循环流化床粉煤灰硫酸铵和硫酸协同酸浸提铝研究  

Study on Synergistic Acid Extraction of Aluminum From Circulating Fluidized Bed Fly Ash by Sulfuric Acid and Ammonium Sulfate

作　　者：李健 高建明 郭彦霞 程芳琴 LI Jian;GAO Jianming;GUO Yanxia;CHENG Fangqin(State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste Resources, Shanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related Wastes, Institute of Resources and Environment Engineering, Shanxi University, 030006 Taiyuan, China)

机构地区：[1]山西大学资源与环境工程研究所,国家环境保护煤炭废弃物资源化高效利用技术重点实验室,山西低附加值煤基资源高值利用协同创新中心,太原030006

出　　处：《煤炭转化》2022年第3期52-60,共9页Coal Conversion

基　　金：国家重点研发计划项目(2017YFB0603100);襄垣县固废综合利用科技攻关项目(2018XYSDJS-04).

摘　　要：采用硫酸铵/硫酸((NH_(4))_(2)SO_(4)/H_(2)SO_(4))混合介质协同提取循环流化床粉煤灰(CFB)中的氧化铝,探讨了酸浸温度、H_(2)SO_(4)浓度、(NH_(4))_(2)SO_(4)添加量与固液比(固体的质量(mg)与液体的体积(L)的比值)对铝及铁钙杂质元素溶出规律的影响,并对酸浸条件进行了优化。对酸浸实验所产生的酸浸液进行结晶实验研究,探究了初始H_(2)SO_(4)浓度、初始(NH_(4))_(2)SO_(4)添加量及结晶温度对铝结晶率的影响。结果表明:酸浸实验中,当酸浸温度为160℃,H_(2)SO_(4)浓度为40%,(NH_(4))_(2)SO_(4)添加量为1.0((NH_(4))_(2)SO_(4)质量与H_(2)SO_(4)质量的比),固液比为1/3时,铝的溶出率可以达到91.4%;结晶实验中,当初始H_(2)SO_(4)浓度为35%,初始(NH_(4))_(2)SO_(4)添加量为1.2时,铝的结晶率及总体回收率较高;当结晶温度为5℃时,铝的结晶率较高,目标晶体更易析出。通过电感耦合等离子体(ICP-OES)对十二水硫酸铝铵(NH_(4)Al(SO_(4))2·12H_(2)O)晶体以及结晶余液中铁钙杂质元素的含量进行测定,明确了杂质元素的分布规律。利用X射线衍射仪(XRD)对不同条件所产生晶体进行表征,明晰所产生晶体的物相结构,最终得到纯度较高的提铝结晶产物。Ammonium sulfate/sulfuric acid((NH_(4))_(2)SO_(4)/H_(2)SO_(4))mixed medium was used to extract alumina from circulating fluidized bed fly ash(CFB).The effects of leaching temperature,sulfuric acid concentration,ammonium sulfate addition and solid-liquid ratio(the ratio of solid mass(mg)to liquid volume(L))on the dissolution of aluminum,iron and calcium impurities were systematically investigated,and attempts were made to obtain the optimum leaching conditions.Meanwhile,the crystallization experiment of the acid leaching solution produced by the acid leaching experiment was carried out to explore the effects of the initial sulfuric acid concentration,the addition amount of initial ammonium sulfate and the crystallization temperature on the aluminum crystallization rate.The results of the acid leaching experiment show that the dissolution rate of aluminum reached 91.4%under the condition of acid leaching temperature 160℃,the sulfuric acid concentration 40%,the ratio of the addition amount of ammonium sulfate to that of sulfuric acid 1.0,and the solid-liquid ratio 1/3.Moreover,the crystallization rate and overall recovery of aluminum are higher under the condition of the initial sulfuric acid concentration 35%and the initial ammonium sulfate addition 1.2.When the crystallization temperature is 5℃,the crystallization rate of aluminum is higher,and the target crystal is easier to precipitate.The content of iron and calcium impurity elements in ammonium aluminum sulfate dodecahydrate crystal and crystal residue is determined by inductively coupled plasma-optical emission spectrometry(ICP-OES),and the distribution characteristics of the impurity elements are clarified.Furthermore,the crystals produced under different conditions are characterized by X-ray diffraction(XRD)to clarify the phase structure of the crystals,and finally the aluminum crystal with high purity is obtained.

关 键 词：循环流化床粉煤灰 氧化铝 硫酸铵 硫酸 十二水硫酸铝铵 

分 类 号：TQ536.4[化学工程—煤化学工程]