What are the powder spheroidization technologies?
With the development of industry, powder technology, especially particle spheroidization technology and equipment, has attracted more and more attention from the industry. Spherical powder has advantages that ordinary powders do not have, such as high specific surface area, high tap density, and good fluidity. It is widely used in lithium-ion batteries, food, medicine, chemical industry, building materials, mining, microelectronics, 3D printing and other industries, and has gradually become an irreplaceable new material. The preparation of high-quality spherical particles has always been the focus and difficulty of the industry.
High-speed airflow impact spheroidization method
At present, the high-speed airflow impact spheroidization method has the advantages of high classification accuracy, adjustable classification accuracy, and large production capacity, so it is widely used in the field of natural graphite, artificial graphite and cement particle spheroidization treatment.
The principle of this method is as follows: the high-speed airflow impact mill uses a rotator that rotates at high speed around a horizontal or vertical axis to subject the material to a series of actions from high-speed airflow, hammer collision, friction, and shearing to obtain ultra-fine powder. Qualified materials are obtained through classification collection. The key is to improve product indicators such as particle sphericity, tap density, spheroidization yield, particle size distribution, etc. .
Taking the spheroidization process of natural flake graphite as an example, it can be roughly divided into four steps, namely, bending—balling—adsorption—compacting.
Common spheroidizing powder applications
1. Lithium-ion battery anode material powder
Natural graphite has the characteristics of easy acquisition and excellent electrochemical performance, and is widely used in lithium-ion battery anode materials. Artificial graphite has the advantages of good cycle performance, low cost and stable structure, so it has gradually become the focus of research. Spherical graphite has the advantages of high rate capacity, high Coulombic efficiency, low irreversible capacity, concentrated particle size distribution, small specific surface area and high tap density. At present, natural flake graphite and artificial graphite mainly obtain spherical graphite through high-speed airflow impact. Improve electrochemical performance.
2. Spherical silica powder
Spherical microsilica powder has good shape, high chemical purity, and low content of radioactive elements. Its application can greatly reduce the thermal expansion coefficient of plastic packaging compounds and improve the thermal stability of plastic packaging compounds. Therefore, it is widely used in the production of integrated circuits. The most important package filling material in integrated circuits.
3. Spherical cement powder
Ordinary cement has porous characteristics and complex pore structure, which will reduce fluidity and gradually harden during hydration reaction. Spheroidizing ordinary cement to obtain spherical cement can improve the physical properties of the material in the following aspects: reducing water demand, reducing porosity, improving fluidity, and increasing cement strength.