Lightweight clay bricks belong to weak acid refractory products, which can resist the corrosion of acid slag and acid gas, and it is a little weak in resistance to alkaline substances. Clay bricks have good thermal properties and are resistant to rapid cooling and rapid heating. The refractoriness of clay bricks is equal to that of silica bricks, up to 1690-1730℃, but the softening temperature under load is more than 200℃ lower than that of silica bricks. Because in clay bricks contains low melting point amorphous glass phase, which composite almost 50% of the brick..
In the temperature range of 0-1000°C, the volume of clay bricks expands uniformly with the increase of temperature, the linear expansion curve is similar to a straight line, and the linear expansion rate is 0.6%-0.7%, which is only about half of that of silica bricks. When the temperature reaches 1200 ℃ and then continues to heat up, its volume will start to shrink from the maximum expansion value. The shrink of the clay brick leads to the loosening of the mortar joints in the masonry, which is a major defect of the clay brick. When the temperature exceeds 1200 ℃, the materials of low melting point in the clay brick gradually melts, and the particles are closely attached to each other due to the effect of surface tension, and then the volume of brick shrinks.
