Pyrometallurgical prodn of lead - in which zinc mfg residues are added to the concentrate to increase removal of sulphur

摘要

In a pyrometallurgical process for the winning of lead by redn. of sintered ore obtd. from the sintering of substances including lead concentrate, the novelty is that prior to sintering, residues from zinc prodn. are mixed with the substances. Sintering pref. occurs in a fluidised bed furnace after a roasting treatment, and the zinc residues are pref. added between roasting and sintering; alternatively, roasting and sintering are undertaken in one furnace continuously. A mixt. of 1 part Pb concentrate, 0.15-0.2 pts Zn residue, 0.04-0.05 pts. siliceous stone, 0.1-0.15 pts limestone, 2.5 pts. returned powder, and 0.3-0.5 pts. Pb shaft furnace slag, is pref. pelletised, then sintered. The Zn residues pref. contain Au, Ag, Cu, Fe, Si, C, and Zn. The zinc residues have a favourable effect on sintering, reducing the % sulphur in the product and increasing the output. Also, the precious metals in the residue are recovered.