(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 采用硫酸浸出−二氧化硫还原方法从中和渣中制取单质碲。研究表明：采用硫酸浸出中和渣，当反应温度为30 ℃、反应时间为0.5 h、硫酸浓度为53.9 g/L、硫酸用量为理论用量的1.5倍时，碲浸出率为99.99%；采用亚硫酸钠还原酸浸液中碲时，碲(Ⅳ)发生水解生成二氧化碲；采用二氧化硫还原酸浸液中碲时，当反应温度为75 ℃、反应时间为2 h、盐酸浓度为3.2 mol/L、二氧化硫流量为0.4 L/min时，碲回收率达到99.84%。X射线衍射(XRD)分析表明二氧化硫还原得到的产物为单质碲，电感耦合等离子体发射光谱(ICP)分析表明，碲粉中碲含量为98.27%。扫描电子显微系统(SEM)分析表明，碲粉的形态为针形。
关键字: 碲渣；硫酸浸出；SO2；碲
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The elemental tellurium was prepared from neutralization sludge by the method of sulfuric acid leaching and sulfur dioxide reduction. The results shows that, in the process of sulfuric acid leaching of neutralization sludge, the leaching rate of tellurium is 100% when the reaction temperature is 30 ℃, reaction time is 0.5 h, sulfuric acid concentration is 53.9 g/L, the dosage of sulfuric acid is 1.5 times of the theoretic addition. Te(Ⅳ) turns to tellurium dioxide when the acid leaching solution is reduced by sodium sulfite. The recovery ratio of tellurium is 99.84% by sulfur dioxide reduction when the reaction temperature is 75 ℃, reaction time is 2 h, hydrochloric acid concentration is 3.2 mol/L, sulfur dioxide flow rate is 0.4 L/min. X-ray diffractometry (XRD) analysis shows that the reduction product is in the forms of elemental tellurium. Inductively coupled plasma-atomic emission spectrometry (ICP) analysis shows that the content of tellurium in the product is 98.27%. Scanning electron microscopy (SEM) analysis shows that the form of powdered-tellurium is needle.
Key words: tellurium sludge; sulfuric acid leaching; SO2; tellurium
