GJENVINNING AV SINK FRA SINKHOLDIG SULFIDISK MATERIALE.

摘要

A process for recovering zinc from zinc-containing sulphidic material which also contains iron and lead includes leaching the material under oxidizing conditions at a temperature in the range of from about 130 DEG to about 155 DEG C. in aqueous sulphuric acid solution with a stoichiometric excess of sulphuric acid relative to the zinc content of the material of from about 50 to about 100% to produce an undissolved residue containing a major proportion of the lead and a leach solution containing a major proportion of the zinc and iron. The sulphur and lead containing residue is separated from the zinc and iron containing leach solution. Elemental sulphur is physically separated from the remaining lead-containing residue, and the remaining lead-containing residue is recovered. The zinc and iron containing leach solution is treated to recover zinc by feeding the solution to another process in which zinc-containing material is treated to recover zinc and which includes an iron-precipitation step.