无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (3): 101-107.doi: 10.19964/j.issn.1006-4990.2024-0227

• 环境·健康·安全 • 上一篇    下一篇

循环流化床粉煤灰酸溶提锂过程中反应机理的研究

李超(), 王丽萍(), 高桂梅, 张云峰, 洪雨, 刘大锐, 许立军, 崔永杰   

  1. 中国神华哈尔乌素露天煤矿,内蒙古 鄂尔多斯 010300
  • 收稿日期:2024-04-23 出版日期:2025-03-10 发布日期:2025-03-21
  • 通讯作者: 王丽萍(1984— ),女,博士,高级工程师,主要从事粉煤灰综合利用;E-mail:chwlp2008@163.com
  • 作者简介:李超(1983— ),男,博士,高级工程师,主要从事粉煤灰中有价元素提取及高附加值开发利用;E-mail:lichao_1122@163.com
  • 基金资助:
    国家科技部十二五科技计划支撑项目(2011BAA04B05)

Study on reaction mechanism of acid leaching lithium from circulating fluidized bed fly ash

LI Chao(), WANG Liping(), GAO Guimei, ZHANG Yunfeng, HONG Yu, LIU Darui, XU Lijun, CUI Yongjie   

  1. Shenhua Haerwusu Open-pit Coal Mine of China,Ordors 010300,China
  • Received:2024-04-23 Published:2025-03-10 Online:2025-03-21

摘要:

准格尔地区的煤中含有锂元素,煤经过电厂燃烧发电后锂元素在烟道灰中二次富集,其中锂含量为290~500 g/t,极具提取价值。以循环流化床粉煤灰为研究对象,利用盐酸高压浸出锂元素,探索盐酸浸出过程中粉煤灰中锂离子的反应机制。实验结果表明,反应温度为160 ℃、时间为1 h、酸灰物质的量比为0.9、搅拌速率为240 r/min时,锂溶出效果最好,溶出率为87.31%。XRD分析结果证实:粉煤灰主要物相为无定型硅铝酸盐、γ-Al2O3、莫来石及少量的方石英;盐酸浸出过程中无定型硅铝酸盐和γ-Al2O3物相会发生溶解,而剩余盐酸浸出渣主要成分为无定型二氧化硅和莫来石。FT-IR和27Al NMR谱图分析结果证实:在盐酸浸出过程中粉煤灰中无定型硅铝酸盐化学键Al—O—Si发生断裂,主要归因于化学键中四配位Al(Ⅳ)与六配位Al(Ⅵ)溶解,造成三维网络结构发生破坏,进而释放了网络结构中的锂离子;与此同时,粉煤灰中γ-Al2O3物相中锂元素也在盐酸浸出过程中发生溶解进入溶液。

关键词: 粉煤灰, 盐酸, 反应机理, 提锂

Abstract:

The coal contains lithium element in zhungeer area,which is enriched in fly ash after being burned in power plants. The lithium content accounts for 290~500 g/t,which has great extraction value.In this paper,the lithium element was leached using hydrochloric acid solution from circulating fluidized bed fly ash,and the reaction mechanism of lithium ions in hydrochloric acid solution was explored in detail.The experimental results showed that the best lithium extraction rate was achieved about 87.31%,when the reaction temperature was 160 ℃,the reaction time was 1 h,the acid ash molar ratio was 0.9,and the stirring speed was 240 r/min.The XRD analysis results testified that the main phases of fly ash were amorphous aluminosilicate,γ-Al2O3,mullite,and a small amount of quartz.During the hydrochloric acid leaching process,amorphous aluminosilicate and γ-Al2O3 phases were dissolved,while the hydrochloric acid leaching residue was mainly composed of amorphous silica and mullite. The analysis results of FT-IR and 27Al NMR spectra confirmed that the chemical bond Al—O—Si of amorphous aluminosilicate in fly ash was broken,which was attributed to the dissolution of four coordinated Al(Ⅳ)and six coordinated Al(Ⅵ)in the chemical bond,causing damage to the three-dimensional network structure and releasing lithium ions in the network structure. Meanwhile,the lithium element in the γ-Al2O3 phase of fly ash was also dissolved into the solution during the hydrochloric acid leaching process.

Key words: fly ash(CFB), hydrochloric acid, reaction mechanism, lithium extraction

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