【摘要】 稻壳燃烧后的灰分中含硅酸酐和无定形硅达９５％，与萤石粉充分混合，在浓硫酸的作用下生成气态ＳｉＦ４和硫酸钙．ＳｉＦ４经水吸收得固相硅胶和氟硅酸溶液，氟硅酸溶液与食盐作用生成氟硅酸钠和盐酸．因过程中的中间产品为气相，故最终产品的纯度一步可达９９％，收率为６２％．本法对以稻壳为燃料装置中灰渣的利用有很大的意义．更多还原

【Abstract】 The ash, which remains after burning rice husk, contains 95 % silica and amorphous silicon. Mixing the ash with fluorite powder in the presence of concentrated sulfuric acid, gaseous SiF 4 and calcium sulfate were obtained. Solidified silica gel and fluorosilicic acid solution can be prepared by absorption of SiF 4 in aqueous solution. Then the fluorosilicic acid solution reacts with salt to produce sodium fluorosilicate and hydrochloric acid. As the intermediate produced in the process is a gaseous form, so that the purity of sodium fluorosilicate may reach 99 % and the yield is 62 %. This method is significant for the utilization of rice husk ash.更多还原