摘要
为有效回收和利用高铝粉煤灰除钙除铁后的酸浸废液,提出了利用酸浸废液制备聚合氯化铝铁(PAFC)的方法。首先,研究碱化剂种类、溶液初始pH、铝铁物质的量比、聚合温度和时间等因素对PAFC生成行为及其絮凝效果的影响;其次,研究模拟水样pH以及絮凝剂添加量对絮凝效果的影响;最后,利用XRD,FTIR和SEM等方法表征PAFC产品的结构。研究结果表明:在反应初期,随着溶液初始p H、铝铁物质的量比、聚合温度以及时间增加,PAFC产品的盐基度增大,聚合程度增加,其网状结构趋于稳定,絮凝性能也逐渐增强;盐基度继续增加,铝、铁高度聚合形成沉淀,导致PAFC的电中和能力以及网捕能力下降,絮凝效果降低。酸浸废液制备PAFC产品的最佳条件如下:氢氧化钠为碱化剂,铝铁物质的量比为15,溶液初始pH为3.0,反应温度为85℃,反应时间为3.0 h。在高岭土模拟废水样初始p H为6~8,PAFC加入量为100~150 mg/L时,PAFC具有良好的絮凝效果,水样的浊度去除率可达到90%以上。制备的PAFC产品存在羟基络合铝、羟基络合铁聚合物,其微观形貌为链网状的立体结构,且存在较多孔隙,吸附捕集污染物的能力强,絮凝效率高。
A method for preparing polymeric aluminum ferric chloride was proposed to recover and utilize acid leaching waste liquor which was obtained by removing calcium and iron from fly ash with high aluminum content.Firstly,the effects of alkalizing agent,pH of initial solution,aluminum-iron molar ratio,polymerization temperature and time on the preparation of PAFC and its flocculation performance were studied.Secondly,the influences of pH of simulated water sample and addition of product on flocculation effect were studied.Finally,the structure of PAFC products was characterized by XRD,FTIR and SEM.The results show that at the early stage,the degree of polymerization and basicity increase with the increase of p H of initial solution,aluminum-iron molar ratio,polymerization temperature and time.The network structure of PAFC products tends to be stable,and the flocculation performance is gradually enhanced.With the increase of basicity,aluminum and iron highly polymerize to form precipitate,which leads to the decrease of electric neutralization capability and netting ability and flocculation effect decrease.The optimum preparation conditions of PAFC products are as follows:the alkalizing agent is NaOH,aluminum-iron ratio is 15,pH of initial solution is 3.0,react temperature is 85℃and react time is 3.0 h.PAFC has the best flocculation performance when the p H of kaolin water sample is 6—8 and the addition of PAFC is 100—150 mg/L,and the corresponding turbidity removal ratio of kaolin water sample can reach higher than 90%.The PAFC products possess a three-dimensional structure with chain network and many pores.They have hydroxyl complex aluminum polymers and hydroxyl complex iron polymers,which results in a good flocculation performance.
作者
刘吉龙
潘晓林
耿学哲
于海燕
LIU Jilong;PAN Xiaolin;GENG Xuezhe;YU Haiyan(School of Metallurgy,Northeastern University,Shenyang 110819,China;Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education),Northeastern University,Shenyang 110819,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第11期3792-3799,共8页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51774079)
中央高校基本科研业务费资助项目(N182508026)。
关键词
聚合氯化铝铁
粉煤灰
酸浸
絮凝
盐基度
polymeric aluminum ferric chloride
fly ash
acidic leaching
flocculation
basicity
