Coating
Layer of clinker that sticks to the burning zone brick in a cement kiln and shields it from heat and wear.
In cement and lime kilns, the semi-molten clinker that adheres to the hot-face brick in the burning zone and builds into a protective layer. Stable coating keeps brick temperatures down and greatly extends lining life, so operators manage flame shape, mix chemistry and burner position to hold it. Coating that falls off exposes the brick and shows up quickly as hot spots on the shell scanner.
Lost the coating at 22 metres overnight, shell's at 400, bring the flame back and try to build it.
Coating is built, not bought: a stable flame, steady feed chemistry and a gentle first heat-up after a reline make it stick.
Also heard as
- kiln coating
- clinker coating
Related terms
Hot spot
Area of a vessel or kiln shell running hotter than normal because the lining behind it is thin or gone.
Ring
Circular buildup of material inside a rotary kiln that dams the flow, or one circular course of lining brick.
Alkali attack
Damage from potassium and sodium compounds that react with alumina-silica refractories and swell them apart.
Red spot
Shell area glowing visibly red from lining loss, the signal to take a kiln or vessel out of service.