Tag Archives: tailings

Repair, Reuse, Recycle: ERG’s critical minerals reprocessing journey

The Musonoi River Valley in the Katanga region in the Democratic Republic of the Congo (DRC) has, for some decades, been the site of land degradation resulting from inadequate and ineffective tailings and other waste management systems.

The local water system and surrounding land has been subjected to pollution from more than 83.2 Mt of legacy tailings spread over an area 11-km long and up to 2.5-km wide. Additionally, 41.1 Mt of tailings have accumulated at the Kingamyambo Tailings Dam.

Remediating and mitigating this damage is now a primary goal of Eurasian Resources Group’s Metalkol Roan Tailings Reclamation (RTR), a reprocessing facility dedicated to cleaning up the historic tailings left by previous mining operators in the Kolwezi area of the DRC. By reclaiming and reprocessing copper and cobalt tailings in the region, the company says its approach goes beyond ‘do no harm’, actively addressing a history of environmental degradation and pollution.

The legacy tailings are extracted through hydraulic mining and dredging, reprocessed and then re-deposited into a modern, closely managed and centralised tailings storage facility. This is subject to regular inspection, monitoring and reporting, supported by a dedicated Engineer of Record and an independent laboratory. Currently Metalkol RTR can produce 21,000 t/y of cobalt, which is says is sufficient for three million electric vehicle batteries, alongside around 100,000 t/y of copper, the company says.

ERG also has reprocessing operations outside of Africa, including at Kazchrome in Kazakhstan, which, it says, is the world’s largest high-carbon ferrochrome producer by chrome content.

Established in 2019, ERG Recycling – ERG’s specialised company aiming to become the largest entity to reprocess industrial waste into commercial products in Kazakhstan – has already implemented many projects including the commissioning of a new workshop that reprocesses slag, dust and other fine waste into high-quality briquettes. This program to reprocess Kazchrome’s 14.7 Mt of slag stockpiles has been expanded, now processing over 100,000 t/y of slag.

These operations have been enhanced by the development of new technology. Having completed the first trial in 2020, the Slimes 2 Tailings Reprocessing project at Donskoy GOK has the potential to enhance Kazchrome’s output of chrome concentrate by recovering 55% of the chromium oxide in chrome-oxide bearing tailings using innovative flotation technology, the company says.

In Brazil, at ERG’s integrated project, BAMIN, which produces a premium 67% Fe grade iron ore and is ramping up to become one of the country’s largest standalone iron ore exporters, the company’s transition from an upstream to a downstream tailings model ensured continued compliance with both local regulations and international standards, it said. The group continues to study additional technological enhancements to ensure the construction and operation of a world-class facility.

The environmental benefits of reprocessing projects like these are very significant for the business and critical to local communities, according to the company.

“As more attention rightly turns towards environmental, social and governance (ESG) issues, it is crucial that tailings are dealt with and stored properly,” ERG said. “Aside from preventing significant issues, such as dam collapses, by reprocessing and responsibly storing these tailings, we are reducing local pollution risks more generally, increasing air quality and decreasing the likelihood of leaching toxic substances into surrounding habitats and water systems.”

Given the legacy of environmental degradation and serious consequences it poses, it is also necessary for mining companies to explore novel ways of rehabilitating the environment.

For example, ERG has been working with a team of agronomists from the University of Lubumbashi in the DRC to look into the experimental planting of trees and their growing potential at the Kingamyambo tailings dam.

Looking forward, these operations will support the sustainable development of affordable batteries and other clean energy technologies.

By producing critical raw materials, such as cobalt, without the risk and cost of needing to develop new mining projects, ERG says it can help make electric vehicles and other renewable technologies more accessible, helping facilitating the net-zero transition.

