Desulfurization thermodynamics experiment of stainless steel pickling sludge

A technical idea of returning stainless steel pickling sludge to smelting process so as to recycle valuable metals of Fe, Cr, and Ni was proposed, expecting to realize sludge detoxification and resource utilization. Thermodynamics calculation showed that not only most valuable elements including Fe, Cr and Ni, but also the harmful element of sulfur in pickling sludge can be enriched into molten metal. As a result, a theoretical study on desulfurization thermodynamics of sludge pre-treatment was conducted, and results indicated that complete desulfurization temperature of pure pickling sludge was above 1400 degrees C. When 0.5-0.8% carbon was added as reducing agent, the complete desulfurization temperature was reduced to 1000 degrees C or below. Desulfurization roasting experiment indicated that desulfurization rate at 1400 degrees C under inert environment was 78.74% and maximum desulfurization rate at 1000 degrees C under reducing environment was 91.62%.