The purity of aluminothermic chromium metal can be enhanced by crushing, briquetting, and vacuum processing. Vacuum processing reduces the level of selected impurities that consumers of this material wish to avoid. The feed materials are heated as they flow downward through the inclined, rotating, cylindrical furnace. These materials react chemically to produce sodium chromate, which is converted to sodium dichromate from which many other chromium chemicals are produced. The refractory industry crushes chromite ore and blends it with magnesia to make shaped and unshaped refractory products.
Shaped refractories are bricks that are assembled where they are used such as in a furnace.
Unshaped refractories are like plaster or grouting. They too are used in furnaces. Background Chromite is the name of the mineral and of the ore mined for its chromium content. Another way of representing chromite in chemical notation is FeO Cr2O3. The Cr2O3 part of this formula is called chromic oxide and provides the most common measure of ore grade.