Applications of Potassium Dihydrogen Phosphate_Industrial Additives

Overview^[1][2]

Potassium dihydrogen phosphate is colorless tetragonal crystal or white crystalline powder, insoluble in alcohol and deliquescent. It melts into a transparent liquid when heated to ℃, and solidifies into opaque glassy potassium metaphosphate when cooled. It is a commonly used buffer used to maintain the pH value of solutions. China’s national standards for potassium dihydrogen phosphate product quality are:

Apply^[3]

Supplement phosphorus and potassium to regulate the balance of anions and cations of pigment carbon black in animals. Potassium is involved in the regulation of osmotic pressure and acid-base balance, in water balance, nerve impulse conduction, muscle contraction, oxygen and carbon dioxide transport, and as an agonist or cofactor in many enzyme reactions. It plays an important role in cell absorption and protein synthesis, carbohydrate metabolism, and maintaining normal activity of heart and kidney tissues.

Phosphorus is the main component of bones and teeth. It is also the main component of nuclear proteins and various enzymes in animals. It participates in the metabolism of glucose, fat, and protein. When animals are deficient in phosphorus, the deposition of calcium in cartilage is blocked, causing abnormal tooth development, osteoporosis or softening, lack of appetite, heterophilia, paralysis and other diseases.

Preparation^[4]

A preparation method of potassium dihydrogen phosphate, including the following steps:

a. Weigh the raw materials superphosphoric acid, depolymerizing agent and potassium chloride. The raw materials are calculated in parts by weight. Depolymerizing agent: 0.05 to 1.2 parts, superphosphoric acid: 20 to 25 parts, potassium chloride: 14 to 16 parts. Among them, the superphosphoric acid is phosphoric acid containing 68% to 85% P2O5, the depolymerizing agent is water, and the potassium chloride is industrial grade and above potassium chloride. First, add superphosphoric acid and depolymerization agent to the mixing equipment for mixing. When the temperature of the raw materials in the mixing equipment no longer rises, add potassium chloride and stir thoroughly. The mixing equipment includes a stirring device for mixing and a jacket for cooling. , during the mixing process, control the temperature of the raw materials ≤ 60°C, and obtain the mixture after mixing evenly.

b. The reaction evaporation kettle is equipped with a jacket. The heating medium is introduced into the jacket to heat the reaction evaporation kettle. After reaching the required temperature for the reaction, control the reaction temperature to 150~250°C and continuously add the mixture. In the reaction evaporation kettle, control the adding speed of the mixture. The reaction evaporation kettle is equipped with a rake-type adjustable speed stirrer. The added mixture is pushed out from the center of the reaction evaporation kettle to the edge of the annular route, so that the hydrogen chloride gas generated by the reaction evaporates and escapes. out until all the hydrogen chloride gas is evaporated, and the product potassium dihydrogen phosphate is in the reaction evaporation kettle. There is an aggregate device on the edge of the reaction evaporation kettle to collect the product potassium dihydrogen phosphate.

c. The hydrogen chloride gas evaporated from the reaction evaporation kettle is anhydrous hydrogen chloride gas. The hydrogen chloride gas passes through a high-temperature dust collector. The high-temperature dust collector is a high-temperature and corrosion-resistant dry dust removal equipment to remove dust in the hydrogen chloride gas. Potassium dihydrogen phosphate is recycled, and the exhaust hydrogen chloride gas is passed into water or alkali to absorb the exhaust hydrogen chloride gas and produce industrial hydrochloric acid or calcium chloride products. The exhaust gas is discharged after reaching the standard.

d. Collect the product potassium dihydrogen phosphate and dust potassium dihydrogen phosphate. After being cooled by the cooling equipment, they enter the crushing equipment for crushing. Finally, they are graded and packaged to obtain the finished potassium dihydrogen phosphate. The cooling equipment and crushing equipment are all sealed. equipment.

Purification method^[5]

(1) Dissolve crude potassium dihydrogen phosphate powder and chelating agent in ultrapure water; in step (1), the mass of the chelating agent is 0.4% of the mass of ultrapure water.

(2) Heat the above dissolved solution to 90°C to form a saturated potassium dihydrogen phosphate solution.

(3) Let the saturated potassium dihydrogen phosphate solution flow into the filter device to filter impurities larger than 0.1μm in the solution;

(4) The filtered potassium dihydrogen phosphate solution enters the cooling tank for cooling crystallization treatment; in the step (4), the potassium dihydrogen phosphate solution enters the cooling tank and is processed at a speed of 220 rpm Stir. While the cooling tank is being stirred, the cooling tank continues to oscillate.

(5) Pour the potassium dihydrogen phosphate solution in solid solution state after cooling and crystallization into a centrifuge to remove water by centrifugation to obtain potassium dihydrogen phosphate crystals with uniform particles.

(6) Transfer the centrifuged solution to ultrapure aqueous solution for reuse.

(7) Dry the potassium dihydrogen phosphate crystal naturally.

After testing, the impurity content was less than 0.02ppm.

Notes^[3]

Excessive use of this product can cause potassium poisoning. Care should be taken not to exceed the animal’s maximum tolerance of potassium (2% for poultry on a daily basis), and the appropriate ratio of phosphorus and calcium should be considered during use. Dust will be generated during the operation of this product. Excessive inhalation of dust will cause irreversible damage to the human body. Wear a qualified dust mask and pay attention to protection.