovery and meeting quality requirements. This is a more stable business model than the boom and bust swings of mining.

Ultimately, a circular economy will impose costs and consumer pressure on mines that generate a lot of waste and environmental impact. This will force changes to an industry that is currently trending to more waste and impact. It should make miners review relationships with downstream smelting, refining and manufacturing customers, and reconsider the case for some level of vertical integration into refining and recycling.  The mining industry, and professionals in it, should build their awareness of where they fit in the materials economy, and their ability to shape more sustainable supply and use of materials. Walter Stahel stated that “excellence in metallurgical and chemical sciences is a precondition for a circular economy to succeed.” As a metallurgist, I’m jumping on that band wagon!

If you’re interested to learn more and engage on the circular economy and mining, please look out for information on the upcoming session that I will be chairing at the 2018 SME Annual Conference in Minneapolis, MN. Email me at laurie@resourcefulpaths.com to find out more.

Cobalt for Batteries – who will control supply, how ethical and sustainable will it be?

Last Wednesday, I gave a presentation to the Berkeley Energy and Resources Collaborative (BERC) on strategic metals for batteries. There has been rapid growth in lithium-ion battery demand, for handheld electronics, electric vehicles and potentially battery storage to level out swings in renewable electricity generation. Tesla has built its battery giga-factory in Nevada, with big promises of economics of scale. These developments have stimulated prices of two of the critical battery ingredients – lithium and cobalt. Cobalt has been in the headlines due the concentration of supply from the Democratic Republic of Congo (DRC), ethical issues from child labour in artisanal mines and the opacity of the supply chain.

How and where is cobalt mined and refined?

Cobalt is almost exclusively mined as a by-product of copper and nickel mining. The richest sources are sedimentary deposits are on the DRC side of the African Copper Belt. There, ores are usually leached to recover copper metal and cobalt as a hydroxide powder. Most cobalt recovered from nickel comes from weathered, laterite deposits, which are found in Australia, Cuba, Madagascar and New Caledonia.

Glencore, one of the world's largest metals mining and trading companies, and Chinese interests have both been making major moves to increase their DRC cobalt reserves. Glencore recently increased its stakes in DRC copper-cobalt mines by buying up the interests of the controversial Israeli billionaire, Dan Gertler. Chinese interests have agreed to acquire the Tenke mine from Freeport McMoRan and Lundin Mining.

Glencore outlines its cobalt mining reserves in its 2016 resources and reserves statement. More than 90% of its cobalt reserves are in Central Africa, with much of the rest in its Murrin Murrin nickel laterite mine. In comparison, the Tenke mine reserves are estimated to contain 510,000 t Co (Lundin, 2017).

Glencore cobalt mining reserves at end 2016 (Glencore, 2017)

In 2016, Glencore produced 28,300 t of cobalt, 24,500 t from its African copper mines, and 3,800 t from its nickel operations in Australia and Canada. The Cobalt Development Institute (2016) reported global refined cobalt production of about 48,000 t in the first half of 2016, a rate of about 100,000 t per year. On that basis, Glencore supplied over a quarter of the world's mined cobalt last year. That's good news for Glencore shareholders as cobalt prices have doubled in the last year. Glencore's production is due to increase later in 2017 as it brings its refurbished Katanga operation back into production.

Source: https://www.bloomberg.com/gadfly/articles/2017-02-23/ivan-glasenberg-s-20-billion-boast

Extraction of nickel and cobalt from laterites is complex and relatively expensive, and several projects were approved for construction when nickel prices were far higher than today. This has resulted in financial pain for owners. For example, one producer, Sherritt International has faced multi-billion dollar write downs on its Ambatovy laterite project in Madagascar. Don't expect any significant increases in cobalt production from nickel laterite operations for a long time.

Ambatovy nickel-cobalt laterite processing plant, Madagascar. Source: http://tiatanindrazana.com/uploads/ambatovy.jpg

Cobalt Development Institute estimates that half the world's cobalt refining is done in China, with much of that sourced from mines in the DRC. With the Chinese acquisition of the Freeport refinery in Finland, Chinese refining control will be further extended.

Source: Cobalt Development Institute, 2016

Artisanal mining and ethical concerns

There has been much concern by NGOs about artisanal mining of cobalt in the DRC, due child labour, dangerous mining practices and environmental damage. CRU, a leading metals intelligence company, estimates 10% of the world's mined cobalt production may come from artisanal sources, and that much of the product is refined in China. Recently, Apple suspended one of its battery suppliers due to concerns of unethically sourced cobalt in its supply chain. After all, who wants to be associated with harm to kids in mines in Africa? On the other hand, artisanal mining can be a much needed source of income for many poor people in Africa.

Children sorting cobalt bearing stones in DRC. Source: Amnesty International, 2016, https://www.amnesty.org/en/documents/afr62/3183/2016/en/

How does this relate to Li-ion batteries?

