PASTE & FILTERED TAILINGS
Responsible management for a sustainable future
Benedikt Sobotka , CEO of Eurasian Resources Group ( ERG ) and Co-Chair of the Global Battery Alliance , looks into the management of historic and new tailings in the mining industry
With the world moving gradually towards a circular economy , responsible waste management is becoming increasingly important in the mining industry . According to a study published by a cohort of Finnish researchers , tailings are the biggest waste stream resulting from mining , in metal value and volume .
It goes without saying that tailings , both historical and contemporary , can significantly impact the environment . They must therefore be thought of as a valuable resource to be reused or recycled , not wasted .
Responsible standards for tailings
Responsibly managing tailings is a key way in which mining companies can reduce their environmental impact and contribute to a more sustainable future . This can be achieved through a number of means , from reducing tailings generation , to enhancing storage and management practices , and finding ways to recover valuable minerals and metals from tailings .
Fortunately , the United Nations Environment Programme , Principles for Responsible Investment , and International Council on Mining and Metals recognise the need for establishing responsible standards . In 2020 , these organisations collectively launched the Global Industry Standard on Tailings Management , which sets a precedent for the safe management of tailings .
The standard requires tailings facilities to match key obligations across six different areas , including the need for regular monitoring and reporting , the development of emergency response plans , and independent oversight and review processes . Fundamentally , the standard delivers a framework for safe tailings facility management while allowing operators flexibility in achieving their goals .
Reprocessing historical tailings
However , it is not just a case of meeting standards . At Eurasian Resources Group ( ERG ), we believe miners should focus on going above and beyond . Since 2021 , ERG ’ s Environmental , Social and Governance ( ESG ) team has been working on a long-term strategy for strengthening the Group-wide approach to tailings management .
This is particularly important at our Metalkol production facility in the DRC , which has been reducing the environmental impact of historic cobalt-copper tailings through safe , efficient reprocessing and storage methods since 2018 . As the world ’ s second-largest standalone producer of cobalt and a major producer of copper , Metalkol reprocesses tailings left by other mining operators in the Musonoi River valley and dry-stacked at the Kingamyambo Tailings Dam .
These two sites are home to around 84.5 Mt of historical tailings across an 11 km stretch of the river and 32.4 Mt of dust-emitting tailings , meaning Metalkol ’ s efforts have been crucial in minimising the environmental impact of these legacy deposits . Metalkol ’ s capacity to extract around 100,000 t of copper and more than 24,000 t of cobalt annually is enough to power over 3.5 million electric vehicles .
So , what technology does the operation use ? Metalkol employs hydro-metallurgical processing to recover cobalt and copper from the tailings . The process includes tank leaching , followed by solvent extraction and electrowinning to produce cobalt hydroxide and copper cathode . But it ' s not just about production . Following reprocessing , the spent tailings residue is safely stored in a new , purpose-built Tailings Storage Facility , which is regularly inspected , monitored ( including for dust levels ) and reported to an independent laboratory . This facility is making a significant
ERG ' s copper and cobalt tailings reprocessing facility in the DRC
contribution to reducing the impact of historical tailings deposits on local water and air quality , as well as land degradation .
Managing contemporary tailings
Beyond the management of historical tailings , it is essential that the mining industry also responsibly manages current tailings . In Kazakhstan , ERG is building a new processing facility at its Kazchrome Donskoy GOK plant for this purpose . Using new chrome processing technologies , the facility will feature gravity , flotation , thickening , and filtering sections .
The combined gravitation flotation technology , developed by ERG ' s Research & Development team , is expected to significantly improve the enrichment of chrome oxide-bearing tailings , achieving a recovery rate of up to 55 %. The facility has a planned annual processing capacity of 1.7 Mt of tailings , with a targeted annual production of more than 500,000 t / y of chromium oxide concentrate .
The Group ’ s commitment to sustainable mining practices is also reflected in its decision to adopt a dry-stack tailings storage facility system at our BAMIN Pedra de Ferro mine in Brazil . This approach is widely acknowledged as a more environmentally responsible solution to ‘ wet ’ tailings management systems . By utilising dry-stack technology , the risks of liquefaction and catastrophic failure are significantly reduced , as is the potential for groundwater contamination .
At ERG , we understand that the mining industry still has a long way to go to reduce its environmental impact , but we can all play a part in promoting responsible practices . Tailings management and reclamation are essential components of responsible mining and promoting circularity . As processing technologies improve , a renewed focus on tailings reclamation can help mining companies meet surging demand for critical minerals – particularly while new mines are being advanced and recycling technologies for end-products like batteries is still being developed .
Construction of a reprocessing facility at Donskoy GOK , ERG ' s chromium mine in Kazakhstan
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P4 International Mining SUPPLEMENT | APRIL 2023