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A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y / F E B R U A R Y 2 0 2 2 1 4 SUSTAINABILITY BRIEF SELECTIVE SEPARATION Researchers developed new pro- cessing methods to more efficiently separate rare metals from mining ores and recycled materials. The approach, developed by MIT researchers, Cam- bridge, Mass., could help ease looming shortages of the essential metals that power everything from phones to auto- motive batteries. Selective adjustments within a chemical process called sulfi- dation allowedmetallurgists to success- fully target and separate rare metals, such as the cobalt in a lithium-ion bat- tery, from mixed-metal materials. The new processing techniques allow met- als to remain in solid form and be sep- arated without dissolving the material. The sulfidation approach could re- duce the capital costs of metal separa- tion between 65-95% from mixed-met- al oxides. Selective processing could also reduce greenhouse gas emissions by 60-90% compared to traditional liquid-based separation. The findings offer one way to alleviate a growing demand for minor metals like cobalt, lithium, and rare earth elements that are used in clean energy products like electric cars, solar cells, and electrici- ty-generating windmills. The chemical reaction exploited by the MIT team changes a material containing a mix of metal oxides to form new metal-sulfur compounds or sulfides. By altering factors like tem- perature, gas pressure, and the addi- tion of carbon in the reaction process, researchers found that they could selec- tively create a variety of sulfide solids that can be physically separated by a variety of methods, including crushing the material and sorting different-sized sulfides or using magnets to separate different sulfides from one another. The next step is to show that the process can work for large amounts of raw ma- terial—separating out 16 elements from rare-earth mining streams, for example. The team built a reactor that can pro- cess about 10 kilograms of raw material per day and have started conversations with several corporations about recy- cling collaborations. mit.edu . MINE RECLAMATION A team of researchers led by Penn State, State College, Pa., is looking to integrate the reclamation of mines and their materials with economic opportunity for surrounding commu- nities. According to the team, almost all production of raw materials for lith- ium-ion batteries, apart from some lithium extraction and refinement, oc- curs abroad today. The researchers examined co- balt and manganese in two categories of byproducts—minerals left by past mining and metallurgical industries in Pennsylvania, and acid mine drainage treatment sludge, which is material that was originally leached from minerals in coal-bearing strata and precipitated from solution. “Preliminary estimates indicate that waste left by coal mining activities in Pennsylvania contain tens of thousands of metric tons of cobalt and hundreds of thousands of metric tons of manganese,” the team reports. Prof. Sarma Pisupati commented about their recovery efforts, “In addition to the expected economic benefits, this can help remediate the environmental degradation caused by previous mining activities.” psu.edu . Novelis, Atlanta, will partner with State Farm Arena, also in Atlanta, to make the venue a TRUE zero-waste facility. TRUE (Total Resource Use and Efficiency) is a standard set by Green Business Certification Inc. Novelis will provide the know-how to organize, sort, and recycle aluminum and other materials, and the arena’s most premium suite level will educate guests on the importance of recycling and will supply aluminum cups, canned water, and recycling bins. novelis.com . MIT’s new processing technique helps alleviate metal shortages. Courtesy of Unsplash/CC0 Public Domain. Sustainable aluminum cup used by sports fans at State Farm Arena in Atlanta. Recovery of critical minerals frommine waste could provide domestically sourced materials for lithium-ion batteries used to power electric vehicles. Courtesy of Pixabay.