Chemicals
Based Technologies - Micronization of Natural Graphite
Powder
Introduction
Graphite powder in micron size range
is one of the basic requirements for making its colloidal
suspension in aqueous or organic medium. To improve
upon the functional properties of suspension, it is
desirable to have accurate and reproducible size distribution
of graphite powder. Grinding of graphite powder in narrow
range is thus, an important unit operation.
Commercially available graphite powder has average particle
size in the range of 8 to 10 µm. Literature survey
on the grinding of graphite indicated that the grinding
below 10 microns is difficult and is further adversely
affected by the presence of absorbed moisture or organic
matter. The reason for difficulty in grinding of graphite
is mainly attributed to its hexagonal layered crystal
structure. During grinding, most of the energy is consumed
in causing slip in the layers rather than fracturing
the particles.
Commercially available grinding equipment including
high energy mills have not been able to generate powder
down to 2.0 µm size in wet or dry condition. BARC
has developed a novel technique for efficient grinding
of Natural Graphite.
Salient Features
of The Process
Simple Process and related equipment
design, low capital and maintenance cost.
The wear parts of this process
is the grinding media.
It is the low specific energy consumption
process to produce powder in the desired size.
This mill can grind 2.75 kg of
natural graphite to less than 2 µm in 12 hours.
Energy Consumption per batch is 40 kwh.
Application
Major application of micron
size natural graphite powder is in the production of
colloidal suspensions for use in metal forming industry.
For further information please contact
:
Head,
Technology Transfer & Collaboration Division,
Bhabha Atomic Research Centre, Trombay,
Mumbai - 400 085
Tel : 091-022-25505337/25593897
Fax : 091-022-25505151
E-mail : headttcd@barc.gov.in
