ammonium paratungstate

chemical compound

Also known as: APT

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Last updated

June 18, 2026

Quick Summary

Ammonium paratungstate (APT) is an intermediate chemical compound used in the production of pure tungsten metal. It is a salt where the ratio of a univalent metal or radical to tungsten can be either 10 to 12 or 6 to 7. For example, ammonium paratungstate has the chemical formula (NH₄)₁₀W₁₂O₄₁·11H₂O.12

The production of APT from tungsten ores involves processes like the autoclave-soda process or acid leaching. These methods aim to remove impurities such as sulfides, arsenides, phosphorus, arsenic, silica, and molybdenum before the tungsten is crystallized into APT. This APT is then further processed to create tungsten oxides, which are subsequently reduced to metallic tungsten powder.1

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tungsten processing
Ammonium paratungstate
Tungsten ores frequently occur in association with sulfides and arsenides, which can be removed by roasting in air for two to four hours at 800° C (1,450° F). In order to produce ammonium paratungstate (APT), an intermediate compound in production of the pure…
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Tungsten ores frequently occur in association with sulfides and arsenides, which can be removed by roasting in air for two to four hours at 800° C (1,450° F). In order to produce ammonium paratungstate (APT), an intermediate compound in production of the pure…
Read More