Pictured above is Metalkol RTR, ERG’s reprocessing facility in the DRC: the world’s second largest standalone cobalt producer

EnviroGold highlights sustainable metal reprocessing credentials at Hellyer, Buchans Tailings projects

EnviroGold Global Limited says the precious (gold, silver) and battery metals (copper, zinc, lead) to be produced at the company’s Hellyer Tailings and Buchans Tailings reprocessing projects are expected to show a 96% reduction in greenhouse gas (GHG) intensity per gold-ounce-equivalent produced and an over 80% reduction in energy intensity relative to industry averages for conventional mining.

EnviroGold Global’s circular-economy business model is designed to produce precious, critical and strategic metals while reprocessing mine waste (tailings), which often contain significant quantities of valuable precious, critical and strategic metals.

EnviroGold Global’s analytics-driven approach to project origination and development leverages extensive mine production data, mill production data and geological records to identify tailings sites that are expected to contain significant quantities of residual metals due to refractory mineralogy and/or to the inefficiency of outdated technology used during legacy mining operations. In addition to recovering precious, critical and strategic metals, the company says it remediates the tailings consistent with environmental best practices, thereby reducing the environmental footprint of legacy mining. Further, by eliminating the extractive phase (mining) of metal production, the company expects to reduce the energy intensity of metal production by over 80%.

Leveraging the framework set forth by the World Resources Institute’s Greenhouse Gas Protocol, EnviroGold Global’s detailed assessments of expected Scope 1 and Scope 2 emissions for the company’s planned operations at the Hellyer Tailings and Buchans Tailings reprocessing projects indicate that the carbon intensity of the gold-equivalent ounces of precious, critical and strategic metals produced by the company will be 96% lower than industry averages for conventional mining. S&P Global Market Intelligence reports that the typical conventional mining operations generated nearly 1 tonne of CO2 per gold ounce produced.

Just last month, EnviroGold Global executed a binding definitive agreement with Hellyer Gold Mines Pty Ltd to reprocess the tailings owned by HGM at its namesake mine in Tasmania, Australia (pictured). Hellyer is owned by NQ Minerals, with the company having a plan to increase its financial year production to 1.5 Mt of tailings reprocessing in 2022, from the estimated 1.4 Mt in 2021. Earlier this month, EnviroGold announced that test work completed to date on its proprietary flowsheet demonstrated gold recovery rates of 83.5% and silver recovery rates of 94.6% from the refractory, volcanogenic massive sulphide tailings at Hellyer.

In 2021, it announced the execution of binding commercial agreements, which saw the Buchans River Delta Reclamation Project added to its portfolio of environmental remediation and asset reclamation projects, saying that it planned to deploy proprietary modular, scalable reclamation technology & systems able to process up to 1,000 t/d of reclaimed tailings to remediate the legacy tailings while removing environmental contaminants and reclaiming valuable commodities at the project.

EnviroGold Global CEO, Dr Mark Thorpe, said: “Whether serving as critical components for batteries, electric vehicles and clean-energy infrastructure, or as a store of value and hedge against inflation, metals have never been more critical to the modern, global circular economy. EnviroGold Global’s Metals Without Mining business model is designed to sustainably satisfy the world’s increasing demand for precious, critical and strategic metals by eliminating the most carbon and energy intensive phases of metal production, creating a win-win for corporate, community and environmental stakeholders.”

The Global Tailings Review reports that the total number of active, inactive and closed tailings storage facilities worldwide exceeds 8,500. The global footprint of tailings exceeds 280,000 Mt with an additional 12,700 Mt produced annually. The value of precious, critical and strategic metals contained in global tailings sites is estimated to exceed $3.4 trillion.

EnviroGold Global’s commercial strategy involves identifying, qualifying and developing tailings reprocessing opportunities, generally targeting tailings sites with at least 6 Mt of tailings and gross recoverable metal value of $124/t of tailings. Tailings sites meeting EnviroGold Global’s internal assessment criteria pass through an advanced screening process, which includes detailed technical/economic modelling incorporating expected recovery rates and site-specific process-level economic analysis.

