废SCR催化剂含钒砷碱浸液选择性分离工艺  

Selective Separation and Recovery of Vanadium from Vanadium-arsenic Bearing Alkaline Leaching Solution from Spent SCR Catalysts

作　　者：刘林峰 胡文斌[1,2] 李兵 王兴瑞[1,2] 王晨晔 李会泉 LIU Linfeng;HU Wenbin;LI Bing;WANG Xingrui;WANG Chenye;LI Huiquan(CAS Key Laboratory of Green Process and Engineering,National Engineering Research Center of Green Recycling for Strategic Metal Resources,Institute of Process Engineering,CAS,Beijing 100190,China;School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;China ENFI Engineering Co.,Ltd.,Beijing 100038,China)

机构地区：[1]中国科学院绿色过程与工程重点实验室,战略金属资源绿色循环利用国家工程研究中心,中国科学院过程工程研究所,北京100190 [2]中国科学院大学化学工程学院,北京100049 [3]中国恩菲工程技术有限公司,北京100038

出　　处：《有色金属（冶炼部分）》2024年第9期102-108,共7页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家自然科学基金资助项目(52274411)。

摘　　要：碱浸法被广泛应用于从废脱硝催化剂中浸取回收钒、钨等有价资源。由于钒和砷的化学性质相似,在碱浸过程中,砷与钒一同溶解到浸出液,导致后续钒元素回收困难,并且处理过程产生有毒废水,危害环境安全。提出了同步钙沉—酸溶—铁盐除砷—钙盐沉钒工艺,在钙沉过程中,通过加入氢氧化钙将钒和砷转化为钒酸钙和砷酸钙固定下来,实现了钒砷高效沉淀与碱溶液回收。酸溶后,采用硫酸亚铁沉淀法实现了酸液中钒砷的有效分离,砷以砷酸铁的形式固定在沉淀渣中。最佳工艺条件为:H 2O 2预氧化30 min、溶液初始pH=3.0、反应温度30℃、反应时间3 h。砷的沉淀率为97.26%,钒的损失率为1.84%。向获得的含钒滤液中加入氢氧化钙得到钒酸钙。该工艺实现了废SCR脱硝催化剂碱性浸出液中钒、砷的高效分离,同时实现了高碱度溶液的回收。The alkaline leaching method has been widely applied for the extraction and recovery of valuable resources such as vanadium and tungsten from spent denitration catalysts.However,due to the similar chemical properties of vanadium and arsenic,during the alkaline leaching process,arsenic is dissolved into the leachate along with vanadium,resulting in difficulties in subsequent vanadium recovery and the generation of toxic wastewater,posing risks to environmental safety.In this study,a novel integrated process of calcium precipitation,acid dissolution,iron salt arsenic removal,and calcium salt vanadium precipitation was proposed.During the calcium precipitation step,vanadium and arsenic are converted into insoluble calcium vanadate and calcium arsenate,achieving efficient precipitation of vanadium and arsenic and enabling the recovery of alkaline leachate.After acid dissolution,effective separation of vanadium and arsenic in the acidic solution was achieved using ferrous sulfate precipitation,with arsenic fixed in the precipitate as iron arsenate.The optimized process conditions include pre-oxidation time of 30 minutes with H 2O 2,initial pH value of 3,reaction temperature of 30℃,and reaction time of three hours.The precipitation rate of arsenic is 97.26%,with loss rate of vanadium of 1.84%.Calcium vanadate is obtained by adding calcium hydroxide to the vanadium-containing filtrate.This process achieves efficient separation of vanadium and arsenic from the alkaline leachate of spent SCR denitration catalysts and the recovery of high alkalinity solution.

关 键 词：废SCR催化剂 钒 脱砷 沉淀 钒酸钙 

分 类 号：TF803.2[冶金工程—有色金属冶金]