高镁铁精矿制备球团试验研究

Experimental study on preparation of pellets using high MgO-bearing iron ore concentrate

目前,镁质球团制备主要是添加镁质熔剂,对高镁精矿直接制备镁质球团研究较少。以国外某高镁铁精粉为原料,系统研究了造球参数、预热参数及焙烧参数对球团性能的影响,并进行了投笼工业试验。结果表明,在膨润土用量1.2%,生球水分8.0%,造球时间15min的条件下,生球落下强度4.2次/(0.5m),抗压强度18 N/P,爆裂温度425℃;在预热温度1050℃,预热时间15min,焙烧温度1250℃,焙烧时间15 min的条件下,预热球团抗压强度524N/P,焙烧球团抗压强度2589N/P;成品球团的全铁品位63.35%,MgO含量1.70%,有害元素含量低,冶金性能优良,是一种优质的高炉炉料。

The preparation of MgO-bearing pellets at present is to add magnesian flux mainly,however,few researches are made on direct preparation of magnesian pellets using high MgO iron ore concentrate.In this paper,with the high foreign MgO iron ore concentrates as raw materials,the influences of balling,preheating and roasting parameters on the pellet performances were studied systematically,and the pilot scale test was carried out.The results show that,under the conditions of bentonite consumption 1.2%,green ball moisture 8.0%and balling time 15 minutes,the green ball drop strength is 4.2 times/(0.5 m),the compressive strength is 18 N/P and the shock temperature is 425 XI.Under the conditions of preheating at 1 050℃for 15 minutes and firing at 1 250 for 15 minutes,the compressive strength of preheated pellets is 524 N/P and that of fired pellets is 2 589 N/P,and product pellets are obtained which are quality BF burdens,with 63.35%total iron grade,1.70%MgO content,low content of harmful elements and good metallurgical performance.