A novel process for preparing Fe–Cr-Ni-C alloy: synergetic reduction of stainless steel dust and laterite nickel ore

In order to improve the recovery ratio of valuable metals in stainless steel dust, reduce environmental pollution, and promote solid waste resource recovery and sustainable development of industry, the synergistic reduction process for preparing Fe–Cr-Ni-C alloy was studied in detail by changing the addition of laterite nickel ore and reduction process conditions. The results show that with the addition of laterite nickel ore, the basicity of raw materials is reduced, the precipitation and aggregation of metal particles are promoted, the separation effect of metals and slags from reduction products is improved, and the metal recovery ratio also improved in the synergistic reduction process. When the ratio of stainless steel dust to laterite nickel ore is 94%:6%, reduction temperature is 1400 °C, reduction time is 20 min, and FC/O is 0.8, the metals and slags of the reduction product can be separated naturally after cooling; the recoveries of Fe, Cr, and Ni are 90.6%, 90.1%, and 91.2%, respectively. The grades of Fe, Cr, and Ni in the Fe–Cr-Ni-C alloy are 62.7%, 18.9%, and 4.1%, respectively. The content of harmful elements S and P in the alloy is low, so it can be directly used as raw material for stainless steel smelting.