The effect of jet pulverization on high purity alumina
Alumina has the disadvantages of uneven particle size distribution, large grain size, and serious agglomeration during the preparation process, which severely restrict its application prospects.
Air jet pulverization is a relatively new type of pulverization process. It uses a high-speed airflow to hit another powder airflow, and the impact speed reaches ultrasonic, so that the powder particles are broken. Due to its pollution-free and high efficiency, it is widely used at present In the fields of chemicals, materials, metallurgy, etc.
At present, jet pulverization technology has been applied in the preparation process of high-purity ultra-fine alumina, but there is little research on the factors affecting its process.
The raw material used in the experiment is high-purity alumina with a purity of 99.998% and a particle size of 12.94μm.
Not much to say, let’s look at the conclusion first:
(1) Air jet pulverization can effectively improve the dispersibility of the powder, reduce the particle size of the powder, and reduce the distribution range of the powder from the original 0-60μm to 0-6μm;
(2) It can be seen that the frequency of the classification wheel has the greatest influence on the particle size during the alumina jet pulverization process. With the increase of the frequency of the classification wheel, the particle size of the alumina sample shows an obvious downward trend.
The second is gas pressure and feeding frequency. As the gas pressure increases, the particle size of the alumina sample also increases, and as the feeding frequency increases, the alumina particle size gradually decreases;
(3) Under the conditions of a classifying wheel frequency of 70.0 Hz, air pressure of 0.8 MPa, and feeding frequency of 4.0 Hz, the obtained high-purity alumina powder has good dispersibility and particle size distribution.
High-purity alumina is an important raw material for inorganic materials. As its application field and scope continue to expand, the requirements for product quality are becoming increasingly strict. How to improve the quality and equipment level of China's high-purity alumina products and occupy the high-end market is the main problem. The key to improving product quality is how to control the particle size and obtain products with uniform particle size distribution while ensuring purity.
The current main work should be divided into two points:
We should improve and upgrade existing processes to improve product quality;
Second, we should develop new "green" environmentally friendly processes with low production costs and easy industrialization technologies.
