某复杂铝土矿中高岭石与一水硬铝石的分离方法问题研究

研究了某低品位复杂铝土矿中高岭石与一水硬铝石矿物相分离的传统选择性溶剂(HF溶液)的不适应性问题。物质组成分析指出,由于此类物料中伴生有含钠(钠长石)和含镁(铁质角闪石)等脉石类矿物,所以在用HF溶液浸取高岭石的反应过程中,与Al 3+同步进入浸出液中的Na+和Mg2+等,又与F-反应,形成NaMgAlF6·xH2O次生沉淀,且其与一水硬铝石矿物相一并留于余渣中,而直接干扰测定。因此,对H2SO4溶液作为选择性溶剂的可替代性问题进行了验证。结果表明:试样于500℃预焙烧后,用H2SO4(12mol/L)溶液沸水浴浸取分离高岭石,于余渣中测定一水硬铝石,可获得比较满意的结果。同时,对钠长石等其它含铝矿物干扰测定的校正方法问题,也进行了探讨。

Research on Problems in Method for Separating Kaolinite from Disporite in a Complex Bauxite

The inadaptability of the traditional selective solvent （HF solution） used for separating kaolinite from disporite in Low-Grade and complex bauxite is studied. The results of material composition analysis showed that such kind of materials contain associated sodium containing mineral （albite） and magnesium containing mineral （ferro-hornblend）. Thus, in the process of leaching kaolinite using HF solution, Na＋ and Mg2＋ were leached into the solution together with AP＋. And these three ions interacted with F- and formed a secondary precipitate （NaMgAlF6 ·xH2O）, which together with diasporite phase remained in the residues and directly interfered the determination of diasporite. Thus, the substitutability of H2SO4 solution as the selective dissolvent for chemical phase analysis of bauxite was verified. After the preliminary roasting at 500 ℃, samples were dissolved by H2SO4 solution （12 mol/L） in boiling water bath and kaolinite were leached and separated. The diasporite in the residue was determined with satisfactory result. In the meantime, the correcting aluminium containing minerals was also discussed. method for the interference by albite and otheraluminium containing minerals was also discussed.