Introduction to Refractory Materials for High-temperature Kilns

Refractory material is an inorganic non-metallic material that can withstand high temperatures. It is usually used to manufacture high-temperature equipment such as industrial kilns and heating furnaces. The main components of refractory materials include refractory aggregates, powders, and binders. There are many types of refractory materials, which can be selected according to different high-temperature application scenarios.

The main performance indicators of refractory materials include refractoriness, load softening point, high-temperature creep value, thermal expansion coefficient, thermal conductivity, slag resistance, etc. Among them, refractory degree refers to the temperature in degrees Celsius at which a conical sample of refractory material can resist the action of high temperature without softening and melting without load.

When refractory materials are used at high temperatures for a long time, they will be corroded by high temperatures, air, slag, etc. Therefore, measures need to be taken for maintenance and repair. For example, regularly replace damaged refractory materials, use high-temperature protective agents, etc.

Refractory materials are divided into shaped refractory materials and unshaped refractory materials. Shaped refractory materials generally refer to refractory bricks, whose shapes have standard rules and can also be temporarily processed during masonry construction as needed.

Refractory bricks line furnaces, kilns, fireboxes, and fireplaces.

Refractory bricks are primarily built to withstand high temperatures but often have lower thermal conductivity to increase energy efficiency. Dense refractory bricks are used in applications with mechanical, chemical, or thermal stress, such as the interior of wood-fired kilns or furnaces, where they are affected by abrasion of wood, melting of ash or slag, and high temperatures. They are weaker but lighter, easier to shape, and better insulating than dense bricks. Under no circumstances should refractory bricks spall, and their strength should remain good during rapid temperature changes.