Dolomite, calcined or sintered; including dolomite roughly trimmed, or merely cut by sawing or otherwise into blocks or slabs of rectangular (including square) shape

HS code 251820 covers dolomite, a type of sedimentary rock composed primarily of the mineral dolomite. Dolomite is a versatile material with a wide range of industrial applications, including as a flux in steel production, a filler in the manufacture of plastics and rubber, and a source of magnesium. The dolomite industry plays a crucial role in supporting various sectors of the economy, from construction to agriculture.

The production of dolomite classified under HS code 251820 typically involves mining, crushing, and processing the raw dolomite rock. The mined dolomite is first crushed and then subjected to calcination or sintering processes. Calcination involves heating the dolomite to high temperatures, which drives off carbon dioxide and results in the formation of calcium and magnesium oxides. Sintering, on the other hand, involves heating the dolomite to a temperature just below its melting point, causing the particles to fuse together and form a more dense and hard material. The processed dolomite may then be further trimmed, sawed, or cut into blocks or slabs of rectangular or square shape.

The main inputs required for the production of dolomite under HS code 251820 include the raw dolomite rock, which is the primary raw material. Additionally, the production process requires energy sources, such as natural gas or electricity, to power the calcination or sintering furnaces. Specialized machinery, such as crushers, grinders, and cutting equipment, are also essential inputs for the various processing steps.

The primary output of the dolomite industry under HS code 251820 is processed dolomite, which can be used in a variety of applications. The calcined or sintered dolomite may be used as a flux in 720110 pig iron and 720270 ferroalloys production, as a filler in the manufacture of 390100 plastics and 400000 rubber, and as a source of magnesium in the chemical industry. The trimmed or sawed dolomite blocks and slabs may also find use in the construction and building materials sectors.