In the selection of refractory materials, new dry-process cement rotary kilns mainly use silica-alumina refractories, high-temperature sintered alkaline refractories, unshaped refractories, prefabricated parts, and heat-insulating refractory products. Among them, refractory bricks are the main ones. The refractory bricks for rotary kiln mainly include high alumina bricks, silicon molybdenum bricks, magnesia alumina spinel bricks, magnesia chrome bricks, dolomite bricks and so on. These refractory bricks should pay attention to the following matters and requirements when masonry.

(1) The composition, particle size and mixing ratio of the mortar used for bricklaying must meet the requirements. The mortar must be stirred evenly and used up within two hours.

(2) The last row of bricks shall not be less than two rows, and the thickness of the bricks shall not be less than 3/4 of the original size. If the gap is less than 1.5 times the thickness of the designed bricks, one row of bricks should be removed and replaced with three rows of bricks. Insert backwards.

(3) In a section of brick laying area, the refractory bricks laid in each row shall be of the same grade (thickness and tolerance).

(4) After the refractory bricks are laid, the longitudinal brick joints should be parallel to the center line of the kiln, and the circumferential brick joints should be perpendicular to the center line of the kiln.

(5) The surface of the finished refractory bricks should be smooth, and the unevenness of the two adjacent bricks should not exceed 3mm.

(6) Brick joints are generally inspected with 2.5mm, 15mm wide and 2.5mm thick plug gauges. The depth of the plugged brick joints shall not exceed 20mm, and there shall not be more than 3 inspection points in 10 inspection points per 5m bricklaying. If the point exceeds the specified brick seam, for the brick seam exceeding 3mm, a thin iron sheet must be inserted and squeezed.

(7) Precautions for bricklaying in winter

① The refractory brick stacking site must be elevated and covered with a rain cloth to prevent ice and snow from getting wet.

②The working place must have heating and thermal insulation facilities, so that the temperature should not be lower than +5℃. Even if the work is stopped or on vacation, the thermal insulation should not be interrupted.