5
2
Asbestic is a name applied to impure very short fibre as
bestos. It is used by plasterers, manufacturers of roofing,
and also for a number of the purposes referred to above.
PREPARATION OF ASBESTOS.
In most cases in Canada asbestos is mined by open-cut
methods. From the mine it is conveyed to the mill, where
it is hand cobbed. The long fibre asbestos is separated as
completely as possible, by hand, from the waste rock, and from
that carrying the short fibre. The waste is discarded and the
balance subjected to a complicated milling treatment in order
to separate the fibre from the gangue. The first crushing is
done by jaw crushers, and the final by cyclone or similar crushing
devices. The fibre is removed partly by means of air currents
and partly by screening out the finely powdered rock.
The asbestos is graded according to length of fibre. The
market price varies greatly according to grade and the demand.
The long fibre always commands a much higher price than the
short.
Amount of asbestos used in the manufacturing industries,
as reported by the consumers;—
Location
No. of firms
reporting
consumption
Domestic
Imported
Tons
Tons
Maritime Provinces..
1
10
11
Quebec....
Ontario.
27
3
537*
25 m
100
Prairie Provinces.
British Columbia..
i
—
Canada (Total!
42
7435
33A