Silica Gel Desiccant is a highly active adsorption material, which is widely used in food, medicine, instrumentation, leather clothing and other fields. So what is the production method of silica gel desiccant?

1. Preparation

1. Equipment: 4 beakers (1 liter), glass rod, water bath, electric constant temperature drying oven, test tube, medicine spoon, measuring cylinder (10 ml), balance, rubber tube.

2. Drugs and materials: silicic acid hydrogel, cobalt chloride, distilled water.

2. How to obtain Silica Gel Desiccant

1. Divide the silicic acid hydrogel obtained in the above experiment into 4 parts, add them to 4 beakers respectively, add about 1 liter of distilled water to each, and add water while stirring with a glass array. It was then left to stand for 12 hours to allow the gel to settle. Do not shake the beaker while standing. The supernatant was sucked out by siphoning. Repeat the same operation three times to remove the sodium ions and chloride ions contained in the gel.

2. After discarding the supernatant, put the beaker together with the remaining gel in a water bath to dry. Then it was transferred to an electric constant temperature drying oven and kept at 120° C. for several hours to make it dry. During the drying process, the gel should be constantly turned to make it into a boron block of several millimeters to 2 centimeters. After solidification, it will leave the bottom of the beaker. Squeeze the solid block with a glass rod, and it is easy to obtain particles of the required size.

Through the above operations, about 18 grams of pure white silica gel can be obtained.

3. The silicic acid xerogel used as Silica Gel Desiccant (commercially called silica gel) is made by soaking in cobalt chloride solution and then drying, so it shows the blue color of anhydrous cobalt chloride. It is desirable to dissolve 0.5 g of cobalt chloride in 10 ml of distilled water. Before transferring to a water bath for drying according to method (2), add it to a beaker (one of the four beakers), stir it with a glass rod, and then mix it with the other beakers. Dry the gel together.