The processed products with silica gel as the main raw material are called silicone products. Silica gel is a porous substance with different particle sizes that is properly dehydrated from silicic acid gel. With an open porous structure, it can adsorb many substances and is a good desiccant, adsorbent and catalyst carrier. The adsorption of silica gel is mainly physical adsorption, which can be regenerated and used repeatedly. Add acid to alkali metal silicate (such as sodium silicate) solution to make it acidified, and then add a certain amount of electrolyte for stirring, that is, to generate silicic acid gel; or add acid or acid to a relatively concentrated sodium silicate solution Ammonium salts can also generate silicic acid gels. The silicic acid gel is left standing for several hours to make it aged, then washed with hot water to remove soluble salts, dried at 60~70 °C and activated at about 300 °C to obtain silica gel. The silicic acid gel is soaked in cobalt chloride solution and then dried and activated to obtain discolored silica gel.
Food-grade silica gel is non-toxic and tasteless, insoluble in water and any solvent, and is a highly active green product. Food-grade silica gel has inherent thermal stability (-40℃-230℃). It is suitable for different occasions. The product has good softness to meet different needs.