还原气氛中碱石灰与高铁铝土矿间的作用机理

Reaction mechanism between ferric bauxite and soda lime in reduction atmosphere

针对高铁铝土矿的综合利用难题,研究了保温过程中碱石灰同高铁铝土矿以及纯碱和石灰之间的相互作用机理.试验表明,在还原气氛中,原矿中的赤铁矿几乎全部被还原为单质铁,但只有少部分氧化铝转化为铝酸钠,其余仍以铝硅酸钠和刚玉形式存在,造成氧化铝和氧化钠的溶出率偏低.这是由于CaO活性较低,不能完全置换出铝硅酸钠中的Na2O和Al2O3.由于低活性石灰的稀释作用,在体系中的相对含量降低,纯碱与高铁铝土矿之间的相互作用减弱.

In response to ferric bauxite comprehensive utilization challenge, both the interaction between the ore and soda-lime, and the interaction between soda ash and lime in heat preservation progress were investigated. The study showed, in reduction atmosphere, most Fe2O3 in ore was reduced to iron, only a small part of Al2O3 was converted into sodium aluminate, the others still existed in forms of sodium aluminosilicate or corundum rather than sodium alu- minate, leading to low dissolution rate of Na2O and Al2O3. This is because of the low activity of CaO, the Na2O and Al2O3 in sodium aluminosilicate can not be completely displaced. For the dilution effect of low active lime, the relative content of soda ash reduced. So the interaction between ferric bauxite and soda ash was weakened.