干法煅烧改性中低品位磷矿石

Modified Medium-Low Grade Phosphate Ores by Dry Calcination

研究磷矿石品位提升的煅烧条件,分析中低品位磷矿石不同条件下的热分解产物,提出其中碳酸盐热分解机理,为中低品位磷矿石利用提供理论依据。结果表明:Ca^2+、Mg^2+以碳酸盐形式大量存在于中低品位磷矿石中,总质量分数约40%,在900 ℃下煅烧粒径为40~60 mm的中低品位磷矿石30 min,可以将90%以上的碳酸盐分解为CaCO3、MgO、CaO和CO2,使磷矿石w(CO2)<6%,w(P2O5)>29%,得到一等品磷矿石,可以满足磷矿石加工要求以用于生产。

The calcination conditions for the upgrading of phosphate ores grade was studied.The thermal decomposition products of medium-low grade phosphate ores under different conditions was analyzed.The mechanism of carbonate thermal decomposition in phosphate rock is proved.All of the above provide theoretical basis for the utilization of medium-low grade phosphate ores.The results indicated that calcium and magnesium ions are abundant in the form of carbonate in medium-low grade phosphate ores and the total mass fraction of calcium and magnesium is about 40% by X-Ray Fluorescence.It is found that more than 90% of carbonates can be decomposed by calcining the phosphate ores with particle sizes of 40-60 mm,at 900 ℃ for 30 min.The mass fraction of CO2<6% and the mass fraction of P2O5>29% of phosphate ores,indicated that the first-class phosphate ores are obtained,which can be applied to the practical production of phosphorus-related products.