Results of New Mining/Economic Study for Mankayan
12 February 2019
Bezant Resources Plc
("Bezant" or the "Company")
Results of New Mining/Economic Study Demonstrate Robust High Level Mining Options for the Mankayan Project, Philippines
Bezant (AIM: BZT), the copper-gold exploration and development company, announces the results of an independent study assessing the optimisation of potential future mine development for its Mankayan copper-gold project, located on the Island of Luzon in the Philippines (the "Mankayan Project"). The study was undertaken by independent consultants, Mining Plus Pty Limited ("Mining Plus"), using prevailing market conditions premised on the Snowden Mining Industry Pty Limited ("Snowden") resource estimate prepared in 2009 under JORC (2004) which defined an indicated resource of 1.1 million tonnes of contained copper and 3.7 million ounces of contained gold and an inferred resource of 0.2 million tonnes of contained copper and 0.6 million ounces of contained gold.
Highlights
• Alternative routes to production: The Mankayan copper-gold porphyry supports different robust routes for potential future development, including, for the first time, a Sub-Level Caving ("SLC") 'stepping stone' scenario, with two main Block Caving ("BC") routes identified for progression, from a total of 11 scenarios assessed, with both supporting an average production grade in excess of 0.64% copper equivalent ("CuEq").
• 5 year lead time to production: Under all four of the representative options selected for further analysis in the study, the time to initial production was approximately five years and the first five years of production was sequenced in order to deliver production from the higher grade areas of the deposit, in some cases demonstrating average grades achievable of up to 0.77% CuEq* during this initial period.
• Off-site costs incorporated: For the first time, off-site costs (for concentrate handling and smelting) were incorporated into the project's economics to more accurately demonstrate development viability.
• Updated analysis: the study has built and improved upon the historic 2014 scoping study update following analysis of the key inputs and characteristics further to the Company's review of the project during 2018.
The three main representative options summarised below, taken from the 11 modelled scenarios, comprise two BC scenarios and one SLC 'stepping stone' scenario (the option numbers being those used in the study)
The two preferred BC scenarios
• Option 4: medium production rate with lower start-up costs than those associated with higher production rate models
• US$1,181m net present value ("NPV")*, US$11,647m total revenue, US$19.1/t average cost, 27% internal rate of return before tax and royalty ("IRR"), US$896m start-up Capex
• Option 8: lower start-up costs, coupled with a good overall project value maintained by ramping-up the production rate after the first footprint
• US$797m NPV*, US$11,473m total revenue, US$19.7/t average cost, 21% IRR, US$633m start-up Capex
SLC intermediary route
• Option 9: a more flexible/low start-up cost SLC method has been determined as an intermediary step towards full block caving scenarios, with start-up Capex of US$529m, a slightly reduced time to first production, a first phase period into higher grade core and US$19.9/t average cost
Note: * - The NPV calculated is for comparative purposes only, as full financial analysis was not undertaken for the study. A mean copper price scenario of US$3/lb was used and all costs are mine and processing combined. Due to the current uncertainty surrounding the Philippine tax/royalty rates, neither have been included in the comparison. Inclusion of tax and royalty would reduce the NPV and IRR, but it is expected that the relative economic merits of each scenario would not change significantly.
Commenting today, Laurence Read, CEO of Bezant, said:
"Mankayan is a major, well delineated copper-gold porphyry style deposit and this latest Mining Plus study serves to demonstrate potential robust development options able to sustain an average mining grade above 0.64% copper equivalent at average costs below US$20 per tonne. This potentially highly efficient, established copper-gold source is situated on Luzon Island and accessible by tarmac road only a day's drive from Manila.
"Historic studies on the project were designed to optimise the mining model without necessarily taking account of extremely influential factors such as capital spread, the high grade core, mining rates and footprint and possible intermediary routes in order to achieve initial production from a significantly reduced capital outlay. This latest study has therefore been most informative and enables Bezant's management team to plan for different potential production scenarios ranging from 6 million tonnes per annum ("Mtpa") to 12 Mtpa without unduly affecting financial ratios.
