菱铁矿石煤基直接还原过程中矿物的转化行为

Conversion Behavior of Minerals in the Coal-based Direct Reduction Process of the Siderite Ore

为了给进一步深入开展菱铁矿石煤基直接还原的工艺研究提供理论指导,以嘉峪关某菱铁矿石为试样,通过XRD、SEM和能谱分析以及热力学计算研究了菱铁矿石煤基直接还原过程中各种矿物的转化行为。结果表明:煤用量较小时,固相反应首先生成铁(镁)橄榄石,多余的铁矿物以孚氏体形式存在并在孚氏体内部形成金属铁核;增加煤用量可使金属铁核周围的孚氏体也被还原为金属铁,从而使铁颗粒得以长大。此外,随着煤用量的增加,主要脉石相铁镁橄榄石也会由于经历铁镁橄榄石→铁橄榄石→孚氏体→金属铁的反应历程而形成部分铁颗粒。

In order to provide theoretical guidance for further research of coal-based direct reduction of siderite ore, a siderite ore from Jiayuguan was chosen for sample to study the conversion behavior of various minerals in the coal-based direct reduction process of the siderite ore, by the technologies of XRD, SEM, energy spectrum analysis and thermodynamics calculation. The results show that： with low consumption of coal, iron （magnesium） olivine is the first product in the process of solid reaction, then the excess iron minerals exist in the wutite form and forming iron core in some fu＇s body; iron particles are growing up with the coal consumption increasing, through the reduction of the wutite around the iron core to iron. In addition, along with the increasing of coal consumption, the main gangne iron magnesium olivine also convert into part of metallic iron through the procedure： iron magnesium olivine-iron peridot-wutite-iron.