We unleash your business potential by maximize the business innovation.
Send EmailE450, Tetrapotassium Pyrophosphate, Tetra Kalium Pyro Phosphat, Potassium Pyrophospate Trihydrate, Potassium Diphosphate, 7320-34-5
CAS: 7320-34-5
Molecular Formula: K4O7P2
Names and Identifiers
Physico-chemical Properties
| Molecular Formula | K4O7P2 |
| Molar Mass | 330.336522 |
| Density | 2.33 |
| Melting Point | 1300 °C (lit.) |
| Water Solubility | SOLUBLE |
| Solubility | It is easily soluble in water, the solution is alkaline, insoluble in alcohol, and loses two molecules of crystal water when heated to 180 ℃, and completely loses water when it reaches 300 ℃. The solubility in 100g of water at 25°C is 187g. |
| Vapor Presure | 0Pa at 20℃ |
| Appearance | White crystalline powder |
| Color | White |
| Odor | Odorless |
| Merck | 14,7663 |
| PH | pH (40g/l, 25℃) : 10.0～11.0 |
| Storage Condition | Room Temprature |
| Sensitive | Hygroscopic |
| MDL | MFCD00011393 |
| Physical and Chemical Properties | Character white powder or block. melting point 1109 ℃ relative density 2.534 solubility: soluble in water, insoluble in ethanol. The aqueous solution is alkaline. The solubility of 100g in water at 25 C is 187g. |
| Use | For non-cyanide plating, dyeing, refined clay, etc |
Risk and Safety
| Hazard Symbols | Xi - Irritant |
| Risk Codes | R36/37/38 - Irritating to eyes, respiratory system and skin. R36 - Irritating to the eyes |
| Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. S22 - Do not breathe dust. |
| WGK Germany | 2 |
| RTECS | JL6735000 |
| TSCA | Yes |
| HS Code | 28353990 |
| Toxicity | LD50 skin in rabbit: > 4640mg/kg |
Upstream Downstream Industry
| Raw Materials | Phosphoric acid Potassium hydroxide Potassium carbonate |
Preparation
neutralization calcination method food-grade 30% phosphoric acid is added to the neutralizer, and food-grade caustic potash solution is slowly added under stirring for neutralization reaction. It is advisable to control the pH value at 8.4, and heat the solution after the reaction, add activated carbon to decolorize, filter to remove insoluble matter, clarify the filtrate is heated to 120~124 ℃ for evaporation and concentration, after cooling to 20 ℃ or less, precipitate crystals, and centrifuge to obtain dipotassium hydrogen phosphate trihydrate, the decrystallized water was heated to 120-130 ° C. To become anhydrous dipotassium hydrogen phosphate, which was added to a calciner to carry out calcination polymerization at 500-600 ° C. And cooled to obtain a finished edible potassium pyrophosphate. When the prepared potassium pyrophosphate product is reacted with 0.1 mol/L silver nitrate solution, it is qualified that no yellow precipitate of Silver orthophosphate appears.
Nature
white powder. Melting point 1109 ℃, relative density 2. 534. Easy moisture absorption and deliquescence, soluble in water insoluble in ethanol, aqueous solution is alkaline. 1009 dissolved in 1879 water at 25 ℃, can chelate with alkaline earth metal and heavy metal ions.
Preparation Method
obtained by melting and losing water molecules of Dipotassium hydrogen phosphate.
Introduction
Easy deliquescence, concentration of 1% aqueous solution pH = 10 · 2. Potassium pyrophosphate has all the properties of other condensed phosphates.
Use
It is mainly used for cyanide-free electroplating, instead of sodium cyanide as a complexing agent for electroplating, and is also a pre-treatment agent for electroplating. It is used as a dispersant for ceramics, clay, latex, pigment and metal surface cleaning agent. The bleaching and dyeing industry is used to remove a small amount of ferric ions from water to improve the quality of bleaching and dyeing.
Product Description
potassium pyrophosphate, also known as tetrapotassium pyrophosphate, is a white powder or bulk solid. The relative density was 2.534. Melting point 1109°C. Soluble in water, solubility 187g/100g water (25°C). The aqueous solution is alkaline, 1% aqueous solution pH = 10.2. Insoluble in ethanol. Properties similar to other polyphosphates.
