Silica gel products are not unfamiliar to everyone, medical or baby products, life of silica gel products are more and more small gifts, so the demand for silica gel also increases, Honglin silica gel brings you more into the cognition of silica gel, the regeneration of silica gel is divided into the regeneration after adsorbing organic impurities and after water absorption:
I. Regeneration of silica gel after adsorption of organic impurities can be divided into the following categories:
1. Roasting method
For the silica gel with coarse holes, it can be heated to 500-600 ℃ gradually in the calciner, and the colloidal particles will be white or tan after 6-8 hours. For the silica gel with fine holes, the roasting temperature should not exceed 200℃.
2. Rinse method
The silica gel will be absorbed in saturated water vapor and then soaked and rinsed in exothermalized water. It can be combined with detergent to remove waste oil or other organic impurities, and then dried and dehydrated after washing with purified water.
3. Solvent washing method
According to the organics adsorbed by silica gel, appropriate solvents are selected to dissolve the organics adsorbed in silica gel, and then the silica gel is heated to remove the solvent.
Ii. Regeneration of silica gel after water absorption
After silica gel absorbs water, it can be removed by means of thermal desorption. There are various heating methods, such as electric heating furnace, flue waste heat heating and hot air drying. Desorption heating temperature should be controlled at 120--180℃, and blue adhesive indicator, color-changing silica gel, and blue silica gel should be controlled at 100--120℃. The maximum temperature for the regeneration of all industrial silica gel shall not exceed the following limits:
Coarse hole silica gel shall not be higher than 600℃;
Fine hole silica gel shall not be higher than 200℃;
Blue glue index agent (or color-changing silica gel) shall not be higher than 120℃;
Silica and aluminum adhesive shall not be higher than 350℃.
After the regeneration of silica gel, its water control generally under 2% can be put back into use.