"The identification of a Sub Level Caving route also provides a potential new way forward for Mankayan by way of an intermediary step towards full block caving which, when combined with new sequencing work, allows for first revenues to be achieved earlier for significantly reduced start-up Capex. The inclusion for the first time of estimated off-site costs in the project's economics represents an important element in assessing margins from the eventual future sales of concentrate.
"Our work with Mining Plus affords us great confidence that the project lends itself to potential future development by medium size mining companies, as well as the majors, seeking to secure a long-term source of physical copper and gold.
"The Board remains positive regarding the fundamentals for copper over the next three years and believes that signs of a supply shortfall are already becoming evident."
Further Information
The Mining Plus study identified and assessed a number of high-level alternative mining options for the Mankayan project as well as substantially improving the underlying economics of the proposed operations. The options considered were designed with the objective of improving production processes, determining pathways with reduced total start-up cost, identifying further potential value from the project and correctly including off-site costs for the first time. The options were based on the work undertaken by GHD Group Pty. Limited ("GHD") and Mining Plus in their 2014 Scoping Study Update and were evaluated using the parameters developed in that historic study.
This latest study has identified a broad range of mining options that can be used to mine the deposit. Relative to the historic study, these options included:
• A focus on higher grade.
• A focus on mining higher grade earlier.
• Reduced start-up costs.
• Accounting for the effect of off-site costs on revenue streams.
• Better or equivalent returns on investment than previous studies.
• Collective demonstration of the flexibility of the deposit to be mined by a wider range of strategies.
In total, eleven options were investigated with four representative options analysed in more detail in the study. Two main options were chosen as preferential block cave development routes at different scales and an SLC intermediary route towards block caving was also determined. The key metrics for each of these four options are set out in Table 1 below and include Option 3, a high rate, major block cave comparator of 24Mtpa.
Preferred Block Cave routes
Option 4: Medium production rate, with four BC footprints in two lifts. Each footprint was sized to meet the required production rate, with the first footprint in each lift located in the highest grade.
Option 8: Staged production rate, starting at 6Mtpa for a small high grade BC, before mining three larger footprints at a production rate of 12Mtpa.
SLC Intermediary route
Option 9: Low production rate, starting with a 6Mtpa low capex high opex sublevel cave before mining three BC footprints (this option could also be ramped up to 12Mtpa for the mining of the three BC footprints).
Block cave comparator scenario
Option 3: High production rate, high rate of return, high start-up cost two lift BC, where the full footprint of the BC is undercut to enable a high production rate.
Table 1: Summary of the Representative Options
|
|
Option |
3 (Comparator) |
4 (Medium rate Option) |
8 (Scaled option) |
9 (SLC ** Intermediary route) |
|
|
Description |
24Mtpa 2 BC footprints over 2 lifts |
12Mtpa 4 BC footprints over 2 lifts |
6Mtpa small BC followed by 3 12Mtpa BC |
6Mtpa SLC followed by 3 6Mtpa BC |
|
IRR before tax and royalty |
Cu $3/lb Au $1,250/oz |
29% |
27% |
21% |
14% |
|
Average Cost per t |
USD/t |
$19.1 |
$19.1 |
$19.7 |
$19.9 |
|
First Footprint Start-up Cost |
USD |
$1,402m |
$896m |
$633m |
$529m |
|
First 5 years of production |
Tonnes |
92 M |
54 M |
29 M |
28 M |
|
Cu (%) |
0.45 |
0.46 |
0.48 |
0.41 |
|
|
Au (g/t) |
0.51 |
0.54 |
0.62 |
0.45 |
|
|
CuEq (%) |
0.70 |
0.72 |
0.77 |
0.62 |
|
|
Total production |
Tonnes |
333 M |
316 M |
315 M |
302 M |
|
Cu (%) |
0.42 |
0.43 |
0.42 |
0.41 |
|
|
Au (g/t) |
0.46 |
0.47 |
0.46 |
0.45 |
|
|
CuEq (%) |
0.63 |
0.65 |
0.64 |
0.63 |
|
|
Mine Life |
Years |
23 |
34 |
38 |
58 |
|
Time to First Production |
5 |
5 |
5 |
4.2 |
|
|
NPV before tax and royalty, 8.5% discount rate* |
Cu $3/lb Au $1,250/oz |
$1,589m |
$1,181m |
$797m |
$361m |
Notes:
* - the NPV used is for comparative purposes only, as full financial analysis was not undertaken for the study.
