摘要
鉴于铝酸钠溶液中S2-使得铁的含量增加而影响氧化铝的品位,研究采用往高压釜内通入氧气的湿式氧化法脱除拜耳液中的S2-的工艺。首先探索各种因素对S2-去除率的影响,然后对湿式氧化法转化硫化物的规律和机理进行探讨。研究结果表明:湿式氧气氧化法S2-的去除率受釜内起始平衡氧气压力、反应温度、反应时间的影响;较适宜的操作条件是:反应温度为200℃,氧气压力为3.0 MPa,S2-的浓度为31.2 mmol/L,此时S2-的去除率为99%;在高温高压下,铝酸钠溶液中的S2-大部分被氧化为SO42-,进行的是深度氧化,只有少部分S2-被氧化为硫代硫酸根、亚硫酸根及硫的其他形态;影响S2-氧化为SO42-的因素主要是反应温度和氧气压力,当温度高达260℃、氧气起始平衡压力达到1.0 MPa时,就有98%以上的S2-被氧化为SO42-。
Based on the fact that the iron content in alumina products is associated with bivalent sulfur ions in aluminate solution,the wet oxidation was used to remove the bivalent sulfur ions in high pressure autoclave.The influence of various conditions on the removal of S2- and the oxidation mechanism was investigated.The results show that the removal efficiency of bivalent sulfur ions is affected by the oxygen pressure inside the reactor,reaction temperature,and reaction time.The optimum conditions for wet oxidation is as fallows.The reaction temperature is 200 ℃,the oxygen pressure is 3.0 MPa,S2- concentration is 31.2 mmo·L-1.Under these conditions,the removal rate of S2- is 99%.At high temperature and pressure,the majority of S2- in aluminate solution is oxidized to SO42-,and only a small part of S2- is oxidized to thiosulfate,sulfite and other forms of sulfur.Conversion of S2- to SO42- is mainly affected by the oxygen pressure and reaction temperature.When the temperature is 260 ℃,and the oxygen pressure reaches 1.0 MPa,more than 98% of S2- is oxidized to SO42-.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2011年第10期2911-2916,共6页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(20971041)
湖南省教育基金资助项目(09B032)
关键词
湿式氧化法
拜耳法
铝酸钠溶液
脱硫
wet oxygen oxidation
Bayer process
sodium aluminate solution
desulfurization
