碘化物浸金过程的热力学分析

Thermodynamic Analysis for Gold Leaching with Iodide

通过推导碘化物浸金过程的热力学判据,提出碘化物浸金的平衡常数判据,对碘-碘化物浸金体系进行了热力学分析。只要氧化剂的氧化电位φ1>+0.561V,碘化物浸金反应在热力学上就能够发生。标准条件下反应式恒压和等温电位变化的判据为ΔG2θ98=-(φ1-0.561)nF,平衡常数判据为lgK2θ98=16.935n(φ1-0.561)。降低浸金液中金的浓度,增加碘、碘化物的浓度,有利于金的浸出。

The thermodynamic criterion and the equilibrium constant criterion of the gold leaching with iodide were proposed. The leaching system of gold with iodine-iodide was tlhermodynamically analyzed. As long as the electrical potential of an oxidant is over ＋ 0. 561 V, the gold leaching process with iodide may proceed based on thermodynamics. It is pointed out that the criterion of the equilibrium constant is lgK298^θ=16.935n（ψ1-0.561） and the criterion of changing potential under constant perature as well as under pressure and equal temthe normal condition is △G298^θ=-（ψ1-0.561）nf. The decrease of the concentrations of gold ions and the increase of the concentrations of iodine and iodide are beneficial to the gold extraction.