Major Breakthrough Made in Scrap Rubber Utilization
A technical demonstration of  crushing  scrap  rubber  into
rubber powder by air chilling was recently held in Nanjing
. Wang Fuhua, Director of No.  609  Research  Institute  of
China Aviation Industrial  Corporation  announced  at  the
meeting that the technology of  scrap  rubber  utilization
developed by the  institute  has  come  to  the  stage  of
commercial production, and both  the  technology  and  the
unit are at the world's leading level.
    The  technology  will  greatly  promote   environmental
protection. According to statistics, China has around  800
000 tons of scrap rubber, mostly scrap tires, each year.
  Production of reclaimed rubber is one of the  major  ways
to dispose scrap rubber in China. However, in  most  cases
the oil process or the water-oil process is  used.   These
processes are outdated,  energy- consuming  and  seriously
polluting. Most countries in the world use the  technology
of crushing scrap rubber into fine rubber powder by liquid
nitrogen chilling.
  However, as the  price  and  production  cost  of  liquid
nitrogen are high in China and there are also problems  in
product supply and storage,  the  technology  of  crushing
scrap rubber by liquid nitrogen  chilling  can  hardly  be
used in the domestic market. Scrap rubber is  mainly  used
to produce coarse rubber powder by mechanical processes in
China.
  The technology of crushing scrap rubber by  air  chilling
is a new process developed by China at the end of the 80's
. Air is used to replace liquid nitrogen as chilling agent.
  Compared  with  rubber  powder  factories  using   liquid
nitrogen chilling, factories using air chilling  can  save
investment by around one-third and the production cost  is
also lower. With  the  process  of  air  chilling,   great
quantities of scrap rubber can be processed and production
lines of 2 000 - 10 000 t/a  fine  rubber  powder  can  be
constructed.