Gunning material is an important refractory material. The use of gunning material is generally divided into wet gunning, semi dry gunning and flame gunning

1. Wet gunning is a method of mixing refractory aggregate, binder and additive with water to make slurry with certain consistency, and then spray the slurry onto the gunning surface with compressed air through gunning machine. It is characterized by simple operation, high adhesion and rapid sintering. However, due to the large water content and fine grain size, the shrinkage is also large. At the same time, due to the thin gunning layer, the durability is not very good.

2. Semi dry gunning is a construction method in which the mixture composed of refractory aggregate, binder and additives is mixed with water through the water ring hole at the end of the spray gun, and then sprayed onto the gunning surface by compressed air. The water consumption can be adjusted at any time according to the situation of gunning and patching, which generally fluctuates in the range of ~ 14%.

It is characterized by high bulk density and small shrinkage of gunning layer, which can obtain thick gunning layer with good durability, but the rebound amount is higher than that of wet method, and there is a little more dust.

3. Flame gunning is a repair method in which the mixture of refractory aggregate, flux or heating agent is transported to the nozzle by compressed oxygen, and then mixed with high calorific value fuel for combustion. The surface of refractory aggregate particles is instantly heated to molten or semi molten state, and then sprayed and adhered to the lining.

It is characterized by dense structure, high strength, strong erosion resistance, erosion resistance and durability. However, the cost of flame gunning device is high, the technology is complex and the construction energy consumption is high.

Refractory materials used in special occasions include high-temperature oxide materials, such as alumina, lanthanum oxide, cymbals, calcium oxide and zirconia, refractory compound materials such as carbides, nitrides, borides, silicides and sulfides. High temperature composite materials mainly include cermet, high temperature inorganic coating and fiber reinforced ceramics.