草酸-草酸铵浸出氰化尾渣中赤铁矿机理及动力学
Mechanism and kinetics of leaching hematite from roasted cyanide tailings by oxalic acid and ammonium oxalate
党晓娥 1李康瑞 2王碧侠 2李林波2
作者信息
- 1. 西安建筑科技大学冶金工程学院,陕西西安 710055;陕西省黄金与资源重点实验室,陕西西安 710055
- 2. 西安建筑科技大学冶金工程学院,陕西西安 710055
- 折叠
摘要
焙烧氰化尾渣处置是目前制约黄金冶炼工业可持续发展的瓶颈,为了提高金的回收率和实现尾渣中铁的高附价值利用,在草酸(H2C2O4)、草酸-草酸铵(H2C2O4-(NH4)2C2O4)浸出焙烧氰化尾渣中赤铁矿试验结果的基础上,对H2C2O4-(NH4)2C2O4浸出赤铁矿的机理以及浸出动力学进行研究,主要考察浸出温度、H2C2O4与(NH4)2C2O4物质的量之比n(H2C2O4)/n((NH4)2C2O4)以及C2O42-总浓度c(C2O42-)ToT对铁的浸出率的影响.结果表明,适当降低n(H2C2O4)/n((NH4)2C2O4)、提高c(C2O42-)TOT和浸出温度,可提高铁的浸出率,缩短赤铁矿达到浸出平衡的时间.H2C2O4-(NH4)2C2O4浸出赤铁矿的反应表观活化能为41.72 kJ/mol,浸出反应受界面化学反应-内扩散混合控制.在n(H2C2O4)/n((NH4)2C2O4)=1和n(C2O42-)TOT/n(Fe3+)TOT≥3时,浸出液中的Fe3+全部以Fe(C2O4)33-形式存在,通过对浸出液进行蒸发、浓缩、冷却、结晶,制备出用途较为广泛的(NH4)3Fe(C2O4)3·3H2O,为氰化尾渣中巨量铁资源的综合利用提供了新途径.研究结果对黄金工业的可持续发展具有重要意义.
Abstract
At present,the disposal of the cyanide tailings is the bottleneck restricting the sustainable development of gold smelting industry.In order to improve the recovery rate of gold and realize the high value-added utilization of iron in tailings,based on the experimental results of leaching hematite from the roasted cyanide tailings by H2C2O4 and H2C2O4-(NH4)2C2O4,mechanism and kinetics of leaching hematite by H2C2O4-(NH4)2C2O4 were studied,and the effects of leaching temperature,molar ratio n(H2C2O4)/n(NH4)2C2O4)and total concentration c(C2O42-)ToT on the leaching rate of iron were mainly investigated.The results reveal that properly reducingn(H2C2O4)/n((NH4)2C2O4),increasing leaching temperature and c(C2O42-)TOT can improve leaching rate of iron and shorten the time of leaching hematite to reach equilibrium.The apparent activation energy of leaching hematite reaction by H2C2O4-(NH4)2C2O4 is 41.72 kJ/mol,and the leaching reaction is controlled by interfacial chemical re-action and internal diffusion.At n(H2C2O4)/n(NH4)2C2O4)=1 and n(C2O42-)TOT/n(Fe3+)TOT)≥3,Fe3+in the leaching solution exists in the form of Fe(C2O4)33-.Through evaporation,concentration,cooling and crystallization of the leaching solution,the widely used(NH4)3Fe(C2O4)3·3H2O is prepared,it provides a new way for the com-prehensive utilization of huge iron resources in cyanide tailings,and the research results are of great significance to the sustainable development of gold industry.
关键词
焙烧氰化尾渣/赤铁矿/草酸-草酸铵/浸出/动力学Key words
roasted cyanide tailings/hematite/H2C2O4-(NH4)2C2O4/leaching/kinetics引用本文复制引用
出版年
2024
NETL
NSTL
万方数据