【作者】 张磊；

【导师】 王青宁；

【作者基本信息】 兰州理工大学 ， 化学工艺， 2009， 硕士

【摘要】 凹凸棒粘土是以一种层链状结构的含水富镁硅酸盐(凹凸棒)为主的粘土矿。由于凹凸棒粘土具有特殊的结构而赋予凹凸棒粘土良好的吸附作用、催化作用、流变性和耐热性,产品广泛应用于石油、化工、建材、造纸、医药、农牧、原子能、太阳能、食品和硅酸盐等工业。本文在综合分析国内外有关凹凸棒粘土文献资料的基础上,将经过改性的凹凸棒粘土作为载体用于合成苹果酯的催化剂,以及首次采用甘肃临泽凹凸棒粘土为原料成功合成出了4A沸石分子筛,既提高了凹凸棒粘土的高层次开发利用,又为沸石分子筛的合成提供了一种来源丰富的新原料。得到如下结论:(1)通过以酸化的凹凸棒粘土为载体,用浸渍法制备了凹凸棒负载磷钨酸催化剂,并采用XRD,IR和紫外分光光度法等手段对催化剂进行了表征。将此用做合成苹果酯的催化剂,考察了反应物的摩尔比、催化剂用量、带水剂用量、反应时间和反应温度等各种因素对苹果酯收率的影响。实验结果表明,凹凸棒负载磷钨酸催化剂催化活性良好,结构稳定且能够重复使用,并得到较佳工艺条件:n(乙酰乙酸乙酯):n(乙二醇)=1:1.5,催化剂用量为2g,带水剂苯为50ml,反应时间为180 min,反应温度为110℃,苹果酯的收率可达到89.7%。(2)凹凸棒粘土因富含有铁等元素限制它的应用。利用超声波的热效应,搅拌作用和强烈振动作用,应用草酸-三氯化钛联合漂白的技术路线,对各地凹凸棒粘土进行除铁漂白。实验结果表明,应用此方法除铁增白效果明显,经除铁增白后的凹凸棒粘土矿反射率可达56.1%,白度可达71.1%。(3)利用除铁增白后的甘肃临泽凹凸棒粘土矿为原料,通过红外,XRD和SEM等分析手段进行分析,可以看出:利用除铁增白后的原生凹凸棒粘土矿可以合成出性能较好的4A分子筛,这就为分子筛的合成提供了一种廉价,无污染的新材料。这不仅拓展了凹凸棒粘土矿的应用领域,而且对于我国特别是西部地区凹凸棒粘土矿产的开发和应用都有积极的意义。更多还原

【Abstract】 Attapulgite is one kind of natural clay mineral,which is hydrated magnesium aluminum silicate with a layer-chain structure (attapulgite).Owing to its properties,such as special crystal structure and superficial character, attapulgite possesses fine adsorptive, catalytic, rheologic, heat resistance capabilities.Its product widely applies to industry and so on petroleum, chemicalindustry, building materials, papermaking, medicine, farming andanimal husbandry, atomic energy, solar energy, food and silicate.Based on lots of comprehensive analysis of the attapulgite literatures, using the attapulgite as the carrier synthesize the catalyst of fructone, and using Gansu attapulgite clay, for the first time , as raw materials successfully synthesizes the 4A Zeolite. The experiment obtains the following conclusion:(1)By using acid-treated attapulgite clay as supporters, attapulgite clay supported phosphotungstic acid catalyst were prepared through impregnation method, and characterized by XRD, IR and UV spectrophotometry. Such catalysts will be used as the catalyst for synthesis of fructone. Influence of molar ratio of ethyl acetoacetate to glycol, the amount of catalyst, the amount of water-carry reagent, the reaction time, the reaction temperature on the esterification was investigated. The experimental results indicated that attapulgite clay supported phosphotungstic acid catalyst had good catalytic activity, structural stability, can be reused. The optimum conditions are: molar ratio of ethyl acetoacetate to glycol is 1:1.5, the amount of catalyst is 2g, the amount of benzene which is water-carry reagent is 50mL, the reaction time is 3h, the reaction temperature is 110℃, and its yield can reach over 89.7%.(2) Attapulgite clay has iron impurities, which greatly restricted the function. Using ultrasound hit, stirring, vibration effects, and oxalic- acid and titanium-chloride joint-bleaching technology, we remove iron and bleach the attapulgite clay, The results showed that this method is effective, and after iron-removing and bleaching attapulgite clay reflectivity can reach 56.1% and the whiteness index can reach 71.1%.(3) Using this attapulgite clay to synthesize Zeolite as material, and tested by IR ,XRD and SEM,we find that attapulgite clay after iron-removing and bleaching can produced Zeolite. Acheap, pollution-free new materials is provided for the synthesis of Zeolite. Using attapulgite for synthesis of zeolite not only has developed the attapulgite application domain, more over, attapulgite minerals in development and application has the positive significance to our country, especially the western.更多还原