NH4Cl体系浸出焙烧后湿法炼锌铁矾渣的热力学

摘要

The thermal decomposition process ofjarosite residue and the solubility of various oxides presented in the decomposed residue in NH4Cl-H2O system were studied.The results of heat decomposition ofjarosite residue show that the insoluble ZnFe2O4 phase in the residue can be decomposed at temperatures ranging from 500 ℃ to 650 ℃ for 1 h.The OLI Systems software was used to study the thermodynamics of the solubility of various metal oxides existing in the decomposed residue in NH4Cl-H2O system.The results show that the solubility of ZnO,PbO,CdO,CuO and Ag2O is high,while the solubility of Fe2O3 is less than 10-4 mol/L in the pH range from 4.0 to 9.0.The calculated data are in accordance with the experimental results.%研究湿法炼锌铁矾渣的热分解过程,及其分解后各种氧化物在NH4Cl-H2O体系中的溶解度.铁矾渣的热分解实验结果表明,渣中不可溶物相ZnFe2O4在500～650℃下焙烧1h后发生分解.采用OLI System软件研究热分解得到的渣中各金属氧化物在NH4Cl-H2O溶液中的溶解度.结果表明,在pH为4.0～9.0范围内,ZnO、PbO、CdO、CuO和Ag2O的溶解度较大,而Fe2O3的溶解度仅为10-4 mol/L.计算结果与实验结果相吻合.