7320-34-5

Usage

Uses

Used in Detergent Industry:
Potassium pyrophosphate is used as a soap and detergent builder, sequestering agent, peptizing and dispersing agent. It enhances the cleaning efficiency of detergents and helps in preventing the re-deposition of dirt and minerals.
Used in Herbicidal Compositions:
In agriculture, potassium pyrophosphate is used as a spray adjuvant in herbicidal compositions, improving the effectiveness of herbicides and ensuring even distribution.
Used in Electroplating Industry:
Potassium pyrophosphate is used as a complexing agent in non-cyanide electroplating, replacing the hazardous sodium cyanide. It also serves as a plating pretreatment agent and a component of pyrophosphate plating solutions.
Used in Ceramic Industry:
In the ceramic industry, potassium pyrophosphate acts as a clay dispersant, improving the processing and quality of ceramic products.
Used in Dyeing and Bleaching Industry:
Potassium pyrophosphate is used for the removal of small amounts of ferric ions in water, which improves the quality of dyeing and bleaching processes.
Used in Food Industry:
Potassium pyrophosphate is used as an emulsifier, texturizing agent, and chelating agent in the food industry. It helps in preventing the generation of struvite in canned fish, discoloration of canned fruit, increasing the swelling degree of ice cream, enhancing the extraction of coffee raw materials, and improving the water-holding capacity of fish. It also aids in improving the taste and yield of noodles, and preventing the aging of cheese.
Used in Analysis and Stabilization:
Potassium pyrophosphate can be used as an analysis agent and a stabilizer for hydrogen peroxide, as well as a filler in soap formulations.

Identification test

Solubility: easily soluble in water but insoluble in ethanol; use (OT-42) method for the determination. Take 1 mL of 1% sample solution and add silver nitrate test solution (TS-2l0)

Content Analysis

Accurately weigh 600 mg of sample for being dissolved in 100 mL water contained in 400ml beaker with hydrochloric acid and pH meter for adjusting the pH of the solution to accurately 3.8. Add 50 mL of 12.5% zinc sulfate solution (125g ZnSO4 7H2O is dissolved in water and be diluted to 1000ml; filter, adjust to pH3.8) and place for 2min. Use 0.1mol/L sodium hydroxide for titrating free acid to pH3.8. Upon being close to the end, after each addition of sodium hydroxide, we should wait for the precipitation of zinc hydroxide before further dissolution. Each ml of 0.1 mol/L sodium is equivalent to 16.52 mg of potassium pyrophosphate (K4P2O7).

Toxicity

ADI 0~70mg/k (the total amount of phosphorus calculated from phosphate; FAO/WHO, 2001). It may cause kidney stones in large doses. Adl 0~70 mg/kg (in terms of phosphorus); According to the provision of the FAO/WHO (1984): for the processed cheese, the total phosphate is 9 g/kg (in terms of phosphorus); luncheon meat: 3 g/kg (base on P2 () 5 meter); frozen shrimp or prawns: 5 g/kg (based on P2 () 5 meter); cooked meat 3 g/kg (based on anhydrous matter).

Limited use

GB 2760-96: Meat 1g/kg; fruit and vegetable peeling GMP. FAO/WHO (1984:, g/kg): instant broth, soup, total phosphate: 1000mg/kg (in term of P2O5); total phosphate of processed cheese: 9 (in terms of phosphorus); luncheon meat: 3 (in term of P2O5); quick-freeze weever, perch, plaice, Atlantic cod, haddock, hake, shrimp or prawn: 5 (in term of P2O5); cooked pig toreshank , cooked ham, and cooked minced meat: 3 (based on anhydrous matter).

Production method

1. The neutralization and calcination method( the ratio of usage amount of raw materials is 1 mol of phosphate and 2 mol of potassium hydroxide): add 30% food-grade phosphoric acid into the neutralizer and the slowly stir and add food grade potassium hydroxide solution for neutralizing reaction for which the pH is suitable for maintained at 8.4; Heat the solution after the completion of the reaction and further add active carbon for decolorization; filter to remove the insoluble matters and the clarified filtrate was further heated to 120~124 ℃ for evaporative concentration; the precipitate will be separated out after cooling to below 20 ℃; centrifuge for separation to obtain trihydrate-di-potassium phosphate and heat to 120~130 ℃ for removing crystal water to generate anhydrous di-potassium hydrogen phosphate; add it to a calciner for being calcined at 500~600 ℃ for polymerization and the edible potassium pyrophosphate is obtained after cooling. The reaction process is as following: H3PO4 + 2KOH → K2HPO4 + 2H2O 2K2HPO4 [△] → K4P2O7 + H2O Have the resulting finished products of potassium pyrophosphate reacted with 0.1 mol/L silver nitrate, and when the reaction solution yields no orthophosphate precipitate of yellow color, the product is qualified. 2. Put 203 kg of potassium hydroxide into the dissolving tank; add water to generate a 48% aqueous potassium hydroxide solution. Put it into the kettle and stir and slowly add drop wise of 85% phosphoric acid for salting reaction. When the added phosphoric acid reaches 100 kg, take one drop of liquid material and add to the white porcelain plate; further add 1 drop of water for dilution and measure the pH using accurate test paper. Stop dropping phosphoric acid when the pH reaches 8.5 to 9.0. Continue for stirring for 0.5 h, stand, and remove the impurities by filtration. The filtrate was then transferred to vaporize pan for concentration; after reaching the glue dry state, it was further transferred to a coking furnace and subject to coking process at 550~650 ℃. After 2 to 3 hour of coking, sampling for measuring the end point (check with 1% silver nitrate solution to until no yellow silver orthophosphate appears). After the completion of the reaction, cool, crystallize to obtain the finished products.

Air & Water Reactions

Soluble in water.

Reactivity Profile

Salts, basic, such as POTASSIUM TETRAPYRO PHOSPHATE, are generally soluble in water. The resulting solutions contain moderate concentrations of hydroxide ions and have pH's greater than 7.0. They react as bases to neutralize acids. These neutralizations generate heat, but less or far less than is generated by neutralization of the bases in reactivity group 10 (Bases) and the neutralization of amines. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible.

Health Hazard

Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways.

InChI:InChI=1/4K.H4O7P2/c;;;;1-8(2,3)7-9(4,5)6/h;;;;(H2,1,2,3)(H2,4,5,6)/q4*+1;/p-4