Copper and flue Recovery from Brass and Zinc or Zn-Fe Alloy Plated Steel Sheet with Cupric Ammine Solutions

摘要

Dissolution of brass was examined in aqueous cupric ammine solutions. Copper and zinc were dissolved easily from #alpha# and #alpha#+#beta# brass at a diffusion-limiting rate. However, the presence of Sn, Fe and Pb in the alloys inhibited the dissolution of copper and zinc. Applicability of selective dissolution of zinc from zinc or Zn-Fe alloy plated steel sheet using aqueous cupric ammine solutions has been investigated for zinc recovery. After 15 mm immersion of the steel in an aqueous 0.5 mol dm~(-3) CuSO_4 -1 mol dm~(-3) (NH_4)_2SO_4 -5 mol dm~(-3) NH_3 solution at ambient temperature, zinc on zinc plated steel was found to be eliminated completely without dissolution of iron. On the other hand, zinc recovery from the Zn-Fe alloy plated steel decreased slightly to be 90 percent and the residual amount of zinc corresponded to 1.3 mg per 1 g of steel.