7
Gold Fields Operating update September
2017 Quarter
Gold head grade
increased by 32
per cent from 0.99 grams per
tonne to 1.31 grams per tonne and copper head grade increased
by 18 per cent from 0.49 per cent to 0.58 per cent. Gold and
copper head grades for the year are expected to be around 1.03
grams per tonne to 1.06 grams per tonne and 0.48 per cent to
0.51 per cent, respectively. Gold recoveries increased from 68.5
per cent to 69.2 per cent. Copper recoveries increased from 88.8
per cent to 89.4 per cent. Gold yield
increased by 32 per cent
from 0.68 grams per tonne to 0.90 grams per tonne and copper
yield increased by 19 per cent from 0.43 per cent to 0.51 per
cent.
In the September quarter, concentrate with a payable content of
48,100 ounces of gold was sold at an average price of US$1,287
per ounce and 8,409 tonnes of copper was sold at an average
price of US$5,689 per tonne, net of treatment and refining
charges. This compared with 36,300 ounces of gold that was
sold at an average price of US$1,255 per ounce and 7,447
tonnes of copper that was sold at an average price of US$4,998
per tonne, net of treatment and refining charges, in the June
quarter.
Total tonnes mined increased by
4 per cent from 4.14 million
tonnes in the June quarter to 4.32 million tonnes in the
September quarter mainly due to higher waste mined in line with
the mining sequence. Ore mined
increased by
1 per cent from
1.79 million tonnes to 1.80 million tonnes. Operational waste
tonnes mined
increased by
7 per cent from 2.35 million tonnes to
2.52 million tonnes. As a result, the strip ratio increased from
1.32 to 1.40.
Ore processed de
creased by
3 per cent from 1.74 million tonnes
in the June quarter to 1.69 million tonnes in the September
quarter as a result of a planned maintenance shutdown in the
September quarter. (94 per cent utilisation in the September
quarter compared with 97 per cent utilisation in the June quarter).
Net operating costs, including gold-in-process movements,
increased by
3 per cent from US$38 million to US$39 million
mainly due to higher mining cost as a result of increased tonnes
mined and higher statutory workers participation. This was
partially offset by a US$1 million gold-in-process credit to cost in
the September quarter compared with a US$2 million charge to
cost in the June quarter.
Capital expenditure
increased by
43 per cent from US$7 million
to US$10 million due to an increase in construction activities at
the tailings dam and waste storage facilities.
All-in sustaining costs and total all-in cost per gold ounce
de
creased by 67 per cent from US$380 per ounce in the June
quarter to US$124 per ounce in the September quarter mainly
due to increased gold sold, partially offset by higher net operating
costs and higher capital expenditure. All-in sustaining costs and
total all-in costs per equivalent ounce de
creased by
13 per cent
from US$724 per equivalent ounce to US$629 per equivalent
ounce due to the same reasons as above.
Australia region
St Ives
Sept
2017
June
2017
Gold produced
000’oz
89.5
102.6
Yield
– underground
g/t
3.55
3.64
– surface
g/t
2.37
2.98
–combined
g/t
2.48
3.07
AISC and AIC
A$/oz
1,071
1,107
US$/oz
848
831
Gold production decreased by 13 per cent from 102,600 ounces
in the June quarter to 89,500 ounces in the September quarter
due to lower grades of ore mined and processed.
At the Hamlet underground operation, ore tonnes mined
de
creased by 30
per cent from 143,000 tonnes in the June
quarter to 100,000 tonnes in the September quarter due to a
significant seismic event which occurred in August. This resulted
in limited access to stoping areas for most of the month. Head
grade decreased by 8 per cent from 4.06 grams per tonne to 3.75
grams per due to reduced mining flexibility.
Ounces mined at the consolidated St Ives mine increased by 14
per cent from 112,100 ounces in the June quarter to 127,300
ounces in the September quarter. Although the mine has
produced more ounces, the mill is constrained in its ability to mill
the Neptune oxide material up to a maximum of 25 per cent. This
Neptune oxide material will continue to sit on stockpile and be
drawn down each month up to the maximum of 25 per cent
addition to the mill.
Development of the Invincible underground mine commenced
during the quarter with the cutting of portals and the
commencement of the twin declines into the Invincible
underground mine. First ore from underground is expected in
late October 2017. The open pit operations are planned to
continue concurrently with the underground operations to end
2019.
At the open pit operations, ore tonnes mined
increased by 46 per
cent from 0.9 million tonnes in the June quarter to 1.3 million
tonnes in the September quarter with Stage 3 of Neptune pit
brought into production during the quarter. Grade mined
decreased by 16 per cent from 3.28 grams per tonne to 2.77
grams per tonne. The lower grade was in line with the mining
sequence
.
In the September quarter, tonnes mined were sourced
as follows: 0.61 million tonnes at 2.9 grams per tonne from
Invincible and 0.69 million tonnes at 2.6 grams per tonne from
Neptune. This compared with 0.68 million tonnes mined at 4.0
grams per tonne from Invincible and 0.20 million tonnes mined at
0.9 grams per tonne from Neptune in the June quarter.
Operational waste tonnes mined increased by 150 per cent from
1.2 million tonnes in the June quarter to 3.0 million tonnes in the
September quarter and capital waste tonnes mined de
creased by
33
per cent from 9.9 million tonnes to 6.6 million tonnes reflecting
a change from pre-strip to operating waste with Neptune Stage 3
brought to production during the September quarter. Total
material movements at the open pits de
creased by 9
per cent
from 12.0 million tonnes to 10.9 million tonnes due to the
reduction in the strip ratio as the pits deepened. The strip ratio
decreased from 12.5 to 7.3.
Throughput at the Lefroy mill
increased by
8 per cent from 1.0
million tonnes in the June quarter to 1.1 million tonnes in the
September quarter due to a scheduled maintenance shutdown in
the June quarter. Yield de
creased by
19 per cent from 3.07
grams per tonne to 2.48 grams per tonne due to the lower grades
mined and processed.
Net operating costs, including gold-in-process movements,
decreased by 13 per cent from A$46 million (US$35 million) to
A$40 million (US$32 million) due to
a gold inventory credit to cost
of A$23 million (US$18 million) in the September quarter
compared with A$5 million (US$4 million) in the June quarter,
partially offset by an increase of A$14 million (US$11 million) in
operational open pit mining costs reflecting the change from pre-
strip to operational waste. The gold-in-process credit reflects a