VP75 Full Auto Clay Brick Machine Project in South Africa

The video is for machine trail in South Africa . 
The whole production line design is very efficient .
Extruder adopts hard plasticity technology .Brick with more hardness and less moinsture.
The production line is with two crushers, one is stone removing crusher, and fine roller crusher .
The whole line is with convertors , auto coal weighting system, water control system .

Cutter adopts servo technology with two steel shelf easy for maintaince.

How to adjust the plasticity of raw materials for making bricks：

In order to overcome some shortcomings caused by raw materials in the production process, it is often necessary to increase or decrease its plasticity to meet the requirements of product technical conditions.

In the production of sintered bricks and tiles, the methods of improving the plasticity of raw materials generally use methods such as weathering, aging and batching to improve the plasticity of raw materials such as clay, shale and coal gangue.

1. natural aging 

In order to destroy the natural structure of clay, shale, and coal gangue, it is necessary to withstand atmospheric action - weathering and freezing, especially when using colloidal and fertile clays that are difficult to loosen. The purpose of this is to make the natural moist raw materials disintegrate (mainly volume changes) under the repeated action of wind, rain, sun, snow, water absorption, drying, cold and heat, expansion and contraction, and become small. particles. At the same time, the raw materials undergo many chemical and physical changes during the weathering process, causing organic substances to decay, soluble salts to be leached, and sulfides to be oxidized, which changes the original composition and improves the technological performance of the raw materials.

Even in the highly mechanized brick factories in developed countries, in order to produce hollow products with high porosity and high quality, there is no shortage of weathering methods for the treatment of raw materials.

The raw materials of some brick factories in my country have been weathered, and their performance has been significantly improved. For example, the raw materials of two brick factories in Changsha, Hunan Province are all mountain soil. The raw materials just excavated have coarse particles, low plasticity, difficulty in forming, and poor quality of finished products; but after one year of weathering, the particles become finer and the plasticity is greatly improved, which can fully meet the Production needs, so these two brick factories have emphasized the use of "next year soil". After a freeze-thaw and weathering from winter to spring in the next year, the plasticity is improved. It should be noted that after the water in the air freezes into ice, the volume expands by 9%, resulting in a huge expansion stress, and the effect on the thinning of raw material particles is obvious.

However, weathering often greatly increases the natural moisture content of the raw materials (for example, the shale raw materials of a brick factory in Hunjiang, Jilin have a moisture content of 5% to 7% before weathering, and a moisture content of more than 13% after weathering), which is easy to be broken, crushed, Blockage of screening equipment and silos.

2. Chen Hua

Aging is to store the broken, crushed and watered raw materials in a closed room. Under the "splitting" action of water, the raw materials are further loosened, the water distribution is uniform, and the content of the organic and inorganic components of the colloid is increased, thereby achieving the purpose of improving its plasticity and improving its technological performance. After 3 days of aging of raw materials in a factory, the dry strength of the bricks has increased by 50%.

3. Refinement

Fine grinding of raw materials can separate out a sufficient amount of clay components, which is good for improving plasticity. Even raw materials without plasticity can obtain a certain degree of plasticity if they are finely ground, but this requires a large investment.

4. Homogenization

In actual production, raw materials with high plasticity are often mixed into raw materials with low plasticity to form raw materials with suitable plasticity. When using this method, great attention should be paid to the uniformity of the distribution of the two materials with different plasticity in the mixture, because the raw materials with low plasticity are often easier to loosen in water than the raw materials with high plasticity, while the clay with high plasticity is less It is easy to loosen, and the loosening of colloidal clay is more difficult. Therefore, if the blending is not uniform, the formed body will also be non-homogeneous, which will cause a lot of waste during the drying and roasting process.

5. Steam (hot water) heating

The mud is heated with steam (hot water) and formed by hot extrusion. After the mud is heated by steam (hot water), the water is evenly distributed in a short time, and penetrates into the gaps of the mud particles at a faster speed, thereby greatly improving the plasticity of the mud.

6. Vacuum treatment

The air entrapped in the mud will reduce its plasticity and cause foaming, delamination and cracks in the formed body. The use of vacuum extrusion molding can not only overcome the above defects, improve the plasticity of the mud, but also increase the strength and density of the green body.

The method of reducing the plasticity of raw materials is generally to add barren materials such as sand, slag, fly ash and clinker powder (such as waste brick powder) into the raw materials to reduce its plasticity. Especially after the internal combustion brick method has been widely used, the effect of adding a blend of combustible components into the raw material is better. If sand is mixed, quartz sand is generally used, and calcareous sand should not be used, because the addition of calcareous sand will reduce the quality of bricks.

When the barren material is mixed into the raw material, there is also the problem of whether the mixed material is evenly distributed in the raw material. Experience has proved that if the admixture is not evenly distributed in the raw material, it will bring bad consequences to the product, reduce the strength, and cause cracks in severe cases.

In short, different raw materials should have different processing methods. Through effective processing, each unit of the raw materials has the same mineral composition, the same particle composition, and the same water content. The raw materials used for making billets have excellent uniformity and stable plasticity.