Abstract
The zinc industry has been in the forefront of hydrometallurgical developments for almost a century. The development of pressure leaching in the 1980s and the development of atmospheric direct leaching in the 1990s for treating zinc-sulphide concentrates have resulted in a number of zinc-refinery expansions without an increase in roasting capacity. Likewise, solvent extraction techniques are now used for the hydrometallurgical treatment of zinc-oxide ores on an industrial scale. The treatment of poor and complex zinc-sulphide resources has been extensively studied using processes as diverse as pyrolusite leaching and heap bioleaching. Finally, the precipitation of relatively pure zinc oxide at the mine site, a process that has been proven to be technically feasible very recently, may significantly change the paradigm of primary zinc production.
The author would like to thank the Editor-in-Chief, Dr. S. Komar Kawatra, for his invitation to publish in Mineral Processing and Extractive Metallurgy Review and for his kind patience during the manuscript preparation. He would like also to thank an anonymous reviewer for some very helpful comments and the meticulous editing of the text.