碱热活化粉煤灰地聚物相调控及其除磷性能  

Phase Regulation of Alkali Heat Activated Fly Ash Based Geopolymer Composites and Its Phosphorus Removal Performance

作　　者：杜挺昊 刘博研 郭昭呈 宋学锋[1] Du Tinghao;Liu Boyan;Guo Zhaocheng;Song Xuefeng(School of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an,Shaanxi,710055)

机构地区：[1]西安建筑科技大学材料科学与工程学院,陕西西安710055

出　　处：《非金属矿》2024年第5期93-97,共5页Non-Metallic Mines

基　　金：陕西省科研攻关项目(2018SF-367);2023年国家级大学生创新创业训练计划项目(202310703057)。

摘　　要：为有效提升地质聚合物的除磷效果,以碱热活化高铝粉煤灰为前驱体,氢氧化钙-二水硫酸钙为混合激发剂,原位合成了富含层状双金属氢氧化物(LDHs)的粉煤灰地聚物。采用X射线衍射(XRD)、扫描电镜(SEM)分析了粉煤灰、碱热活化粉煤灰及碱热活化粉煤灰地聚物的物相组成,并以碱热活化粉煤灰地聚物为吸附剂,采用静态吸附试验考察了其除磷效果。结果表明,碱热活化可使高铝粉煤灰中的莫来石、刚玉相转化为活性铝硅酸盐和硅酸盐矿物。氢氧化钙-二水硫酸钙混合激发碱热活化粉煤灰地聚物的晶相矿物主要为沸石相(4A型沸石、淡红沸石、浊沸石)及水铝钙石、三硫型水化硫铝酸钙(AFt)层状双金属氢氧化物相,具备了脱氮除磷功能。当氢氧化钙和二水硫酸钙质量比为1∶1时,碱热活化粉煤灰地聚物对H_(2)PO_(4)^(-)-P的吸附效果最佳,在H_(2)PO_(4)--P初始质量浓度为100 mg/L,固液质量比为1∶100的吸附条件下,其吸附容量为9.913 mg/g,去除率达到99.13%。In order to improve the phosphorus removal effect of geopolymer effectively,fly ash geopolymer composite rich in LDHs was synthesized in situ using alkali heat-activated high-alumina fly ash as precursor,calcium hydroxide-calcium sulfate dihydrate as mixed activators.The main mineral composition of the fly ash,the alkali heat-activated fly ash and the alkali heat-activated fly ash geopolymer were analyzed by XRD and SEM.The phosphorus removal effect of alkali heat-activated fly ash geopolymer composites was investigated by static adsorption test.The results show that alkali heat activation can transform the mullite and corundum phases into active aluminosilicate and silicate.The crystalline phase minerals of the alkali heat activated fly ash geopolymer excited by the mixture of calcium hydroxide and calcium sulfate dihydrate are mainly zeolite phase(4A zeolite,stellerite,laumontite)and the layered double hydroxide phase of hydrocalumite and AFt,which have the function of nitrogen and phosphorus removal.When the mass ratio of calcium hydroxide to calcium sulfate is 1∶1,the alkali heat-activated fly ash geopolymer have the best adsorption effect on H_(2)PO_(4)^(-)-P.Under the adsorption conditions of an initial H_(2)PO_(4)^(-)-P concentration of 100 mg/L and solid-liquid mass ratio of 1∶100,the adsorption capacity is 9.913 mg/g,and the removal rate is 99.13%.

关 键 词：地聚物 碱热活化粉煤灰 层状双金属氢氧化物 除磷性能 

分 类 号：TB332[一般工业技术—材料科学与工程] X703.5[环境科学与工程—环境工程]