by dipotassium hydrogen phosphate melting loss of water molecules and prepared at room temperature for white crystalline powder or granules, in the air has a strong hygroscopicity, easily soluble in water, but insoluble in ethanol, the aqueous solution is alkaline, which has the effect of inhibiting food spoilage and fermentation. The pH value of 1% aqueous solution is about 10.5, and the solubility of potassium pyrophosphate in 100g water at 25 ° C is 187g, in an acid or alkaline solution, water is hydrolyzed to potassium phosphate, which is mixed with water to form a viscous slurry. Combined with other condensed phosphate, such as potassium pyrophosphate 10%, sodium pyrophosphate 10%, potassium polyphosphate 30%, Sodium polyphosphate 30%, sodium metaphosphate 20% ratio made of ham, sausage Binder, usually used to prevent the production of aquatic canned struvite stone, to prevent the color of canned fruit, to improve the degree of expansion of ice cream, coffee raw material extraction, ham, sausage yield, enhance the water holding capacity of fish, to improve the taste of noodles and improve the yield, prevent cheese aging, in order to make the plating layer smooth and firm, the formula of the plating solution in industrial production is often very complex. Cyanide has previously been used as a complexing agent to formulate plating solutions. However, due to the highly toxic CN-, the health of electroplating workers is very harmful, at the same time, the discharge of CN-containing sewage, waste gas also seriously polluted the environment. Therefore, cyanide-free plating is now mainly used for electroplating, and the complexing agent for replacing cyanide is potassium pyrophosphate.
potassium pyrophosphate has all the properties of other polymeric phosphates, similar to sodium pyrophosphate, but the solubility is larger, and can chelate with alkaline earth metals and heavy metal ions; It can interact with Ca2 + in hard water, mg2 + forms a stable complex to soften hard water, improve washing ability, and remove soil. Can also form a protective film on the surface of iron, lead, zinc, aluminum and other metals; Pyrophosphate ion (P2O74-) has a strong dispersion ability for fine dispersed solids, can promote fine, homogeneous mixing of trace amounts of substances. High purity and low iron potassium pyrophosphate has a stable pH buffer capacity, and can maintain the pH value of the solution for a long time.
Technical requirements
1. Appearance: white powder or block
2. Industrial potassium pyrophosphate shall meet the requirements of Table 1 (ZB/TG12006-88)
Project indicators
First-class product
Potassium pyrophosphate (K4P2O7) content,% ≥ 96.0 95.0 94.0
Iron (Fe) content,% ≤ 0.03 0.05 0.10
Water-insoluble matter content,% ≤ 0.10 0.20 0.25
PH (1% aqueous solution) 10.0-10.7
Orthophosphate compliance test
3. Food additive potassium pyrophosphate shall meet the requirements of table 2 (FAO / WHO,1980)
Project indicators
Food Grade
Potassium pyrophosphate (K4P2O7) content,% ≥ 95.0
Ignition Weight Loss% ≤ 0.5
Water-insoluble matter content,% ≤ 0.2
Arsenic (As) content,% ≤ 0.0003
Heavy metal (Pb) content,% ≤ 0.002
Fluoride (in F) content,% ≤ 0.001
Lead (calculated as Pb) content,% ≤ 0.001
4. Potassium pyrophosphate for electroplating shall conform to the requirements of table 3 (HG/T3591-1999)
Project indicators
Potassium pyrophosphate (K4P2O7) content,% ≥ 98.0
Iron (Fe) content% ≤ 0.01
Water-insoluble matter content,% ≤ 0.10
PH (10g/L aqueous solution) 10.5±0.5
Lead (calculated as Pb) content,% ≤ 0.003
Hull cell test (plating under DK ≥ 10A/dm2) qualified
Toxicity
ADI 0 to 70mg/k (total phosphate amount in terms of phosphorus; FAO/WHO,2001).
Reports of renal calculi in large doses.
Adl 0~70 mg/kg (in phosphorus). According to FAO/WHO(1984), the total phosphate of processed cheese is 9 g/kg (calculated as phosphorus); The amount of lunch meat is 3 g/kg (calculated as P2()5); frozen shrimp or shrimp 5 g/kg (P2()5); Cooked meat 3 g/kg (anhydrous).
Identification and content
identification test the solubility was readily soluble in water and insoluble in ethanol (OT-42).
Take 1% sample solution 1M1, add silver nitrate test solution (TS-2l0)
content analysis a sample of about 3.8 mg was accurately weighed and dissolved in ml of water in a mL beaker, and the pH of the solution was accurately adjusted to using hydrochloric acid and a pH meter. Add 12.5% zinc sulfate solution (125g ZnSO4? 7H2O dissolved in water, diluted to 1000ml, filtered, adjusted to pH 3.8)50ml, placed 2min. The free acid was titrated with 0.1mol/L sodium hydroxide to pH 3.8. At the end point, after each addition of sodium hydroxide, the precipitated zinc hydroxide should be redissolved. Each ml of 0.1 mol/L sodium hydroxide corresponds to 16.52mg of potassium pyrophosphate (K4P2O7).
