Ammonium Silicotungstate
Ammonium silicotungstate ((NH4)4SiW12O40) is a complex tungstate salt used in ion-exchange resins, analytical chemistry, and as a catalyst. As a complex salt containing both silicon and tungsten, it is classified as a tungstate under this tariff item, consistent with the chapter note on double or complex salts.
Import Duty Rates by Country of Origin
| Origin Country | MFN Tariff | Surtaxes | Total Effective Rate |
|---|---|---|---|
| 🇨🇳China | Free | — | Free |
| 🇲🇽Mexico | Free | — | Free |
| 🇺🇸United States | Free | — | Free |
| 🇩🇪Germany | Free | — | Free |
| 🇯🇵Japan | Free | — | Free |
More Specific Codes
This product may fall under a more specific subheading:
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If the silicon component is considered the principal anion
Double or complex silicates may be classified under other salts of oxometallic acids.
If the product is a mixture rather than a single chemically defined compound
Mixtures of chemical products not elsewhere specified fall under this heading.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right tariff item — and can price the duty on it in the same conversation.
Import Tips & Compliance
• Clearly document the chemical structure to show it is a complex tungstate rather than a silicate, as this affects classification
• If the product is used in ion-exchange applications, provide end-use documentation to support the tariff classification
• Consider requesting an advance ruling from the CBSA if there is any ambiguity about the complex salt classification
Related Products under Tariff item 2841.80.00
Ammonium 12-Tungstophosphate
Ammonium 12-tungstophosphate is a heteropolyacid salt used as an industrial catalyst. As a complex tungstate of ammonium, it falls under tariff item 2841.80.00. The product is a chemically defined compound.
Ammonium Metatungstate
Ammonium metatungstate (AMT) is a soluble white powder with the formula (NH4)6[H2W12O40]·xH2O, used in catalysts, fire-retardant treatments, and electroplating solutions. It is an ammonium salt of tungstic acid in its polymeric metatungstate form, falling squarely within the tungstates heading.
Ammonium Metatungstate Granules
Ammonium metatungstate granules are a spray-dried form of ammonium metatungstate, a complex ammonium salt of tungstic acid. They are used primarily as a precursor for producing tungsten powder and in thermal spraying applications. As an ammonium tungstate, it falls under tariff item 2841.80.00.
Ammonium Paratungstate
Ammonium paratungstate (APT) is a white crystalline powder with the formula (NH4)10[H2W12O42]·4H2O, used primarily as an intermediate in the production of tungsten metal and tungsten carbide. As an ammonium salt of tungstic acid in its paratungstate form, it is classified as a tungstate under this tariff item.
Ammonium Tungstate Hydrate Flakes
Flaked ammonium tungstate hydrate ((NH4)2O·12WO3·10H2O) is a hydrated form of ammonium tungstate used in analytical reagents and plating baths. The hydrated salt form remains classified as an ammonium tungstate under this tariff item, as hydration does not alter its chemical identity as a tungstate salt.
Ammonium Tungstate Powder
Ammonium tungstate powder is an ammonium salt of tungstic acid, used as a precursor in tungsten carbide production and as a source of tungsten in various applications. It is a chemically defined compound that meets the criteria of Chapter 28 notes. This product is correctly classified under tariff item 2841.80.00 as a tungstate.