常压低温拜耳法新工艺研究

Research on new Bayer process at atmospheric pressure and low temperature

采用一段常压低温(113℃±3℃)溶出、二段加压脱硅分离的拜耳法新工艺,可以达到三水矿的常压溶出及分离钠硅渣的双重目的。采用该工艺可使氧化铝溶出率达到94%,外排赤泥含碱量控制在0.5%以下,二段脱硅可得到纯钠硅渣,在降低赤泥对环境的污染的同时实现了资源的综合利用,是对传统拜耳法的技术创新。

In order to digest gibbsite at atmospheric pressure and separate hydrated sodium alumino - silicate,the new Bayer process with two - stage digesting was adopted, which the first stage was digested at atmospheric pressure and low temperature （113±3℃） and the second stage was pressure desilicated. The Al2O3 extraction yield could be 94%, and alkali contents of discharged red mud could be controlled under 0.5% and the pure hydrated sodium alumino - silicate could be gain after two - stage digesting. This new process was technological innovation, which could reduce the environmental pollution caused by red mud and realize comprehensive utilization of resources.