After silica gel absorbs water, it can be removed by thermal desorption. There are many heating methods, such as electric furnace, flue waste heat heating and hot air drying. (Relevant little knowledge: the problems that should be paid attention to in the regeneration of silica gel and the method of storage and packaging). The temperature for removing the additional heat should be controlled at 120-180℃. For blue gel indicator, discoloration silica gel, and DL-type blue silica gel, the temperature should be controlled at 100-120℃. The maximum temperature during regeneration of various industrial silica gels should not exceed the following limits:
The coarse-pored silica gel shall not be higher than 600℃;
The fine-pored silica gel shall not be higher than 200℃;
Blue glue indicator agent (or discoloration silica gel) shall not be higher than 120℃;
The silica-alumina glue shall not be higher than 350°C.
After the regenerated silica gel, its moisture content is generally controlled below 2% before it can be put into use again.