New methods of materials separation and metal production utilizing sulfide chemistries may support a paradigm shift in sustainable metallurgy. We leverage sulfidation with elemental sulfur, aluminothermic reduction, and slag refining to obtain a chromium–nickel–molybdenum ferroalloy and stainless steel using a sulfide-based route without direct greenhouse gas emissions. The absence of carbothermic reduction from the mineral, concentrate, and matte feedstocks tried herein indicates that argon-oxygen-decarburization may no longer be necessary to refine stainless steel products.