拜耳法管道化溶出系统的能量分析

An Analysis of Energy Consumption of Tube Digestion in Bayer Process

对拜耳法生产氧化铝管道化溶出的能量进行了数值模拟,研究了生产过程中节能降耗的途径.模拟结果表明:在预热段中,初级结疤厚度对能耗影响很大,需要严格控制,提高预热级数可以提高矿浆预热终温,但效果不明显;在熔盐加热段中,各级结疤厚度对结果影响效果相同,表现为当其处于0～1 mm区间时热利用率变化幅度很大,而采用多内管、细内径的工艺方式可以有效的减少熔盐需求流量,同时发现当溶出温度取值增加至275 ℃以后,熔盐需求流量巨幅增长,而热利用率降低明显.

The energy balance system of tube digestion in Bayer process is simulated for alumina production and studied the way to reduce energy consumption. The results showed that in preheating section, the primary scale thickness affected the energy consumption greatly so that it should be strictly controlled. The slurry temperature could be increased by upgrading the preheating grade, but the effect was not significant. In melting-salt heating section, the effects of scale thickness of different stages were alike, i e, the heat availability decreased enormously with the increment of the scale thickness from 0 to 1 mm. The demanded melting-salt volume could be cut down by using more minor diameter inner tubes. The demanded melting-salt volume increased as well as the heat availability decreased obviously with the increment of the digestion temperature to 275℃.