The company has reviewed over 325 global tailings sites to date and has eight “major projects” in its global tailings reprocessing portfolio. EnviroGold Global expects to commence commercial metal production in 2022 at its Hellyer Tailings reprocessing project. The company will continue to acquire the rights to tailings reprocessing opportunities around the globe and subsequent to achieving commercial metal production at the Hellyer project will leverage strategic operating partnerships to scale up commercial metal production at multiple projects simultaneously.

Gravitas Minerals after iron ore recovery boost with Kalahari Process

Gravitas Minerals is leveraging its Optima Concentrator™ gravity separator to recover iron ore from tailings facilities and provide ‘value from waste’.

Using hindered settling, fluidised bed and autogenous dense medium separation technology to separate iron ore from gangue based on density, the Optima Concentrator has high throughput capacities of up to 40 t/h sq.m. This, the company says, is the ultimate low-footprint, water-only solution for fine iron ore recovery.

The company is using the Optima Concentrator to develop its so-called Kalahari Process™, which produces an iron ore product with a minimum grade of 63% Fe from various iron ore feed sources. The process has seen great success to date by yielding recoveries of up to 80%. In addition, the process is ideally set up for the direct reuse of water by dry stacking of both the product and tailings streams, according to the company.

An agglomeration stage added to the process can also produce fit-for-handling high-grade pellets, the company claimed. Another option would be to market the product as fines concentrate, a norm in the West African and Indian markets.

Gravitas Minerals Director, Tebogo Kale, said: “By utilising the Kalahari Process, iron ore producers can unlock the full potential of their mineral resource. In so doing, they can prolong the lifespan of their tailings’ facilities by up to 50%, reduce the disposal of iron ore tailings and the associated environmental impact, increase their revenues and ultimately boost profits.”

ALROSA looks to reclaim Aikhal tailings pit as part of 650 ha land restoration project

ALROSA plans to reclaim the tailings pit of processing plant No. 8 at its Aikhal Division by 2029 in a project worth over RUB2.5 billion ($34.3 million) that will seek to restore 650 ha of land and have it planted with pine forests, the diamond miner says.

The tailings pit is located 1.2 km southwest of the village of Aikhal (pictured) in the Sokhsolookh River valley in Yakutia, Russia. The decision to reclaim the facility followed the completion of mining at the Komsomolsky open pit and the closure of processing plant No. 8 at the end of 2020.

During the plant’s operations, tailings were stored in the tailings pit as a liquid slurry. In terms of environmental danger, the slurry belongs to the lowest hazard waste category (virtually non-hazardous waste or category 5 under the Russian Federal Law on Industrial and Consumer Waste), ALROSA says. The tailings pit was a key hydrotechnical facility ensuring water recirculation at the processing plant: after the slurry settled in the pit, clarified water was fed back into the plant to be re-used in processing diamond ore, the company explained.

The reclamation project will be implemented in two stages.

The first stage will include draining the pit and restoring a part of the original course of the Sokhsolookh River back to its natural state.

Later on, from 2025 to 2029, the tailings facility will be dismantled, and work will be carried out to improve the land, dig drainage ditches, install waterproofing, lay fertile soil and landscape the area. To achieve this, 160,000 Scots Pine seeds have been sown in 2021 in a disused sand and gravel open pit not far from the Aikhal village. This conifer is not native to this area and does not grow locally on its own.

Once all the work is complete, the land beneath the tailings pit will be restored to its original condition and, as mentioned, over 650 ha of replanted area will be handed over to local authorities.

Weir Minerals and Andritz expand tailings processing collaboration with IsoDry

Weir Minerals and Andritz have signed an agreement at MINExpo 2021 expanding their shared commitment and strategic cooperation to supply equipment for processing tailings in the mining industry.

The foundations of this agreement have been built on a shared understanding and vision to enable the sustainable and efficient delivery of the natural resources essential to create a better future for the world, they say.

Since 2018, Weir Minerals’ and Andritz’s partnership has seen them collaborate on joint tailings projects. This shared history as partners has reinforced their abiding belief that, together, both Weir Minerals and Andritz are stronger, they said.

