Removal of copper from ferrous scrap with ammonia leaching method. (1st Report). Dissolution Rate of Copper in Aqueous Ammonia Solution.

Abstract

It is desirable to obtain high copper dissolution rate for relnoval of copper from ferrous scrap by ammonia leaching. In this study, a new ammonia leaching process using a injection. rnethod in a closed circuit system is proposed to improve copper dissolution rate and to prevent ammonia from vaporization loss. The copper dissolution. rate have been measured under injection of oxygen. The tests were carried out in a 24iter reaction flask under conditions of 30-40°C, oxygen flow rate 4-12 Nl/min, and concentration of cupric copper 0-50 g/l. It has been found that copper dissolution rate increases with increase in temperature, O2 flow rate and concentration. of cupric copper. A kinetic model based on mixed reaction-diffusion controlhas been found to be in good agreement with the experimental results.