** - SLC has been designed to be part of a continuation into a full block cave scenario, however the standalone IRR and mine life are included for continuity.
Analysis of the information in Table 1
The general trend is that the higher production rate options (higher start-up costs) return higher rates of return and discounted cashflows, due to the reduced effect of time discounting over a shorter mine life. Other points of note include:
• Options 3 and 4 have a very similar average cost per tonne, due to the higher start-up cost of option 3 being offset by the sharing of fixed production costs over a larger tonnage.
• The options target higher grade first, which can be seen in the comparison between the grade of the first 5 years versus the total production. The lower production rate cases can be more selective, thereby consequently returning a higher grade in the first five years.
• Option 9 (SLC) has a lower first five years grade than the BC options. This is due to it being a top-down method (hence starting in lower grade ore) and the higher dilution of the method, with each level being mined next to the dilution from the level above. This effect is mitigated by the greater selectivity of the SLC footprint.
• Option 9 (SLC) has a slightly lower lead time to first production because mining starts at the top and advances downwards (as opposed to the BC, which is bottom up).
• Although not explicitly modelled in the study, the SLC is less sensitive to geotechnical parameters than the BC, due to the rock being broken-up by drill and blast, rather than breaking due to the action of caving. Such drill and blast control of breaking comes at a considerably higher mining cost.
Comparison to historic 2014 scoping/economic study
As a result of changes to the model (e.g. inclusion of off-site costs, exclusion of tax and royalties and more accurate modelling of cave mixing) it is difficult to compare the above options directly with the 2014 Scoping Study Update. However, at equivalent metals prices, the historic study achieved a maximum IRR of 21%.
Whilst aggregating parameters from the 2014 Scoping Study Update, some discrepancies were found, which although not material to the accuracy level of previous studies have been resolved in the latest study. These included:
• Off-site costs for concentrate handling and smelting not being included.
• Timing of mill costs not being aligned to the start of production.
• Draw strategy of caves targeting high grade without following typical cave management rules for propagation.
• Over estimate of the mining cost per tonne reduction at higher production rates.
• Under estimation of mixing early and overestimate of dilution later.
Optimisation Methodology
Block caving (BC) mass mining methods are typically very low cost, but also very inflexible in the geometry of ore that they can mine. Accordingly, they typically have high planned dilutions or low planned recoveries relative to stoping methods where there is far greater flexibility to mine only the desired mineralisation. They are also long mine life, such that the time discounting of future revenues is significant and it therefore becomes very important to mine higher value material early.
Sublevel caving (SLC) mass mining methods have similar characteristics to block caves, but they are more flexible in their geometry. This flexibility comes at a much higher mining cost.
To ensure that the options were compared equivalently, a mining model was developed which used the following process to optimise the options and therefore achieve a like with like comparison.
• The geological model was regularised and then vertically mixed to model the dilution/recovery of the block caving process.
• The model was separated (manually) into zones in plan view for different footprints.
• Within each zone potential footprints were found based on the mining costs and grade, with the aim to maximise the undiscounted cash flow.
• Different combinations of lifts were tested in each zone, scheduled, and the combination that generated the highest discounted cash flow selected.
• Based on the selected combination of lifts, the opportunity cost (delay to the rest of the project due to mining low but payable grade) was calculated for all time periods.
