is grade king in gold mining? - ulrich et al - sep 2016 - centre for exploration targeting / the...
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IS GRADE KING IN GOLD?A preliminary analysis of gold production costs at Australian & New Zealand minesSam Ulrich, MAusIMM12
Matt Kanakis3†
David Groves1
Steffen Hagemann1
John P. Sykes, MAusIMM14
& Allan Trench, FAusIMM156
1. Centre for Exploration Targeting, The University of Western Australia2. Ravensgate Mining Industry Consultants, Australia3. KPMG, Australia4. Greenfields Research, United Kingdom5. Business School, The University of Western Australia6. CRU Group, United Kingdom† Today’s presenter
AusIMM New Zealand Branch Conference: Wellington, New Zealand: 6 September 2016
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
We need to mine and find better gold ore
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 2 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
But what is better ore? Higher grade?Cos
ts ($A
U)
Grade (g/t)
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Higher grade = lower cost mines
Lower grade = higher cost mines
Source: Kanakis (2014)
Slide 3 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
No! It is more complex than that
0200400600800
100012001400160018002000
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00
All in S
ust
ain
ing C
osts
($A
U)
Operating Grade Q4 (g/t)
Open Pit Underground
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014)
Slide 4 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Initial investigation: Gold costs and geology (Kanakis, 2014)
Is grade king in gold?
A preliminary analysis of gold production costs at Australian and New Zealand mines
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 5 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Back in 2013 it was all about ‘costs’
0
2
4
6
8
10
12
1989 1994 1999 2004 2009
Million
s of
ounce
s
Australian Production of Gold (1989-2013)
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: USGS and Taggart (2013)
2013 Gold Industry Paradigm
• Rising mining costs;
• Flat production growth;
• Flat or falling prices;
• Weak shareholder returns.
• Interest was in linking costs and geology at a higher-level than ‘deposit-scale’ so that we could begin making predictive statements about what types of deposit generally are mined with lower costs.
0
200
400
600
800
1000
1200
1400
1600
1800
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
US$
/ou
nce
Increases in costs over time
Growth Capex Cost
All-In-Costs
Gold Price
Slide 6 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Study covered all of Australia & NZ
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014)
Slide 7 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
All the famous gold geological provincesQ4 2013
Australia & NZ gold production by Geological
Province
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
% of Total Gold Production
No. of Operating Gold Mines
Source: Kanakis (2014)
Slide 8 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Initial results: There are gold cost-geology linkages (Kanakis, 2014)
Is grade king in gold?
A preliminary analysis of gold production costs at Australian and New Zealand mines
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 9 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Sedimentary vs. igneous host rock unclear
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Sedimentary
Igneous
Neither
Source: Kanakis (2014)
Q4 2013 Australia & NZ
% of deposits by host rock in each cost
quartile
Slide 10 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
But plutonic over volcanic igneous matters
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Volcanic
Plutonic
Neither
Source: Kanakis (2014)
Q4 2013 Australia & NZ
% of deposits by host rock in each cost
quartile
Slide 11 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Does mineralisation-style matter?
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Increasing dispersion of mineralisation
Increa
sing
thick
ness o
f mineralisation
Quartz reef / lode / lens
Quartz tension vein
Uneconomic thin quartz veins
Thick laminated quartz veins
Ladder quartz veins
Thin stockworkvein system
Thicker veins in shear zone
Dispersed breccia hosted mineralisation
LODE / VEIN STYLE MINERALISATION
ALTERATION ZONE & DISSEMINATED SULPHIDE HOSTED MINERALISATION
Source: Kanakis (2014)
Slide 12 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Disseminated mineralisation is important
Q4 2013 Australia & NZ
% of deposits by mineralisation style in
each cost quartile
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Vein / Reef Style
Disseminated Style
Source: Kanakis (2014)
Slide 13 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Refractory mineralisation may also matter
Q4 2013 Australia & NZ
% of deposits by free-milling vs refractory ore in each
cost quartile
NB: Potentially due to the by-products often found in refractory sulphide ores (e.g. copper).
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Free-milling
Refractory
Source: Kanakis (2014)
Slide 14 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Does deposit geometry matter?
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014)
Slide 15 of 33
cylindrical
equidimensional
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Equidimensional geometry matters too
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Q4 2013 Australia & NZ
Cost curve by deposit geometry
NB: Gently dipping planar deposits also give lower costs than steeply dipping planar deposits.
Source: Kanakis (2014)
Planar Deposit
Cylindrical Deposit
Equidimensional Deposit
Slide 16 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Initial implications: Geology matters! (Kanakis, 2014)
Is grade king in gold?
A preliminary analysis of gold production costs at Australian and New Zealand mines
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 17 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Grade is engineered away; geology is not
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014)
Slide 18 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Initial study weaknesses: Not big enough… (Kanakis, 2014)
Is grade king in gold?
A preliminary analysis of gold production costs at Australian and New Zealand mines
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 19 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
What about deposit type? We don’t know
• Orogenic and epithermal deposits gave variable results;
• Porphyries were very low cost except for Boddington;
• Not enough data for IOCG deposits;
• There is not much to go with here…
• This was effectively a study of the economics of orogenic gold deposits.
0 10 20 30 40 50
Orogenic
Epithermal
Porphyry
VHMS
IOCG
No. mines in the study by deposit type
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014)
Slide 20 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Mine maturity & cost cycle unconsidered
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014); Trench & Sykes (2014)
Slide 21 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Correlation not causality• Some hypotheses suggested for link between geological
factors and gold production costs, but no causality confirmed:
– Grade advantage is engineered away in complex deposits?
