deadburned

Deadburned is a term used in materials science, particularly in ceramics and refractories, to describe a material that has been heated to a high enough temperature to become highly unreactive. The concept applies mainly to oxides produced from carbonates, such as magnesia (MgO) and dolomite (CaMg(CO3)2), and sometimes to lime-based materials. The process, often termed dead burning, involves calcining or firing the material at temperatures well above the standard calcination point, causing partial sintering and a dense, low-reactivity product.

The purpose of dead burning is to produce materials with high refractoriness and stability at elevated temperatures, while minimizing hydration and chemical reactivity with silica or other reactive components. Dead-burned magnesia (DBM) and dead-burned dolomite (DBD) are common examples. These products are valued in refractory applications for steelmaking and other high-temperature processes because their low reactivity helps maintain strength and integrity under harsh conditions.

In production, the starting mineral is heated in a furnace to several hundred to over a thousand degrees Celsius above typical calcination temperatures, often approaching the sintering range. The result is a material with reduced surface area and limited chemical reactivity. While advantageous for high-temperature performance, dead-burned materials may be less easy to machine and form, and excessive burning can lead to unwanted over-sintering and reduced mechanical toughness.

Compared with standard calcined oxides, dead-burned varieties are chosen when long-term high-temperature stability and resistance to hydration or chemical attack are paramount. They are less suitable for applications requiring rapid reactivity or hydration, such as certain cementitious processes. See also calcination, refractory materials, magnesia, and dolomite.