The alkali metal explosion cleaning process, also known as high temperature alkali metal explosion, its basic working principle is: put the casting into a caustic soda solution with a temperature of 750-800℃ and a mass concentration of 90%-95%. When sand and caustic soda form a molten glass-like substance, there will be residue on the surface of the casting, then the casting is quickly placed in water. At this time, due to the violent chemical reaction, the surface of the casting will produce high-pressure steam and explode, so that the shell on the surface of the casting is cleaned up. The alkali explosion cleaning process is especially suitable for cleaning the surface residual sand of metal castings with deep holes, small holes, and complex cavities.
Operation Process of Alkali Metal Explosion Cleaning Process:1. Preheat the casting while heating the lye.
2. When the lye temperature reaches 700°C or higher, put the preheated castings into the lye.
3. The casting should be kept at a temperature above 700℃ for about 20 minutes (depending on the size of the casting and the amount of residual sand to determine the time).
4. Take out the casting, drain the lye, and quickly put it into the pool to explode.
5. Circulate the preheated castings into the lye.
6. Put the alkali-exploded castings into the hydrochloric acid bath, neutralize them, and then wash them with water.
7. Clean up the residual sand in the lye from time to time to ensure the quality of the lye.
Features of Alkali Metal Explosion Cleaning:1. It is easy to clean the deep hole of the casting and the residual sand in the complex cavity.
2. Alkali explosion is more efficient than alkaline boiling process for cleaning castings.
3. Due to the irritating effect of caustic soda vapor, alkali explosion cleaning is very corrosive to equipment. Therefore, environmental protection measures need to be strengthened in the alkaline explosion process.
4. Due to the need to consume a large amount of caustic soda, the cost of the alkaline explosion cleaning process is much higher than other processes.
Precautions for Alkali Metal Explosion Cleaning Process:1. Operators must dress safely, wear masks, glasses, and face shields, and do not expose their skin to the outside when operating an alkali explosion.
2. All operating utensils and tools must be preheated. Cold and damp tools are strictly prohibited from entering the lye, causing an explosion and the lye splashing and hurting people.
3. When the crucible leaks, don't panic and take measures in time.
4. Strictly achieve safe production and environmentally friendly production.