Advantages of granulated powder process

    It is understood that the granulated powder not only expands the usability of alumina ceramics, but also greatly improves its performance through simple pressing. The alumina ceramic granulated powder has excellent fluidity and maintains the original hardness, so that it can be tightly packed when feeding, but does not adhere to each other. It is very suitable for production.

The first stage of alumina ceramic granulated powder is sprayed by pressure spray and centrifugal force, so that it can be quickly converted into solid alumina particles with high fluidity.

Technical factors of powder granulation:

    In terms of materials, there are the suspension properties of the slurry, fluidity, viscosity and solid content, and the dispersion particle size of the slurry; in terms of additives, such as binders, different powder equipment selections.

Each craft has its own strengths:

1. Advantages of the mixing and granulation method: the structure of the molding equipment is simple, the output of the single machine is large, and the particles are easy to dissolve; the disadvantage is that the uniformity of the particles is not good, and the strength of the formed particles is low.

2. The advantages of the pressurized granulation method are that the formed pellets have a large volume density, a small amount of added plasticizer, simple equipment and technology, and the disadvantage is that they are broken by a crusher.

3. The advantage of fluidized granulation is high production efficiency, but the disadvantage is that the prepared particles are relatively loose, and the sphericity and surface finish are very poor.

4. The advantage of spray and dispersion mist method is that the granulation process and drying process of the powder are carried out at the same time. The disadvantage is that the particle strength is low, the particle size is small, the particle morphology is difficult to prepare, and defects such as hollows and surface pits are easy to appear.

Raw material related:

    After the granulation process is clarified, the raw materials need to be selected. If the flow granulation is selected, it is necessary to ensure that the raw material has sufficient fineness to ensure the rolling granulation; if the extrusion granulation is selected, the raw material is kneaded with water Whether the plasticity is enough; if it is a slurry product of wet grinding or liquid phase synthesis, is it easy to atomize;

Auxiliary related:

    In terms of materials, ceramic powder will have many 1um particles after grinding. Due to the weak force, their fluidity will become very poor, which directly affects the suspension performance, viscosity, solid content and the slurry Dispersion particle size, etc., these are solved by additives.

Granulation powder related:

    Generally speaking, granulated powder has good fluidity, the density gradient of dry-pressed products is small, and the ceramic products produced by firing have fewer defects. However, the particle size and fluidity of the granulated powder will be affected. Some insiders said that the general The granulated powder prepared by the process has poor fluidity below 25um, so generally sub-micron granulated powder between 50um-150um is used more.