To reduce the issues of high pollutant emissions and lengthy processes in
extracting zinc from zinc sulfide ore, a new technical approach is proposed
that involves the synergistic use of iron oxide and vacuum carbothermal
reduction to extract zinc from zinc sulfide ore. The iron oxide is sourced
from high-iron-content metallurgical residue. Under vacuum conditions,
carbon reduces iron oxide to metallic iron, which then displaces zinc in
sulfide to produce zinc vapor. The zinc vapor is finally condensed to obtain
metallic zinc. This study investigates the extraction of zinc from zinc
sulfide under vacuum conditions using iron powder, pure iron oxide powder,
and iron oxide from roasted cyanide tailings as iron sources. The main
factors examined were reduction temperature and holding time on zinc
volatilization rate. The results show that at a molar ratio of
nFe:nZn=1.1:1, a temperature of 1000?C, and an initial furnace pressure of
10 Pa, iron powder, pure iron oxide powder, and iron oxide from roasted
cyanide tailings can all achieve a zinc volatilization rate of over 99% from
zinc sulfide. Different iron sources react with zinc sulfide to form FeS,
and no sulfur-containing gases are produced in the zinc extraction process.