氯化物中黄钠铁矾除铁的热力学与动力学

THE THERMODYNAMICS AND KINETICS OF SODIUM JAROSITE FORMATION IN CHLORIDE SOLUTION

对氯化物体系中锰结核浸出溶液采用黄钠铁矾净化除铁的热力学与动力学进行了研究．热力学分析表明，氯化物溶液中氯离子浓度升高能增大黄钠铁矾的溶解度，但在一般情况下（如ｃＣｌ－＜１０ｍｏｌ／Ｌ），完全可以将溶液中的铁以铁矾形式降到理想的程度；黄钠铁矾生成的最佳ｐＨ值范围为１．０～３．０；溶液中钠离子浓度升高有利于铁矾沉淀．动力学研究表明，氯化物中黄钠铁矾形成的表观活化能为９４．６６ｋＪ／ｍｏｌ，沉矾过程受化学反应控制．这些研究结果对锰结核浸出液中铁的分离以及氯化物体系中铁矾的沉淀具有指导作用．

The research on the thermodynamics and kinetics of sodium jarosite formation in chloride solution was presented in this paper. The thermodynamic analysis indicated that the rise of the activity of the Cl - in chloride solution could increase the solubility of the sodium jarosite, but normally (such as c Cl - <10 0 mol/L), the iron ions in the solution could be decreased undoubtly to satisfactory content in the form of the jarosite. The high Na 2+ concentration was favourable for jarosite formation and the optimum pH range was 1 0～3 0. The results of the kinetics study showed that the apparent activation energy for sodium jarosite formation in chloride soution was 94 66 kJ/mol, indicating that the jarosite preciptation process belonged to chemical reaction control. The results achieved are of much significance for iron purification from the pregnant leach liquor generated from the leaching of manganese nodules and for jarosite preciptation from the chloride solution.