Cradle to Gate
Identity ID
91991204-dd91-48a7-b4a2-f4989f82c6a3
Materials
Associated ID
97025e2b-f330-486d-92ed-4a7f3b6df10d
Included activities starts
Included activities ends
Description
The product represented by this dataset is tungsten powder, a metallic tungsten powder product prepared from ammonium paratungstate through pyrolysis and reduction processes. It appears as grey-black powder with a metallic luster, and its crystal structure is body-centered cubic. Tungsten powder has a melting point as high as about 3400℃ and a boiling point of about 5555℃, being one of the metal categories with the highest melting point, and it is extremely hard: sintered tungsten bars can reach a hardness of 200-250, and processed tungsten rods can reach 350-400. Tungsten powder is chemically stable, insoluble in water, slightly soluble in nitric acid, sulfuric acid, and aqua regia, soluble in a mixed acid of nitric acid and hydrofluoric acid, and in the molten state can react with sodium hydroxide or sodium carbonate. The upstream feedstock of this product is ammonium paratungstate, and downstream it is the core fundamental raw material for preparing tungsten processing materials, tungsten-based alloys, and various tungsten products. It is widely used in cemented carbide, aerospace high-temperature-resistant components, precision cutting tools, metallurgical electrodes, and military equipment, and is the core fundamental powder raw material in the tungsten deep-processing industry chain. The dataset includes the main raw and auxiliary materials, energy, and waste in the production process; infrastructure such as the manufacturing of production equipment and the construction of plants is not included within the dataset boundary. The data inventory is formed by merging data from multiple sources.
Activity Description
APT is used as raw material and calcined in a tungsten oxide calcining furnace to produce blue tungsten oxide powder and purple tungsten oxide powder respectively, which are then transferred to the next process for tungsten powder production. Using blue tungsten oxide powder (or purple tungsten oxide powder) as raw material, hydrogen reduction is carried out in a four-tube furnace and a fourteen-tube pusher-type electrothermal reduction furnace, where the materials are electrically heated to a reduction temperature of 750–950°C to obtain tungsten powder.
Process Description
Tungsten powder is metallic tungsten in the form of gray-black powder with metallic luster and a body-centered cubic crystal structure. Its melting point is as high as about 3400°C and its boiling point is about 5555°C. It is one of the highest melting points among metals. Tungsten has extremely high hardness. The hardness of sintered tungsten bars can reach 200-250, and the hardness of processed tungsten rods can reach 350-400. Tungsten powder has stable chemical properties, is insoluble in water, is slightly soluble in nitric acid, sulfuric acid and aqua regia, is soluble in mixed acid of nitric acid and hydrofluoric acid, and can react with sodium hydroxide or sodium carbonate in the molten state. Tungsten has two variants, α-type and β-type. The α-type has a body-centered cubic structure that is stable at room temperature and pressure, while the β-type only appears in an oxygen-containing environment and is stable below 630°C. If it exceeds this temperature, it will irreversibly transform into the α-type. Tungsten powder is an important raw material for preparing tungsten processing materials, tungsten alloys and various tungsten products.
Time period
2021
2026
Geography
China
Geography comment
Generated by merging multiple data sets in this geographical location.
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
APT is used as raw material and is calcined in a tungsten oxide calcining furnace to produce blue tungsten oxide powder and purple tungsten oxide powder respectively, which are then transferred to the next process to produce tungsten powder. Using blue tungsten oxide powder (or purple tungsten oxide powder) as raw material, hydrogen is passed through a four-tube furnace and a fourteen-tube pusher electrothermal reduction furnace, and electrically heated to a reduction temperature of 750~950°C to obtain tungsten powder.