摘要
为降低广西某选矿厂铅锌矿尾砂对环境的危害,同时达到固废减量化、资源化的目的,以矿渣、钢渣为主要原料制备胶凝材料(metallurgical slag cementitious material,MSC),并与尾矿砂混合制备膏体充填料协同固化砷。研究结果表明:尾砂中As 质量分数为0.11%,As原始浸出质量浓度为0.66mg/L,经MSC固化后As 浸出质量浓度为0.031mg/L,固化率达95.3%;As 可以通过类质同象替换进入C-S(A)-H 凝胶或类沸石相中代替Si 原子或Al 原子的位置,AsO4^3-可与Mg(OH)2和Ca(OH)2反应生成溶解度较低的复盐沉淀,且砷可以被水化产物C-S(A)-H凝胶包裹、吸附,Na2SO4与Na3AsO4反应生成低溶解度复盐类沉淀,这些都是砷被稳定固化的机制。
In order to reduce the environmental risk of lead and zinc tailings in a concentrator in Guangxi,and at the same time achieve the purpose of reducing and recycling solid waste,blast furnace slag and steel slag were used as the main raw materials to prepare cementitious materials (metallurgical slag cementitious material,MSC),and mixed with tailings to prepare paste backfilling materials,which could also immobilize arsenic.The results show that the arsenic in tailings is 0.11%.The leaching mass concentrations of arsenic is 0.66 mg/L.After metallurgical slag cementitious material's solidification,the leaching mass concentrations of arsenic is 0.031 mg/L,and the curing efficiency is 95.3%. Arsenic atom can replace the aluminum atom or silicon atom which is in the structure of C-S(A)-H gel and zeolite-like phase,AsO34- can also react with Mg(OH)2 and Ca(OH)2 in formation of calcium arsenate with lower solubility,and arsenic can be adsorbed and encapsulated by C-S(A)-H gel,furthermore,Na2SO4 reacts with Na3AsO4 resulting in the formation of double salt precipitates with low solubility,which is all the mechanism for solidification of arsenic.
作者
鄢琪慧
倪文
高巍
李云云
张钰莹
YAN Qihui;NI Wen;GAO Wei;LI Yunyun;ZHANG Yuying(School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of High-efficient Mining and Safety of Metal Mines,Ministry of Education,Beijing 100083,China;Key Laboratory of Resource-oriented Treatment of Industrial Pollutants,Beijing 100083,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第7期1544-1550,共7页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51504014)~~
关键词
矿渣
钢渣
固化
砷
胶结充填
blast furnace slag
steel slag
solidification
arsenic
cemented backfilling
