An investigation on the kinetics of lead recovery from smelting furnace slag using hydrochloric acid

Abstract

With regard to the large amount produced from this type of slag in flash lead smelting furnace of Ghaniabad plant and considerable lead content of the slag, the recovery of lead is of prime importance. This research work was under taken to study the lead recovery from the mentioned slag using a hydrometallurgical process. Solving in water is done on slag for 30 minutes. XRD analysis showed that PbS is the main mineral in the slag and the difference between washed and unwashed samples is lack of Na2O in washed one so that before washing this compound existed. The slag sample was first crushed and washed in distilled water. The residue was classified into different sizes. The slag powder was then leached in Hydrochloric acid under different conditions to evaluate the effect of such parameters as pH, temperature and slag particle size on the dissolution rate of lead. It was depicted that the most critical parameter affecting the leaching rate is pH whereby the decrease of down to negative number the leaching rate increased pH significantly. Finally kinetic study of slag leaching showed that the diffusion of in the solid particle controlled the lead leaches process. This was confirmed by calculation of activation energy where was obtained as 9.47 kJ mol−1 calculated.