Contesto del progetto
The client is located in the state of Minas Gerais, Brazil. It’s a company specializing in the deep processing of natural graphite. Its products are primarily used in the fields of conductive additives for lithium-ion batteries and specialty lubricants. The client needs to grind natural flake graphite to a D50 of approximately 2.8 micrometers, with a narrow and uniform particle size distribution to avoid the production of excessive ultrafine powder due to over-grinding.
Production Challenges
Graphite has a layered structure. It is soft and naturally lubricious. During conventional ball milling, interlayer slippage tends to occur rather than effective fracturing, resulting in high energy consumption and low efficiency during grinding. At the same time, the customer’s existing production line features a compact layout, limiting the space available for installing new equipment. Furthermore, the new equipment must integrate seamlessly with the existing classification and conveying systems, creating stringent installation requirements.
EPIC Solution
Taking into account the material properties of graphite, the EPIC engineering team selected a fluidized-bed air jet mill solution. This process utilizes high-speed airflow to drive particles to collide and crush one another, eliminating the need for grinding media and preventing mechanical grinding from damaging the layered structure of graphite. Key components are lined with alumina ceramic to ensure zero metal contamination throughout the process and guarantee product purity.
During the installation phase, the EPIC technical team visited the Brazilian client’s site twice to conduct on-site surveys. Based on the actual space available in the plant, they redesigned the equipment layout, compactly integrating the air jet mill, cyclone separator, and baghouse dust collector. They also custom-designed non-standard piping fittings, successfully achieving a seamless integration of the new equipment with the client’s existing conveying system. During commissioning, engineers overcame challenges related to cross-border communication and time zone differences. Through a combination of on-site and remote methods, they repeatedly optimized the nozzle airflow pressure and classification wheel speed parameters. Ultimately, the D50 of the final product stabilized at around 2.8 micrometers, with a narrow and uniform particle size distribution, successfully meeting the client’s technical specifications.
Key Results:
D50 ≈ 2.8 μm. It’s a narrow, unimodal particle size distribution. D90 < 9 μm, virtually no coarse particles remaining. The product fully meets the customer’s application requirements.
Technical Specification:
Material: Natural Graphite
Particle Size: D50 2.8 μm
Output: 57kg/h