Preparation of ultrafine silica from potash feldspar using sodium carbonate roasting technology

作     者：Jia-nan Liu Xiao-yi Shen Yan Wu Jun Zhang Yu-chun Zhai 

作者机构：School of Metallurgy Northeastern University School of Resources and Materials Northeastern University at Qinhuangdao 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2016年第23卷第8期

页      面：966-975页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 

基　　金：financially supported by the National Nature Science Foundation of China (No. 51204054) the National Basic Research Program of China (No. 2007CB613603) the Basic Scientific Research Business Expenses Project of the Ministry of Education (No. 140204011) 

主　　题：potash feldspar sodium carbonate roasting silica optimization 

摘      要：A novel process was developed for the preparation of ultrafine silica from potash feldspar. In the first step, potash feldspar was roasted with Na_2CO_3 and was followed by leaching using Na OH solution to increase the levels of potassium, sodium, and aluminum in the solid residue. The leaching solution was then carbonated to yield ultrafine silica. The optimized reaction conditions in the roasting process were as follows： an Na_2CO_3-to-potash feldspar molar ratio of 1.1, a reaction temperature of 875°C, and a reaction time of 1.5 h. Under these conditions, the extraction rate of SiO_2 was 98.13%. The optimized carbonation conditions included a final solution p H value of 9.0, a temperature of 40°C, a CO_2 flow rate of 6 m L/min, a stirring intensity of 600 r/min, and an ethanol-to-water volume ratio of 1：9. The precipitation rate and granularity of the SiO_2 particles were 99.63% and 200 nm, respectively. We confirmed the quality of the obtained ultrafine silica by comparing the recorded indexes with those specified in Chinese National Standard GB 25576―2010.