Despite ongoing efforts to find alternative materials, cobaltCobalt remains important in the productionProductions of rechargeable batteriesBattery essential for the energy transition. Currently, most cobaltCobalt is sourced from unethical and politically unstable regions as a by-product of nickelNickel and copperCopper extractionExtraction. However, primary cobaltCobalt deposits, such as those in the Iron Creek area, could provide a reliable and responsible supplySupply of this metalMetals. In these deposits, cobaltCobalt is encapsulated within the pyritePyrite (FeS2) lattice, making traditional beneficiationBeneficiation methods ineffective. This study evaluates the potential of thermal decompositionThermal decomposition of pyritePyrite as an effective beneficiationBeneficiation strategy for cobaltiferous minerals by employing a factorial design to assess the effects of key process parameters on two concentrates from a differential flotationFlotation stage. Thermal decompositionThermal decomposition in an inert atmosphere facilitated partial desulfurization, converting pyritePyrite into lower sulfides—pyrrhotite and troilite—while increasing cobaltCobalt grades by 5–17% and producing high-purity sulfur as a valuable by-product. Subsequent magnetic separation of the calcine yielded final concentrates containing 3.0–3.5% cobaltCobalt, representing an overall improvement of 66–192% compared to previous studies. This technologyTechnology is currently patent pending.