This shared success has led both Weir Minerals and Andritz to renew their ongoing commitment and announce they’ll be expanding their offer to all regions around the globe.

Using Andritz’s proven separation and dewatering technologies, Weir Minerals says it has strengthened its whole-of-mine capabilities, showcasing market-leading products from extraction to comminution, mill circuit and tailings management.

“Weir Minerals has been providing tailings solutions for decades; we have dedicated research facilities – the Weir Technical Centre in Melbourne, Australia, and the Sustainable Mining Centre in Venlo, Netherlands – that are challenging conventional ways of thinking about tailings, while also developing practical, innovative and sustainable solutions that will reduce operating costs and improve safety,” Ricardo Garib, Weir Minerals Division President, said.

“Decreasing ore grades mean that mines are producing more tailings than ever before. One of the challenges with tailings management is that there cannot be a one-size-fits-all approach; each mine requires a tailored solution that carefully considers the minerals being processed, as well as the site’s climatic and geological conditions. Weir Minerals prides itself on having both the expertise and equipment that allows us to partner with miners everywhere to plan and implement tailings solutions based on their operations’ unique challenges and this agreement with Andritz enhances those capabilities,” he said.

Steve Huff, President Andritz Separation, said: “Andritz has a long history working across a range of different industries. We are very proud of the work we’ve done with Weir Minerals; together, we’re excited about continuing to provide a joint offering of sustainable and value-added tailings solutions. Both companies bring a different expertise and know-how to the partnership; we complement one another and ultimately, it’s our customers who’ll benefit.”

Tailings management forms an important element of Weir Minerals’ broader integrated solutions approach, which considers problems and challenges from all perspective and draws on a range of experts – process engineers, design engineers, product experts and materials scientists, among others – to identify potential challenges and opportunities and provide tailored solutions.

Charlie Stone, Weir Minerals VP Sales and Business Development-Mill Circuit, said: “This latest agreement enhances our overall tailings offering and enables us to provide our customers with a complete tailings solution. Under the brand name IsoDry, we will continue to offer customers a range of mechanical separation technologies, such as thickeners, filter presses, centrifuges, and vacuum belt filters.”

Weir Minerals has strengthened its tailings team to support the market and ensure that it can provide innovative solutions based on each customer’s specific requirements.

The agreement provides the opportunity for potential future collaboration on technology, harnessing Andritz’s separation technology in conjunction with Weir Minerals’ minerals and tailings processing technology. Many of these products – Warman® pumps to transport fluid tailings, GEHO® pumps to handle paste, Cavex® hydrocyclones to dewater tailings and the Multiflo® range of dewatering solutions – have been integral to helping miners manage their waste for generations, they said.

Weir Minerals and Andritz have also reiterated their shared commitment to sustainability; it is an essential part of both their business and corporate strategies. Both companies say they have outlined ambitious plans to reduce their carbon emissions, while their approach to ESG initiatives extends to all aspects of their organisations.

Jord International addresses pressing issues for BMA Caval Ridge

Jord International has recently taken up a challenge from BHP to come up with a safer solution to filter press maintenance at the Caval Ridge metallurgical coal mine, in Queensland, Australia, as part of the New South Wales-based company’s expanding remit to unlock new technologies for the wider mining industry.

The plant and systems designer, developer and service provider was awarded the project, part of BHP’s Supplier Innovation Program challenge, earlier this year. It has seen Jord design and construct the first concept prototype in tandem with the maintenance team at the mine.

The prototype comprised a belt cartridge installer within a self-contained steel frame that holds a new belt and removes the old, damaged belt. The first commercial belt installer is expected to be in use by July, according to BMA.

Craig Samuel, Jord’s Mechanical Engineer for Aftermarket and Reliability, said the filters the company worked with at BMA Caval Ridge are 3 m wide x 5 m long, with the product path through the filter around 14 m long. While the solution was designed for Caval Ridge specifically, he said it could have applications on any site or with any commodity using filter presses.

