Manufacturing Method of Dicalcium Phosphate
Dicalcium phosphate is an important chemical widely used in food, feed, medicine, agriculture and other fields. Its manufacturing methods are mainly as follows:
I. Neutralization method
Neutralization method is the method of reacting phosphoric acid with limestone or calcium hydroxide to produce calcium dihydrogen phosphate and water. The specific steps are as follows:
1. Mix phosphoric acid with limestone or calcium hydroxide in a certain proportion and add it to the reactor.
2. at a certain temperature, carry out a neutralization reaction to generate calcium dihydrogen phosphate and water.
3. Through the process of filtration, washing and drying, the product of calcium dihydrogen phosphate is obtained.
The advantage of the neutralization method is that the process is simple and easy to operate, but the product obtained is less pure and contains more impurities.
Two, crystallization method
Crystallization method is a method to make calcium dihydrogen phosphate crystallize and precipitate from the solution by controlling the temperature, concentration, pH value and other factors of the solution. Specific steps are as follows:
1. Mix phosphoric acid with appropriate amount of water to make phosphoric acid solution.
2. Add an appropriate amount of calcium hydroxide to the phosphoric acid solution and adjust the pH to 2.0-2.5 to saturate the solution with calcium dihydrogen phosphate.
3. Control a certain temperature and concentration, so that calcium dihydrogen phosphate crystals precipitated.
4. Through centrifugal separation, washing, drying and other processes, to obtain calcium dihydrogen phosphate products.
The advantage of the crystallization method is that the product obtained is of higher purity, but the operation is more complex and requires the control of several factors.
Third, ion exchange method
Ion exchange method is the use of ion exchange resin in the ion exchange with the ions in the solution, so as to obtain the method of calcium dihydrogen phosphate. The specific steps are as follows:
1. Pass the phosphoric acid solution through the column equipped with cation exchange resin, so that the hydrogen ions in the solution are exchanged with the metal ions in the resin to generate the corresponding phosphate.
2. the generated phosphate solution is mixed with an appropriate amount of calcium hydroxide solution to generate a calcium dihydrogen phosphate precipitate.
3. Through the processes of filtration, washing and drying, the product of calcium dihydrogen phosphate is obtained.
The advantage of the ion exchange method is that it can obtain products with higher purity, but the investment in equipment is larger and the operating cost is higher.
The above methods have their own advantages and disadvantages, according to the specific production needs and conditions, choose the suitable method for the manufacture of dicalcium phosphate. No matter which method is used, the operating conditions of each process need to be strictly controlled to ensure the quality and yield of the product.
