Investigation on cooperative desulfurization efficiency for bearing carbon stainless steel dust briquettes chromium and nickel recovery process

During the stainless steel making process, Fe-Cr-Ni of lower sulfur content can be recycled from stainless steel dust (SSD) by briquettes reduction. An investigation of cooperative desulfurization efficiency for bearing carbon SSD briquettes reduction process is conducted. First, slag amount prediction model is established through corundum crucible erosion behavior in order to analyze the desulfurization efficiency. Next, the effects of carbon amount, CaF2 amount, silicon ferrous, basicity and feeding modes on the desulfurization rate and the sulfur distribution ratio are analyzed. Furthermore, sulfur distribution ratio prediction model between SSD briquettes and molten iron is originally established in the principle of thermodynamic equilibrium. Results show that basicity, CaF2, silicon ferrous and carbon amount could promote the desulfurization rate and sulfur distribution ratio. When simultaneously adding iron ingot and SSD briquettes, feeding mode has a higher desulfurization rate and better metal/slag separation than when adding iron ingot prior to SSD briquettes. During the experiment, desulfurization rate varies from 55% to 70% and the sulfur distribution ratio results range from 2 to 10. The sulfur distribution ratio prediction results greatly match with experimental results implying that the desulfurization rate analysis method through corundum crucible erosion behavior is more accurate.