基于同时平衡原理的Pt-I^(-)-H_(2)O系热力学分析  

Thermodynamic analysis for Pt-I^(-)-H_(2)O system based on principle of simultaneous equilibrium

作　　者：尚琛瑜 李绍英 赵留成 秦建秋 张雅宁 刘宏宇 杨玉钱 白丽梅 SHANG Chenyu;LI Shaoying;ZHAO Liucheng;QIN Jianqiu;ZHANG Yaning;LIU Hongyu;YANG Yuqian;BAI Limei(College of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China;Collaborative Innovation Center of Mineral Resources Green Development and Ecological Restoration,Tangshan 063210,China)

机构地区：[1]华北理工大学矿业工程学院,唐山063210 [2]矿产资源绿色开发与生态修复协同创新中心,唐山063210

出　　处：《中国有色金属学报》2025年第3期1030-1038,共9页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(51604118);河北省自然科学基金资助项目(E2022209079);河北省科技支撑计划资助项目(236Z4104G);2024年度华北理工大学大学生创新创业训练项目(X2024002)。

摘　　要：碘化法是一种对环境友好、浸出速率快的贵金属浸出技术。针对铂的碘化浸出,采用基于同时平衡原理的方法绘制了298K时I_(2)-I^(-)-H_(2)O体系和Pt-I^(-)-H_(2)O体系的热力学平衡图,阐明碘化浸铂的热力学规律。结果表明:在c_(T)(I)为10 mol/L的条件下,当溶液pH值低于9.4时,碘主要以I^(-)和I_(3)^(-)形式存在;当溶液pH值继续增大,碘的存在形式逐渐转化为IO_(3)^(-);增大Pt-I^(-)-H_(2)O体系中含碘组分的总浓度c_(T)(I^(-)),还原电位φ_(sol/Pt)降低,PtI_(2)沉淀逐渐溶解,Pt^(4+)/PtO_(2)的平衡pH值增大,对铂的浸出十分有利。在铂的总浓度c_(T)(Pt)为0.0001 mol/L的条件下,当c_(T)(I^(-))大于0.145 mol/L时,PtI_(2)沉淀彻底溶解,铂主要以PtI_(4)^(2-)络合离子形式存在。Pt-I^(-)-H_(2)O体系的热力学分析为高效碘化浸铂提供了理论依据。Iodination leaching is an environmentally friendly technology with fast leaching rates for precious metal.For the iodization leaching of platinum,the thermodynamic equilibrium diagrams of the I_(2)-I^(-)-H_(2)O and Pt-I^(-)-H_(2)O systems at 298 K were plotted based on the principle of simultaneous equilibrium to elucidate the thermodynamic law of the iodization leaching of platinum.The results show that,under the condition of c_(T)(I)of 10 mol/L,I^(-)and I_(3)^(-) exist as the main forms when the solution pH is less than 9.4.As the solution pH continues to increase,the iodine-containing components are gradually converted to IO-3.With the increase of c_(T)(I^(-))in Pt-I^(-)-H_(2)O system,the reduction potential ofφsol/Pt decreases,PtI_(2)precipitates gradually dissolve and the equilibrium pH of Pt4+/PtO_(2)increases,which is very favorable to the leaching of platinum.Under the condition of c_(T)(Pt)0.0001 mol/L,when c_(T)(I^(-))is greater than 0.145 mol/L,the PtI_(2)precipitates are completely dissolved,and the platinum-containing components mainly exist in the form of PtI_(4)^(2-) complex ion form.The thermodynamic analysis of the Pt-I^(-)-H_(2)O system provides a theoretical basis for the efficient iodization leaching of platinum.

关 键 词：Pt-I^(-)-H_(2)O体系 I_(2)-I^(-)-H_(2)O体系 同时平衡原理 热力学 φ-pH图 组分分布图 

分 类 号：TD982[矿业工程—选矿]