‌As a typical representative of refractory tungsten products, tungsten heater is deep-processed products made from pure tungsten wire or doped tungsten wire. Known as "tungsten heater" in English, they generally contain over 99.95% tungsten and have diameters ranging from ‌0.2–1.2 mm‌.

As a common impurity element in ammonium metatungstate (AMT), sodium primarily affects its physicochemical properties and application performance in the following ways:

Like ammonium paratungstate, ammonium metatungstate (AMT) is also an important tungstate, with the chemical formula (NH₄)₆H₂W₁₂O₄₀·xH₂O, where x typically ranges from 0 to 23. Common forms include (NH₄)₆H₂W₁₂O₄₀·4H₂O and (NH₄)₆H₂W₁₂O₄₀·H₂O.

Ammonium metatungstate (AMT) is an important intermediate product of the transition metal tungsten, with a molecular formula of H₂₈N₆O₄₁W₁₂, containing nitrogen, hydrogen, tungsten, and oxygen. However, in practice, besides these four elements, AMT also contains impurity elements such as Al, As, Bi, Ca, Cu, Fe, Mg, Mn, Mo, Na, Ni, Pb, Si, Sn, and Ti. The impact of aluminum on the properties of AMT is as follows:

Ammonium metatungstate (AMT) and ammonium paratungstate (APT) are two common tungsten compounds, differing in chemical composition, physicochemical properties, applications, and production processes.

Ammonium metatungstate (AMT), as an important inorganic compound, possesses unique physicochemical properties and is widely used in ceramics, textiles, and catalysts. AMT has the following characteristics:

The thermal decomposition process of ammonium metatungstate (AMT) is a complex, multi-stage reaction involving the removal of crystal water, structural phase transitions, and the eventual formation of tungsten oxide. Specifically, the thermal decomposition of AMT can be pided into the following stages:

The wire cut molybdenum wire is a molybdenum product mainly made of refractory metal molybdenum (Mo). It is a thin wire made by forging and drawing molybdenum bars, and serves as a cutting wire for wire cutting machines. Its English name is "wire cut molybdenum wire", and its diameter generally ranges from 0.12 to 0.20 mm.

Ammonium metatungstate (AMT) is a highly water-soluble tungstate compound, widely used in tungsten chemical industries and catalyst preparation due to its high solubility in water (approximately 300-330 g/100 mL at 25°C). However, its solubility in organic solvents is significantly different, typically much lower or nearly insoluble. Below is an overview of AMT's solubility in some common organic solvents:

Ammonium metatungstate (AMT), besides being soluble in dilute acid solutions such as dilute hydrochloric acid, dilute nitric acid, and acetic acid, can also dissolve in alkaline solutions like ammonia water.