Manufacturing method of heavy soda ash
I. INTRODUCTION
Heavy soda ash is an important raw material for the production of chemicals, which is widely used in many fields, such as glass, soap, detergents, food and so on. In order to meet the demand for heavy soda ash in different fields, it is of great significance to study its manufacturing method. In this paper, the manufacturing methods of heavy soda ash will be introduced in detail, including ammonia alkali method, combined alkali method and natural alkali processing method.
II. Ammonia-alkali method
Ammonia-alkali method, also known as Solvay method, is the main method of producing heavy soda ash in the world at present. This method takes table salt, limestone and coke as raw materials, and produces heavy soda ash through calcination, absorption, carbonization, filtration, calcination and other processes. The specific steps are as follows:
1. Calcination: Calcine limestone into quicklime, and then react with raw water to produce slaked lime.
2. Absorption: Saline water is mixed with ammonia and carbon dioxide is passed through to produce sodium bicarbonate and ammonium chloride.
3. Carbonation: Sodium bicarbonate is crystallized and separated by centrifugation to obtain a sodium bicarbonate product.
4. Filtration: the ammonium chloride solution is filtered to obtain the ammonium chloride product.
5. Calcination: Sodium bicarbonate is heated and decomposed in a calciner to produce heavy soda ash and carbon dioxide.
3. Combined alkali production method
The combined alkali production method, also known as Hou's alkali production method, was founded by Mr. Hou Debang, a famous Chinese chemist. This method combines the ammonia-alkali method and ammonia synthesis process, realizes the recycling of sodium chloride and carbon dioxide, and reduces energy consumption and production cost. The specific steps are as follows:
1. Absorption: ammonia and carbon dioxide are passed into brine to produce sodium bicarbonate and ammonium chloride.
2. Carbonization: Sodium bicarbonate is crystallized and separated by centrifugation to obtain sodium bicarbonate product.
3. Filtration: the ammonium chloride solution is filtered to obtain the ammonium chloride product.
4. Decomposition: Sodium bicarbonate is decomposed by heating in a calciner to produce heavy soda ash and carbon dioxide.
5. Synthesis: Carbon dioxide and ammonia are reacted in a synthesis tower to produce urea and water.
6. Recycling: The water is returned to the absorption process and recycled; the urea is recycled as a by-product.
Four, natural alkali processing method
Natural alkali processing method is the method of using natural alkali ore resources to produce heavy soda ash. Natural alkali ore is rich in sodium carbonate and sodium bicarbonate, after mining, crushing, dissolution, filtration, evaporation and other processes, you can make heavy soda ash. The specific steps are as follows:
1. extraction: extract the natural alkali ore by mining equipment.
2. Crushing: The extracted natural alkali ore is crushed into ores with certain particle size.
3. Dissolving: The crushed ore is added to water and dissolved to produce a mixed solution of sodium carbonate and sodium bicarbonate.
4. Filtration: The mixed solution is filtered to remove insoluble impurities.
5. Evaporation: the filtered solution is evaporated to precipitate heavy soda ash.
V. Conclusion
The main methods of manufacturing heavy soda ash are ammonia alkali method, combined alkali production method and natural alkali processing method. Different methods have different advantages and disadvantages and scope of application, so choose the suitable method for production according to the actual situation. At the same time, attention needs to be paid to safety, environmental protection and quality in the production process to ensure the quality and efficiency of the product.
