The Czech company PneuDemont, Pilsen has patented a recycling
process which converts waste tires into granulate using an ozone-rich
atmosphere. According to Montana Steel, Munich, Germany, whose
owner is one of the patent holders, untreated waste tires are
introduced continuously via a trap into a horizontal sealed
tunnel and are then transported and stretched by a system of
drums so as to ensure that ozone enters the pores in the rubber.
The entire process takes place at room temperature.
Depending on ozone concentration
and the mechanical loads involved, the tire granulation process
takes between 6 and 10 minutes and retains the original physical
and chemical properties of the rubber, according to Montana
Steel. Unshredded steel cords, as well as textile fibers are
exposed for separation without any mechanical or magnetic intervention.
After a year of tests at a pilot
facility, the first commercial production plant for tires up
to 16" has been sold and is due to come on stream this month.
This processing plant will have a production capacity of 1.500
kg of rubber granulate per hour and will produce different grain
sizes ranging from zero to 40 mm. The yield is about 25% up
to 2 mm, 35% 2.0 to 5.0 mm, 10% 5.0 to 10.0 mm and balance up
to 40 mm, according to the company. Montana Steel estimates
production costs at US$0.07 to $0.09 per kg rubber granulate.
A plant for truck tires, based
on the same system design but using larger equipment dimensions
to accommodate truck tire sizes is expected to come on stream
by October 2000. Contact Montana Steel GmbH, P. O. Box 1329,
D-85531 Haar/Munich, Germany (49) 89 463056, fax (49) 89 468979.
