铝土矿盐酸浸出过程研究

以澳大利亚难处理三水铝土矿为对象、盐酸为浸出剂进行无焙烧浸出试验,考察浸出温度、矿物粒度以及浸出时间对氧化铝浸出率的影响。结果表明,优化工艺条件为:矿物粒度-55μm、浸出温度100~110℃、浸出时间120 min、盐酸浓度10%、浸出液固比100∶7。此条件下氧化铝的浸出率为95.49%,氧化铁的浸出率为96.72%。以该酸浸液为原料,使用TBP-苯体系进行铝铁分离萃取试验,在萃取温度25℃、相比O/A=1∶1、盐酸浓度1.5 mol/L,萃取时间10 min的条件下,经单级萃取,溶液中铁元素的萃取率可达95%,铝元素损失率为6%,铁铝萃取分离系数为408,经3级以上逆流萃取,铁铝分离系数可达800以上。以纯水作为反萃剂,在温度25℃、相比O/A=1∶1、反萃时间5 min、单级反萃,铁的反萃率达95%。

Study on Leaching of Bauxite with Hydrochloric Acid

The leaching experiments without roasting process were carried out with Australia gibbsite as material and hydrochloric acid as leaching reagent.Effects of temperature,granularity and time on leaching performance of bauxite were studied.The results show that the optimum leaching conditions are as follows.Granularity is-55 μm,leaching temperature is 100~110 ℃,and leaching time is 120 min when the concentration of HCl is 10% and L/S is 100∶7.Under these conditions,the leaching rate of Al2O3 and Fe2O3 is 95.49% and 96.72%,respectively.In the single stage separation experiments of iron and aluminum by using tributyl-phosphate-benzol as extraction system,under the conditions of phase ratio of O/A of 1∶1,concentration of hydrochloric acid of 1.5 mol/L and extraction time of 10 min,the extraction rate of iron is over 95%,loss rate of aluminum is 6% and βFe/Al can reach 408 with the above leaching solution as raw materials.βFe/Al is up to over 800 via three stages reflux extraction.When O/A equals to 1∶1 and reacting time is 5 minutes,the stripping ratio reaches 95% with pure water as stripping agent via single stage extraction at room temperature.