Synergistic and Efficient Leaching of Zinc from Isa Furnace Dust with Ammonia and Ammonium Carbonate

In response to the issues of low zinc leaching efficiency and potential environmental pollution during the leaching of zinc from Isa furnace dust, this study proposes a method of synergistic leaching using ammonia and ammonium carbonate, which effectively improves zinc leaching efficiency while mitigating environmental pollution. Following single-factor experiments, the optimal conditions for the reaction were determined as follows: employing a leaching agent composed of a mixture of ammonia and ammonium carbonate, both at a concentration of 3.5 mol/L, at a leaching temperature of 323 K, for a duration of 3 h, with a liquid-to-solid ratio of 5:1. Under these optimal conditions, the zinc leaching efficiency reached 96.03%, representing an improvement of 5–20% compared to other methods. Additionally, a kinetics study was conducted on the leaching process, revealing that the leaching of Isa furnace dust conforms to the shrinking core model, with the reaction being controlled by chemical kinetics. The kinetic equation is given by 1-(1-x)^1/3=2.166×t×e^{(−13.701/RT)}.