Conversion of coal gangue into alumina, tobermorite and TiO_2-rich material  

作　　者：罗骏 李光辉 姜涛 彭志伟 饶明军 张元波 

机构地区：[1]School of Minerals Processing & Bioengineering, Central South University

出　　处：《Journal of Central South University》2016年第8期1883-1889,共7页中南大学学报（英文版）

基　　金：Projects(51234008,51174230)supported by the National Natural Science Foundation of China;Project(NCET-11-0515)supported by the Program for New Century Excellent Talents in University,China;Project supported by Co-Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China

摘　　要：A large amount of coal gangue from coal mining and processing is regarded as waste and usually stockpiled directly. In order to recycle the valuable elements from the coal gangue, an integrated process is proposed. The process consists of three steps: 1concentrating alumina from the coal gangue via activation roasting followed by alkali leaching of Si O2 which produces alumina concentrate for alumina extraction by the Bayer process; 2) synthesizing tobermorite whiskers from the filtrated alkali liquo containing silicate via a hydrothermal method and reusing excess caustic liquor; and 3) enriching titanium component from the Baye process residue by sulfuric acid leaching. Alumina concentrate with 69.5% Al_2O_3 and mass ratio of alumina to silica(A/S) of 5.9pure 1.1 nm tobermorite whisker and TiO_2-rich material containing 33% TiO_2 are produced, respectively, with the optimal parameters Besides, the actual alumina digestion ratio of alumina concentrate reaches 80.4% at 270 oC for 40 min in the Bayer process.A large amount of coal gangue from coal mining and processing is regarded as waste and usually stockpiled directly. In order to recycle the valuable elements from the coal gangue, an integrated process is proposed. The process consists of three steps： 1concentrating alumina from the coal gangue via activation roasting followed by alkali leaching of Si O2 which produces alumina concentrate for alumina extraction by the Bayer process; 2） synthesizing tobermorite whiskers from the filtrated alkali liquo containing silicate via a hydrothermal method and reusing excess caustic liquor; and 3） enriching titanium component from the Baye process residue by sulfuric acid leaching. Alumina concentrate with 69.5% Al_2O_3 and mass ratio of alumina to silica（A/S） of 5.9pure 1.1 nm tobermorite whisker and TiO_2-rich material containing 33% TiO_2 are produced, respectively, with the optimal parameters Besides, the actual alumina digestion ratio of alumina concentrate reaches 80.4% at 270 oC for 40 min in the Bayer process.

关 键 词：coal gangue RECYCLE ALUMINA titanium dioxide TOBERMORITE 

分 类 号：TD849.5[矿业工程—煤矿开采] TF803.21[矿业工程—矿山开采]