用拜耳法处理高硫铝土矿时,矿石中的硫化物会与含铁物质在铝酸钠溶液中反应,进而导致严重的设备腐蚀和氧化铝产品降级.本文作者研究含铁物质对含硫离子(S2-,S2O32-,SO32-和SO42-)在铝酸钠溶液中转化的影响.研究结果表明:铁粉、Fe2O3和Fe3O4均难以与so32-和SO42-反应,而且所有含铁物质,特别是铁粉,均能促进S2O32-转化为SO32-和S2-;在高温条件下铁粉与铝酸钠溶液反应生成Fe(OH)3-,进而可与S2-反应生成FeS2,但Fe2O3和Fe3O4对S2-的反应影响很小;升高温度、延长反应时间、增加铁粉添加量、提高溶液中Na2Ok与A12O3的摩尔比和苛碱浓度均有利于S2O32-向SO32-和S2-转化.本研究结果有助于在拜耳法处理高硫铝土矿过程中开发减缓设备腐蚀和降低碱耗的技术.
Sulfides in the high-sulfur bauxite lead to serious steel equipment corrosion and alumina product degradation via the Bayer process, owing to the reactions of sulfur and iron-containing phases in the sodium aluminate solution. The effects of iron-containing phases on the transformation of sulfur-bearing ions (S2-,S2O32-,SO32- and SO42-) in sodium aluminate solution were investigated. Fe, Fe2O3 and Fe3O4 barely react with SO32- and SO42-, but all of them, particularly Fe, can promote the conversion of S2O32- to SO32- and S2- in sodium aluminate solution. Fe can convert to Fe(OH)3- in solution at elevated temperatures, and further react with S2- to form FeS2, but Fe2O3 and Fe3O4 have little influence on the reaction behavior of S2- in sodium aluminate solution. Increasing temperature, duration, dosage of Fe, mole ratio of Na2Ok to Al2O3 and caustic soda concentration are beneficial to the transformation of S2O32- to SO32- and S2-. The results may contribute to the development of technologies for alleviating the equipment corrosion and reducing caustic consumption during the high-sulfur bauxite treatment by the Bayer process.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%