煤种对嘉峪关某菱铁矿直接还原的影响

为研究煤种对某菱铁矿直接还原-磁选的影响,进行两种煤在不同煤用量条件下的对比试验,并运用XRD和SEM探讨两种煤的灰分及挥发分指标对直接还原过程的影响机理。结果表明:在采用两种煤的条件下,还原铁的品位都随煤用量的增加而降低,烟煤回收率随煤用量增加先增加后降低,石煤回收率随煤用量增加而增加。在同样煤用量时,烟煤焙烧产物铁颗粒较石煤大且向矿石边缘积聚明显,主要是与石煤相比,烟煤灰分较低,挥发分较高,导致烟煤对菱铁矿直接还原的速度不平稳。

Effects of coals on direct reduction roasting of siderite ore from Jiayuguan

In order to research effect of coal on the process of direct reduction-magnetic separation of siderite,comparative tests of two coals were conducted under conditions for different consumptions of coal,and the influence mechanisms of ash and volatility index of the two coals for direct reduction process were investigated by means of XRD and SEM.The results show that: under conditions using the two coals,the iron grades of the products decrease according to coal consumption increasing;the recovery rate for using bituminous coal increases first and then reduces with coal dosage increasing,and the recovery rate for using stone coal increases with coal dosage increasing.In the same coal consumption,the roasting iron particles for using bituminous coal are bigger than those for using stone coals,and obviously gather to the edge of ore.It is primarily that the ash of bituminous coal is lower than that of stone coal,and the volatility of bituminous coal is higher than that of stone coal,which leads to the speed of siderite direct-reducting relatively unstable.