Refractory mud for coke ovens requires good plasticity and adhesion at room temperature to facilitate construction, and small shrinkage after drying to prevent cracking; sintering or consolidation can occur at operating temperature, with a certain strength to ensure the solidity and tightness of the furnace body; its refractoriness and load softening temperature should be higher than the operating temperature.
The selection of refractory mud for coke ovens
Refractory mud for coke oven is divided into silica fireclay and clay fireclay. Silicon fireclay is used when building silicon bricks, and clay fireclay is used when building clay bricks. Silica fire clay is prepared by silica right, waste silica brick and combined with clay on. Silica is the main component, the higher the SiO2 content in silica, the better the refractoriness. Adding waste silica brick powder is to improve the high temperature bonding ability of silica fire clay and silica brick, because the expansion of waste silica brick powder and silica brick is basically the same, which can make the brick seam against the brick surface.
The content of waste silica brick powder in the silica fire clay is between 20% and 30%. Silica fire clay is added with clay, which can increase the plasticity of silica fire clay, reduce the permeability and water loss rate, generally adding 15%?20% or so. According to the amount of SiO2 content can be divided into high temperature, medium temperature, low temperature silica fire clay.
Clay fireclay is prepared by calcined clay (clinker), waste clay brick powder and bonded clay (raw material). Clinker is the main component of clay fireclay, accounting for about 75%? 80%, raw clay is the binding agent, it is added to increase the plasticity of clay fireclay, reduce permeability and water loss, but the amount should not be too large, otherwise it is easy to produce cracks, with 20%? 25% is appropriate, sticky fireclay in the temperature below 1000 ℃ coke oven use.
Masonry coke oven, according to the different parts of the brick type and temperature and the use of different refractory mud. From the top of the combustion chamber to the middle and upper part of the ramp area using medium-temperature silica fireclay, from the lower part of the ramp area to the middle of the heat storage chamber using low-temperature silica fireclay, the lower part of the heat storage chamber using low-temperature silica fireclay with water glass. The clay fireclay is mainly used for building clay brick parts and repairing coke ovens.