PROCESS FOR THE RECOVERY OF LEAD FROM SCRAP BATTERIES

摘要

A process for the treatment of battery paste originating from spent batteries, wherein the battery paste is subjected to a first lead precipitation step at high alkalinity to partially precipitate and separate the lead, the liquid residue thereof is subjected to a second lead precipitation step at lower alkalinity to precipitate and separate remaining lead, and a sodium sulphate solution remains, is improved according the invention. Thus, the battery paste can be subjected to a filtration step before said first lead precipitation step, wherein the solid fraction of the filtration step is subjected to the lead precipitation step. The sodium sulphate solution remaining after the second lead precipitation step is subjected to a biological sulphate reduction and then to a controlled biological sulphide oxidation step to produce elemental sulphur and a reusable alkaline solution.