马钢球团配用黏性姑精矿实验研究

Experimental study on use of viscous Gushan concentrate in pelletizing of Masteel

为了解决黏性姑山赤铁精矿(姑精矿)用于烧结生产引起烧结质量指标降低,球团生产混合料难以混匀,球团质量变差,生产波动大等问题,开展了将姑山磁铁精矿B精、C精和姑精矿在矿浆状态下预先混匀成姑山混合精矿实验,并研究了姑精矿粒度、配比等因素对生球制备、球团预热焙烧制度和球团性能的影响。结果表明:在矿浆状态下混匀可使姑精矿在姑山混合精矿中分布均匀,添加姑精矿润磨后,造球混合料细粒级含量增加,姑精矿较磁铁精矿润磨性能好;使用造球混合料2号造球,生球落下强度为7.8次/(0.5 m),较磁铁精矿生球落下强度提高1.3次/(0.5 m)。在预热温度950℃、预热时间18 min、焙烧温度1200℃、焙烧时间20 min时,焙烧球团强度为2987 N/球,较磁铁精矿混合料焙烧球团强度降低129 N/球,姑精矿的加入对球团的焙烧强度不利。生产中可以通过适当提高焙烧温度或姑精矿细度的措施来满足高炉对球团强度的要求。

In order to solve the problems of the reduction of sintering yield and quality,the difficulty of mixing for pelletizing,the poor quality of roasted pellets,and the obvious fluctuation of production caused by use of Gushan hematite concentrate(hereinafter called Gujing)in sintering production,the experiment of mixing magnetite concentrate B,C and Gujing into Gushan mixed concentrate in advance under pulp condition was carried out,and the effects of Gujing′s particle size and ratio on the green pellets preparation,preheating and roasting conditions and pellets quality were studied.The results show that the distribution of Gujing in Gushan mixed concentrate is uniform by pulp mixing.By adding Gujing,the fine-grained content of the pelletizing mixture increases after wetting grinding,which indicated that Gujing has better grindability than magnetite concentrate in this experiment.When pelletizing mixture No.2 was used,the dropping strength of the green pellets is 7.8 times/(0.5 m),which is 1.3 times/(0.5 m)higher than that of the magnetite concentrate.Under preheating temperature 950℃for 18 min and roasting temperature 1200℃for 20 min,the strength of the roasted pellet is 2987 N per pellet,which is lower than that of the roasted pellet of magnetite concentrate by 129 N per pellet.It is said that the addition of Gushan mixed concentrate is not good for the roasting strength of the pellets.In production,the strength requirements of blast furnace for pellets can be met by properly increasing the roasting temperature or the fineness of the Gujing.