Dechromization and dealumination kinetics in process of Na_2CO_3-roasting pretreatment of laterite ores  

碳酸钠焙烧预处理红土镍矿过程除铬和铝动力学(英文)

作　　者：郭强[1,2] 曲景奎[1,2] 韩冰冰[1,2] 魏广叶[1,2] 张培育[1,2] 齐涛[1,2] 

机构地区：[1]湿法冶金清洁生产技术国家工程实验室,北京100190 [2]中国科学院过程工程研究所,绿色过程与工程院重点实验室,北京100190

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第12期3979-3986,共8页中国有色金属学报（英文版）

基　　金：Project(51125018)supported by the National Natural Science Foundation for Distinguished Young Scholars of China;Project(51204153)supported by the National Natural Science Foundation of China;Project(2011BAC06B07)supported by the National High Technology Research and Development Program,China

摘　　要：A novel process was proposed for the activation pretreatment of limonitic laterite ores by Na2CO3 roasting. Dechromization and dealumination kinetics of the laterite ores and the effect of particle size, Na2CO3-ore mass ratio, and roasting temperature on Cr and Al extraction were studied. Experimental results indicate that the extraction rates of Cr and Al are up to 99%and 82%, respectively, under the optimal particle size of 44–74μm, Na2CO3-to-ore mass ratio of 0.6：1, and temperature of 1000 ℃. Dechromization within the range of 600–800 oC is controlled by the diffusion through the product layer with an apparent activation energy of 3.9 kJ/mol, and that it is controlled by the chemical reaction at the surface within the range of 900–1100 ℃ with an apparent activation energy of 54.3 kJ/mol. Besides, the Avrami diffusion controlled model with on apparent activation energy of 16.4 kJ/mol is most applicable for dealumination. Furthermore, 96.8%Ni and 95.6%Co could be extracted from the alkali-roasting residues in the subsequent pressure acid leaching process.开发碳酸钠碱熔焙烧预处理红土镍矿的新工艺,对红土镍矿碱熔脱除铬和铝动力学以及矿石粒度和碱矿质量比、焙烧温度等影响铬和铝浸出率的因素进行系统研究。结果表明：在矿石粒度为44-74μm、碱矿质量比为0.6：1和焙烧温度为1000℃的条件下,铬和铝的浸出率分别达到99%和82%以上。在600-800℃温度范围内,除铬反应受产物层扩散控制,其表观活化能为3.9 k J/mol;在900-1100℃温度范围内,除铬反应受表面化学反应控制,其表观活化能为54.3 kJ/mol。此外,在600-1100℃温度范围内,除铝反应受Avrami内扩散控制,其表观活化能为16.4 kJ/mol。在后续对碱熔渣进行加压酸浸过程中,镍和钴的浸出率分别达到96.8%和95.6%。

关 键 词：dechromization DEALUMINATION KINETICS Na2CO3-roasting pretreatment laterite ore nickel cobalt 

分 类 号：TF046.2[冶金工程—冶金物理化学]