Zinc Phosphate Powder: A Great Alternative to Flint & Steel

Zinc phosphate, is an inorganic compound, the chemical formula is Zn3(PO4)2, is a white crystalline powder, soluble in inorganic acid, ammonia, ammonium salt solution, insoluble in ethanol, almost insoluble in water, mainly used in medicine, dental adhesions, also used in anti-rust paint, phosphor, etc.

Basic properties of zinc phosphate

Chemical formula: Zn3(PO4)2

Molecular weight: 386.170

CAS Login number: 7779-90-0

EINECS Accession number: 231-944-3

Melting point: 900 ℃

Water soluble: Almost insoluble

Density: 3.99 g/cm³

Appearance: white crystalline powder

Stability: It will not decompose when used and stored in accordance with regulations. The solubility in water decreases with increasing temperature, soluble in dilute acid and dilute ammonia. Two molecules of crystalline water are lost at 100℃ and become anhydrous at 250℃.

Preparation of zinc 2 phosphate

1. The solution of 3.4g ZnCl2 dissolved in 290mL water was added to 1L of the solution of 210mL pyridine  phosphate containing 1mol phosphoric acid and 0.5mol pyridine  phosphoric acid, and heated in a water bath for 4h. The precipitate in the system was converted into crystals.

2.ZnSO4·7H2O 5.8g dissolved in 100mL water solution and 2.5g Na2HPO4 heated to boiling and stirring, crystal zinc phosphate tetrahydrate precipitation was obtained.

3. Neutralize 100g of 69% H3PO4 solution with ZnO(about 42g) under boiling condition (121℃), pay attention to supplement the volatile water. The solution was cooled to room temperature and placed in an ice bath. Stir vigorously to add 10 times the volume of ice water, strain, and strain the filtrate into a porcelain dish placed over a steam bath. Stir. After a while, the transparent sheet of zinc phosphate tetrahydrate was precipitated, filtered, washed with boiling water, and dried to produce 16g of product.

4. 15% of the zinc oxide method will dilute phosphoric acid solution in the reactor, the content is about 20% of the zinc oxide grout mix slowly to produce zinc phosphate reaction, heat preservation under 30 ℃, add 2 water zinc phosphate crystal seed, under the condition of pH value of 3 heated to 80 ℃, the filtration, hot water washing, crushing, drying under 120 ℃ for a quick finished at last. The equation is as follows:

2H3PO4+3ZnO→Zn3(PO4)2·2H2O+H2O

5. Direct method: add 20% zinc oxide slurry solution to the reactor containing 20% phosphoric acid solution, adjust the pH value to 2.0 under stirring, add seed crystal, adjust pH = 3, heat to 80℃ reaction for 0.5h, filter, wash separation, filter cake dried at 120℃ to no water. The filter cake ball is ground to a hydrophobic substance. In order to obtain the product with fine particle size and good dispersibility, the slurry was firstly modified with surfactant and then reacted with phosphoric acid under certain conditions.

Applications of zn phosphate

Use alkyds, base phenols, paints and other paint-free paints for the production of anti-toxic pigments and solvents, paints, and also for industrial applications.

Used as an analytical reagent.

It is used as the base material for various coatings such as alkyd, phenolic, epoxy resin, etc. It is also used in the production of non-toxic anti-rust pigments and water-soluble coatings. Also used in chlorinated rubber, flame retardant for synthetic polymer materials.

Used as medical and dental adhesives, also used in anti-rust paint, phosphor, etc.