Expandable Graphite with Extra Low
                 Sulfur Content Developed
Expandable graphite with extra low sulfur content has  been
  developed  jointly  by  Hebei   Research   Institute   of
Environmental Protection and Hebei Agricultural University
. The product can instantly expand by 150 - 320 times at  a
high temperature.
Expandable graphite currently used in China has high sulfur
content. When used as sealing  material,   it  will  erode
metal surface and therefore reduce the  vacuum  degree  of
vessels and shorten the service life of sealing materials.
The new product takes an organic substance  as  the  major
inserting agent, an innovation both at home and abroad. No
sulfur is used in the production process,   and  therefore
the product has extremely low sulfur content and excellent
environmental effect. The product can expand by 320 times,
and has unique features of  compression,   resilience  and
extremely low stress relaxation.   When  used  as  sealing
material, its properties are far superior to  conventional
sealing materials such as asbestos, rubber and  expandable
graphite. It can be extensively used in sectors of aviation,
spaceflight, atomic energy, petrochemical  production  and
automobile manufacturing.
The production cost of the expandable graphite  with  extra
low sulfur content is around 6 000 yuan per ton. The price
in the international market is more than 30 000  yuan  per
ton.
China is a big producer  of  flaky  graphite.   The  export
amount accounts for around 50% of the  world  total  trade
amount of flaky graphite. The production of flaky graphite
can not only have remarkable economic returns,   but  also
greatly enhance the  market  competitiveness  of  domestic
sealing materials.