“The idea came from the understanding of how the filter belts are installed, and a cartridge-style installer just made sense considering Caval Ridge has a readily available crane to move the cartridge around,” Samuel told IM. “The mechanics of the installer required some out-of-the-box ideas to develop a continuously variable speed ratio between the new belt roll and the old belt roll.”

Samuel said he expected the belt change time to be cut in half with this new solution.

Jord has already applied for another BHP Supplier Innovation Program challenge that could leverage a dust management and cleaning innovation, but the company has also been investing in research and development to commercialise new minerals beneficiation technologies for more efficient and effective liberation of ore, according to Kevin Barber, Jord’s General Manager of Resources.

“Our goal is to unlock new technologies that provide step-change improvements to current processes in the industry,” he said of these new technologies. “It’s about using less energy, using less water and removing some of the environmental challenges with particular focus on tailings. We’re finding alternative ways of dealing with problematic ores and resources.”

Barrick Gold advances emissions reductions targets after a year of ESG positives in 2020

Barrick Gold has decided to up the ESG ante with a new emissions reduction target to 2030 that makes its goal of reaching net zero emissions by 2050 that much more achievable.

The company said its ESG strategy delivered tangible results in 2020, included zero Class 1 environmental incidents, a new record of 79% water recycling and re-use by its operations, and the introduction of fully functional community development committees at all its operating sites to guide its social investment programs.

Speaking in a virtual presentation on sustainability this week, Barrick President and CEO, Mark Bristow, said: “At the beginning of last year, we set an emissions reduction target of 10% by 2030 against a 2018 baseline that combined the data from the legacy Barrick and Randgold operations as well as newly acquired assets. Through the year, we worked on identifying further reduction opportunities and this has enabled us to set an updated target of at least 30% by 2030 with an interim reduction target of 15% based on projects already being implemented, while maintaining a steady production profile.”

He added: “Ultimately our aim is to achieve net zero emissions by 2050, achieved primarily through greenhouse gas reductions and offsets for some hard-to-abate emissions,” he said.

Sustainability has long been a strategic business priority for the company, according to Bristow.

“Our strategy is based on four pillars: the creation of economic benefits for all stakeholders; the protection of health and safety at our mines and in their host communities; a respect for human rights; and the minimisation of our environmental impacts. For us, ESG is not a corporate compliance function: it’s integral to how we manage our businesses worldwide.”

In the same presentation, Barrick’s Group Sustainability Executive, Grant Beringer, said all the company’s sites had been certified to the ISO 14001:2015 environmental management standard. Each site had also been empowered to manage its own environmental issues under the oversight of the group’s strategic leadership. There was a particularly rigorous approach to management of tailings facilities, the company added.

Beringer said: “Our tailings and heap leach management standard has been aligned with the recently updated guidelines of the International Council on Mining and Metals, of which Barrick is a member, as well as those of the Mining Association of Canada. The standard sets out six levels of inspection and surety for the safe operation of tailings and heap leach facilities.”

Sedgman books tailings dewatering work at QCoal’s Byerwen coal mine

CIMIC Group’s minerals processing company, Sedgman, has been awarded a contract to design and construct a tailings dewatering facility at QCoal’s Byerwen coal mine in central Queensland, Australia.

The project will result in a lower operational risk profile, less power usage, and improved water recovery and management of dewatering chemicals, Sedgman says.

Sedgman Managing Director, Grant Fraser, said: “We are pleased to continue working with QCoal with a key focus on reducing impacts and undertaking environmentally responsible practices. The tailings dewatering contract at Byerwen is a great opportunity to achieve joint goals in ESG, an important focus for the industry.”

Construction work for the Byerwen mine will commence this month and the project will conclude in mid-2022.

Back in October, Sedgman was awarded two contract extensions by QCoal to continue to operate and maintain its Sonoma and Byerwen mines processing plants in Queensland.

