(中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 為實(shí)現(xiàn)硅酸鋅高效轉(zhuǎn)化為硫化鋅(ZnS)，研究了在不同條件下硅酸鋅硫化轉(zhuǎn)化行為和物相轉(zhuǎn)變機(jī)制。采用HSC和Factsage軟件計(jì)算構(gòu)建了硅酸鋅硫化反應(yīng)的熱力學(xué)基礎(chǔ)，通過(guò)熱重分析和焙燒實(shí)驗(yàn)研究了硅酸鋅的硫化轉(zhuǎn)化行為，并考察了硫化過(guò)程中物相轉(zhuǎn)變規(guī)律及礦物微觀形貌特征變化。結(jié)果表明：黃鐵礦主要通過(guò)分解產(chǎn)生氣體硫與硅酸鋅發(fā)生硫化反應(yīng)，溫度、黃鐵礦用量和碳用量都是影響硅酸鋅硫化行為的主要因素，適當(dāng)升高溫度、增加碳和黃鐵礦用量可提高鋅硫化率，且添加鈉鹽有助于硅酸鋅硫化。在最佳條件下，硅酸鋅硫化率可達(dá)92%，硫化焙燒產(chǎn)物主要是纖鋅礦、閃鋅礦、磁鐵礦和方英石。實(shí)現(xiàn)了鋅的選擇性硫化，但是人造硫化鋅礦晶粒較小且結(jié)晶較差，添加鈉鹽能夠有效促進(jìn)人造硫化鋅的結(jié)晶和晶粒生長(zhǎng)。
關(guān)鍵字: 硅酸鋅；硫化焙燒；熱力學(xué)計(jì)算；物相轉(zhuǎn)變
（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
