Austenitic Stainless Steel Heat Production from Lithium-Ion Battery Black Mass: A New Route for Circular Steelmaking

The increasing use of lithium-ion batteries for electric mobility has created a growing need to develop efficient recycling routes for recovering critical raw materials, such as nickel, cobalt, and manganese. Black mass, the material obtained after dismantling batteries, is a significant secondary source of these elements in spent batteries. This study evaluated the technical feasibility of using nickel-rich compounds derived from recycled black mass as an alternative raw material for producing American Iron and Steel Institute (AISI) 304 stainless steel. Experimental laboratory-scale melts were conducted using both untreated black mass and nickel concentrates obtained after treating the black mass through carbothermic reduction, lithium recovery as Li 2 CO 3 , and high-intensity wet magnetic separation. The results show high yields of the main elements (Ni, Cr, and Mn), exceeding 80%, and final chemical compositions comparable to those of conventionally industrially produced AISI 304 stainless steel. In comparison with industrial heats, the microstructural characterization of laboratory scaled melts revealed the presence of intergranular precipitates of chromium carbides and micro-inclusions of manganese sulfides with traces of residual elements, whose low concentrations do not limit their industrial application. The results confirmed the potential of the recycled black mass as a partial substitute for primary nickel in stainless steel production.