Limit of use
GB 2760-96: meat products 1g/kg; Fruits and vegetables peeling GMP.
FAO/WHO(1984:,g/kg): ready-to-eat broth, soup, the total phosphate 1000mg/kg (P2O5); processed cheese its total phosphate 9 (in terms of phosphorus); Lunch meat 3 (in terms of P2O5); Frozen perch, flounder, Atlantic cod, haddock, cod, shrimp or shrimp 5 (P2O5); Cooked pig leg meat, cooked ham, cooked meat powder 3 (anhydrous).
maximum allowable amount of food additive
The Chinese name of the additive is allowed to use the Chinese name of the food additive function maximum allowable usage (g/kg) maximum allowable residue (g/kg)
Tetrapotassium pyrophosphate food processing aids for food industry/generally should be made before the final product out, with the exception of the provisions of residues in food
Reference Information
| pH range of acid-base indicator discoloration | 10 |
| Product description | potassium pyrophosphate, also known as tetrapotassium pyrophosphate, is prepared by melting dipotassium hydrogen phosphate and losing water molecules, room temperature for white crystalline powder or particles, in the air has a strong hygroscopicity, easily soluble in water, but insoluble in ethanol, aqueous solution is alkaline, inhibit food spoilage, the role of fermentation, the pH value of the 1% aqueous solution is about 10.5, the solubility of potassium pyrophosphate in 100g water at 25 ° C. Is 187g, and the water is hydrolyzed into potassium phosphate in an acid or alkali solution and mixed with water to form a viscous slurry. Combined with other condensed phosphate, such as potassium pyrophosphate 10%, sodium pyrophosphate 10%, potassium polyphosphate 30%, Sodium polyphosphate 30%, sodium metaphosphate 20% ratio made of ham, sausage Binder, usually used to prevent the production of aquatic canned struvite stone, to prevent the color of canned fruit, to improve the degree of expansion of ice cream, coffee raw material extraction, ham, sausage yield, enhance the water holding capacity of fish, to improve the taste of noodles and improve the yield, prevent cheese aging, in order to make the plating layer smooth and firm, the formula of the plating solution in industrial production is often very complex. Cyanide has previously been used as a complexing agent to formulate plating solutions. However, due to the highly toxic CN-, the health of electroplating workers is very harmful, at the same time, the discharge of CN-containing sewage, waste gas also seriously polluted the environment. Therefore, cyanide-free plating is now mainly used for electroplating, and the complexing agent for replacing cyanide is potassium pyrophosphate. |
| function | potassium pyrophosphate has all the properties of other polymeric phosphates, similar to sodium pyrophosphate, but with greater solubility, can chelate with alkaline earth metals and heavy metal ions; Can form stable complexes with Ca2 and Mg2 in hard water to soften hard water, improve washing ability and remove dirt. Can also form a protective film on the surface of iron, lead, zinc, aluminum and other metals; Pyrophosphate ion (P2O74-) has a strong dispersion ability for fine dispersed solids, can promote fine, homogeneous mixing of trace amounts of substances. High purity and low iron potassium pyrophosphate has a stable pH buffer capacity, and can maintain the pH value of the solution for a long time. |
| identification test | solubility is readily soluble in water, as determined by the ethanol (OT-42) method. Take 1% sample solution 1 ml, add silver nitrate test solution (TS-2l0) |
| content analysis | accurately weigh a sample of about mg and dissolve it in of water in a 400ml beaker, the pH of the solution was accurately adjusted to 3.8 with hydrochloric acid and a pH meter. Add 12.5% zinc sulfate solution (125g ZnSO4? 7H2O dissolved in water, diluted to 1000ml, filtered, adjusted to pH 3.8)50ml, placed 2min. The free acid was titrated with 0.1mol/L sodium hydroxide to pH 3.8. At the end point, after each addition of sodium hydroxide, the precipitated zinc hydroxide should be redissolved. Each ml of 0.1 mol/L sodium hydroxide corresponds to 16.52mg of potassium pyrophosphate (K4P2O7). |
| toxicity | ADI 0-70mg/k (total phosphate based on phosphorus; FAO/WHO,2001). Reports of renal calculi in large doses. Adl 0-70 mg/kg (calculated as phosphorus). According to FAO/WHO(1984), the total phosphate of processed cheese is 9 g/kg (calculated as phosphorus); The amount of lunch meat is 3 g/kg (calculated as P2()5); frozen shrimp or shrimp 5 g/kg (P2()5); Cooked meat 3 g/kg (anhydrous). |
