Two effective solutions to poor quality clay bricks

The quality of bricks is always poor and bricks are fragile. What are the main reasons?

There are many reasons for the bending of bricks. The main reason should be mechanical problems, such as an auger (especially a structure of a auger head), a machine head, a machine mouth, a cutting table, a brick separator etc.

The second reason may be that the molding moisture is too high and the strength of the green bricks is too low;

Third, there may be too much substance with a low melting point in the bricks, and a large amount of liquid phase is formed during firing which leads to deformation under the pressure of upper bricks. Since the material composition contained in each brick has a specific reasonable stacking height limit, it is called a reasonable stacking height. The rough surface of the brick is mainly caused by not fine enough raw material.

The quality of bricks is always poor and bricks are fragile. First, we should check whether the performance of raw materials meets the requirements of sintered bricks. If the clay minerals contained in the raw materials are too small or the montmorillonite is too high, the quality of the products may be poor.

Second, you should carefully check the performance of the clay brick machine extruder you are using. The poor quality of the extruded green bricks can also cause the product to break up ;

Third, review whether the production process you have chosen is reasonable. For example, insufficient care of raw materials processing can lead to poor quality product.

There are two main reasons for brick collapse in pre-heating zone:

1. The pre-heating zone is too short, the temperature rises too fast, and the temperature and humidity are super high;

2. The green bricks which are sent to kiln haven’t dried out.

The solutions are as follows:

1. The pre-heating zone is too short. It should be considered from the design of the kiln: lengthen the pre-heating zone properly, if the original design is not long enough, the fire of the burning zone can be moved backwards in operation, so that the pre-heating zone can be appropriately extended.

At the same time, the moisture removal fan should be added to the pre-heating zone in order to remove the moisture.

2. Strengthen the drying intensity of the drying kiln: to ensure that the bricks pushed out from the drying kiln are dry enough. (5-7% moisture can be retained). When inspecting the green bricks from the drying kiln, be sure to check the bricks in the center of the kiln car to see if they are dry enough. Often the bricks in edges are dry, but the bricks in middle is still in high temperature, which is the main reason for bricks collapse in the pre-heating zone.

3. Change the stacking method and control the stacking density.

A suitable stacking density should be: 230-260 bricks/m3. And you should follow the principle of sparse in the middle of the kiln car, and dense in edges. In particular, the middle passage should be large enough to ensure that the air and moisture movement in the middle.