How to Choose Refractory Bricks?

Refractory bricks are materials that can withstand high temperatures and can withstand the physical and chemical effects of high temperatures. In a high temperature kiln or furnace, refractory bricks are a necessary lining material. The choice of refractory material is directly related to whether the whole kiln can work properly and its operating cost.

When choosing refractory bricks, it is important to consider not only their cost, but also whether their performance meets the operational requirements of the furnace. If you also have doubts in this regard, you can refer to the following principles before choosing refractory materials.

The first thing to consider is the refractoriness of the refractory bricks. Refractoriness refers to the performance of refractory materials to resist the action of high temperatures. It indicates the temperature of the material when it softens to a certain degree. Refractory degree must be higher than the actual working temperature. For example, clay bricks have a refractoriness of 1730°C and a service temperature of 1350°C.

High Alumina Bricks

Next, the high temperature structural strength of the refractory must be considered. The refractory material will be under certain pressure in use, and the structural strength of the refractory material will change under high temperature, so its high temperature structural strength must be considered. It is characterized by its load-bearing refractory material, the use temperature of the refractory material must be lower than its load-bearing refractory material. For example, the refractoriness of clay brick is 1730℃, its load-bearing refractoriness is 1350℃, so the maximum use temperature is only 1350℃.

Third, refractory bricks must have high thermal stability. Certain parts of the kiln will have large temperature fluctuations. For example, when the furnace door is opened, cold air enters. The temperature of the furnace lining drops sharply. This requires the refractories to have a certain thermal stability to ensure normal operation.

Straight Fireclay Bricks

Fourth, refractory bricks require high temperature chemical stability. At high temperatures, the chemical properties of refractory materials may change and interact with specimens, furnace gas, etc., resulting in failure. Therefore, in the selection of refractory materials must be considered its chemical stability. For example, magnesium bricks can only be used as alkaline slag-resistant refractories, while silica bricks can only be used as acid-resistant slag refractories.

Fifth, the capacity of the refractory brick. When the refractory material can meet the above performance, it is appropriate to use the low weight of the material to reduce heat storage, improve the insulation effect, reduce the quality of the furnace body, reduce energy consumption. Therefore, the current refractory materials more than the use of lightweight refractory materials and set insulation, refractory in one of the new ceramic fiber as refractory materials, can greatly reduce the cost.

Six, used as electric furnace lining, must consider its electrical conductivity, must be used at high temperatures with insulating properties of refractory materials.

These are a few important properties that should be considered when choosing refractory bricks for furnace lining. In short, the choice of refractory materials ultimately to follow two major principles: First, the performance of refractory materials to meet production requirements, the second is to consider its economic requirements on the basis of the first, to minimize production costs.