How Much Refractory Mud is Needed to Build Refractory Bricks?

Refractory bricks are an indispensable material for industrial furnaces and kiln construction. Before laying refractory bricks, the mortar to be used should be prepared. The maximum particle size of the grout should not exceed 20% of the masonry joints. The mud’s physical and chemical properties should match the refractory bricks’ variety and quality. When purchasing refractory bricks, it is best to specify the manufacturer to prepare the corresponding refractory slurry to prevent mixing.

1. Refractory mud preparation procedures

The general requirements for the preparation of refractory slurry should be based on the type of masonry, and the consistency and liquid content of the slurry should be determined based on tests. At the same time, check whether the slurry’s masonry properties (bonding time) meet the masonry requirements. The bonding time of the slurry depends on the material and size of the refractory product, and generally should not exceed 2 minutes. The number and consistency of different slurries are selected according to the type of masonry.

The determination of mud consistency should be carried out by the requirements of the current national industry standard “Refractory Mud Consistency Test Method”. The slurry bonding time is measured according to the requirements of the current National industry standard “Refractory Mud Bonding Time Test Method”.

There are two methods of preparing mud: natural binding of water and chemical binding. In the construction of industrial furnaces and kilns, most of them are prepared by chemical combination and corresponding coagulants are added. It is characterized by fast solidification speed, high bonding strength, and no brittleness after sintering at high temperatures. However, after the water-bonded mortar masonry is used, the high-temperature water in the kiln volatilizes, and the mortar masonry is easily brittle and the masonry is not strong. In addition, the refractory mud prepared on the same day should be used up on the same day.

2. Calculation method of refractory mud dosage

There is currently no good way to measure the demand for refractory mud from industrial furnaces as a whole. Since the furnace types of industrial furnaces are different and the types of bricks are also different, it is possible to build special-shaped refractory bricks, non-standard refractory bricks or the laying locations are different. The amount of refractory mud used for single-brick construction of the furnace wall is also different. The furnace roof and the hearth are different. Currently, the basis for using refractory clay in industrial furnace and kiln project budgets or estimates is standard refractory bricks for building furnace walls. In addition, reference should be made to the masonry mortar joint, which is an essential parameter for measuring the refractory mortar used for standard refractory bricks. The masonry mortar joints should be positioned first. The first-level gray seams are less than 1mm, the second-level gray seams are less than 2mm, and the third-level gray seams are less than 3mm. For the three types of mortar joints, the secondary mortar joints are usually used for clay refractory bricks or high alumina refractory bricks.

For example, to calculate the total amount of refractory mortar required for 1,000 high-alumina refractory bricks, the calculation method must first know: a = masonry mortar joint (2mm) B = single-sided area of ​​brick specifications (T-3 size 230*114*65 )

C=the mass of refractory slurry used (the quality of high-aluminum slurry is 2300kg/m3) d=the amount of slurry required for each brick—finally, the mud consumption d=230*114*2*2500=0.13kg (consumption per block). The total consumption of 1,000 high-alumina refractory bricks is about 130kg of refractory slurry. This calculation method is a basic principle calculation method, and its specific consumption should be more than 10% of the theoretical data.