(中南大学 资源加工与生物工程学院，长沙 410083)
摘 要: 为实现硅酸锌高效转化为硫化锌(ZnS)，研究了在不同条件下硅酸锌硫化转化行为和物相转变机制。采用HSC和Factsage软件计算构建了硅酸锌硫化反应的热力学基础，通过热重分析和焙烧实验研究了硅酸锌的硫化转化行为，并考察了硫化过程中物相转变规律及矿物微观形貌特征变化。结果表明：黄铁矿主要通过分解产生气体硫与硅酸锌发生硫化反应，温度、黄铁矿用量和碳用量都是影响硅酸锌硫化行为的主要因素，适当升高温度、增加碳和黄铁矿用量可提高锌硫化率，且添加钠盐有助于硅酸锌硫化。在最佳条件下，硅酸锌硫化率可达92%，硫化焙烧产物主要是纤锌矿、闪锌矿、磁铁矿和方英石。实现了锌的选择性硫化，但是人造硫化锌矿晶粒较小且结晶较差，添加钠盐能够有效促进人造硫化锌的结晶和晶粒生长。
关键字: 硅酸锌；硫化焙烧；热力学计算；物相转变
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:To achieve the sulfidation of zinc silicate to zinc sulphide, the sulfidation behaviors and phase transformation mechanism of zinc silicate were investigated under different conditions. The thermodynamic basis forzinc silicate sulfidation was studied by using HSC and Factsage calculation. The sulfidation behaviors of willemites were then investigated via TG-DSC analysis and roasting experiments. Meanwhile, the phase transformations and microtopography changes during the roasting process were studied by XRD and SEM-EDS, respectively. The results show that the sulfidation of zinc silicate is mainly through the reactions of zinc silicate with the gas sulfur produced from the decomposition of pyrite. Temperature, pyrite dosage, and carbon dosage are the main factors affecting the sulfurization behavior of zinc silicate. Properly increasing the temperature pyrite dosage, and increasing carbon dosage and pyrite dosage can improve the sulfidation of zinc silicate, and the addition of sodium salt is conducive to the sulfidation of zinc silicate. Under the optimum conditions, the sulfidation rate of zinc reaches 92%. During the sulfide roasting process of zinc silicate, the roasted products are mainly composed of wurtzite, sphalerite, magnetite and cristobalite, implying that the selective sulfide of zinc has been achieved. However, the synthetic zinc sulfides have fine grains and poor crystallization, and the addition of sodium salts can effectively promote crystallization process and grain growth of ZnS fines.
Key words: zinc silicate; sulfide roasting; thermodynamic calculation; phase transformation