Cobalt is one of the key materials used in the battery cathodes. There are various cathode chemistries containing different levels of cobalt. To date, the most common has been lithium cobalt oxide (LCO), which contains 7% Li and 60% Co by weight. Other cobalt containing cathodes include lithium nickel manganese cobalt oxide (NMC) which contains between 12% and 20% Co, and lithium nickel cobalt aluminium (NCA) which contains 9% Co. The Tesla giga-factory is designed to produce NCA cathodes (Pillot, 2016). Other chemistries contain no cobalt at all, e.g. lithium iron phosphate (LFP) and lithium manganese oxide (LMO). Some alternative chemistries have the advantage of being less flammable than LCO, an important consideration for consumers given the notorious Samsung Galaxy Note problems. High cobalt prices and supply chain risks may also stimulate greater efforts in battery recycling and substitution. Researchers and battery manufacturers will continue to innovate to make safer, cheaper and more efficient batteries. 

High cobalt prices will also stimulate new mines, some in more stable places like Australia and USA. However, such mines would need consistently higher cobalt prices to justify the capital investment, and cobalt has a history of price volatility - in 2008 it topped US$45/lb only to fall to around $10/lb in early 2016. In the meantime, Glencore and the Chinese will control cobalt mining and refining. Hopes for more ethical and sustainable cobalt supply will rest on greater transparency in supply chains, consumers taking a greater interest in where the ingredients for their gadgets and green cars come from, and cooperation between governments, mining companies and NGOs to ensure safe and responsible mining practices.

References

Glencore Annual Report, 2016

http://www.lundinmining.com/s/Reserves.asp, Accessed 6 Mar 2017

Christophe Pillot, Avicenne Energy, The Rechargeable Battery Market and Main Trends 2015-2025, IMLB 2016

Cobalt Development Institute, Cobalt News, 2016

Canadian Mineral Processors Conference 2017 – Innovation to Sustain Mining

In mid-January, I attended the 49th annual Canadian Mineral Processors Conference in Ottawa. CMP had over 500 delegates from across Canada, and countries including Australia, UK, USA, Mexico, South Africa and Finland. There were many papers that focused on innovation and sustainability in mining themes.

The conference opened with a presentation by Dominic Fragomeni, “The Need to Innovate: Celebrate the Past…Look to the Future”. He described some of the successful innovations in mineral processing such as adoption of fine grinding stirred mills, alternative flotation machines, and advanced process techniques for refractory gold ores, such as non-cyanide leaching (e.g. thiosulfate), pressure oxidation and the Albion fine grinding and leach process. Dominic posed the question about innovation in mineral processing – “is our effort too fragmented?” (in my opinion, yes!), and reiterated the need for collaboration to solve complex challenges facing the mining industry.

Two papers were presented on ore sorting, which has the potential to substantially reduce the energy and water consumption per unit metal produced from an ore. Brent Hilscher (Sacre-Davey) showed some promising results of sorting silver, gold and zinc ores using XRF (X-ray fluorescence) and XRD (X-ray diffraction) detectors. In one case, a silver mine in Peru, ore sorting allowed the mine to decouple mining method and cut-off grade from mill feed grade, resulting in higher resource recovery and lower operating cost. Therefore, the mine didn’t have to shut down. Other applications included scavenging high grade rocks from otherwise uneconomic waste piles. In one of these cases, this also had the benefit of lowering the gold associated sulfide content of the pile to prevent it from producing acid rock drainage - a win for both profit and the environment. A second sorting paper on pre-concentration of gold bearing quartz ores was presented by Jorn Rohlender (Outotec). The paper described the process for determining the amenability of an ore to sorting, then different levels of pilot tests to confirm viability of a full-scale installation. Case studies of orogenic gold deposits in Northern Europe were presented. Tests suggested that typically 75 – 90% of gold could be recovered by rejecting 55 – 35% of weight in the feed, resulting in head grade upgrade ratios of 1.9 to 1.4. The benefits included increased resource recovery, reduced transport costs from satellite deposits and lower energy requirements for grinding. 

Two papers were presented on cyanide destruction, which is an important unit operation to ensure that gold mines can maintain environmental compliance, and minimize the potential harm to bird and aquatic species surrounding their sites. Anca Nacu (Kemetco Research) described the different demonstrated cyanide destruction technologies and the advantages and disadvantages of their applications. The importance of test work and need to consider site specific conditions were emphasized. Neri Roux (Research and Productivity Council) described cyanide destruction investigations at Anaconda Mining’s Point Rousse gold project. It was found that by segregating the two residue sources, implementing new monitoring instrumentation and adding reagent addition controls, sodium metabisulfite (MBS) reagent addition could be reduced significantly, saving money. Further reductions were demonstrated with addition of ozone in conjunction with these changes.