| usage limit | GB 2760-96: meat products 1g/kg; Fruits and vegetables peeling GMP. FAO/WHO(1984:,g/kg): ready-to-eat broth, soup, the total phosphate 1000mg/kg (P2O5); processed cheese its total phosphate 9 (in terms of phosphorus); Lunch meat 3 (in terms of P2O5); Frozen perch, flounder, Atlantic cod, haddock, cod, shrimp or shrimp 5 (P2O5); Cooked pig leg meat, cooked ham, cooked meat powder 3 (anhydrous). |
| Use | is mainly used for cyanide-free electroplating, instead of sodium cyanide as a complexing agent for electroplating. It is also used as a pre-treatment agent for electroplating and a pyrophosphoric acid plating solution. Detergent components for clothing, metal surface cleaning agents and bottle cleaning agent components, additives for various cleaning agents are formulated. It is used as a clay dispersant in the ceramic industry, as a dispersant and buffer for pigments and dyes. The bleaching and dyeing industry is used to remove a small amount of ferric ions from water and improve the quality of bleaching and dyeing. Analytical reagents, hydrogen peroxide stabilizer, electroplating, soap filler. used for cyanide-free electroplating, dyeing, refined clay, etc. used as filler for analytical reagent, hydrogen peroxide stabilizer and soap used as emulsifier, tissue improver, chelating agent in food industry, it is also used as a raw material for alkali water for flour products. Combined with other condensed phosphate, usually used to prevent the production of aquatic canned struvite stone, to prevent the color of canned fruit; Improve the expansion degree of ice cream, ham, sausage yield, ground fish water holding capacity; to improve the taste and improve the yield, prevent cheese aging. |
| production method | neutralization calcination method food-grade 30% phosphoric acid is added to the neutralizer, slowly add food-grade caustic potash solution for neutralization reaction under stirring, and control the pH value at 8.4, heat the solution after the reaction, add activated carbon to decolorize, filter to remove insoluble substances, clear filtrate is heated to 120~124 ℃ for evaporation concentration, after cooling to 20 ℃ or less precipitation crystallization, centrifugal separation, to obtain trihydrate dipotassium hydrogen phosphate, heated to 120~130 ℃ to remove crystallization water, it was converted into anhydrous dipotassium hydrogen phosphate, which was added to a calciner to carry out calcination polymerization at 500 to 600 ° C. And cooled to obtain a finished edible potassium pyrophosphate. The final potassium pyrophosphate product prepared from H3PO4 + 2KOH → K2HPO4 +2H2O2K2HPO4 [Δ] → K4P2O7 + H2O reacted with a 0.1 mol/L silver nitrate solution, and was deemed to be qualified in the absence of yellow precipitated Silver orthophosphate. 203 of potassium hydroxide was driven into a dissolution tank, and water was added to form a 48% potassium hydroxide aqueous solution. This was introduced into a reaction kettle, and 85% Phosphoric acid was slowly added dropwise with stirring to conduct a salt formation reaction. When the phosphoric acid was added dropwise to 100, 1 drop of liquid was added to the white porcelain plate, and 1 drop of water was added to dilute, and the pH value was measured by precision test paper. If the pH value reaches 8.5~9.0, the dropwise addition of phosphoric acid is stopped. Stirring was continued for 0.5 h, allowed to stand, and impurities were removed by filtration. The filtrate was transferred to an evaporator and concentrated in a gel-dried state, and then transferred to a coke oven for coking treatment at 550-650 °c. After coking for 2~3 h, the end point of the measurement was sampled (1% silver nitrate solution was used for inspection until no yellow Silver orthophosphate appeared). After completion of the reaction, the reaction was cooled and crystallized to obtain a finished product. neutralization calcination method according to the ratio of 1mol phosphoric acid to 2mol potassium hydroxide, 30% phosphoric acid is first added to the neutralizer, and potassium hydroxide solution is slowly added under stirring for neutralization reaction, it is advisable to control the pH value at 8.4, the solution after the reaction is heated, and activated carbon is added to decolorize, insoluble matters are removed by filtration, and then concentrated by evaporation, then cooled to crystallize, centrifuged to separate, get dipotassium hydrogen phosphate (K2HPO4? 3H2O), heated to 120~130 deg C to remove the water of crystallization, into anhydrous dipotassium hydrogen phosphate, it is calcined at 500~600 deg C high temperature polymerization for about 2~3H, after cooling, prepared potassium pyrophosphate product. When the product potassium pyrophosphate prepared by h3po4 + 2KOH → K2FIPO4 +2H2O2K2HPO4 [Δ] → K4P2O7 + H2O reacts with 0.1mol/L silver nitrate solution, no yellow Silver orthophosphate is considered acceptable. |
