黄铁矿在拜耳法溶出过程中的反应行为研究
来源期刊：有色金属科学与工程2011年第5期
论文作者：宋超 彭志宏 魏欣欣 齐天贵
文章页码：1 - 5
关键词：黄铁矿；铝酸钠溶液；热力学；反应行为
Key words：pyrite ; sodium aluminate solution ; thermodynamic analysis ; reaction behavior
摘 要：对铝土矿中含硫矿物黄铁矿在拜耳法溶出过程中的反应行为进行了研究热力学分析表明：在373-573K的温度范围内，黄铁矿分解反应的吉布斯自由能都为负值，且随着温度的升高而减小，说明黄铁矿容易与碱液反应实验研究表明：在原矿浆预脱硅条件下(温度约为100℃，时间8～10 h)，黄铁矿中会有超过一半的硫反应进入溶液；而在铝土矿高温溶出过程中，绝大部分黄铁矿都将反应，硫会进入铝酸钠溶液中；黄铁矿经高温溶出后的溶液在降温静置后会析出墨绿色物质，该物质为氢氧基硫代铁酸钠(Na2[FeS2(OH)2·2H2O)，是一种羟基铁硫聚合物。
Abstract:
The reaction behavior of pyrite in process of Bayer digestion were studied in this paper. The thermodynamics analysis showed that the gibbs free energy of reaction between pyrite and alkali solution was negative and decreased with the raising of temperature in range from 373 K to 573 K, and the sulfur as the form of pyrite can easily react with alkali liquor. The experiment researches indicated that there were more than half of the sulfur dissolved into solution in pre-desilication process, and the dissolution rate of sulfur was up to 90 % in the high-pressure digestion process. When the temperature dropped, the sulfur in solution was precipitated as a kind of dark green material, which was hydroxyl-Fe polymers (Na2[FeS2(OH)2·2H2O).
