硅渣土中硅的提取及白炭黑制备的实验研究

发布时间：2018-03-15 03:26

本文选题：硅渣土　切入点：二氧化硅　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：硅渣土是铝土矿与硫酸在加压条件下生成水处理剂(A12(SO4)3)时产生的固体废弃物。目前,硅渣土主要用于水泥、瓷砖的生产,产品品质低,且用量有限,大部分以废渣堆集,既浪费资源,又污染环境。硅渣土富含硅和少量铝及钛等元素,可用于生产含硅产品。本文通过采用活化剂-Na2C03在高温下焙烧活化原料,然后用水浸出,并以此浸出液为原料采用硫酸沉淀法制备白炭黑产品,开发了一条处理硅渣土的新工艺。硅渣土焙烧-浸出的最佳工艺条件为:焙烧温度800 ℃,活化剂-Na2C03加入量35 g,焙烧时间20 min,液固比7:1,浸出温度90 ℃,浸出时间1.5 h,搅拌速度300r/min,洗液体积30ml/次,Si02的溶出率达到79.13%,A1203的溶出率仅为8.24%,Ti02的溶出率为47.95%。采用响应曲面法拟合二氧化硅溶出率的二阶响应曲面模型精确合理,能够用于硅渣土中二氧化硅溶出率的分析和预测,且焙烧温度..无水碳酸钠量和浸出温度对二氧化硅溶出率交互影响非常显著。综合考虑二氧化硅溶出率和成本,确定二氧化硅溶出率的工艺参数优化结果:焙烧温度为850 ℃附近,无水碳酸钠35 g附近,浸出温度90 ℃附近。进一步验证了浸出原料的工艺条件。以浸出最佳工艺条件下得到的浸出液为原料,采用硫酸沉淀法制备白炭黑产品,其最佳工艺条件为:反应温度80 ℃,体系终点pH值=4,反应时间1.0 h,煅烧温度为700 ℃,煅烧时间30 min,搅拌速度为200r/min。所得产品采用FTIR、XRD、BET、SEM、SEM-EDS、XPS等方法进行了表征。定性和定量分析结果表明,所制备的产品确实为白炭黑,产品纯度95.07%,白度92.90%,比表面积29.38 m2/g,孔容 0.36 m3/g,平均孔径 31.05 nm。本论文采用碱性焙烧,用水浸出硅渣土,经制备、洗涤、干燥、煅烧等工艺处理,得到了纯度高的市场需求量大的白炭黑产品,论文在原料浸出工艺技术和产品选取硅源具有创新性。本课题属于固体废弃物资源循环再利用技术,可解决水处理剂生产企业的废物处理问题,具有明显的社会价值和经济效益。
[Abstract]:Silicon is muck with sulfuric acid to produce water in bauxite under conditions of high pressure treatment agent (A12 (SO4) 3) solid waste generated. At present, the silicon residue is mainly used for cement, ceramic tile production, product quality is low, and the amount is limited, most of the waste collection, waste of resources, but also pollutes the environment. The silicon rich muck a small amount of silicon and aluminum and titanium elements, can be used in the production of silicone products. Through the use of activator -Na2C03 in high temperature roasting activation of raw materials, and then water leaching, and the leaching solution for preparing silica products prepared by sulfuric acid precipitation method, a new process has been developed to deal with silicon. The optimum conditions of silicon muck muck roasting leaching for roasting temperature of 800 DEG C, -Na2C03 activator dosage 35 g, calcination time 20 min, solid-liquid ratio 7:1, extraction temperature 90, leaching time of 1.5 h, stirring speed 300r/min, fluid volume 30ml/ times, Si02 dissolution rate reached 79. 13%, A1203 dissolution rate was only 8.24%, Ti02 dissolution rate of 47.95%. by response surface method fitting silica two order response surface model is accurate and reasonable rate of dissolution, can be used to analyze and predict the dissolution rate of silica slag, and the calcination temperature. Anhydrous sodium carbonate and leaching temperature on the silica dissolution the rate of interaction is very significant. Considering the dissolution rate of silica and cost, to determine the optimal results of parameters of dissolution rate of silica: calcination temperature near 850 DEG C, anhydrous sodium carbonate near 35 g, near the leaching temperature of 90 DEG C. Further verify the technological conditions of leaching materials. The leaching liquid obtained in the optimum process the leaching conditions by using sulfuric acid as raw materials, preparation of silica precipitation method, the optimum conditions were: reaction temperature is 80 DEG C, the system end point pH value =4, the reaction time is 1 h, the calcination temperature is 700 DEG C, calcination 30 min, stirring speed is 200r/min. the product by FTIR, XRD, BET, SEM, SEM-EDS, XPS and other methods were investigated. The qualitative and quantitative analysis results show that the prepared product is white carbon black, 95.07% purity, whiteness 92.90%, specific surface area of 29.38 m2/g, pore volume of 0.36 m3/g. The average pore size of 31.05 nm. using the alkaline roasting water leaching silicon dregs, the preparation, washing, drying, calcining process, the high purity of the market demand of the silica products, paper has innovation in raw material leaching technology and product selection of silicon source. The project belongs to the resources recycling of solid waste reuse technology can solve the problem of waste treatment, water treatment agent production enterprises, has obvious social value and economic benefits.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.2

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