酸化沉淀法制取二氧化硅抗结剂

Abstract

SiO2抗结剂是一种白色蓬松粉末，能解决产品因吸潮受压形成的结块，同时具有吸附作用，吸湿或易从空气中吸收水分。主要被添加于颗粒、粉末状食品中防止颗粒或粉末食品的聚集结块，保持其松散或自由流动。本研究以水玻璃和硫酸为原料，在硫酸钠无机盐溶液中，在磁场作用下用酸化沉淀法制备二氧化硅抗结剂，控制反应的pH值为7~8，研究在不同温度下制得的SiO2抗结剂的收得率和粒度。结果表明，随着温度的升高，SiO2抗结剂的收得率逐渐增加，50℃时收得率仅为62.3%，温度达到90℃时，收得率达到87.2%；随着温度的升高，SiO2抗结剂的粒度增大，为了满足抗结剂粒度2~9 μm的要求，SiO2抗结剂的制备温度不宜超过70℃。 SiO2 anticaking agent is a kind of white fluffy powder, which can prevent the product from forming caking due to moisture absorption or pressure, and easy to absorb moisture from the air because of its adsorption. SiO2 anticaking agent is mainly added to particles and powder food to prevent particles or powder food aggregation, agglomeration, and maintain its loose or free flowing. In this study, sodium silicate and sulfuric acid were used as raw materials, SiO2 was prepared by acid precipitation under the action of magnetic field in sodium sulfate inorganic solution, the pH value of solution retained at 7 - 8, and the yield and grain size of the SiO2 anticaking agent at different temperatures were studied. The results showed that with the increase of temperature, the yield of SiO2 anticaking agent gradually increased, the yield is only 62.3% at 50˚C, and it reached to 87.2% at 90˚C; furthermore, with the increase of temperature, the particle size of SiO2 anticaking agent increased, and the particle size of the anticaking agent is 2 - 9 μm. In order to meet this requirement, the preparation temperature of the SiO2 should not exceed 70˚C.