摘要
根据《中华人民共和国固体废物污染环境防治法》有关规定,烟气脱硝过程中产生的废钒钛系催化剂因其毒性对生态环境和人体健康产生有害影响,被列为危险废物(HW50772-007-50),因此对其中有价金属特别是钒金属进行提取是非常重要的技术手段和解决方案。本文考察了不同无机酸与有机酸组合对废钒钛系催化剂中钒元素的浸出效果,在搅拌转速500 r/min、液固比20 mL/g、反应温度110℃和浸出时间5 h的相同条件下,优选出了硫酸−草酸组成的混酸。对该组合进行了工艺优化,结果表明,当液固比为20 mL/g、硫酸浓度为20 wt%、草酸浓度为0.3 mol/L、反应温度为140℃和浸出时间为7 h时,钒元素的浸出率最大为95.65%。在最优工艺条件下得到的浸出渣主要成分为锐钛矿型二氧化钛,对其浸出后的比表面积和孔结构分析,与浸出前的状态相比,浸出渣的比表面积增大了13.5%,平均孔容也有所增加,表明其可以作为原料重新回收利用。
According to the relevant provisions of Law of the People's Republic of China on the Prevention and Control of the Environmental Pollution of Solid Wastes,the waste vanadium and titanium catalysts generated in the process of flue gas denitrification are classified as hazardous wastes due to their toxicity and harmful effects on the ecological environment and human health(HW50772-007-50),and therefore the extraction of the valuable metals therein,especially vanadium metals,is a very important technological means and solution.In this paper,we investigated the leaching effect of different combinations of inorganic and organic acids on vanadium from spent vanadium and titanium catalysts,and a mixed acid consisting of sulphuric acid-oxalic acid was preferred under the same conditions of stirring speed of 500 r/min,liquid-solid ratio of 20 mL/g,reaction temperature of 110°C and leaching time of 5 h.The process optimisation of this combination was carried out by using a mixture of sulfuric acid and oxalic acid to extract vanadium.The process optimisation of this combination was carried out,and the results showed that the maximum leaching rate of vanadium was 95.65%when the liquid-solid ratio was 20 mL/g,the concentration of sulphuric acid was 20 wt%,the concentration of oxalic acid was 0.3 mol/L,the reaction temperature was 140°C,and the leaching time was 7 h.The leaching slag obtained under the optimal process conditions was mainly composed of anatase titanium dioxide,and the analysis of its specific surface area and pore structure after leaching showed that the specific surface area of the leaching slag had increased by 13.5%and the average pore volume had also increased compared with the state before leaching,which indicated that it could be recycled as a raw material.
作者
李扬
李杰
程文婷
LI Yang;LI Jie;CHENG Wenting(Longking-Coalogix Environmental Protection Technology(Shanghai)Co.,Ltd.,Shanghai 200331;Jiangsu Longking-Coalogix Environmental Protection Technology Co.,Ltd.,Yancheng 224051;State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste Resources(Institute of Resources and Environmental Engineering,Shanxi University),Taiyuan 030031)
出处
《电力科技与环保》
2024年第3期304-312,共9页
Electric Power Technology and Environmental Protection
基金
国家自然科学基金项目(22208198)
国家重点研发计划(2022YFC3901305)
国家节能低碳材料生产应用示范平台项目(TC220H06N)。
关键词
混酸协同
废钒钛系催化剂
钒浸出
mixed acid synergistic
spent deNOx catalyst
vanadium leaching