Gabriel Garcia Curiel (Dundee Sustainable Technologies) presented a new method to stabilize arsenic from copper concentrates. This addresses a serious issue in the global copper and gold industries – a rising tide of arsenic that is coming from increasingly complex ores that contain arsenic bearing copper minerals such enargite (Cu3AsS4), tennantite (Cu12As4S13) and arsenopyrite (FeAsS). The technique sequesters arsenic by vitrification into a stable glass phase. The technique, which has been tested in a demonstration plant in Quebec, appears to be significantly cheaper than existing hydrometallurgical techniques that stabilize arsenic into the crystal phase, scorodite. This may make the difference between leaving a copper deposit in the ground, or mining and processing it economically and in an environmentally acceptable manner. 

Peter Mehrert (ALS) presented laboratory and pilot plant results from the HydroFloat (TM) technology that showed potential for substantial increases in the recovery of copper sulphides at coarse sizes (> 400 um). This technology may eventually support plants in reducing power requirements through increasing grind size prior to flotation, while maintaining metal recoveries. This results in lower GHG emissions, and makes tailings easier to dewater, which in turn can reduce costs and risks associated with tailings disposal.

Several other papers covered flowsheet and equipment developments to improve metal recovery and product quality, including flash flotation, the use of fine grinding and Jameson cell technology to increase nickel grades at an Australian mine, and pyrite leaching of tailings at Penasquito mine in Mexico.

During the networking breaks, I met some eager students and shared my perspectives on careers in mining, and the importance of sustainable practices in maintaining a viable mining industry. Overall, the CMP was an excellent conference. It was great to meet both old and new colleagues, learn about industry innovations, and reinforce the message that sustainable business is good business. 

A reunion with Professor Alban Lynch

This week, while I was in Brisbane, I had the pleasure of catching up with Professor Alban Lynch. Alban doesn’t travel much anymore, but recently he went to Melbourne to celebrate his induction into the Australian Prospectors and Miners’ Hall of Fame, for his services to innovation and research in mineral processing globally.

Source: http://www.im-halloffame.com/inductees/comminution-2013-prof-alban-lynch/

I first met Alban in 1990 at University of Queensland, during a 1st year engineering function to promote the Minerals Process Engineering stream. Amongst students, he was notorious for asking, on meeting them, “Hi, I’m Professor Lynch, what’s your name? What’s your GPA?”. He had his reasons - Alban was looking for students who were capable and driven to solve technical challenges in the industry. I met the cut-off standard, signed up for minerals processing, and soon Alban organized a vacation job for me at Broken Hill. On arrival in this birthplace of Australian industry, me and two other 18-year-old UQ students checked into the unglamorous Tourist Lodge on Argent St. We were introduced to the Chief Metallurgist, Fran Burgess, and soon were sampling the grinding circuit in the lead-zinc-silver concentrator on the southern end of the lode. We got practiced at laboratory screen sizing and data analysis, and were commended for the quality of our work to characterise the circuit performance. Fran would later become my boss for several years, I also worked with her at Elura, Century and Rosebery mines in what became a serious dive into the lead-zinc-silver metallurgical industry. 

Alban had other influences over my career. He awarded me my industry scholarship with Mount Isa Mines, which launched my career as a graduate. At university, he insisted that multidisciplinary collaboration was critical for industry success. The message stuck, I bought into this approach on graduation. I worked for one of his esteemed students, Dr. Bill Johnson, in Mount Isa. I hired and supervised several university students for vacation work at mines in Australia, recalling the value these experiences gave me early in my career. 

This week, we talked about industry challenges, particularly declining ore grades and the brain drain of industry professionals and institutions. While Alban was troubled by directions in recent years, he seemed hopeful that students, if provided the right practical opportunities, could learn and rise to industry challenges. There was a story of hope of JKMRC students visiting Penoles base metals processing sites in Mexico to help solve real plant problems.

Alban was curious about my goals for Resourceful Paths, particularly regarding energy efficiency and effectiveness. He asked many questions. How long did I think SAG mills would be considered the preferred answer for breakage circuits? What were my views on dry grinding and how might this help reduce water use in processing? How much did I know about the cement industry? Had I heard about advanced air classifiers? Had I researched compression grinding? Was the deterioration in metallurgical schools as bad in Canada as it was in Australia? What were my thoughts on the eventual mining and processing of the low-grade copper halo ore at Mount Isa? What was Fran’s role there? How was I going to change the industry as a lone consultant?

Alban, as always, wanted thoughtful reflection, planning and results. I collated my action list. “You need to find a university to collaborate with, preferably with graduate students that need practical assistance. Learn about cement grinding and classification. Visit operating sites and report back on their practices. Get the resources from wherever you can to make your consultancy work.” It was clear that I had much to think about. I was expected to find my own resourceful path, sustain my future and make a significant and practical difference to industry. As a good student, I intend to deliver on my homework.

Ore sorting and pre-concentration - potential to boost profit and ease risks

Ore sorting and pre-concentration methods are used to separate waste from ore, and direct materials to optimal processing or disposal destinations. For amenable ores, they can increase feed grade, lower ore throughput and operating costs, and reduce environmental impact.

Historically, sorting was done by hand, for example, at a zinc mine in Wisconsin around World War II. Hard waste rock was removed at the grizzly to prevent production bottlenecks and drop downstream operating costs.

