某一水硬铝石矿较难溶出的原因分析及强化措施

Causes analysis and strengthening measures for the difficult digestion of a diaspore ore

经过扫描电镜及能谱仪分析检测,试验所用铝土矿的各种不同粒度的矿粒表面均广泛分布着含钛矿物。在铝土矿进行高压溶出时,这部分钛因在一水硬铝石的表面形成一层致密的保护膜阻碍了氧化铝的溶出,使得矿石溶出性能恶化,在石灰加入量高达15%时氧化铝实际溶出率只有82.3%。该矿石经过预处理后,同样溶出温度及溶出时间条件下,石灰加入量为9%时氧化铝实际溶出率即可达到84.7%,矿石溶出性能得到较大改善,溶出技术指标得到明显优化,同时因石灰加入量减少约6个百分点,可降低赤泥产出量,在提高经济效益的同时减少了环境污染。

Through the SEM and EDS analysis,it is found that titanium-bearing minerals are widely distributed on the surface of different particle sizes of bauxite.In the high-pressure digestion process of bauxite,this part of titanium forms a dense protective film on the surface of diaspore,which hinders the digestion of alumina and worsens the digestion performance of the ore.The actual digestion rate of alumina is only 82.3%when the lime input is as high as 15%.After the pretreatment of such ore,and under conditions of the same digestion temperature and digestion time,the actual digestion rate of alumina can reach 84.7%when the lime input is 9%.The digestion performance of the ore is improved greatly,and the digestion technical indexes are optimized obviously.Meanwhile,since the lime input is reduced by about 6%,the red mud output can be cut down to improve economic efficiency and reduce enviromental pollution.