Phosphorous acid

Phosphorous acid is a binary strong acid, corrosive, hygroscopic, and belongs to dangerous chemicals. The valence of phosphorus is +3, CAS number is 13598-36-2, and the molecular formula is H3PO3. It has the characteristics of strong reducibility, strong acidity, good water solubility and stable property. The price of phosphorous acid is closely related to the price of yellow phosphorus, glyphosate and other products, and also has an important connection with the production process, production raw materials and quality grade. In general, phosphorous acid produced by hydrolysis of phosphorus trichloride (PCl3) has high purity, less impurities and low odor, and belongs to excellent grade products.

1,Basic information

English name: Phosphorous acid

CAS Number: 13598-36-2

Appearance: White crystal

Melting point: 73.6℃

Boiling point: 200℃(decomposition)

Solubility: soluble in water, alcohol, strong hygroscopicity.

Density: 1.65g/cm3

Molecular formula: H3PO3

Molecular weight: 82

Density: 1.65g/cm3

UN number: 2834

EC NO: 237-066-7

Hazard Code: 81502

Hazard category: 8

Hazardous characteristics: corrosive, decomposed by heat to produce phosphine.

Executive standard: HG/T2520-2006

2, Indicators

Phosphorous acid≥ 99.0%

PO4≤0.1%

Cl≤0.005%

SO4≤0.0001%

Pb≤0.0002%

Fe≤0.001%

3,Product features:

(1) Excellent grade phosphite high purity, less impurities, almost no odor, suitable for export, good stability in the synthesis process with high requirements. And other by-product production of phosphorous acid quality has a big difference,

(2) Good stability, strong reducibility and better controllability of operation.

(3) The residue is orthophosphate or phosphate, which is harmless to the environment and is an effective source of fertilizer for plants.

(4) Good water solubility, quickly dissolved in water at room temperature, can be made into 70% aqueous solution.

4,Danger description

(1) Especially avoid contact with eyes, which can cause serious eye damage.

(2) May have a corrosive effect on metals.

(3) Avoid direct contact with skin, causing irritation to skin rot.

5,Production process

There are many kinds of phosphite production and preparation process, the main raw materials include propionyl chloride, valeryl chloride, isobutyryl chloride, valeryl chloride, butyryl chloride and other hydrolysis by-products, of which phosphorus trichloride (PCl3) hydrolysis of phosphite quality is better, iron ion content is low, almost no odor. Phosphorous trichloride (PCl3) hydrolysis method is listed below. The specific process is as follows:

The hydrolysis method will slowly add water to PCl3 under stirring for hydrolysis reaction, to produce Phosphorous acid, after refining,cooling crystallization,decolorization,It to make phosphorous acid finished product. Its PCI3+3H2O→ H3PO3+3HCl, hydrogen chloride produced in the production process recycling, can be made into hydrochloric acid.

6,Product application:

(1) Used as one of the raw materials for the production of potassium dihydrogen phosphite, aluminum phosphite, potassium phosphite and calcium hydrogen phosphite.

(2) Used as a reducing agent in the chemical reaction, it is relatively mild and controllable in the actual reaction.

(3) The plastic industry is used as a raw material for the manufacture of plastic stabilizer. (4) In addition, it is also used in synthetic fiber and pesticide industry.

7,Preventive measures

(1) Wear  protective  gloves/wear  protective  clothing/wear  a  protective  eye  patch/wear  a protective mask.

(2) Wash your skin thoroughly after work.

(3) Store only in the original container. Do not inhale dust or fumes.

(4) Do noteat, drink or smoke while using this product.

8. Packing: Plastic woven bag lined with plastic bag or kraft paper lined with plastic bag. Net weight 25kg.

Phosphorous acid should be stored separately from oxidizing agents and alkaline chemicals, and the warehouse should be ventilated and dry. Phosphorous acid has many advantages such as good stability, strong reducibility, storage resistance, cheap price and so on. In the same kind of antioxidants it can be decomposed into harmless orthophosphate, environmental protection is strong. After mixing with potassium hydroxide, it can produce potassium phosphite salt with bactericidal and disease resistance, and the effect is very good in agriculture.