高铁铝土矿直接还原过程中Na_2CO_3的损失机制  

Mechanism of Na_2CO_3 Loss in the Direct-reduction System of Ferric Bauxite

作　　者：胡文韬[1] 王化军[1] 孙传尧[1,2,3] 季春伶[1] 何洋[1] 王翠玲[1] 

机构地区：[1]北京科技大学土木与环境工程学院 [2]北京矿冶研究总院 [3]矿物加工科学与技术国家重点实验室

出　　处：《金属矿山》2012年第1期104-107,共4页Metal Mine

摘　　要：广西高铁、低铝硅比一水硬铝石型铝土矿资源禀赋差,难以利用。将原矿中的赤铁矿还原为粉末铁单质磁选分离、水铝石转化为铝酸钠溶出分离的直接还原—溶出方法是综合利用此类资源的有效途径。分析Na2O在产物中的分布、实现Na2O的循环使用,有利于降低处理成本和保护环境。研究表明,扩散损失占Na2O总损失的87.76%,其中扩散到坩埚的占68.69%;43.60%的Na2O以固相扩散的形式损失5,6.40%以气相扩散损失;还原物料与容器间的Na2O含量差显著影响Na2O的扩散量,低于22%时扩散量较小;还原性气氛和促进剂组分可促进Na2CO3的分解。Low alumina-silica ratio ferric bauxite is difficult to be processed for its poor quality.Direct reduction is an effective method to utilize this type ores.The hematite is reduced to iron which can be recovered by magnetic separation,and the Al2O3 is translated into sodium aluminates which can be recovered from the solution.Analyzing distribution of Na2O in final products and implementing recycling use of Na2O are beneficial to reduce processing cost and protect environment.The experiment results show that 87.76% of the Na2O loss is diffusion loss,among which 68.69% spread to pot,43.60% was in solid（liquid）phase and 56.40% in gas phase.The Na2O content difference between raw-material and crucible affected the diffusion amount of Na2O,appreciably.There is little Na2O diffusion when the content difference is below 22%.The amount of Na2CO3 loss is increase with the accelerant content and the reducing atmosphere.

关 键 词：高铁铝土矿 铁 氧化铝 直接还原 碱耗 

分 类 号：TQ424.25[化学工程]