高硫高碳复杂铝土矿拜耳法不排盐生产实践

遵义某氧化铝厂使用高硫铝土矿采用拜耳生产氧化铝。对某一时期系统碳碱升高后对生产过程的不利影响进行了总结，分析明确了碳碱升高的主要原因。该铝土矿中的含碳矿物主要为菱铁矿，母液中的硫酸盐在溶出过程中会显著降低碳酸盐从赤泥排走的量。在生产组织上把只控制高碳铝土矿使用改变为同时控制高硫铝土矿和高碳铝土矿的使用，系统碳碱比逐渐恢复到正常水平，蒸发过程无需排盐，进而降低了生产成本。

Plant Practice of Bayer Process without Salt Discharge of High Sulfur and High Carbon Complex Bauxite

An alumina refinery in Zunyi applies Bayer process to produce alumina with high sulfur bauxite as raw materials. Effect of rising of carbon and alkali in system on production is summarized. The causes of rise of carbon and alkali is studied and analyzed. The results show that siderite is the main carbonaceous mineral in bauxite, and amount of sulphate in mother liquor will significantly reduce amount of carbonate discharging from red mud during dissolution. In terms of production organization, control of use of high-carbon bauxite is changed to control of high-sulfur bauxite and high-carbon bauxite simultaneously. As a result, carbon alkali ratio of system is restored to normal level without salt discharging operation during evaporation process, and production cost is reduced.