Source:  http://mining.jamison.museum/mining-in-southwestern-wisconsin

Development of cheap bulk mining, crushing, grinding and flotation processed reduced reliance on such manual methods. However, grades from metals mines have been steadily falling, as richer, higher grade deposits have been mined out. Globally, grades at copper mines have fallen from over 1.5% Cu in 1980 to less than 1% this year (see below). Historically, much higher grades were mined, for example, over 8% Cu in Australia during the 1880’s (Mudd, 2010). 

Source:  http://www.teck.com/media/Presentations-Webcasts-RBC-June-14-2016.pdf

Lower grades present challenges to mining companies and society - as ore grades decline, more energy and water is needed to produce the same mass of metal, and tailings and GHG emissions per unit metal increase. This is exacerbated as ores get more complex, e.g. harder to break, smaller mineral grain sizes and more intergrown mineral textures. Ore sorting and pre-concentration may help profitably tackle these challenges.

Modern ore sorting relies on sensors to detect properties of particles, and based on readings, respond with a control action. There are two methods:

• Bulk sorting, where loads of material (e.g. in a shovel, in a truck or a length of material on a conveyor) are directed to a destination based on measured properties
• Particle sorting, where individual particles are measured by a sensor, and those that meet certain criteria are ejected into a separate bin, by an air jet or mechanical diverter.

Bulk sorting can only be successful if there is sufficient heterogeneity in the ore (i.e. ore grade and properties vary spatially) and if sorting occurs before that heterogeneity is removed through mixing. Therefore, bulk sorting would work best close to the mining face and before any mixing and blending processes. Particle sorters are efficient on coarse particles, but machines tend to be limited to 300 t/h.

Sorting processes rely on speed of sensors to give accurate information in time to take a control action to divert off spec particles or material. Increased computing power has made this more viable in recent years. A variety of sensors are available, some include:

• X-Ray Transmission (XRT) – for base metals, industrial minerals, diamonds (nickel sulphide example below)
• Electromagnetic (EM) – for base metals
• Near Infrared (NIR) – for base metals, industrial minerals
• Colour – for base metals, industrial minerals, diamonds
• Radiometric - for radioactive materials
• Magnetic Resonance (MR) – under development for bulk sorting of copper ore (chalcopyrite)

Duffy et al (2015) give a more comprehensive review.

Source: TOMRA-Commodas Ultrasort, Sorting Opportunities, Sensors and Applications Overview: Why Send Waste to the Mill, Presentation, 2012

Aside from sorting, pre-concentration processes that exploit a difference in particle properties to upgrade feeds include:

• Screen sizing, and discarding or redirecting low grade size fractions, e.g. nickel laterites are often screened to remove coarse particles, resulting in upgraded Ni and Co grades (Denn, 2000)
• Dense medium separation, which is applied at several major lead-zinc mines such as Mount Isa and McArthur River in Australia, using cyclones filled with a suspension of ferrosilicon and water 
• Gravity separation, e.g. using the Inline Pressure Jig, which is used at the Pirquitas silver-tin mine in Argentina (Gray, 2011)

Use of such methods requires that processing and materials handling systems are configured to be operable, efficient and cost effective. In the case of dense medium plants, this includes incorporating conveyors to transfer feed and sorted fractions, and selection of crushing and grinding equipment that is compatible with the upgraded ore from the dense medium plant.

Mount Isa Mines Lead-Zinc Concentrator Heavy Medium Plant. Source: 

http://www.mineforce.com/projects/fine-ore-feed-conveyor

The economic drivers for ore-sorting and pre-concentration are strong where:

• Waste can be rejected with minimal loss of valuable metal – this requires ore characterization testing and benchmarking of technologies
• Water, energy and grinding media unit costs are high - rejecting waste will reduce consumption of these, and therefore save operating costs
• Reject material is hard and abrasive – further saving operating costs from power, media and equipment wear
• Satellite deposits are mined some distance from a central processing plant – rejecting waste could reduce ore transport costs
• Increasing ore grade and reducing tonnes allows mine and mill production to be debottlecked – this could lift metal production as well as dropping operating costs
• Sorting or pre-concentration lowers deleterious components in ore, improving recovery and product quality
• Tailings disposal options are limited – reduced tailings production may reduce tailings risks and enhance viability of safe options for disposal (e.g. tailings filtration, co-disposal with coarse wastes)

Economics can be evaluated by comparing:

• Capital cost to install ore sorting or pre-concentration
• Net change in operating costs, considering operation of sorting or pre-concentration vs. the drop in downstream consumables costs
• Net change in metal production after accounting for metal loss from sorting or pre-concentration, and any impacts on downstream processes
• Any incremental savings or costs associated with waste disposal (e.g. less tailings)

An example of the economic and environmental benefits of ore sorting at a Canadian gold project are described here. Estimated operating cost, GHG emissions and water consumption reduced by 50% to 66%. Lower tonnes at higher grade leads to lower operating costs and less wastes (sustainable business is good business!).

