NaOH-Na2SnO3-Na2PbO2-H2O四元水盐体系相平衡研究 刘静欣.DOC

NaOH-Na2SnO3-Na2PbO2-H2O四元水盐体系相平衡研究 刘静欣 郭学益 刘旸 江晓健 (中南大学 冶金与环境学院，长沙 410083) 摘要：采用等温溶解法测定了20 、40 、60 条件下，NaOH-Na2SnO3-Na2PbO2-H2O 四元水盐体系及边界三元水盐体系NaOH-Na2SnO3-H2O、NaOH-Na2PbO2-H2O的相平衡数据。实验结果表明，在三元体系中，锡酸钠的溶解度随碱度的升高而降低，在高碱度条件下，40 溶解度较高，亚铅酸钠的溶解度随温度的升高而升高，而随碱度升高呈现S形变化；在四元体系中，锡酸钠、亚铅酸钠之间相互影响，但溶解度变化趋势与三元体系一致。此研究成果可为碱、锡、铅的分离提供基础数据。 关键词：锡酸钠；亚铅酸钠；碱液；相平衡；溶解度 中图分类号：TQ13；TF81 文献标志码：A Study on the phase equilibrium of quaternary saline system NaOH-Na2SnO3-Na2PbO2-H2O LIU Jing-xin, GUO Xue-yi, LIU Yang, JIANG Xiao-jian (School of Metallurgy and Environment, Central South University, Changsha 410083, China) ABSTRACT: Phase equilibrium of quaternary saline system NaOH-Na2SnO3-Na2PbO2-H2O, ternary saline system NaOH-Na2SnO3-H2O and NaOH-Na2PbO2-H2O were determined by employing the method of isothermal solution saturation at 20 ℃, 40 ℃ and 60 ℃. The results show that solubility of Na2SnO3 in ternary system decreased with increasing of alkalinity, and solubility at 40 ℃ was higher in solution with high alkalinity. Solubility of Na2PbO2 in ternary system increased with the increasing of the temperature, but its change with alkalinity followed an S-shape curve. In the quaternary system, interaction between Na2SnO3 and Na2PbO2 was observed, however, their solubility had the same trend with that in ternary systems. Conclusions obtained in this study can be used as basic data for separation of NaOH, Na2SnO3 and Na2PbO2. KEYWORDS: Na2SnO3; Na2PbO2; Alkali solution; Phase equilibrium; Solubility 0 引言 随着一次资源的日渐枯竭和二次资源地位的逐渐提升，碱介质冶金由于其选择性强、资源综合利用率高、设备腐蚀小、劳动条件好、有利于环保等优点日益得到重视和发展[]。碱性精炼、碱性焙烧、碱性浸出等工艺被越来越多的用于粗金属提纯、低品位原矿处理及二次资源的回收领域，锡、铅的提取及加工过程是碱介质冶金最具代表性的应用之一。粗铅[]、锡渣[,]、污泥[]、废弃电路板[,]等含锡物料经过碱性处理后，得到高碱性含锡溶液，同时还含有铅、锌、铜等杂质元素。关于氧化铅、锡酸钠在碱性溶液中的相平衡情况有少量报道[,,]，但关于锡、铅混合于碱液中的研究则尚未见报道。 本文通过对NaOH-Na2SnO3-H2O、NaOH-Na2PbO2-H2O、NaOH-Na2SnO3-Na2PbO2-H2O水盐体系相平衡的研究，找出碱-锡-铅盐三者之间的结晶规律，为碱性溶液中有价金属的提取提供新思路。 1 实验 试剂 所用主要试剂为三水合锡酸钠（Na2SnO3·H2O，AR）、氢氧化钠（AR）、亚铅酸钠（自制，按照PbO：NaOH摩尔比1：2充分混合，820 ℃无氧熔炼3 h []）等。 实验操作 溶解度法