Cradle to Gate
Identity ID
cf8decd7-50ab-46d5-85af-0bbd33ca49e9
Materials
Associated ID
2a6fee01-271a-46da-8753-bc4bd4e52747
Included activities starts
Included activities ends
Description
This dataset represents the production of crude magnesium. Owing to the characteristics of the reduction and condensation processes, crude magnesium is usually silvery-white or greyish-white metallic lumps, relatively brittle in texture, with its surface easily covered by a layer of oxide film to prevent further oxidation. It has metallic characteristics such as low density and good thermal and electrical conductivity, but its chemical activity is relatively strong and it easily reacts with oxygen, carbon dioxide and moisture in the air, and therefore usually needs to be stored under protective conditions. The key upstream starting raw material of the product is magnesium pellets; the downstream is an intermediate product/raw material that is further refined to obtain high-purity magnesium ingots. The dataset includes the main raw and auxiliary materials, energy and wastes of the production process, while infrastructure such as the manufacture of production equipment and plant construction is not included within the dataset boundary; the data inventory is formed by merging data from multiple sources.
Activity Description
The entire production process includes the reduction process, covering the entire process from pellets to crude magnesium.
Process Description
The main component of crude magnesium is metallic magnesium. Due to the characteristics of the reduction and condensation process, crude magnesium is usually in the form of a silver-white or gray-white metal block with a brittle texture. The surface is easily covered with an oxide film to prevent further oxidation. It has metallic properties of low density, good thermal and electrical conductivity, but is highly chemically active and easily reacts with oxygen, carbon dioxide and moisture in the air, so it usually needs to be stored under protective conditions. Crude magnesium is an intermediate product/raw material that is further refined to obtain high-purity magnesium ingots, and plays a connecting role in the magnesium smelting process.
Time period
2023
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
The prepared pellets are put into a heat-resistant steel reduction tank located in the reduction furnace. The mouth of the tank is sealed with a cooling water jacket equipped with a crystallizer. A steam jet pump is used to generate a vacuum so that the pressure in the reduction tank reaches about 3~10Pa (absolute). The reduction furnace uses the coal gas produced in the gas making process as heating fuel. When the heating temperature reaches 1150~1200°C, the sphere is in a molten state, and the reducing agent ferrosilicon reduces magnesium oxide to metallic magnesium in a vacuum environment. Metal magnesium at high temperature sublimates into metal magnesium vapor, and the metal magnesium vapor is indirectly cooled by cooling water at the mouth of the reduction tank, causing the magnesium vapor to condense into solid crude magnesium. After the reduction reaction proceeds for 10 to 11 hours, about 85% of the MgO in the spheres has been reduced to metallic magnesium. Open the lid of the reduction tank and use a hydraulic press to take out the metallic magnesium. The remaining waste residue in the reduction tank is removed with a slag scraper.