CONTROL CABIN

Ls

7 ie oe *
54° WIDE PANFEEDER

NS - IMPACT BREAKER

TUNING FORK
GRIZZLEY lal
42"x 48" DIAMOND JAW CRUSHER
SETTING 5

‘

1’

/ emp :
625 ee '
36° BELT .
Dy SUERTE PUNCH PLATE
>
SS

30° BELTS

ia

eum 20 SEL
30"BELT

30° BELT

TRAMLINE

TO CONCENTRATOR +—
STOCKPILE
IMARY

PR ‘
bee

DISCHARGE

pi CASSIAR ASBESTOS CORPORATION LIMITED
a CRUSHING and CONCENTRATING PLANT

\

4' STANDARD CONE CRUSHER
Bd SETTING 3"

t

x

=e |
30" BELT cure —-
S Ea
4 Pac 30" BELT
Be ee u 100 TON

TRAMLINE BIN

TRAMLINE

NGINE

ROOM

Fone ;
>\ LENGTH - 15,500’
\ 2,200' DIFFERENCE IN ELEVATION
\
\
36" BELT \ \

———+TO DRYER

60" REVERSIBLE _BELT
_

=a As
HAZEMAG 36"BELT { \ r

CRUSHER
CRUSHER. ¥en
USH Up
—tf

TERTIARY

SCREENS Sy TO TAILS
Risse sad

Ll 24°BELT
Vv cue ——~TO TAILS
CYCLON' CLASSIFIER

———~ TO DRYER

SECONDARY
SCREENS

24" RELT

36 cELT

CONCENTRATOR
STOCKPI
——+TO DRYER ue

—~TO MILL

DRY ROCK STORAGE

FIGURE 7 — Cassiar’s crushing and concentrating plant flowsheet.

the inlet openings of the pump if left on the sump
bottom, with subsequent overheating of the pump,
which will destroy the seals.

The 8-in.-diameter pipeline is 2500 ft (762 m) in
length, fitted with a check valve to protect the pump
from water backflow pressure and discharges at the
northwest corner of the pit. Pit configuration prohibits
pump discharges at any other location for safety
reasons regarding dump lubrication.

Crushing

Crushing is carried out at the pit, the trucks dump-
ing onto a variable-speed 54-in.-wide plate feeder, dis-
charging onto a tuning-fork grizzly, with the oversize
+6-in. going into a 42- by 48-in. Diamond jaw crusher,
set at a 5-in.-opening. All crushing operations (Fig. 7)
are controlled from a cabin located above the 54-in.
plate feeder. The operator can visually observe and
control the trucks dumping, and can also observe the
feed discharging into the jaw crusher by means of
a 30-in.-diameter convex mirror. T.V. camera monitors
have been installed in the operator’s cabin,
which allows the monitoring of strategic locations in
the crushing cycle. Indicator lights display equipment
running and ammeters connected to conveyor drive
motors show overload conditions. The conveyors are
equipped with zero speed switches, which should trip
the motor in the event of belt slippage.

The flowsheet (Fig. 7) depicts the complete crush-
ing operation, which is controlled by a crew of four
persons, including the tramline operator. Radio com-
munications and a paging system are available in the
crushing plant, tramline loading station and tramline
discharge terminal. Crushed product delivered to the
tramline for transportation to the mill has a nominal

size of —8-in. after having passed through the 4-ft
standard Symons cone crusher.

Dust lifts are installed at all major conveyor
transfer points, the air being supplied by two 8000-cfm
Wheelabrator baghouses, operating at 2-in. W/G, dis-
charging back onto the conveyor system. The primary
crushing plant walls have recently been covered with
20-gauge galvanized sheeting, which reduces the ad-
herence of dust to the inside walls and also enhances
the inside appearance with an increased lighting effect.
A Hoffman 4000-cfm vacuum cleaning system oper-
ating at 11.5-in. W/G has been in operation for 2 years
and is extremely useful in collecting dust or spillage up
to a maximum fraction size of half an inch. A primary
separator has been installed in the primary crushing
area. Discharge is through airlocks and the collected
material is discarded to the waste dump, due to high
contamination by foreign objects. A piping system
provides 2-in.-diameter inlets at strategically located
points to allow use of the vacuum system in all areas
of the primary and secondary crushing plants.

Heating the crushing plant is essential in winter. It
is accomplished by oil-fired hot air in conjunction with
propane radiant heaters. Transfer points are heated
with a propane blow torch fitted securely inside an
8-in.-diameter pipe.

The flowsheet depicts the route of the crushed as-
bestos ore, which is conducted from the cone crusher/
Tyrock screens to the tramline loading station by two
30-in.-wide belts. An alternate route is available for
the ore in the event of a major period of downtime
experienced on the tramline. This consists of a bypass
chute onto a 30-in.-wide belt dumping on a stockpile
capable of stocking 5000 tons. The ore can then be
transported to the wet rock stockpile at the mill by
truck.

— 29 —