煤燃烧和CO_2气化过程中铀的释放规律  

Release Characteristics of Uranium During Coal Combustion and CO_2 Gasification

作　　者：刘东原 赵永椿[1] 张军营[1] 郑楚光[1] Liu Dongyuan Zhao Yongchun Zhang Junying Zheng Chuguang(State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Chin)

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074

出　　处：《燃烧科学与技术》2016年第6期506-512,共7页Journal of Combustion Science and Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2014CB238904)

摘　　要：对煤燃烧过程中铀的存在形态和转化特性进行了热力学模拟，并对模拟结果进行实验验证．实验结果表明，煤燃烧过程中铀的释放率低于18％（CO2气化条件下低于22％），铀释放率随着实验温度的升高并非呈单调递增趋势，在800～1000℃范围内，铀释放率随实验温度的升高而降低．实验表明铀能与碱金属／碱土金属反应生成铀酸盐，且煤燃烧过程中铀主要与钙元素结合，生成的铀酸钙能抑制铀的挥发，此结论可为降低煤燃烧过程中铀的释放率提供依据．The occurrence and transformation characteristics of uranium during coal combustion are simulated in this paper, and the simulation results are validated experimentally. Experimental data show that the release rate of uranium is lower than 18% during coal combustion （lower than 22% in CO2 gasification）, and that the release rate does not simply increase as the experiment temperature rises, within the range from 800 ℃ to 1 000 ℃, the release rate of uranium decreases with the increase of temperature. A detailed exploration about this phenomenon is presented in this paper, and the experimental results show that uranium and alkali/alkaline earth metal elements can generate uranate. Uranium mainly combine with calcium to generate calcium uranate, which can restrain the volatilization of uranium during coal combustion. This conclusion provides a theoretical basis for reducing the release rate of uranium in the process of coal utilization.

关 键 词：铀释放率 铀酸盐 赋存形态 迁移转化 煤燃烧 

分 类 号：X591[环境科学与工程—环境工程]