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Annual Report 2015 63
Table 9: Stockman Project – June 2015 Mineral Resources (and 2014 comparison)
Mineral Resource – 30 June 2014
Mineral Resource – 30 June 2015
Tonnes (Mt)
Cu % Zn % Ag g/t Au g/t Tonnes (Mt) Cu % Zn % Ag g/t Au g/t
Currawong
Measured
-
-
-
-
-
-
-
-
-
-
Indicated
9.5
2.0 4.2
42
1.2
9.5
2.0 4.2
42
1.2
Inferred
0.8
1.4 2.2
23 0.5
0.8
1.4
2.2
23 0.5
Sub-Total
10.3
2.0 4.0 40 1.1
10.3
10.3
4.0 40 1.1
Wilga
Measured
-
-
-
-
-
-
-
-
-
-
Indicated
3.0
2.0 4.8
31
0.5
4
3.0
2.0 4.8
31
0.5
4
Inferred
0.7
3.7
5.5
34 0.4
0.7
3.7
5.5
34 0.4
Sub-Total
3.7
2.3
4.9 32 0.5
4
3.7
3.7
4.9
32 0.5
4
GRAND TOTAL
14.0
2.1
4.3
38 1.0
4
14.0
14.0
4.3
38 1.0
4
Notes:
1.
All Resource tonnes have been rounded to the nearest one hundred thousand tonnes and grade to the nearest 1/10
th
percentage/gram
per tonne.
2.
The Mineral Resource estimate is unchanged since 2012.
3.
Mineral Resources include massive sulphide and stringer sulphide mineralisation. Massive sulphide Resources are geologically defined;
stringer sulphide Resources are reported above cut-off grades of 0.5% Cu.
4.
Au grades for Wilga are all Inferred due to paucity of Au data in historic drilling.
5.
Block modelling used ordinary kriging grade interpolation methods within wireframes for all elements and density.
6.
Mining as at end of historic mine life (1996) has been removed from the Resource estimate for Wilga.
7.
Resources are inclusive of Reserves.
8.
The Competent Persons statement is incorporated in the JORC Code (2012) Competent Persons Statements section of this report.
9.
JORC Code (2012) Table 1 Parameters are in IGO’s ASX release of 28 October 2015.
Table 10: Stockman Project – June 2015 Ore Reserves (and 2014 comparison)
Ore Reserve – 30 June 2014
Ore Reserve – 30 June 2015
Classification Tonnes (Mt)
Cu % Zn % Ag g/t Au g/t Tonnes (Mt) Cu % Zn % Ag g/t Au g/t
Currawong
Proved
-
-
-
-
-
-
-
-
-
-
Probable
7.3
2.2
4.1
40 1.2
7.4
2.1
4.3
40 1.2
Sub-Total
7.3
2.2
4.1
40 1.2
7.4
2.1
4.3
40 1.2
Wilga
Proved
-
-
-
-
-
-
-
-
-
-
Probable
1.1
2.5
5.3
30 0.5
2
1.6
2.1
5.6
31
0.5
2
Sub-Total
1.1
2.5
5.3
30 0.5
2
1.6
2.1
5.6
31
0.5
2
GRAND TOTAL
8.4
2.3
4.3
39 1.1
2
9.0
2.1
4.5
39 1.1
2
Notes:
1.
All Reserve tonnes have been rounded to the nearest one hundred thousand tonnes and grade to the nearest 1/10th percentage/gram per
tonne.
2.
Gold (Au) grades are Inferred at Wilga due to a paucity of gold assays in historic drilling. Revenue from gold in the Wilga ore was included in
the estimation of the Ore Reserve. The contribution to Revenue of this gold was estimated to be $8.65 per gram of gold
in situ
. This inclusion
was not material to the value of the mining envelopes considered and did not warrant downgrading of any portion of the Ore Reserve
attributable to Wilga. The contribution from Wilga represents 18% of the Total Ore Reserve.
3.
The Ore Reserve was estimated using the Net Smelter Return (NSR) method. The NSR value represents unit revenue per tonne net of all
off-site costs. These off-site costs included road transport, sea transport, treatment charges, refining costs and state royalties. The NSR value
did not include site costs such as mining, geology, processing and site administration. These site costs were applied in the form of an NSR
cut-off, used to guide the limits of a practical and economic mining envelope. For 2015, the Currawong NSR cut-off was $97/t and for Wilga it
was $105/t.
4.
Revenue factor inputs (US$): Cu $6,591/t, Zn $2,979/t, Ag $20.17/troy oz, Au $1,146/troy oz. Exchange rate AU$1.00 : US$0.84.
5.
Metallurgical recoveries – 81.5% Cu, 40.7% Ag, and 20.4% Au in Cu concentrate; 76.4% Zn and 18.5% Ag in Zn concentrate.
6.
Long hole open stoping with cemented paste backfill is the primary method of mining proposed at Stockman.
7.
Historic mining at Wilga has been removed from the Reserve estimate.
8.
The Ore Reserve estimate includes Inferred and unclassified material in the form of mining dilution estimated to be approximately 780,000t
at 0.31 Cu%, 1.0 Zn%, 5.2g/t Ag and 0.1g/t Au.
9.
The Competent Persons statement is incorporated in the JORC Code (2012) Competent Persons Statements section of this report.
10. JORC Code (2012) Table 1 Parameters are in IGO’s ASX release of 28 October 2015.