Refractory bricks can be divided into heavy and light, while light bricks can be divided into specific gravity and material. Heavy metals can be classified into alkaline, acidic, or neutral.
So, how to choose suitable refractory bricks for the lining of the kiln?    
The first thing to consider is the material, and the choice of material depends on the temperature, degree of erosion, and properties of the furnace. Then look at whether it is lightweight or heavy. If it is lightweight, it depends on the temperature and then choose to use lightweight clay bricks or lightweight high alumina bricks. For insulation layers with a temperature greater than 1300 ℃, choose mullite lightweight bricks or high alumina lightweight bricks. If it comes into direct contact with flames, choose corundum mullite lightweight bricks or alumina hollow ball bricks.   
If it is the working layer, it is necessary to consider heavy refractory bricks, or first look at the temperature. If the temperature is 1000 ℃ and not more than 1100 ℃, choose clay bricks. If it is more than 1200 ℃, choose high alumina bricks. Of course, if the temperature is between 1300 and 1350 ℃, choose first grade high alumina bricks, second grade high alumina bricks, or third grade high alumina bricks at 1200 ℃. Above 1500 ℃, corundum refractory bricks must be used.
In addition, it is necessary to consider whether the kiln lining is in an acidic or alkaline atmosphere, and silicon bricks should be selected for acidic gas fields. If the glass kiln pool, it is a series of zirconium cast refractory bricks. If it is an alkaline atmosphere, choose alkaline refractory bricks, that is, the magnesium refractory brick series.
Another consideration is the size of the designed refractory brick type. To meet the requirements of furnace construction operations, it is also necessary to consider the production convenience of refractory bricks. This is because the refractory bricks can be mechanically pressed during the forming process, and the size of the refractory bricks is too long to be mechanically pressed. The strength of manually formed refractory bricks is lower than that of mechanically pressed refractory bricks, and low strength will inevitably affect the service life of the refractory bricks. So when choosing refractory bricks, it is necessary to consider both the convenience of furnace construction operation and the convenience of refractory brick manufacturers for manufacturing. Of course, it is best to use national standard models for design.
The upper part of the blast furnace body is built with clay bricks; The middle part is built with magnesium bricks, magnesium chromium bricks or magnesium chromium bricks; High alumina bricks are used for the lower part of the furnace body and the tuyere area with a temperature of 1300 ℃, and for individual parts with a temperature of 1500 ℃, fine and dense clay bricks, high alumina bricks, or magnesium chromium bricks are selected for strict application conditions. The hearth is built with magnesium bricks and magnesium chromium bricks.
Lead zinc enclosed blast furnace is a new type of furnace for processing lead zinc oxide ore or lead zinc. It directly produces lead and zinc through tempering. The furnace hearth and waist are built with magnesium chromium bricks, the furnace top and the connection with the lead mist chamber are built with dense clay bricks, and the side walls are built with clay combined with silicon carbide bricks. The bottom and top of the lead-zinc separation room are constructed with dense clay bricks. The bottom of the lead liquid flow channel and the lead outlet channel are constructed with secondary high alumina refractory bricks, and the channel walls are constructed with magnesium chromium bricks or chromium bricks.
In short, the selection of refractory bricks is based on different furnace types, temperatures, and degrees of erosion.