Recovering zinc from zinc-containing sulphidic material.

摘要

A process for recovering zinc from zinc-containing sulphidic material which contains iron and lead and/or silver, which comprises the leaching of said material under oxidizing conditions at from about 130 to about 170°C in an aqueous sulphuric acid solution with a stoichiometric excess of sulphuric acid relative to the zinc content of from about 40 to about 100% to produce an undissolved residue containing lead and/or silver and a leach solution containing zinc and iron. The residue is separated and treated to recover values of lead and/or silver. The leach solution is treated by feeding the solution to another process step in which zinc-containing material is treated to recover zinc which includes iron-precipitation.

Said other process step can be a zinc oxide leach, a sulphide leach of another zinc sulphide low in lead and silver or a two-stage roasvleach of material which contains sulphide with precipitation of the iron as jarosite or goethite.