Monopotassium Phosphate - China

Brief Overview

Monopotassium phosphate is also known as potassium dihydrogen phosphate (KDP), with the chemical formula of KH₂PO₄. KDP is a soluble salt of potassium and dihydrogen phosphate, commonly used as a food additive, fungicide, or fertilizer. It is also recognized as safe by the US Food, Drug, and Administration, making it a safe choice for food additives. KDP is an excellent source of potassium and phosphorus. Its buffer properties make it a suitable chemical for fertilizer mixtures and urea and ammonium phosphate, as it can prevent ammonia from escaping by maintaining a relatively low pH and salt index. KDP does not contain any chlorides or sodium, which are harmful to plants, thus making it an excellent fertilizer for all stages of growth. KDP can be observed to be colorless with a crystalline structure and is easily soluble in water with a melting point of 252.6ºC.

Manufacturing Process

Monopotassium phosphate is produced using phosphoric acid and potassium hydroxide. Alternatively, potassium chloride can replace the more expensive potassium hydroxide. However, the removal of hydrogen chloride has to be done, and they can be expelled through various methods such as ion exchangers, long-chain tertiary amines, or distillation with octanes.

Food Industry

KDP is a food additive to help stabilize and regulate the acidity and moisture in food. Its properties as a buffer allow it to stabilize the pH value and increase the food's ionic strength, thus improving the adhesion of water-holding capacity in food. It is also often used to manufacture flavoring agents, fermentation additives, nutritional fortifiers, yeast food, and baked goods.

Agriculture Industry

KDP is a high-quality fertilizer material in agriculture crops, especially when nitrogen fertilizer is limited. They are sources of phosphorus and potassium for plants, the two main elements necessary for growth and development. Seeds are typically soaked and dressed using acidic potassium phosphate to stimulate growth. After it is dissolved in water, it is applied to the field through an irrigation system or foliar spray. Crops commonly treated by this agrochemical are tobacco, corn, cotton, soybean, and vegetables.    

Other Applications

KDP  is used as a fire retardant for fabric, wood, and paper. KDP can be used for metal surface treatment. They are even used to manufacture metaphosphate in the medical or food industry.