Traditional brick making has several steps.

1. Take soil. The soil used for brick burning is taken from the ancient soil two feet below the surface, which is slightly darker than the surface soil. It 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 in this period soft and sticky, which was a good material for firing bricks and tiles.

2. The excavated clay is exposed to the sun, rain and snow for about half a year in the process of open-air accumulation, so that its internal decomposition is loose, and then it is manually crushed and screened, leaving only fine pure soil.

3. moisten the pure soil with water, and then stir it repeatedly to refine it, or step on it to turn it into thick mud. 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 the final brick.

4. Fill the mud into the wood blank mold, compact it, and scrape off the excess mud with an iron bow to form a blank. Before making the blank, sprinkle a layer of fine sand under the wooden mold to prevent the mud from sticking to the ground.

5. After demoulding, the brick blank should be placed on the back of the sun and dried in the shade to prevent cracks and deformation caused by sun exposure.

6. After the bricks are completely dried (about one to two months), they are fired in the kiln. This process is the most important part of the whole brick making process. Bricks generally use coal as fuel, and filter bricks with higher density are slowly burned with wheat straw and pine branches.

7. After more than ten days of firing, the green body has been basically sintered. If the flame is turned off slowly at this time, the outside air enters the kiln and the green body turns red after cooling. This is our common red brick, while the blue brick rusts in the kiln. The method is to seal the vent hole at the top of the kiln with soil when sintering the green body at high temperature, so as to reduce the air entry and turn the temperature in the kiln into a reducing atmosphere. In this way, the red high-order iron oxide of the green body is reduced to blue-gray low-priced iron oxide. In order to prevent the low-priced iron in the green body from being oxidized again, iron is drunk on the top of the kiln sealed with soil, so that the water becomes steam at high temperature and absorbs the heat in the kiln. During the cooling process, the green body in the kiln continues to maintain the reducing atmosphere until it is completely cooled, and then discharged from the kiln. Completed the process from loess to blue brick.