The mining industry owes its shareholders and stakeholders serious consideration of ore sorting and pre-concentration technologies to produce metals more economically and sustainably. Continued development of equipment, systems design and operating practice should see these technologies play an important role in the future of mining.

References:

Gavin Mudd, The Environmental sustainability of mining in Australia: key mega-trends and looming constraints, Resources Policy 35 (2010) 98–115

Duffy, K, Valery, W, Jankovic, A and Holtham, P, 2015. Integrating bulk ore sorting into a mining operation to maximise profitability, in Proceedings MetPlant 2015, pp 273–287 (The Australasian Institute of Mining and Metallurgy: Melbourne).

In-Line Pressure Jig Preconcentration Plant at the Pirquitas Mine, A H Gray, G Delemontex, N Grigg and T Yeomans, MetPlant 2011, Perth, WA

S M Denn, C G Ferguson and S L Makin, Upgrade Ability and Geology of Cawse Nickel Ore, 4th International Mining Geology Conference, Coolum, QLD, 200

What drives GHG emissions from copper production?

November has been a big month for climate change. The Paris Agreement went into effect on 4th November. The Marrakech COP 22 climate talks kicked off a few days later, then unexpectedly, on 9th November the world awoke to the news that Donald Trump was president elect of the USA, after he promised, while campaigning, to kill the Paris Agreement and bring back coal. This week, the director of NASA's Goddard Institute for Space Studies personally wrote to Australian Senator Malcolm Roberts of the hard right One Nation party to correct misconceptions held by the climate change skeptic. In recent days, there are reports of unprecedented low sea ice levels at both poles.

Despite the political turbulence, most scientists agree that climate change is occurring, and mining companies are recognizing a need to measure and reduce GHG emissions from their operational activities. I’m sharing analysis about GHG emissions associated with production of my favourite metal, copper, and looking at ways these might be reduced.   Copper, due to its superior electrical and heat conductivity, is a key metal for a green and high tech future. However, its extraction can come at considerable environmental impact. For those not that familiar with copper production and use, check out the International Copper Study Group World Copper Factbook for some background.

About 80% of global copper mine production comes sulphide ores that ore processed using grinding and flotation plants to produce concentrates for smelting. The rest comes from mines using dump or heap leaching, solvent extraction and electrowinning to produce cathode copper. Most copper mines are large, low grade, open pits. Typically, these operations treat over 50,000 t/d of ore with copper head grades below 1%, and sometimes as low as 0.3%. The economic viability of these mines depends on keeping operating costs per tonne of ore below the payable revenue per tonne. 

For these mines, energy is a significant fraction of operating cost and the main source of GHG emissions. The energy use for these operations is primarily in two forms:

• Diesel (or other liquid fuels), primarily for movement of ore and waste rock from pits
• Electricity
  • For crushing and grinding; pumping water and slurries; and operating flotation machines in the case of sulphide ores
  • For crushing; conveying; pumping solutions; and electrowinning copper metal for oxide ores 

In addition, a mine often uses consumables, such as steel grinding media, which produced GHG emissions in their manufacture.

I use a driver tree methodology to understand GHG emissions. Here’s an example that shows emissions from diesel, electricity and grinding media for an open pit copper sulphide mine with a concentrator.

The driver tree methodology can also be used to analyze and improve profitability of a copper mine, as many of the same drivers that reduce environmental impact (less energy, water and steel grinding media consumption) also reduce operating cost. Sustainable business is good business.

What determines the GHG intensity of copper production (t CO2 equivalent/t Cu)? To use a classic metallurgist’s answer, “it depends”. The biggest factors are:

• Ore head grade (i.e. copper and valuable by-product content) as this determines the mass or ore that must be moved and processed to recover a given unit of copper.
• The mining method and geometry, especially for open pits as this determines the quantity of waste that must be moved (determined by stripping ratio), and the length and elevation of ore and waste movement. These in turn drive diesel consumption for haul trucks.
• Mineralogical properties of the copper ore such as level of oxidation, mineral textures, grain size etc., as these determine the type and intensity of processing needed to extract the metal.
• Ore hardness, as this determines how much energy is needed for breakage.
• Geographical factors, as the proximity to power and water sources is closely tied to the GHG intensity of electricity and the energy requirements to deliver water.

We can relate the basic environmental and economic drivers in a 3D display, using the example of power consumption and costs. From an economic perspective, the profitability of a mine relates to:

• Head grade – drives tonnes of ore per unit metal produced
• Ore hardness – drives power consumption per tonne of ore
• Power unit cost – the power unit cost multiplied by power consumption drives power cost per unit ore treated

Hence, a mine with high head grade (hence high revenue per tonne of ore), low hardness and low power cost (hence low operating cost per tonne of ore) will tend to be more profitable, while a low grade mine with hard ore and expensive power will be marginal or uneconomic. The analogy can be extended to GHG emissions, if we substitute power unit cost with GHG intensity of electricity. Hence a high head grade and low hardness ore at a site supplied with renewable power will have very low GHG emissions. In contrast, a low head grade mine with hard ore at a site with coal fired power will have very high GHG emissions. I’ve calculated the extreme scenarios below for demonstration. It makes a big difference – both for economics and GHG emissions.

