硫酸固相转化法从粉煤灰中提取氧化铝  

Extraction of Alumina from Coal Fly Ash Using Sulfuric Acid Solid Phase Conversion Technology

作　　者：蒋训雄[1] 蒋开喜[1] 范艳青[1] 汪胜东[1] 冯林永[1] 李达[1] 

机构地区：[1]北京矿冶研究总院,北京100160

出　　处：《有色金属工程》2017年第3期30-35,共6页Nonferrous Metals Engineering

基　　金：国家高技术研究发展计划(863计划)资助项目(2007AA06Z128);北京矿冶研究总院科研基金项目(02-1502)

摘　　要：针对现有粉煤灰提取氧化铝方法中存在的问题,采用硫酸固相转化法从粉煤灰中提取氧化铝,考察了硫酸用量、反应温度和时间、升温速度等因素对铝转化率的影响。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱分析(EDS)等手段对粉煤灰提取铝工艺过程中各样品的微观形貌和结构组成变化进行研究。结果表明,粉煤灰与浓硫酸反应后,粉煤灰中的偏高岭石、莫来石等铝硅酸盐矿物颗粒受到硫酸浸蚀转变成硫酸铝和二氧化硅;固相转化后的熟料用水洗即可将铝浸出而与硅分离;硫酸用量、温度及升温速度对转化率的影响较大,转换率可达94%以上。In order to overcome the problems existing in the technology of alumina extraction from coal fly ash, the sulfuric acid solid transformation method was introduced. The effects of process parameters such as sulfuric acid dosage, heating rate, temperature and reaction time were studied. The morphology and microstructure of the samples obtained during in the process of extracting aluminum were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy dispersive spectrometer （EDS）. The results show that after the sulfuric acid solid transformation process, the aluminosilicate mineral particles such as kaolinite and mullite in fly ash are transformed into aluminum sulfate and silica by sulfuric acid eroding, and then the aluminum and silicon in fly ash could be separated by water washing. The sulfuric acid dosage, temperature and heating rate have great influence on the recovery of the aluminum and the conversion rate can reach more than 94%.

关 键 词：粉煤灰 氧化铝 硫酸固相转化 相变 

分 类 号：X773[环境科学与工程—环境工程]