(中南大学冶金与环境学院，长沙 410083)
摘 要: 针对植酸盐分解白钨矿的问题，绘制了298 K温度下Ca-Phy-W-H2O体系的热力学平衡图，阐明了体系中各物质的优势区域、重要组分随pH值和游离植酸总浓度的变化规律，进一步研究植酸盐分解白钨矿的可行性及热力学条件。理论分析表明，植酸盐可有效分解白钨矿，随着pH值的升高，稳定生成的固相产物依次为H2WO4、CaWO4和Ca6Phy。当体系pH＞7.5后，Ca2+与Phy12-的结合作用急剧增强，导致游离 浓度迅速上升，在pH＞10之后趋于平缓，此时固相分解产物为Ca6Phy。溶液中维持较低浓度的游离植酸即可实现白钨矿的分解，同时提高溶液的pH可促进白钨矿的分解。
关键字: Ca-Phy-W-H2O体系；白钨矿；植酸盐；热力学；分解
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:In order to solve the problem of scheelite decomposition by phytate, the thermodynamic equilibrium diagram of Ca-phy-W-H2O system at 298 K was drawn. The variation law of dominant regions and important components in the system with pH and total concentration of free phytic acid was clarified. The feasibility and thermodynamic conditions of phytate decomposition scheelite were further studied. Theoretical analysis shows that phytate can effectively decompose scheelite. With the increase of pH value, the stable solid products are H2WO4, CaWO4 and Ca6Phy. When pH＞7.5, the binding of Ca2+ and Phy12- increases rapidly, resulting in a rapid increase in the concentration of free and insignificant increase after pH＞10. At this time, the solid phase decomposition product is Ca6phy. The decomposition of scheelite can be achieved by maintaining a low concentration of free phytic acid in the solution, and increasing the pH value of the solution can promote the decomposition of scheelite.
Key words: Ca-Phy-W-H2O system; scheelite; phytate; thermodynamics; decomposition
