A polytungstic acid, a colorless crystal. It belongs to 12-tungsten isopolyacids, the simple structural formula is H6[H2(W3O10)4]•nH2O, n is 10 or 23; the density is 3.93g/cm3, it decomposes at 50℃; the solubility is very large, 88.57 g/100cm3 water (25°C).
It is derived from the conversion of metatungstic acid salt. Metatungstate is an important industrial product developed in the late 1970s, mainly used as a catalyst. Ammonium metatungstate can be prepared from ammonium paratungstate, or from microcrystalline powder white tungstic acid. Many other metatungstates, including various metal salts and polycarbonate ammonium salts, can be directly or indirectly prepared from microcrystalline powder white tungstic acid. Ammonium paratungstate is another polytungstate, its simple structure is (NH4)10[H2W12O42]•nH2O, it is prepared from sodium tungstate solution by ion exchange method, and the corresponding free acid cannot be obtained. Sodium-free tungsten trioxide can be obtained by burning ammonium paratungstate.
Use
- Used in mordants, analytical reagents, catalysts, water treatment chemicals, and in the manufacture of fireproof and waterproof materials, as well as phosphotungstate, borotungstate, etc.
- Used in the manufacture of metal tungsten, tungstic acid, tungstate, etc.
- Used in mordants, pigments, dyes and inks.
- It is used as fabric weighting agent in textile industry. This product is used as fabric auxiliary agent. The mixture composed of tungstic acid, ammonium sulfate ammonium phosphate, etc. is used for fireproofing and waterproofing of fibers. This fiber can be used to make fireproof rayon and rayon. It can also be used for leather tanning.
- Used for anti-corrosion of electroplating coating.
- It can be used as a cosolvent to introduce enamel pigments, which can lower the firing temperature and complement the color.
- Used in the manufacture of petroleum industry and aviation and aerospace materials.
Storage Method
It should be stored in a cool, ventilated and dry warehouse. The packaging container is intact.
Resolve Resolution
- Calcium tungstate-hydrochloric acid decomposition method
Wolframite is pulverized and reacted with sodium hydroxide to generate sodium tungstate. The solution is filtered and purified, and then undergoes metathesis reaction with calcium chloride solution to obtain calcium tungstate, which is then treated with hydrochloric acid. The resulting tungstic acid is washed, dried, and pulverized to obtain the finished tungstic acid product. Its reaction equation is:
MnWO4•FeWO4+ 4NaOH → 2Na2WO4 + Fe(OH)2•Mn(OH)2
Na2WO4+ CaCl2→ CaWO4+ 2NaCl
CaWO4+ 2HCl → H2WO4+CaCl2
- Ammonium paratungstate-hydrochloric acid decomposition method
Wolframite is subjected to alkali hydrolysis with sodium hydroxide, reacted with hydrochloric acid and ammonium chloride solution, filtered and washed to obtain refined ammonium tungstate solution, then acidified with hydrochloric acid to obtain tungstic acid, and then dehydrated, dried and crushed to obtain the finished tungstic acid product. Its reaction equation is:
MnWO4•FeWO4+ 4NaOH → 2Na2WO4+ Fe(OH)2•Mn(OH)2
12Na2WO4+ 14HCl → 5Na2O 12WO3+ 14NaCl + 7H2O
5Na2O•12WO3+ 10NH4Cl → 5(NH4)2O•12WO3+ 10NaCI
5(NH4)2O•12WO3+ 10HCI + 7H2O → 12H2WO4 + 10NH4Cl [3]
Security Information
Hazardous transport code: no
Dangerous goods sign: None
Safety mark: S24/25
Hazard identification: R36/37/38
More details of tungstic acid product, please visit website: tungstic-acid.com
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Email: sales@chinatungsten.com
Tel.: 86 592 5129595
