摘要
将一水硬铝石矿与Ca(OH)_2和过饱和NaOH溶液均匀混合后在微波炉中焙烧。利用X线衍射分析技术,研究不同实验因素(微波焙烧温度、NaOH添加量、Ca(OH)_2添加量和保温时间)对一水硬铝石矿-氢氧化钠-氢氧化钙体系相变规律的影响。研究结果表明:升高微波焙烧温度、增加NaOH和Ca(OH)_2的添加量,延长微波保温时间均有利于NaAlO_2和Ca_2SiO_4的形成,从而提高铝硅分离的效果。但当Ca(OH)_2添加过量时反而对熟料的物相结构不利。实验的最优条件为:NaOH与Al和Fe的物质的量比n_(NaOH)/(n_(Al)+n_(Fe))为1.0,CaO与SiO_2的物质的量比n_(CaO)/n_(SiO_2)为2.0,微波焙烧温度为800℃,保温时间为20 min。此时,熟料的结构疏松多孔,浸出效果好。
A slurry mixture of diasporic bauxite and alkaline(Ca(OH)2+supersaturated NaOH solution)was roasted with microwave energy.The effects of operation parameters,such as microwave roasting temperature,NaOH amount,Ca(OH)2amount and holding time on the phase transformation of the diasporic bauxite-NaOH-Ca(OH)2system were investigated by X-ray diffraction analysis.The results show that increasing the microwave roasting temperature and the amounts of NaOH or Ca(OH)2,and prolonging the holding time are all favorable for the form of NaAlO2and Ca2SiO4,and will likely improve the separating effect of aluminum?silicate minerals.However,the excess amount of Ca(OH)2is detrimental to the phase constitution of the roasted product.The optimum conditions are obtained as follows:mole ratio nNaOH/(nAl+nFe)is1.0;nCaO/nSiO2is2.0;microwave roasting temperature is800℃and holding time is20min.The roasted product obtained at the optimum conditions is porous,and its leaching effect is good.
作者
黎氏琼春
巨少华
彭金辉
王仕兴
周烈兴
王应兰
LE Thiquynhxuan;JU Shaohua;PENG Jinhui;WANG Shixing;ZHOU Liexing;WANG Yinglan(National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming 650093, China;Microwave Energy and Equipment Technology, Kunming 650093, China;Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2017年第12期3152-3159,共8页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51264022)
2015年度云南省博士研究生学术新人奖资助项目(2015)
云南省应用基础研究计划项目(2015FA017)~~
关键词
微波加热
一水硬铝石矿
相变
氢氧化钠
氢氧化钙
microwave heating
diasporic bauxite
phase transformation
sodium hydroxide
calcium hydroxide
