Experimental Studies on Reduction Mechanisms of Lead-Rich Slag with Different PbO Concentrations

Smelting reduction of lead-rich slag is a clean technology recently developed in China to produce primary lead metal. The technology has the advantages of more efficient capture of SO2 and lead fugitive emissions and low energy consumption. The extent of the slag reduction was continuously measured by the product gas volume. Effect of PbO concentration on the reduction of lead-rich slag was determined in the temperature range 1073–1473 K. The reduction of lead-rich slag by carbon was found to be chemically controlled at early stage and then diffusion-controlled at late stage. The activation energy for chemically controlled reduction decreases with increasing PbO concentration in lead-rich slag. The reaction mechanism has been discussed by experimental results and FactSage 8.1.