Efficient Utilization of Stainless Steel Dust and Chromium-Containing Slag by Carbothermal Direct Reduction: Synergistic Mechanism and Optimization Analysis

摘要

Stainless steel dust as the main solid waste produced in the process of stainless steel smelting has the characteristics of high basicity, low treatment efficiency, and low recovery. In this study, chromium-containing slag with low basicity was added to stainless steel dust on the basis of carbothermal reduction. Through the study of the effect of single factor of reduction process and multiple factors based on response surface method (RSM) on the recovery of metal Fe, Cr, and Ni, the efficient reduction of valuable metal components in stainless steel dust was realized. The results show that the addition of chromium-containing slag and reduction temperature have a significant impact on the metal recovery of the reduction product, and there is a significant interaction between the metal recovery of Fe, Cr, and Ni in the reduction product. The optimum process parameters are as follows: the addition of chromium-containing slag is 6%, the reduction temperature is 1425 degrees C, the reduction time is 28 min, and the molar ratio of fixed carbon to metal oxide (FC/O) is 0.9. The predicted recoveries of Fe, Cr, and Ni were 94%, 93%, and 97%, respectively. [GRAPHICS] .