The table above shows a worst case scenario, a typical low grade copper mine using coal fired electricity would produce in the order of 3 – 5 t CO2e/t Cu produced. A large open pit copper mine may use in the order of 200,000 L/d of diesel, with an emissions factor of about 2.7 kg CO2 e/L, resulting in 200,000 t CO2 e/y of emissions. That’s typically around 2 – 4 t CO2e/t Cu produced. The grinding media use is typically 1 kg steel/t ore, and assuming 2 t CO2e/t steel consumed, this results in about 0.3 – 0.6 t CO2e/t Cu produced of embedded emissions.

This means that copper in concentrate production at an open pit mine site typically results in around 5.5 – 9.5 t CO2e/t Cu if powered by diesel and coal fired power, and with readily accessible water supply. Significant reductions (>50%) could be achieved if:

• The open pit mine transitions to a higher grade underground mine with less waste movement (reduces both power and diesel related emissions)
• Coal power is converted to lower GHG intensive sources, e.g. combined cycle natural gas, or renewables
• Diesel for haul trucks is replaced with low GHG energy sources, e.g. biofuels or low GHG electricity
• Modifications are made in the process area to significantly reduce energy and steel media consumption, e.g. ore sorting to separate low grade, uneconomic material from ore stream; SAG mills are replaced with high pressure grinding rolls; higher quality and lower wearing media is used in grinding

For sites with no nearby water, a significant amount of power may be required to treat and pump water to the mine site, this is now commonly the case in Chile. For such mines, it becomes critical to consider both the GHG intensity of power for water treatment and conveyance, and practices to minimize water consumption (e.g. maximizing water recovery and reclaim from tailings) in order to manage costs and GHG emissions. 

The economic, environmental and social factors for the above alternatives need to be considered in order for copper mining to stay viable. Continued efforts by industry to optimize and advance the improvement initiatives discussed will be important to reduce GHG emissions in metals production, even in the face of declining ore grades. The past paradigm of "bigger is better" won't be sufficient in the face environmental constraints for the mining industry, whether these be GHG emissions, water consumption or disturbance footprint. 

Lessons from Samarco Fundao failure and integrated approaches to reduce tailings risk

This week marks the one-year anniversary of the Samarco Fundao tailings dam failure. This event, which cost the lives of 19 people, destroyed the town of Bento Rodrigues, and caused severe pollution along 600 km of the Rio Doce, was one of the worst tailings failures in history.

Bento Rodrigues town after Fundao tailings dam failure

Source: http://www.miningmagazine.com/wp-content/uploads/2016/08/812786-1-eng-GB_the-fundao-tailings-dam-burst-on-november-5-2015-photo-senado-federal.jpg

A comprehensive study was undertaken to determine the causes of immediate failure, and this is publically available on the Fundao Investigation website.  The report found that the failure was due to a liquefaction flowslide, triggered by three minor earthquakes. However, the root cause was linked to construction defects in a critical drain of the starter dam in 2009. 

To recap, tailings are the waste product produced from minerals processing plants after mineral or metal extraction. They contain solids and water. Solids particle size may vary from a sand to slimes consistency depending on the ore and processing method. Associated water may be contaminated by reagents used in processing (e.g. cyanide) or reaction products from contact with tailings solids (e.g. acid rock drainage). Tailings are placed in tailings storage facilities (TSFs), usually held back by large embankments. Safe containment is the critical design consideration, as failures can cause fatalities, destruction of assets and severe environmental damage.  Embankments can broadly be built using one of three methods: upstream, downstream and centerline construction. These, along with advantages and disadvantages, are outlined in the figure below. 

Tailings embankment construction methods (Steven G. Vick, Siting and Design of Tailings Impoundments, SME, 1981)

The Fundao dam used the higher risk upstream method, and sands fractions of tailings were used in the embankment construction. In this case, construction defects in the starter dam, combined with insufficient control of the deposition of sands and slimes fractions over several years left an embankment susceptible to failure. To avoid failure, upstream embankments require considerable control over placement of sand and slimes fractions into the TSF, and limits to the rise rate (rate at which the embankment is built up) to ensure proper compaction and drainage. Some jurisdictions (e.g. Chile) ban the upstream method due to unacceptable risk of failure especially due to earthquakes.

