石灰石对镍铁冶炼的影响

THE EFFECT OF LIMESTONE IN THE FeNi SMELTING PROCESS

镍铁冶炼采用回转窑-电炉方法,选择自然熔炼渣型,是国际上比较普遍的工艺路线,而在我国无论是高炉流程还是铁合金矿热电炉流程,均在熔炼过程中配加了熔剂石灰石或石灰。缅甸达贡山镍矿项目在试生产阶段仍选择了配加熔剂石灰石。文章在整理分析试生产阶段数据的基础上,对石灰石在试生产各阶段中还原焙烧、渣熔点、回收率、杂质元素以及泡沫渣层面的影响和作用进行了分析,结果表明在还原焙烧阶段石灰石限制影响氧化物的还原,对渣熔点以及熔渣排放温度的选择影响不大,对回收率和杂质元素控制有一定的影响,且泡沫渣产生时石灰石的存在会恶化工况。

RKEF process and natural smelting slag pattern are widely used in the world. But in China, no matter using blast furnace or ferroalloy submerged-arc furnace, flux limestone or lime will be fed in the smelting process. During the commissioning of Myanmar Dagaung Taung Nickel project, it added flux limestone. Based on the trial data, it analyzed limestone impact on reduction roasting, slag melting point, recovery rate, impurity element and foamed slag. The result shows that during the roasting stage, limestone restricts the oxide reduction, it has some influence on recovery rate and impurity elements, but little effect on slag melting point and molten slag emission temperature; and the existence of limestone worsens foamed slag operating mode.