What is light Fire brick and how to select it?

With the continuous development of science and technology, there are more and more new products on the market, and we will encounter more and more things. The price of magnesia brick provides us with more choices. When we need to use something, we should first understand what it is, what it is used for, whether it is good or not, and a series of related knowledge. Let's take light Fire brick as an example, and talk about what it is and related knowledge

What is lightweight Fire brick is first understood from the definition of the name. Refractory products with small density, light weight and low thermal conductivity are used for thermal insulation. For example, clay insulation brick, high alumina polymer light brick, mullite insulation brick, floating bead brick, alumina hollow ball brick, etc. are all lightweight Fire brick products

High quality sintered magnesium bricks

The heat storage loss of industrial furnace masonry and heat dissipation loss of furnace body surface generally account for 24~45% of fuel consumption. Using light bricks with low thermal conductivity and small Heat capacity as furnace body structural materials can save fuel consumption; Meanwhile, due to the rapid heating and cooling of the kiln, it can improve equipment production efficiency; It can also reduce the weight of the furnace body, simplify the kiln structure, improve product quality, lower environmental temperature, and improve labor conditions

1、 Definition of lightweight Fire brick:

Generally, it refers to a density less than 1.3 × 103Kg/m3 Fire brick. Light weight means that this Fire brick is light in weight

2、 Light Fire brick has the following characteristics:

1. Low density, lightweight, can reduce the weight of the furnace body and simplify the kiln structure;

2. High porosity, low thermal conductivity, good insulation, can save fuel consumption, and improve equipment production efficiency;

3. Low mechanical strength and cannot be used for load-bearing structures;

4. Poor wear resistance, unsuitable for use in areas that come into contact with furnace materials or are severely worn;

5. The porosity is high and cannot be used in areas that come into direct contact with slag and liquid metal

Lightweight Fire brick is light in weight for heat preservation and insulation, but its strength is not high and its abrasion resistance is poor, so it cannot contact with high temperature flame; In the weight of heavy refractory bricks, their insulation and insulation capabilities are poor, but they have high strength, high wear resistance, and high temperature resistance. When building high-temperature equipment, light refractory bricks and heavy refractory bricks can be combined according to the design plan according to the actual situation, which will achieve good results and improve the service life and efficiency of the equipment

3、 Production method of light Fire brick

(1) Combustible additive method, which involves adding combustible materials such as wood chips or coke powder that are easily burned during the mixing process. When the combustible materials are burned during the brick firing process, many pores are left in the brick, which is a commonly used method;

(2) Foam method, that is to say, in the matching process, add rosin soap and other foaming agents, and then burn into porous products;

(3) By chemical method, when certain substances are added in the matching process, a foaming chemical reaction can occur, such as dolomite or periclase with gypsum and dilute sulfuric acid as foaming agent, a lot of CO2 can be produced, which can be cast immediately and fired after drying. Light Fire brick have little difference in fire resistance from ordinary Fire brick with the same raw materials, while the softening point under load is slightly lower

If lightweight bricks are used at high temperatures for a long time, they will continue to sinter and shorten, forming cracks and even damage. Therefore, most lightweight bricks have a problem with the operating temperature, such as light clay bricks that only need 1150 ℃, up to 1400 ℃, light high aluminum bricks that do not exceed 1350 ℃, and light silicon bricks that can reach 1600 ℃. Due to the fact that lightweight silicon bricks do not have the problem of high-temperature shortening and have a relatively stable volume, they can be used to build lining that directly touches the furnace gas

The light Fire brick has poor slag resistance, so the light Fire brick cannot directly touch the molten metal and slag. The mechanical strength and abrasion resistance of this kind of brick are also slightly poor, and it is not suitable for the parts with Jet stream scouring and high sensation. Similar to the process of light Fire brick, the lightweight refractory concrete can be made by adding appropriate foaming agent in the refractory concrete matching, and the bulk density is only half of the clay brick, The thermal conductivity is one-third of that of clay bricks. If materials such as vermiculite or ceramsite are used as aggregates, the density and thermal conductivity are lower