(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 为实现湿法炼锌窑渣磁选铁精矿(以下简称窑渣铁精矿)中银、铜、铁等有价元素的综合回收，提出一种基于盐酸浸出的新工艺，从理论和实验两方面开展研究。在本研究中介绍新工艺研究的理论部分——浸出热力学分析。物相分析表明：窑渣铁精矿中主要含铁物相为Fe、FeO、FeS、Fe2O3、Fe3O4和FeSiO3。计算绘制了Fe-Cl--H2O系φ—pH优势区图以及FeS、FeO、FeSiO3-H2O系和FeS、FeO、FeSiO3-Cl--H2O系的lg c —pH图，分析窑渣铁精矿盐酸浸出的热力学可行性。结果表明：各含铁物相在盐酸浸出中均能溶解，[Cl-]T越高，其溶解度就越大，由于不同阴离子在体系中溶解性质的差异，因此，Cl-影响FeO、FeS和FeSiO3溶解的pH范围不同，分别为4.2~10.8、0.4~10.8和0~10.8。
关键字: 窑渣铁精矿；浸出；热力学；电势(φ)—pH优势区图；浓度对数—pH图
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:For the propose of recovering valuable metals, such as Ag, Cu and Fe comprehensively, in the iron concentrate separated magnetically from kiln slag in zinc hydrometallurgy (hereinafter referred to as kiln slag iron concentrate), a new process of comprehensively utilizing kiln slag iron concentrate was proposed and investigated thermodynamically and experimentally. The first part of the research, i.e., thermodynamic analysis of leaching, was introduced. The phase analysis shows that the main iron containing phases in kiln slag iron concentrate are Fe, FeO, FeS, Fe2O3, Fe3O4 and FeSiO3. The φ—pH predominance diagram of Fe-Cl--H2O system, as well as the lg c —pH diagrams of FeS, FeO, FeSiO3-H2O system and FeS, FeO, FeSiO3-Cl--H2O system were calculated and plotted, aimed at analyzing the thermodynamic feasibility of hydrochloric acid leaching kiln slag iron concentrate. The analysis results show that all of iron phases in the kiln slag iron concentrate are able to dissolve in hydrochloric acid leaching, and the higher the [Cl-]T, the greater the solubility. Due to different natures of anions in the system, the effects of Cl- on the solubility of FeO, FeS and FeSiO3 are not the same, the pH value ranges valid in Cl- effect are 4.2-10.8 for FeO, 0.4-10.8 for FeS and 0-10.8 for FeSiO3.
Key words: kiln slag iron concentrate; leaching; thermodynamic analysis; φ—pH predominance diagram; lg c—pH diagram