Unfortunately, Fundao is not a one-off: many failure events have occurred in recent decades, across different commodities and regions. WISE has compiled a database to record these. Some significant events (including fatalities in certain cases) include:

• Base metals: e.g. Mount Polley, BC, Canada, 2014; Philex, Philippines, 2012; Los Frailes, Spain, 1998
• Precious metals: e.g. Baia Mare, Romania, 2000
• Iron ore: e.g. Fundao, Minas Gerias, Brazil, 2015; Herculano Mineração Ltda, Minas Gerias, Brazil, 2015; Mineração Rio Verde Ltda, Minas Gerias, Brazil, 2001
• Bauxite residue (also known as “red mud”): e.g. Luoyang, Henan province, China, 2016; MAL Maygar, Ajka, Hungary, 2010
• Industrial minerals: e.g. Stava, Italy, 1985
• Fly-ash from coal fired power stations: e.g. Tennessee Valley Authority, Kingston, Tennessee, 2008

Some general considerations for embankments that can be drawn from historical failures and good engineering practice include:

• Consequence of failure increases as dams become higher, as the stored potential energy behind the dam increases, and this should be considered in design and operating practice
• Accumulation of ponded water on a TSF near an embankment creates risk of piping failure in the embankment, and in general, storing large quantities of water in a TSF can increase consequences in the event of a failure; water management should include decant from deposited tailings as well as water runoff from precipitation, and appropriate water diversion, pumping and treatment facilities are required
• The quality of foundation preparation, drain and filter layers and fill materials, and quality control of fill placement, including compaction are important in ensuring the embankment functions as designed, and to avoid failures
• Dams that have their lives extended through brownfield expansions may need additional scrutiny and safety factors in design, as the final embankment may end up quite different to that which the initial designer expected
• Risk management and emergency response plans are needed for communities and assets in the line of fire of a potential tailings embankment failure
• Cost concerns from clients can potentially lead to pressure for designs that include inherent risk; the consultants need to hold to appropriate standards in these situations
• Failures can even occur to tailings dams with a safe design, in situations where the operator does not control operations to safe design conditions; consultants need to assist clients to maintain safe practice, and promptly escalate and document safety concerns internally and within client organizations to avoid potential failures.

In addition to the embankment design aspects, there are some processing considerations that can help reduce tailings related risks:

• Increasing tailings density, e.g. by using high density or paste thickening (this is one example supplier, there are several others), centrifuging or tailings filtration (dry stack), can significantly reduce the overall volume of tailings directed to the TSF, and change rheology to greatly reduce consequence and likelihood of failure
• A co-benefit of higher density tailings deposition is increased water recycling and reduced net water consumption
• Selective mining, preconcentration and ore sorting may reduce the quantities of ores processed in grinding and separation circuits, hence reducing the quantity of tailings and subsequent risks
• In certain underground mines, it may be possible to place a considerable portion of tailings mixed with a binder material (e.g. cement, flyash) as paste or hydraulic backfill, reducing the volume and risk of surface TSFs 
• Also, in some surface disposal cases, binders such as flyash may be added to stabilize tailings and reduce risk of contamination of contact waters
• Other beneficial reuse opportunities may allow a significant proportion of tailings to be sold to customers, for example, agricultural lime from carbonate rich zinc ores in Tennessee, iron recovery from certain iron rich copper tailings (e.g. Palabora) or potentially producing geopolymer materials from treatment of silica rich iron tailings
• Through major flowsheet changes, e.g.change from grinding and flotation flowsheet to leaching and extraction flowsheet, it may be possible to eliminate TSFs altogether; the economic and environmental aspects of the alternative flowsheet would need to be considered to determine viability

Major tailings failures such as Fundao are a stark reminder of the risks associated with tailings. Dam safety requires appropriate expertise from civil and geotechnical engineers, who can assess both the siting and ground conditions for the embankment, and safe design, construction and operation practices. A shift away from upstream embankment construction, water management in TSFs, and greater vigilance in construction standards, operating practices and design changes over life of mine can all help to reduce risk. An integrated design approach should be considered that includes mining method, process flowsheet, TSF site selection, embankment construction method, process plant and tailings dewatering facilities siting, tailings conveyance facilities (e.g. pumps and pipelines), tailings deposition control, appropriate beneficial reuse circuits, and water diversion and reclaim features. Additional tailings dewatering, and reducing the quantity of surface tailings through mine backfill, beneficial reuse or flowsheet changes can lower risk. These considerations may help the mining industry ensure economically and environmentally acceptable outcomes, and face the increasing scrutiny from stakeholders and regulators that has resulted from incidents such as Fundao. 

Mining for value - a new focus on grade

Welcome to the inaugural Resourceful Paths sustainability in mining blog, where I share insights on making a safer, more profitable, environmentally friendly and socially accepted industry.

First, let’s reflect on safety. Friday marked the 50th anniversary of the Aberfan disaster, where 116 children and 28 adults were killed when a coal waste dump in Wales collapsed and engulfed a school and homes in this village. The harrowing events and aftermath are described here. Preventing incidents like these is part of what gets me up each day.

Back to mining. 

In the last 2 weeks, I’ve been to three mining related events in Vancouver:

• SRK Cave Mining Forum 
• CIM Vancouver Branch presentation “Jericho Mine – Lessons Learned”
• University of Exeter Global Conversations “Mining – Is Bigger Always Better?”

