拜耳法分解槽结疤洗涤苛化工艺研究及应用  

Research and practice of washing causticizing process for the scab in Bayer process decomposition tank

作　　者：王明理 WANG Ming-li

机构地区：[1]杭州科创有色金属研究有限公司,浙江临安311300

出　　处：《中国有色冶金》2021年第2期54-58,共5页China Nonferrous Metallurgy

摘　　要：国内拜耳法氧化铝厂分解工序大都采用大型平底机械搅拌分解槽,此分解槽的槽壁极易结疤,并且生长快,传统清理方法会造成结疤中的有机物重新进入系统,不能减少对生产的危害。通过分析,发现分解槽结疤中主要成分为Al(OH)_(3),其次为碳酸钠、草酸钠和其他成分的有机碳(TOC),因此确定了采用洗涤苛化法去除结疤中有机物的方案。实验室和工业化试验结果表明:加入过量的石灰乳、Na_(2)C_(2)O_(4)、Na_(2)CO_(3),TOC的去除率依次为97.32%、93.99%、73.45%,洗涤后分解槽结疤中的全碳含量为0.013%。工业应用十个月后,系统中的有机碳和草酸盐含量显著降低。Domestic plants producing alumina by Bayer process,the decomposition process mostly adopts large flat bottom mechanical stirring decomposition tank.The wall of the decomposition tank is easy to scab,and the scab grows fast.The traditional cleaning method will cause the organic matter in the scar to re-enter the system,which can not reduce the harm to the production.The results show that the main component of the scab is Al(OH)_(3),followed by sodium carbonate,sodium oxalate and other organic carbon(TOC),therefore,the method of washing causticization was determined to remove the organic matter in the scab.The results of laboratory test and industrial test showed that the removal rates of Na_(2)C_(2)O_(4)、Na_(2)CO_(3) and TOC were 97.32%,93.99%and 73.45%respectively when excessive lime milk was added,and the total carbon content in the scab of decomposition tank after washing was 0.013%.After ten months of industrial application,the contents of organic carbon and oxalate in the system decreased significantly.

关 键 词：拜耳法 氧化铝 分解槽结疤 结疤成分 草酸钠 有机物 洗涤苛化工艺 去除率 

分 类 号：TF821[冶金工程—有色金属冶金] TF803.22