– Non-equidimensional deposits have greater strip ratios?
– Bulk mining more important than ‘high grade’ mining?
– Higher bond work index of unmineralised host rock is more costly to process?
– Refractory deposits more costly to process but this is overcome by the presence of valuable by-products?
– Complex deposits have higher unit labour costs?
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014)
Slide 22 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Expanded investigation: Gold costs and geology (Ulrich et al., 2016-19)
Is grade king in gold?
A preliminary analysis of gold production costs at Australian and New Zealand mines
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 23 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
In 2016 we’re back to focusing on growth
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: USGS; Perth Mint
2016 Gold Industry Paradigm
• Falling costs;
• AUD weakening;
• Strong returns;
• Focus on production growth;
• Rise of Northern Star, Evolution etc.
• Discovery of Gruyere, Andy Well etc.
• But how long can this last?
7
7.5
8
8.5
9
9.5
10
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Millions
of ou
nces
Australian Production of Gold (2006-2015)
1,000
1,200
1,400
1,600
1,800
2,000
Jan-11
Jul-1
1
Jan-12
Jul-1
2
Jan-13
Jul-1
3
Jan-14
Jul-1
4
Jan-15
Jul-1
5
Millions
of ou
nces
Gold Price AUD vs USD (2011-2015)
Slide 24 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
But running short of ‘quality’ ore• Australia & NZ good at growing ‘resources’ (i.e. EDR),
now often 5-35 years worth;
• But struggle to make dramatic increases in ‘reserves’;
• Many of Australia’s best mines are its oldest;
• 14% of gold is mined at operations with less than 2 years of reserves…
• 38% of gold is mined at operations with less than 5 years reserves…
• Average reserve life is 5.4 years.
• More high quality (i.e. reserve standard) ore discoveries required – both greenfield and brownfield;
• Once again we’re trying to understand ‘high quality’…
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Ulrich et al., (2016)
Slide 25 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Hypothesis remains: grade is not quality
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Q1 2016 Australia & NZ All-in-Sustaining Cost (ASIC) vs Gold Grade
Source: Ulrich et al., (2016)
Slide 26 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Causality emerging: Focus on mining
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Grades and costs correlate at the processing stage, but not the mining stage, suggesting that the geological factors influencing processing (e.g. bond work index) are less important than those that influence mining (e.g. geometry).
Q1 2016 Australia & NZ ASIC Mining Cost vs Gold Grade
Q1 2016 Australia & NZ ASIC Processing Cost vs Gold Grade
Source: Ulrich et al., (2016)
Slide 27 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
More analysis to come…• Longer time series of
analysis to confirm initial findings;
• And account for mine maturity and cost cycle;
• Deeper investigation into causality linking geology and cost in gold mining;
• Wider consideration of non-technical industry factors that may be important.
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Ulrich et al., (2016)
Slide 28 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Conclusions: How does geology drive costs and why does it matter?
Is grade king in gold?
A preliminary analysis of gold production costs at Australian and New Zealand mines
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 29 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Are we rising or stalling?• The Australia & NZ gold mining industry must remain competitive through the industry cost cycle:
– Reducing costs during periods when margins are squeezed (i.e. 2013);
– Bringing on new, competitive supply when margins are increasing (i.e. now).
• A ‘rise & stall’; or ‘rise & fall’ scenario is a material risk otherwise; – Emerging signs of success in both production growth (Northern Star, Evolution etc.) and recent discoveries (Andy Well, Gruyere, Tropicana etc.)
– However whilst ‘resource’ growth is strong, we remain short of mineable ‘reserves’;
– A focus on discovering and mining more ‘reserves’ rather than ‘resources’ required.
• ‘Grade is king’ over-simplifies the sector’s mine economics;– Geological factors such as mineralisation style, deposit geometry and host rock are at least as important as grade at an industry-level;
– Future greenfields and brownfield exploration may have to consider these factors earlier in the exploration process (but how?);
– M&A due diligence may need to add greater weight to such factors;
– Non-grade geological factors may increase in importance in mine planning.
• Clearly more research is required in this important area of study.
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 30 of 33
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
If Grade is KING; Geology is the ACE
• Equidimensional deposit;
• With disseminated mineralisation;
• Hosted in plutonic igneous rocks;
• Potentially with by-product rich refractory ore;
• And maybe some high grade ore…
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New Zealand
Source: Kanakis (2014)
Slide 31 of 33
THANK YOU
CONTACT DETAILS
Sam Ulrich: [email protected]
Matt Kanakis: [email protected]
David Groves: [email protected]
Steffen Hagemann: [email protected]
John P. Sykes: [email protected]
Allan Trench: [email protected]
AusIMM New Zealand Branch Conference
Wellington, New Zealand: 4-6 September 2016
Is grade king in gold? A preliminary analysis of gold production costs at Australian and New Zealand mines
Further reading
• Ulrich, S., Kanakis, M.D., Groves, D., Hagemann, S., Sykes, J.P. & Trench, A. 2016. Is Grade King in Gold? A Preliminary Analysis of Gold Production Costs at Australian and New Zealand Mines. AusIMM New Zealand Branch Conference. Wellington, New Zealand. 4-6 September.
• Kanakis, M.D. 2014. Geological Factors that Influence the Cost of Production in Currently Operating Gold Mines within Australia and New Zealand. BSc (Mineral Geoscience) Honours Thesis. The University of Western Australia.
05 Sept 2016AusIMM New Zealand Branch Conference, Wellington, New ZealandSlide 33 of 33