Chromium is a common element found in many different metals including iron and steel. It has many uses and applications, and can be incorporated into various forms of steel to make it stronger and more durable.
It is also used in a range of ceramics to create colours, from grey through to black. This material is used to add colour to engobes, slips and underglazes and is a popular colorant for glazing clay bricks and paving units in addition to roof tiles, plain ceramics and ceramic floor tiles.
Chromite sand is a key component in green sand castings, which are used for intricate and high end production requirements due to its superior thermal and chemical resistance properties. It is also a popular component for tundish linings, which are refractory lined vessels that are used to transfer molten metal from a smelter or furnace to the casting area.
During the continuous casting process of stainless steel, chromite powder is deployed as part of a compound that prevents the molten metal from settling in any tap holes and blocking them up, which can be costly to remedy and can cause violent and dangerous expulsions of pressure during the pouring process. Its extreme heat tolerance ensures that the molten metal stays liquid and free flowable without a blockage, which is necessary to maintain both efficiency and safety during the casting process.
It is also used as a refractory plaster for the tundish, ladle and furnace linings that are used to transport molten metal around a foundry. It is manganese heavy, which assists with resistance to slag(7).