Method for preparing hydrated silicon dioxide

[0027] Example 1:

[0028] Prepare 15% sulfuric acid in advance for use. Put the iron-making quenching slag into an oven and dry it at 120℃ for 90 minutes, remove the adsorbed water on the surface and the pipe, weigh 100g of the slag sample with an analytical balance, and pour it into a 1000ml beaker, and take 850ml of the pre-configured The 15% sulfuric acid solution was slowly poured into the beaker to react with the slag, and continuously stirred with a glass rod, and continuously monitored the temperature change with a mercury thermometer. When the temperature of the reaction system no longer rises, move the beaker to a constant temperature water bath at 70°C to continue the reaction. During the process, use a pH meter to observe the changes in the pH value of the system. When the reaction progresses for 40 minutes, pause the stirring and stand for observation (the pH value of the system is below 1 and is basically stable). If there are no obvious bubbles in the system, the acid hydrolysis process ends. .

[0029] The reaction product was suction filtered and the filter cake was washed 3 times with 80 ml of distilled water. The filtrate was poured into another clean 1000 ml beaker, and then the pH value was adjusted to 3 with NaOH or ammonia water, and the beaker was placed at 95°C. After aging in a constant temperature water bath for 5 hours, the silicic acid in the system has polymerized and gelled. Take out the beaker, pour 300ml of distilled water into the beaker and stir well, let it stand, cool to room temperature, filter, wash the filter cake repeatedly with distilled water until the pH value is equal to 6, then dry and grind the filter cake to obtain the final product hydrated dioxide Silicon SiO 2 ·MH 2 O.

[0030] Example 2:

[0031] Prepare 10% sulfuric acid in advance for use. Put the copper smelting water quenching slag into an oven for drying at 120°C for 90 minutes, remove the adsorbed water on the surface and the pipe, weigh 50g of the slag sample with an analytical balance, and pour it into a 1500ml beaker, take 1200ml of the pre-configured The 10% sulfuric acid solution was slowly poured into the beaker to react with the slag, and continuously stirred with a glass rod. The temperature change was monitored with a mercury thermometer. When the temperature of the reaction system no longer rises, move the beaker to a constant temperature water bath at 70°C to continue the reaction. Use a pH meter to observe the changes in the pH value of the system. When the reaction progresses for 35 minutes, the stirring is suspended and left to stand for observation (the pH of the system is less than 1 and is basically constant). If no obvious bubbles are generated in the system, the acidolysis process ends. The reaction product was filtered with suction and the filter cake was washed with 100 ml of distilled water 3 times, the filtrate was poured into another clean 1500 ml beaker, and the pH value was adjusted to 5.5 with NaOH or ammonia water, and then filtered, and the beaker containing the filtrate was placed Aging in a constant temperature water bath at 95°C for 2 hours, take out the beaker and cool to about 60°C, slowly add concentrated sulfuric acid to the aging system, and wait until the color of the liquid in the system becomes light green and the precipitate is completely white. Stop joining. Let it stand for a period of time until the white matter gathers and settles at the bottom of the beaker, and when the upper part is a clear liquid, perform suction filtration. In the process of suction filtration, add distilled water and repeatedly rinse the filter cake until the pH value is equal to 6, then the filter cake is dried and ground to obtain the final product hydrated silica SiO 2 ·MH 2 O.