Tag Archives: tailings

The ICMM addresses mine tailings reduction ambition with new roadmap and initiative

Today, the International Council on Minerals and Metals (ICMM) has published a Tailings Reduction Roadmap which, it says, lays out innovative approaches and solutions capable of significantly reducing tailings from the mine life cycle, as part of a broader Tailings Innovation Initiative.

The initiative brings together a third of the global mining and metals industry to collaborate with technology innovators, including suppliers and academia, to accelerate technology for reducing tailings waste and to explore the potential to eliminate it in the long term, the ICMM says.

The Tailings Reduction Roadmap sets out short- and long-term technology options. These include mature solutions that can be implemented in the short term, such as coarse particle flotation technology to enhance the recovery of coarser particles of ore that have traditionally been seen as waste, and solutions with the potential to reduce tailings in more significant quantities, but that will require further development over the next 10-15 years, such as higher precision mining and artificial intelligence.

Developed through a series of engagements between technology suppliers, innovators and ICMM members, the roadmap offers strategic direction to the mining industry on how to accelerate the development and adoption of technologies to reduce tailings, the ICMM says. It addresses technological challenges, such as testing new technology on a different range of ore characteristics, as well as enabling factors, including business case and regulatory requirements, in parallel.

ICMM members are already piloting technologies laid out in the roadmap that match their commodities and site characteristics, so that learnings can be applied to solutions that can be scaled up to benefit the whole industry.

Rohitesh Dhawan, CEO of ICMM, said: “Catastrophic tailings failures in recent years including at South Africa’s Jagersfontein mine just last week have brought into sharp focus the need for urgent action to produce less tailings as we supply the metals and minerals that are critical for the energy transition and sustainable development. If we continue to use traditional production processes, we run the risk of multiplying tailings waste many times over. There is no easy solution, and we will continue to need tailings storage facilities into the future. However, this initiative signals our clear intent to act with urgency and purpose to find ways of minimising or potentially eliminating waste at every stage of the mining cycle.

“Work has already begun, but if we are to match our ambition, we need to work collaboratively in accelerating the types of breakthroughs that can be adopted widely in any existing or future operations around the world. Our ambition is that ICMM’s Tailings Reduction Roadmap and wider Tailings Innovation Initiative will help to identify and accelerate opportunities for wider collaboration and serve as a catalyst for advancing more partnerships between industry and technology innovators on piloting these technologies.”

ATG and Metso Outotec’s tailings-to-fertiliser tech progresses in BHP Tailings Challenge

Auxilium Technology Group (ATG), a start-up connected to the University of Arizona, in collaboration with Metso Outotec, has been announced as one of two finalists in the BHP Tailings Challenge, an international competition to promote the development of new technologies to reuse mine tailings.

Last year, ATG was one of 10 companies and academic research groups chosen to move on to the laboratory stage of the BHP Tailings Challenge, from an initial field of 154 applicants from 19 countries. Metso Outotec and ATG signed an agreement to collaborate on this initiative and, in April 2022, BHP chose two finalists, ATG and Americas Tailings Inc, a company that has developed a process to turn mine tailings into fertiliser products.

For the next phase, ATG plans to build a pilot tailings processing plant at the San Xavier Underground Mining Laboratory, owned by University of Arizona. Metso Outotec will contribute with advice on engineering and scale up using Metso Outotec products.

Metso Outotec supported the ATG process design concept by estimating engineering costs and providing Metso Outotec Plant Solutions technology competence. The concept considers pre-designed plant units known as “Process Islands” for almost all the process areas of the future plant, the company said.

Metso Outotec’s approach supported the project from optimal equipment sizing to optimising engineering costs and modularising the plant to meet future capacity requirements.

Mining companies like BHP are eager to find alternatives for the use of tailings, which are costly to store and regulated under environmental laws because they contain pollutants.

After initial cleaning of the tailings, the proposed process includes use of the material as construction aggregate or an insulating “geofoam” that can be sprayed or 3D printed to produce insulating blocks.

Hatch identifies opportunities to cut Australian tailings generation by as much as 30%

A new report from multi-disciplinary engineering, operational and development project, Hatch, estimates Australia’s mining waste can be reduced by 30% using already available technologies.

One of the biggest challenges currently facing the mining industry is managing the volume of tailings generated as minerals mining ramps up to meet the demands of the transition to renewable energy.

Undertaking an in-depth analysis to identify the technologies required to reduce or eliminate tailings of six key commodities (copper, gold, nickel, iron ore, coal and bauxite), Hatch investigated how tailings production would be impacted by applying the key technologies ‘themes’: advanced geometallurgy, ore sorting, advanced sensing and particle sorting, in-situ extraction, and preferential fracturing.

The company’s analysis revealed that technologies available today could reduce tailings by 20-30%, also identifying that, in the next 10-20 years, the integration of these technologies in future projects or expansions could provide an opportunity to reduce tailings by more than 50%.

Managing Director of Australia and Asia at Hatch, Jan Kwak (pictured), says the challenge of reducing tailings is a complex effort that is best solved utilising the innovative capacity of the entire mining supply chain.

“A balanced spread of researchers, METS (mining equipment, technology and services) companies, and operators in the mining industry are actively commercialising technologies,” he said. “Half (50%) of stakeholders identified are METS companies, whose core business is the supply of equipment and services of these technologies, indicating commercialisation is underway. This group was also present across the technologies that our analysis has shown to have higher TRLs (Technology Readiness Levels).”

The TRL ranking system measures the maturity of technologies, whereby Hatch graded technologies from zero (idea stage) to nine (commercial application).

For in-situ mining and preferential fracturing technology themes, there is a larger representation of research organisations and partnerships. This suggests collaboration is required to advance technological development, according to Hatch.

“It is vital that these stakeholders are highly engaged in the tailings reduction challenge in order to achieve the greatest cut through and introduce real change and advancement in the reduction of tailings, which will be needed to support the increase in mining activity while meeting emissions reduction targets,” added Kwak.

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.”