欢迎访问过程工程学报, 今天是

过程工程学报 ›› 2020, Vol. 20 ›› Issue (5): 540-547.DOI: 10.12034/j.issn.1009-606X.219275

• 反应与分离 • 上一篇    下一篇

粉煤灰中重金属元素砷的赋存状态与分离方法

刘福立1,2, 马淑花2*, 任 坤2,3, 王晓辉2   

  1. 1. 辽宁工程技术大学矿业学院,辽宁 阜新 123000 2. 中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室,北京 100190 3. 中国矿业大学(北京)化学与环境工程学院,北京 100083
  • 收稿日期:2019-08-16 修回日期:2019-10-09 出版日期:2020-05-22 发布日期:2020-05-18
  • 通讯作者: 马淑花
  • 基金资助:
    内蒙古自治区科技重大专项

Occurrence state and separation method of heavy metal element arsenic in coal fly ash

Fuli LIU1,2, Shuhua MA2*, Kun REN2,3, Xiaohui WANG2   

  1. 1. College of Mining, Liaoning Technical University, Fuxin, Liaoning 123000, China 2. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 3. School of Chemical and Environmental Engineering, China University of Mining and Technology-Beijing, Beijing 100083, China
  • Received:2019-08-16 Revised:2019-10-09 Online:2020-05-22 Published:2020-05-18

摘要: 粉煤灰中重金属元素在环境中的迁移转化和累积效应是粉煤灰综合利用过程中面临的壁垒问题,明晰粉煤灰中重金属元素的赋存状态并探索一种高效脱除方法是解决粉煤灰大宗利用的关键。利用改进的BCR连续提取法发现,粉煤灰中重金属元素砷的水溶态和酸可溶态占比较高,证明重金属砷容易在环境中迁移,从而影响周边环境。基于粉煤灰中重金属砷的赋存状态特征,建立了硫酸一步脱除重金属元素砷的新方法,考察了硫酸浓度、反应温度和反应时间对重金属砷脱除率的影响。结果表明,砷的脱除率随硫酸浓度增大而增大,随反应温度升高而降低,随反应时间增加而增大。综合考虑重金属砷的脱除率、粉煤灰中常量元素的损失率和球形颗粒的破坏程度,确定硫酸一步法脱除粉煤灰中重金属砷的最佳条件为硫酸溶液物质的量浓度2.0 mol/L、反应温度20℃、反应时间60 min,此时重金属砷的脱除率达75.21%。

关键词: 粉煤灰, 重金属, 砷酸盐, 分离方法

Abstract: The migration, transformation and accumulation in the environment of heavy metal elements in coal fly ash are the barriers to the comprehensive utilization of coal fly ash. To clarify the occurrence state of heavy metal elements in coal fly ash and to explore an efficient removal method, it is the key to solve the large-scale utilization of coal fly ash. The improved BCR continuous extraction method found that the water soluble and acid exchangeable states of heavy metal element arsenic in fly ash accounted for a high proportion, which proved that heavy metal arsenic easily migrated in the environment and affected the surrounding environment. Based on the occurrence characteristics of heavy metal arsenic in coal fly ash, a new method for removing heavy metal element arsenic by sulfuric acid was established. The effects of sulfuric acid concentration, reaction temperature and reaction time on the removal rate of heavy metal arsenic were investigated. The results showed that the removal rate of arsenic increased with the increase of the concentration of sulfuric acid solution, decreased with the increase of reaction temperature, and increased with the increase of reaction time. Considering the removal rate of heavy metal arsenic, the loss rate of constant elements in coal fly ash and the degree of damage of spherical particles, the optimum conditions for removing heavy metal arsenic from coal fly ash by one-step method of sulfuric acid determination were as follows: the sulfuric acid concentration of 2.0 mol/L, the reaction temperature of 20℃, and the reaction time of 60 min. At this time, the removal rate of heavy metal arsenic reached 75.21%.

Key words: coal fly ash, heavy metal, arsenate, separation method