添加剂对低品位菱铁矿制备高品位碳化铁的影响

Effect of additive on high-grade iron carbide preparation with low-grade siderite

低品位菱铁矿作为一种典型的难处理铁矿目前难以应用于钢铁行业。为了促进低品位菱铁矿的利用,提出了渗碳-磁选-酸浸制备优质电炉原料(碳化铁)的新工艺,并探究了添加剂对菱铁矿球团渗碳产物中碳化铁和脉石分离的作用机制以及对酸浸过程中碳化铁提纯效果的影响规律。结果表明,添加剂能显著促进碳化铁颗粒长大、改善碳化铁与脉石的嵌布关系,强化脉石矿物在酸中的溶解。添加剂的作用效果由强到弱依次为:硫酸钠、碳酸钠、碳酸钾、碳酸锂。添加了硫酸钠的菱铁矿球团经过渗碳、磁选、酸浸后可获得铁品位、化合碳含量和总回收率分别为90.24%、6.94%和74.80%的高品位碳化铁精矿。

Low grade siderite is a complex and refractory iron ore, which is hard to be used in iron and steel industry currently. For effective utilization of low grade siderite, a novel technology was proposed to utilize the low grade siderite as electric furnace burden by carburization roasting, magnetic separation and acid leaching process. The effect of additive on the separation of iron carbide and gangue was investigated, and also the effect of additive on iron carbide purification in the acid leaching was studied. The results show that additive can significantly promote the growth of iron carbide particles, improve the embedding relationship between iron carbide and gangue, and enhance the dissolution of gangue minerals in acid. Additive effect ranking from strongest to weakest is as follows: Na;SO;>Na;CO;>K;CO;>Li;CO;. After carburizing, magnetic separation, and acid leaching treatments, the iron carbide concentrate made from the siderite pellets with Na;SO;additive owns iron grade, combined carbon content and total recovery rate of 90.24%, 6.94% and 74.80%, respectively.