PRECIPITATION OF ZINC-SULFIDE FROM ZINCATE SOLUTIONS WITH ELEMENTAL SULFUR IN THE PRESENCE OF REDUCING AGENT

A new method is proposed for obtaining zinc sulfide from boiling alkali zincate solutions with elemental sulfur and a strong reducing agent (hydrazine hydrate). The latter is used to eliminate the sulfites formed when sulfur undergoes disproportionation in alkalis. The influence of the zinc, sulfur, free alkali, and N2H4-H2O concentrations on the qualitative and quantitative characteristics of the ZnS precipitates is examined, as is the influence of the order in which the solutions are added. The method makes it possible to obtain ZnS with specified particle sizes. Moreover, there is no need to use toxic, explosive hydrogen sulfide.