镍对赤泥还原铁组织和性能的影响

Effect of Nickel on Microstructure and Properties of Red Mud Reduced Iron

赤泥是阻碍铝工业绿色可持续发展的重要原因之一。本实验选用广西平果铝拜耳法高铁赤泥作为最初原料,通过碳热熔融还原技术得到含镍铸铁作为实验原料,参考并选用美国ASTM A532M-1993标准中的镍浓度范围,通过加入纯镍和铬铁进行调制,得到五组镍浓度梯度的实验样品。对五组样品进行成分分析、金相显微组织观察、显微硬度测试和摩擦磨损试验,得到以下结论:在碳含量为5%的情况下,随着赤泥还原铁中镍含量的增加,碳元素逐渐石墨化,试样的硬度和耐磨性能逐渐降低。当镍含量为大于4.5%时,在制样组织中可以明显观察到游离石墨。

Red mud is one of the important reasons hindering the green and sustainable development of the aluminum industry. In this experiment, Guangxi Pingguo aluminum Bayer process red iron mud was selected as the initial raw material;nickel-containing cast iron was obtained through carbon thermal melting reduction technology as the experimental raw material, and the nickel concentration range in ASTM A532M-1993 was selected as reference, and by adding pure nickel and ferrochrome for modulation, five groups of experimental samples with nickel concentration gradient were obtained. Based on the composition analysis, metallographic microstructure observation, microhardness test and friction and wear test of the five groups of samples, the following conclusions are drawn: when the carbon content is 5%, with the increase of the nickel content in the red mud reduced iron, the carbon element is gradually graphitized, and the hardness and wear resistance of the samples decrease gradually. When the nickel content is greater than 4.5%, free graphite can be observed in the sample tissue.