Study On New Technology Of Preparation Nano-SiO₂ Using Rice Husk

In this article,a certain production application values and the future development new technology for the preparation of high-purity nano-silicon dioxide using rice husk is explored.The rule of law burning is employed to pre-process rice husk to get rice husk ash,and atmospheric water glass-reaction process is used to improve chemical precipitation Nano—silicon dioxide.Factors such as hydrochloric acid soaking time,the combustion temperature,time factors etc.on the effects of the process of burning of rice husk to rice husk ash,and the ratio of sodiμm hydroxide, sodiμm hydroxide solution and rice husk ash reaction time on the preparation of water glass are explored.It also explores the factors of surfactants,additives,the reaction pH,temperature,reaction time,concentration of sodiμm silicate,the concentration of sulfuric acid,acid pH,ripening condition and so on,on the preparation of nano-silica through the reaction of sulfuric acid and water glass. Experiments demonstrate that:the optimμm conditions for the preparation of rice husk of rice husk ash are as follows:1.1 percent of the hydrochloric acid soaking 24h, the combustion temperature 550℃,burning time 4.5h.Rice husk ash and water glass sodiμm hydroxide solution prepared in the best conditions are as follows:rice husk ash in the silicon dioxide with sodiμm hydroxide volμme of 2.5 molar ratio,reaction time 4.5～5h.Through orthogonal water glass to identify the best preparation of silicon dioxide nano-technology conditions are as follows:reaction pH 8.5,the concentration of sodiμm silicate 0.30mol/l,sulfuric acid concentration of 0.5mol/l, additives NaCl concentration 1.0mol/l,reaction Time for 50min,the reaction temperature is 50℃,acid pH value of 4.5.Surfactant selects SDBS and Sodiμm polyacrylate to compound.Ripening temperature of 90℃,aging time of 1h. Experiments also discussed the mechanism of the process.Transmission electron microscopy(TEM),specific surface area test(BET),X-ray diffraction(XRD),and the size distribution instrμment thermogravimetry analyzer(TG),and so on are employed to characterize the product performance.The results show that:the silicon dioxide prepared under the optimμm conditions are nano-for amorphous and have an uniform particle size;the size distribution is 50～100nm,with an average size D₅₀ to 72nm,the treated surface area is 456.32m2/g,whiteness is 94.6,and the content of silicon dioxide(dry basis) is 98.6 percent.