Ammonium Paratungstate

What is ammonium paratungstate ?

Ammonium paratungstate is a white crystalline salt of ammonium and tungsten, with the chemical formula (NH4)10(H2W12O42)•4H2O.
APT is the most important precursor for the majority of tungsten products. Exceptions are only products of melting metallurgy and Menstrum WC produced directly from ore concentrates. All other intermediates such as tungsten trioxide, tungsten blue oxide, tungstic acid and ammonium metatungstate can be derived from APT, either by thermal decomposition or chemical conversion.
Ammonium paratungstate is produced separating tungsten from its ore. Once the ammonium paratungstate is prepared, it is heated to its decomposition temperature, 600 °C. Left over is WO3, tungsten(VI) oxide. From there, the oxide is heated in an atmosphere of hydrogen, reducing the tungsten to elemental powder, leaving behind water vapor. From there, the Tungsten Powder Grades can be fused into any number of things, from wire to bars to other shapes. 

Applications

Ammonium Paratungstate is used as a laboratory reagent or as a source for high-purity tungstic acid, tungsten metal powder, or carbide. Other applications are in the fields of absorbent gels, coloring agent in the porcelain industry and the catalyst industry.

Chemical composition of APT

Grade	WO3 (%,Min.)	Impurities (%, Max. )
		As	Fe	Ca	(K+Na)	Co	Mg
Special	88.8	0.001	0.001	0.001	0.002	0.0005	0.0005
1st	88.5	0.001	0.001	0.001	0.002	0.001	0.0005
Mn	Ni	Si	Ti	Mo	Cu	V	P
0.0005	0.0005	0.002	0.0005	0.002	0.0005	0.0005	0.0007
--	0.0007	0.002	0.001	0.005	0.0007	0.001	0.0007
S	Cr	Al	Sb	Pb	Sn	Bi	Cd
0.0007	0.0003	0.0003	0.0002	0.0001	0.0001	0.0001	0.0001
0.0007	--	0.0005	0.0005	0.0001	0.0001	0.0001	0.0001

Properties of APT

Packing: In sealde plastic bags with outer iron drums of 100/200 kgs net each. we can meet your special requirements.