铝土矿中铝、铁和硅有价组分的综合利用研究

Research on Comprehensive Utilization of Aluminium, Iron and Silicon from Bauxite

针对山东某地铝土矿高铝、高铁、高硅、低铝硅比的特点,设计了一个综合利用矿石中铝、铁、硅的工艺流程。通过硫酸铵焙烧、水浸、过滤,矿石中的铝、铁等有价组元进入浸出液中,二氧化硅在渣中富集。利用不同金属离子的溶度积的差别,通过加入沉淀剂碳酸铵调节溶液pH值,滤液中的铁和铝分别以氢氧化铁和氢氧化铝的形式析出,再经高温煅烧得氧化铁和氧化铝粉体。氧化铁的回收率可达85%以上,氧化铝的回收率可达95%以上。硫酸铵低温焙烧铝土矿的工艺实现了铝、铁和硅的综合利用,整个流程无废物、废水和废气的排放。

A novel clean technology for comprehensive utilization of aluminium, iron and silicon from bauxite in Shandong Province was presented. The chemical compositions of aluminium, iron and silicon were high and the alumina-silica ratio was low in the ore. The aluminium and iron entered in solution, the silica was concentrated in residue by roasting using ammonium sulfate, leaching, and filtering. Ferric hydroxide and aluminium hydroxide were synthesized respectively by adding ammonium carbonate solution into the filtrate to adjust pH value of solution using the distinction of metal ions solubility product. Iron oxide and aluminium oxide were generated by calcining. The recovery rate of iron oxide was more than 85%, and the recovery rate of aluminium oxide was more than 95%. Aluminium, iron, and silicon were extracted and transformed into products in the whole technology, respectively. Then achieved the comprehensive utilization of bauxite and no pollutant was discharged.