What is this brick made of?

Bricks are made of clay (including shale, coal gangue and other powders) as the main raw materials. Brick is the most traditional masonry material. From clay as the main raw material, it has gradually developed into the utilization of industrial wastes such as coal gangue and fly ash, and at the same time, it has developed from solid to porous hollow, from sintering to non-sintering.

Brick burning steps:

1, borrow soil. The soil used for brick burning is commonly called clay, which has good plasticity. It is said that this soil was formed about 80,000 to120,000 years ago. At that time, the earth's climate was warm and humid, and the rich biological effects made the soil formed during this period soft and sticky.

2. The excavated clay will be weathered for half a year, naturally decomposed and loosened, and then crushed and sieved by hand, leaving only fine pure soil.

3. Moisturize the pure land with water and refine it repeatedly like kneading dough. Of course, it's definitely not by hand here. It can be trampled into thick mud by cows. It takes about 5 to 6 times to turn over the mud and refine it manually. This process plays a vital role in the quality of bricks.

4. Using refined clay to make blank and shape. When molding, the clay should be compacted, and the place where the bricks are placed should be covered with fine sand to prevent you from sticking. Bricks should be dry in the shade, and there should be no cracks and deformation in the sun.

After the bricks are completely dried (about one to two months), they can be fired in the kiln, which is the most important part. Bricks generally use coal as fuel, and filter bricks with higher density burn slowly with fuels such as wheat straw and pine branches.

6. After firing for more than ten days, the green body is sintered. If the flame is turned off slowly at this time and the outside air enters the kiln, our common red bricks will come out. If it is necessary to sinter the green brick at high temperature, it is necessary to seal the vent hole at the top of the kiln with mud to reduce the air entry, so that the temperature in the kiln is conducive to the reduction of the components of the green brick, and the red high-order iron oxide of the green brick is reduced to blue-gray low-price iron oxide. In order to prevent the low-priced iron in the blue bricks from being oxidized again, the iron drinking water at the top of the kiln sealed with soil achieved the purpose of cooling down until it was completely cooled and discharged from the kiln.