| 摘要 |
PCT No. PCT/NO85/00014 Sec. 371 Date Oct. 29, 1985 Sec. 102(e) Date Oct. 29, 1985 PCT Filed Mar. 8, 1985 PCT Pub. No. WO85/03952 PCT Pub. Date Sep. 12, 1985.This is a method for the complete leaching of the valuable metals in a metal sulphide material which contains copper, zinc, lead, silver and iron by the use of a solution which essentially contains cupric chloride/sulphates. After the valuable metals have been recovered, the solution is regenerated whereby ferrous chloride and cuprous chloride/sulphate is oxidized to a ferric hydroxide solid and a cupric chloride solution respectively. The regenerated solution is split into two part-solutions and returned to the process. One part-solution goes to a metathesis stage where the fresh metal sulphide material is added in large excess with respect to the part-solutions's content of copper. The result is that only the valuable metals like zinc, lead and silver are leached while copper and iron remain in the residue. The other part-solution goes to a leach stage where the residue from the metathesis stage is added. The ratio between the residue and the solution is about stoichiometric, while the characteristic feature of this stage is how the leach operation is performed. This results in a well leached residue and an almost completely reduced solution in just one leach stage. The residue from this stage goes to a third leach stage where all remaining valuable metals are leached completely by the use of chlorine gas/oxygen gas coming from the zinc electrolysis stage. Iron is precipitated as a hydroxide. The ratio between the part-solution which goes to the metathesis stage and the part-solution which goes to the leach stage is between 1:1 and 1:100. |