Each covered the important topic of managing ore grades. Mining strategies can span between:

• Big and cheap – use bulk mining methods that extract low grade ore, accept dilution and deal with it downstream, and operate at high tonnages for economies of scale
• Selective and expensive – use careful, precise underground mining methods that extract high grade ores and minimize dilution, and operate at low tonnages and focus on high recoveries

The terms "cheap" and "expensive" relate to costs per t of ore. In practice the most important indicator of economic viability of a mine is costs per unit of payable metal produced, which is driven by the feed grade and metal recovery, as well as the cost per t of ore. 

The premise of bulk mining is that the lower operating costs outweigh downstream impacts of processing a low grade feed. The result - large open pits mines, which have installed large conveyors, crushers, SAG and ball mills and flotation cells to process ores, and built massive (> 100 Mt) rock dumps and tailings dams for the wastes produced. If metal prices are high enough, and the ore is amenable to low cost processing, the huge capital costs of such facilities can be economically justified. The environmental impacts of the large waste footprints and water and energy consumption can be high, especially in certain geographical areas.

BC, Canada has several copper-gold-molybdenum metal sulphide mines and low grade operations such as Highland Valley Copper dominate. I compiled a chart of net smelter return (NSR) from Q2 2016 Management Discussion and Analysis (MD & A) from operators, and NI 43-101 Technical Reports for the projects. The NSR represents cash flow from payable metal recovered after deducting transport, treatment and refining charges to the customer.  Of these, New Afton (0.85% Cu, 0.7 g/t Au) has by far the highest NSR. It is the only operating underground mine shown on the chart - the others are open pits, and mostly have NSR of $20/t or less (e.g. Mount Milligan – 0.55% Cu, 0.22 g/t Au).

New Afton, a block cave mine, was featured at the Cave Mining Forum. The mine is heavily instrumented, and carefully models and monitors fragmentation and dilution by low grade picrite material to manage mine and concentrator production. It is also collaborating on research to include ore sorting to reduce dilution and maximize mining ore recovery. While New Afton has the smallest ore tonnage (approx. 15,000 t/d) of any of the mines charted, it made a healthy cash margin of $48 M in Q2 2016 based on New Gold’s MD&A. It's an example of a profitable, moderate scale underground mine that has lower environmental footprint (e.g. less tailings, minimal waste rock dumps) than open pit copper-gold mines in BC. 

The CIM talk was a case study on the small Jericho diamond mine in Nunavut. It holds some of the same lessons that apply to large metal mines. It failed primarily because the owner fast tracked studies and scaled the pit and process plant production too far. As a result, it mined low grade, uneconomic ore that neither contained the expected diamond values nor achieve design recovery. It’s a case of diseconomies of scale, and it can easily sweep a mine out of existence. A smaller Jericho operation, focused on the higher grade central zone may have been profitable. It’s still not clear who will pay for the rehabilitation of the failed mine. In such cases, it is usually borne by society.

Professor Jeffrey, Head of Camborne School of Mines, University of Exeter, described the challenges of “bigger is better” - capital cost overruns, long delays, complex logistics, risks of tailings failures and, in some developing countries, potential nationalization. This is making some large projects, which have increasingly larger tonnages at lower metal grades, difficult to justify, i.e. too big to build. He described initiatives by mining companies, Original Equipment Manufacturers and researchers to develop new machines, automation systems, robotics, miniaturized equipment, ore sorting systems and data analytics techniques that could allow more selective mining and arrest the decline in ore grades. These in turn could reduce the scale, capital cost and complexity of downstream processing and tailings storage facilities. He emphasized that mining education and inter-disciplinary engagement to design better mining and processing systems underpin the solutions to future industry challenges.

While New Afton has higher grades than open pit mines in BC, the block caving method that it uses is generally a higher tonnage, lower grade, mass mining method compared to selective mining methods used for some high grade vein deposits. For example, the Macassa Mine, in the Kirkland Lake region of Ontario produces ore with >15 g/t Au. There, methods such as cut and fill and long-hole stoping are used, in combination with paste backfill. Paste backfill, which allows a significant portion of mill tailings to be returned underground, and hence reduces surface tailings disposal footprint and risks of tailings embankment failures. It also helps increase water recycling and support ground conditions in underground mines which can extend mine life.

Some of the innovations described by Professor Jeffrey may make selective underground mining methods much more cost effective and widely practiced, by reducing feasible minimum mining widths, reducing the size and complexity of mine ventilation systems and allowing access to previously inaccessible veins. The processing facilities and environmental impacts for such mines could be of modest scale, and the resulting costs per unit metal produced could be highly competitive.

Each deposit is different, and its geology and geometry may limit the mining method (open pit vs. underground, bulk vs. selective). In any case, mining companies should enthusiastically explore for moderate sized, high grade deposits, not just massive, low grade ones. They should properly study and test mineral resources and assess mining and processing systems incorporating new technologies that reduce dilution, waste production and energy and water use. These strategies could improve profitability, reduce environmental impacts and lower project risk. Here’s to a revival in profitable, socially accepted, moderate scale underground mines, producing high grade ore with minimal waste footprint, low energy and water consumption and negligible risk of tailings failures.