摘要
As clean energy,the microwave is commonly used to pretreat various ores.In this work,the microwave dielectric properties of limonitic laterite ore were measured by resonant cavity perturbation technique and the effects from microwave were systematically investigated.Results indicated that limonitic laterite had high microwave absorbance.After microwave pretreatment,the microstructure of the laterite became less aggregated and more porous and the main phase transformed from goethite to hematite that improved leaching in nitric acid(1.2 kg HNO3/kg ore);Ni,Co,Fe,and Mg extraction ratios were 95.2%,98.1%,1.8%and 15%,respectively,after leaching for 60 min at 200°C and 500 r/min.Furthermore,in the process of goethite to hematite by microwave pretreatment,the nickel-containing mineral is activated,which makes nickel be leached easily.The leaching process has high Ni extraction ratio compared to that without microwave(82%)and conventional pretreatment(90.4%).Therefore,microwave pretreatment of limonitic laterite before nitric acid pressure leaching is an effective way to improve the selectivity and extraction of the leach.
微波作为一种清洁能源,常用于矿石的预处理。本文采用谐振腔微扰法测定了褐铁型红土镍矿的微波介电性能,系统地研究了微波活化处理对硝酸加压浸出的影响。结果表明,褐铁型红土镍矿具有良好的微波吸收性能。微波预处理后,红土镍矿主要物相由针铁矿转变为赤铁矿,且变得疏松多孔;再经300°C焙烧30 min后,在200°C、酸矿比1.2:1、搅拌速度500 r/min的条件下浸出60 min,Ni、Co、Fe、Mg的浸出率分别为95.2%、98.1%、1.8%、15%。相较于常规焙烧(82.1%)和不做预处理(90.4%)的浸出,Ni浸出有了明显的提高。经过微波处理后矿物由于吸波性能存在差异,被包裹的含镍矿物被打开,同时积累了很大内应力,使褐铁型红土镍矿中的镍更容易被浸出。因此,在浸出前对褐铁型红土镍矿进行微波预处理是一种有效提高选择性浸出的方式。
作者
HE Fei
MABao-zhong
WANG Cheng-yan
MAYu-tian
ASSELIN Edouard
CHEN Yong-qiang
ZHANGWen-juan
ZHAO Jian
和飞;马保中;王成彦;马玉天;ASSELIN Edouard;陈永强;张文娟;赵健(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Nickel and Cobalt Resources Comprehensive Utilization,Jinchang 737104,China;Department of Materials Engineering,the University of British Columbia,Vancouver,BC,V6T 1Z4,Canada)
基金
Project(51974025)supported by the National Natural Science Foundation of China
Project(2018IA055)supported by the International Cooperation Project of Key Research and Development Plan of Yunan Province,China
Project(JKY2019-09)supported by State Key Laboratory of Nickel and Cobalt Resources Comprehensive Utilization,China。
