Classification and production methods of lightweight refractories

In this article, Henan refractory brick manufacturers want to talk to you about the classification and production methods of lightweight refractories. Lightweight refractories refer to refractories with high porosity, low bulk density and low thermal conductivity. Lightweight refractories have a porous structure (the porosity is generally 40-85%) and high thermal insulation.

There are many classification methods for lightweight refractories

1. Classified by volume density. Lightweight bricks with a bulk density of 0.4~1.3g/cm~2 and ultralight bricks with a bulk density of less than 0.4g/cm~2.

2. Classified by operating temperature. Application temperature 600～900℃ is low temperature insulation material; 900～1200℃ is medium temperature insulation material; above 1200℃ is high temperature insulation material.

3. Classified by product shape. One is formed lightweight refractory bricks, including clay, high alumina, silica and some pure oxide lightweight bricks; the other is unshaped lightweight refractory materials, such as lightweight refractory concrete.

The heat storage loss and heat dissipation loss on the surface of the industrial kiln body generally account for 24 to 45% of the fuel consumption. The use of lightweight bricks with low thermal conductivity and small heat capacity as the structural material of the furnace body can save fuel consumption; at the same time, due to the furnace It can be heated and cooled quickly, improves the production efficiency of the equipment, reduces the weight of the furnace body, simplifies the structure of the kiln body, improves the product quality, reduces the environmental temperature, and improves the working conditions.

The disadvantages of lightweight refractories are large porosity, loose structure and poor slag resistance. The slag quickly penetrates into the pores of the brick, causing it to decompose, and cannot be used directly in contact with molten slag and liquid metal; it has low mechanical strength, poor wear resistance, and poor thermal stability. It cannot be used for load-bearing structures, nor can it be used for contact with furnace materials and severe wear. Of the site.

Due to the above-mentioned shortcomings of lightweight refractory materials, parts of industrial kilns that are in contact with the charge, hot air carries slag, large flow, and parts with high mechanical vibration are generally not used. Lightweight refractories are often used as heat preservation or heat preservation materials for kilns.