Second Cat 994K wheel loader arrives at Capstone’s Pinto Valley in latest innovation push

Capstone Mining has brought a second Caterpillar 994K wheel loader to its Pinto Valley operation in Arizona, USA, as it looks to reduce its emissions and improve its operating cost base at the copper mine.

Last year, the mine added to its fleet a Cat 994K loader, which, the company says, burns circa-30 less gallons of fuel per hour (1.9 litres/min) than its current shovels. “This reduced our CO2 emissions and operational cost savings on approximately 116,000 gallons of fuel in 2020,” Capstone said.

The second 994K, added last week, will, in partnership with the first wheel loader, displace around 10,000 shovel hours a year and save approximately 410,000 gallons of fuel and millions in maintenance costs, the company claimed.

Capstone concluded: “Pinto Valley is innovating and optimising for exciting times ahead.”

This is not the only area of innovation the company is currently pursuing at Pinto Valley, an operation it acquired from BHP back in in October 2013.

In its 2020 results, released last month, Capstone said the implementation of phase one of its PV3 Optimization project at Pinto Valley had delivered a 10% sustainable throughput improvement compared with 2019.

The PV3 Optimization project has been designed to achieve safer, more reliable and higher capacity operations without major investments in new comminution equipment. It is doing this by leveraging new inexpensive technologies.

Phase one work, which included improved blast fragmentation processes, installation of a new secondary crusher and screen decks as well as a new mill shell, was completed last year. This saw the mine achieve throughput of 57,168 t/d in the December quarter, 10% higher than the annual 2019 average of 51,137 t/d. December 2020 mill throughput achieved 60,717 t/d, which represents a new monthly record in the mine’s operating history.

Phase two of the PV3 Optimization project is expected to be completed in the second half of 2021, upon completion of upgrades to a conveyor, mill auto controls, cyclone packs and retrofits to the thickeners, it said.

During the month of December, the company conducted a pilot plant test of Eriez HydroFloat coarse particle technology at Pinto Valley, with Capstone saying the results had surpassed expectations of a 6% improvement target to overall copper recovery. In fact, the tests showed a 6-8% increase in overall copper recovery was achievable, which, when combined with expected higher throughput rates, could result in an additional 9-12 MIb/y (4,082-5,443 t/y) of copper production at the operation, it said.

“Additional benefits to the technology include allowing the operation increased throughput by operating at a coarser grind size, which is expected to lower power costs, improve water consumption and lead to improved stability in the tailings storage facility,” Capstone said in its 2020 results. “The estimated $70 million expansionary capital, which includes the installation of Eriez HydroFloat and related equipment, if approved by the board of directors, is expected to be spread over half two 2021 and early 2022, with start-up expected in Q2 (June quarter) 2022.”

Capstone said it expects to release an updated NI 43-101 technical report that encompasses the PV3 Optimization Phase 1 and Phase 2 projects and improvements in the second half of 2021.

At the same time, it is also looking into a PV4 study at Pinto Valley.

Capstone explained: “Feasibility work on scenarios to take advantage of approximately one billion tonnes of mineral resource not currently in the mineral reserve mine plan, which is at similar grade to the current mineral reserves, will be conducted for Pinto Valley.”

The PV4 study is expected to be released in late 2022 and will contemplate using existing mill infrastructure rather than building new facilities, with higher mining rates, higher cutoff grades to the mill and increased tonnage available for leaching.

Extensive column leach test work in collaboration with Jetti Resources LLC will take place over 2021. Jetti’s patented catalytic technology, designed to allow for the efficient and effective heap and stockpile leach extraction of copper, has been a success at Pinto Valley’s leaching operation, where it expects to recover up to 350 million pounds of cathode copper over the next two decades from historic and new mineralised waste piles.

“Capstone is a pioneer in the application of this leach technology and we intend to use it to enhance the economics of a future expansion at Pinto Valley,” it said.