Copper and zinc recovery from brass and zinc or zinc alloy plated steel sheet with cupric ammine solutions

摘要

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