Magnesia, fused or dead-burned (sintered); whether or not containing small quantities of other oxides added before sintering, other magnesium oxide, whether or not pure, (not natural magnesium carbonate)

HS code 251990 covers a range of magnesium oxide products that are produced through specialized high-temperature manufacturing processes. These materials have a wide variety of industrial applications, making them an important component in the broader chemical and mineral processing industries. Their unique properties and versatility make them essential inputs for the production of various 252010 Magnesium hydroxide and peroxide and 281610 Hydroxide and peroxide of magnesium products.

The key production technique for HS code 251990 items is the process of fusing or dead-burning magnesium oxide. This involves heating magnesium oxide to extremely high temperatures, often exceeding 1,600°C, to sinter the material and drive off any impurities or volatile components. The resulting product is a dense, crystalline form of magnesium oxide with enhanced chemical and physical properties compared to the raw mineral.

The primary raw material input for this industry is natural magnesium oxide, which is typically extracted from mineral deposits such as magnesite or dolomite. Other minor oxide additives may also be incorporated before the sintering process to modify the final product characteristics. Specialized high-temperature furnaces and kilns are required to achieve the necessary processing temperatures, along with various material handling and processing equipment.

The main outputs from this industry are various grades and forms of fused or dead-burned magnesium oxide. These materials find widespread use as refractory materials, in the production of 252010 Magnesium hydroxide and peroxide and 281610 Hydroxide and peroxide of magnesium, as well as in other industrial applications such as the manufacture of 252010 Magnesium hydroxide and peroxide and 281610 Hydroxide and peroxide of magnesium.