Potassium hydroxide is widely used in chemical industry because of its strong alkalinity and corrosiveness. It can also be used as a variety of reagents in different fields, such as desiccant, absorbent, refractory adhesive, etc. So, let's take a look at the preparation method of its refractory adhesive.
1. Development of refractory adhesive
① Preparation method of refractory liquid: 8kg granular potassium hydroxide, 7kg powdered sodium carbonate (soda) (Asahi nitrate company), 30kg metal silicide and 60L water are successively added into the reaction tank. In the reaction tank, the natural reaction starts, the violent reaction starts from the lower product, and the convection occurs from the lower part to the upper part. When the reaction temperature is between 80 ℃ and 90 ℃, the reaction is active. The reaction temperature is not higher than 92 ℃. About 48l (70kg) of refractory liquid can be obtained by solid separation.
The residual solid is metal silicide. If washed with water, about 22 kg of metal silicide remains. In the residual metal silicide block, about 8 kg of metal silicide block is added, and the total amount of metal silicide is 30 kg, which is supplied to the secondary reaction.
Similar to the initial reaction, 8kg granular sodium carbonate and 7kg powdered sodium carbonate (soda) (produced by Xuni subsidiary) were added to the reaction tank, then 22kg residual metal silicide block and 8kg new metal silicide block were added in turn, and 60L water was added to start the secondary reaction of preparing refractory liquid. In the preparation process, according to the order of adding granular potassium hydroxide, then adding powdered sodium carbonate (soda), then adding metal silicide block, and then adding water, the reaction starts from the lower product, forming the up-down convection type active reaction, so the prepared refractory liquid has better performance.
② Preparation of refractory adhesive: add refractory liquid, cut old newspaper (other old newspaper can also be used), rice husk and cotton into the reaction tank, mix them evenly to make refractory material.
2. If coated with fire-resistant liquid, the paperboard coated with fire-resistant liquid will not burn after burning for 30 minutes under a flame close to 1000 ℃. The refractory adhesive mixture was dehydrated to 45% water content under pressure, and the lightweight refractory was prepared at 180 ℃ for 1 h. The refractories were observed at 1500 ℃ for 30 minutes. After 10 minutes, the refractory surface vitrified. After burning for 30 minutes, the refractory is cut. The depth of vitrification was only 0.8 mm, and the fire did not enter the refractory. In addition, refractories have good sound insulation and impact resistance. It can cut, saw, nail, screw and other processing performance is similar to wood.