摘要
通过二氧化碳浸提垃圾焚烧飞灰固渣中的钙,使钙从固体飞灰中转移到溶液中,分离得到碳酸钙。分别采用飞灰直接脱钙和飞灰水洗后脱钙两条路线进行脱钙,研究了反应压力、反应温度、反应时间和液固比等因素对脱钙效率的影响以及不同条件下碳酸钙的回收效率。综合考虑实际应用最终确定条件为:水洗飞灰反应压力3.5 MPa,液固比30,反应温度5℃,反应时间120 min,循环脱钙3次后,脱钙效率达71.93%。通过加入石灰水降低碳酸钙溶解度,提高碳酸钙回收效率,最终获得碳酸钙产品纯度和回收率达97.65%和97.69%,符合HG/T 2226—2019《普通工业沉淀碳酸钙》标准要求。研究为飞灰的资源化与减量化提供了新的方法,具有广泛的市场前景。
Calcium in the solid residue of waste incineration fly ash was extracted by carbon dioxide leaching,so that calcium was transferred from the solid fly ash to the solution and separated to obtain calcium carbonate.Two routes of direct decalcification of fly ash and decalcification of fly ash after washing were used for decalcification,respectively,and the effects of reaction pressure,reaction temperature,reaction time and liquid-solid ratio on the decalcification efficiency and the recovery efficiency of calcium carbonate under different conditions were investigated.Considering the practical application,the final conditions were as follows:Reaction pressure of washed fly ash 3.5 MPa,liquid-solid ratio_(3)0,reaction temperature 5℃,reaction time 120 min,decalcification cycle three times,and the decalcification efficiency reached 71.93%.By adding lime water to reduce the solubility of calcium carbonate and improve the efficiency of calcium carbonate recovery,the final calcium carbonate product purity and recovery rate of 97.65%and 97.69%were obtained,which meets the requirements of the standard of HG/T 2226—2019‘General Industrial Precipitated Calcium Carbonate’.This study provides a new method for the resourcefulness and reduction of fly ash,which has a wide market prospect.
作者
张洲
徐丽琴
黄家会
赵安琪
杨志辉
柴喜林
姬梦琪
ZHANG Zhou;XU Liqin;HUANG Jiahui;ZHAO Anqi;YANG Zhihui;CHAI Xilin;JI Mengqi(School of Metallurgy and Environment,Central South University,Changsha 410083,China;Key Laboratory of Preparation and Application of Black Talc Functional Materials,Jiangxi Provincial Department of Education,Shangrao Normal University,Shangrao 334001,China;Central South(Shangrao)Metallurgical Industry Research Institute Co.,Ltd.,Shangrao 334001,China;Jiangxi Gaia Environmental Protection Technology Co.,Ltd.,Shangrao 334001,China)
出处
《应用化工》
北大核心
2025年第8期2037-2042,共6页
Applied Chemical Industry
基金
江西省教育厅科技项目(GJJ201719)
上饶市科技局项目(2020I002,2021F007)。
关键词
垃圾焚烧飞灰
二氧化碳
浸提
脱钙
碳酸钙
waste incineration fly ash
carbon dioxide
extraction
decalcification
CaCO_(3)
