Mineral phase change and element transfer behavior during stainless steel sludge reduction with carbon
ZHANG Jixin, LI Qiuju, ZHOU Cang, LI Chonghe, WANG Dan
1.State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200444, China;2.Shanghai Key Laboratory of New Technology Development and Application of Iron and Steel Metallurgy, Shanghai University,Shanghai 200444, China;3.Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Abstract:Abstract: Stainless steel pickling sludge is a hazardous waste, but it contains a lot of valuable heavy metals, so it is of great significance how to resource utilization of stainless steel sludge. The interaction and transformation of iron, chromium, nickel and other elements in the process of carbothermal reduction reaction were studied, and the influencing factors of iron, chromium as well as nickel elements distribution in the sludge were explored. The phase of sludge and its reduction samples were analyzed by XRD, and metallographic microscope and SEM-EDS were used to analyze the morphology and migration behavior of metal particles in sludge reduction process. The results show that NiO combines with Fe2O3 to form NiFe2O4 spinel phase, which is reduced to form Ni-Fe metal phase during sludge carbon reduction process. FeO combines with Cr2O3 to form FeCr2O4, which forms FeCrC metal solid solution with carbon reduction. Ni-Fe-Cr-C alloy particles containing carbon are lower melting point which can transfer and grow up through convergence. There will form a micro molten pool as the reduction temperature is 1300℃, which provides better migration and growth conditions for the metal droplets. The nonmetallic elements form slag pellets with [Si-O] network structure, which is composed of Ca2Al (AlSiO7).
张继新1,李秋菊1,周仓2,李重河2,王丹3. 不锈钢酸洗污泥碳还原过程中的物相变化及元素迁移行为[J]. 钢铁研究学报, 2021, 33(9): 920-928.
ZHANG Jixin1, LI Qiuju1, ZHOU Cang2, LI Chonghe2, WANG Dan3. Mineral phase change and element transfer behavior during stainless steel sludge reduction with carbon. JOURNAL OF IRON AND STEEL RESEARCH , 2021, 33(9): 920-928.