S|
FLOW _ SHEET
| ROCK REJECT PLANT SHOVE

aaa ls BIN
1970 “SY PAN FEEDER
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| CRUSHER
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DRYER
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REJECT .
lA ° CONVEYO!
J \ TAILINGS 281% (eaeeaal == RO ed

1 CONVEYOR

iS — TRUCK NG Teams BIN

FIGURE 1 — Flowsheet of the rock plant, 1970.

TABLE 1 — Comparison of Delivery Methods at Cassiar

1 2 4 5 6 7
SYSTEM PRESENT T-L TRUCKS T-L CONV. ~ TRUCKS

Location of Crusher Mine Mine Mill Mine Mine Mill
Location of Rock Reject Mine Mill i Mill Mill Mill Mill

Unit Costs Loading Bay 0.21 0.21 0.175 0.17 0.17 0.17
(Dollars)
Haul to Prim; Crusher 0.25 0.25 0.144 0.144

Primary Crushing 0.67 0.15 0.28 0.14 0.14 0.26
Concentration 0.18 0.17 0.17

Delivery to Mill Area 0.887 0.30 0.54 0.27 0.135 0.54
Dryer Saving (Deduct)

TOTAL 2.017 0.09 0.995 0.894 0.759 0.97

Dollars Cost per Year 2,420,000 1,310,000 1,197,000 1,340,000 1,140,000 1,140,000
Savings per Year 1,110,000 1,223,000 1,880,000 1,560,000
Power Savings 60,000 37,500

Total Savings per Year 1,170,000 1,223,000 1/5} ‘000 1,917,500 1,560,000
After-Tax Savings

Capital For Delivery System 2,660,000 1,833,000 2,910,000 4,750,000 1,064,000
For Conc. Plant 2,000,000 2,500,000 2,200,000 2,200,000 2,700,000
For Dryer 450,000 450,000 450,000
Tailings Disposal

(1700 ft) 340,000 340,000 340,000 340,000 340,000

TOTAL
Rate of Capital /Savings 7.1 6.36 5.6 6.28 5.93
Yield

(16-Yr Life) | Rate of Yield 6% 20.7% 23.4% 21% 22.2%

Notes: 1. At the 1500,000 ton per year rate, assume costs for the present system would be the same per ton. Cost per year = $3,020,000
2. Assume $0.07 per ton to stabilize the rock reject pile.

Seis