• The zones and footprints were refined to maximise the cash flow less the opportunity cost.
• The lift positions were refined to maximise the cash flow less the opportunity cost.
• The opportunity costs were re-calculated from the updated schedule and the process repeated.
To generate the SLC shapes, the Datamine process "minable reserves optimiser" (MRO) was used to create an optimised SLC shape before selecting the levels, which, when combined with the remaining block cave levels returned the best discounted project value.
Assumptions and variable economics used in the study
A breakdown of the key assumptions used by Mining Plus and the effects of a copper price range of US$2.5 - US$3.5/lb is provided below.
Performance of representative options at US$3/lb, US$2.5/lb and US$3.5/lb for copper
|
|
Option |
3 |
4 |
8 |
9 |
|
|
Description |
24Mtpa 2 BC footprints over 2 lifts |
12Mtpa 4 BC footprints over 2 lifts |
6Mtpa small BC followed by 3 12Mtpa BC |
6Mtpa SLC followed by 3 6Mtpa BC |
|
IRR before tax and royalty Au @ $1,250/oz |
Cu $3/lb |
29% |
27% |
21% |
14% |
|
Cu $2.5/lb |
24% |
22% |
18% |
11% |
|
|
Cu $3.5/lb |
34% |
30% |
24% |
17% |
|
|
Average Cost per t |
|
$19.1 |
$19.1 |
$19.7 |
$19.9 |
|
Start-up Costs |
|
$1,402m |
$896m |
$633m |
$529m |
|
First 5 years of production |
Tonnes |
92M |
54M |
29M |
28M |
|
Cu (%) |
0.45 |
0.46 |
0.48 |
0.41 |
|
|
Au (g/t) |
0.51 |
0.54 |
0.62 |
0.45 |
|
|
CuEq (%) |
0.70 |
0.72 |
0.77 |
0.62 |
|
|
Total |
Tonnes |
333M |
316M |
315M |
302M |
|
Cu (%) |
0.42 |
0.43 |
0.42 |
0.41 |
|
|
Au (g/t) |
0.46 |
0.47 |
0.46 |
0.45 |
|
|
CuEq (%) |
0.63 |
0.65 |
0.64 |
0.63 |
|
|
Mine Life |
|
23 |
34 |
38 |
58 |
|
Time to First Production |
|
5 |
5 |
5 |
4.2 |
|
Total Cost |
|
$6,356m |
$6,032m |
$6,200m |
$6,019m |
|
Total Revenue before tax and royalty Au $,1250/oz |
Cu $3/lb |
$11,971m |
$11,647m |
$11,473m |
$10,776m |
|
Cu $2.5/lb |
$10,612m |
$10,325m |
$10,170m |
$9,550m |
|
|
Cu $3.5/lb |
$13,330m |
$12,970m |
$12,777m |
$12,004m |
|
|
NPV before tax and royalty, Au $1,250/oz, 8.5% discount rate* |
Cu $3/lb |
$1,589m |
$1,181m |
$797m |
$361m |
|
Cu $2.5/lb |
$1,116m |
$839m |
$534m |
$161m |
|
|
Cu $3.5/lb |
$2,061m |
$1,524m |
$1,061m |
$562m |
Note:
* - The NPV used is for comparative purposes only, as full financial analysis was not undertaken for the study.
Summary of Mining Parameters
|
Parameter |
Value |
Comments |
|
Recovery/Dilution |
|
|
|
BC Mixing |
100m Vertical |
Matches the values from the Laubscher Mixing Chart in the historic Scoping Study |
|
SLC Recovery |
80% |
Typical values for a neutral drawn SLC over multiple levels |
|
SLC Dilution |
25% |
|
|
SLC Cut-off |
0.75% CuEq |
Chosen as the highest grade for a footprint that could maintain 6Mtpa |
|
BC Cut-off |
0.21% CuEq + Opportunity Cost |
Typically much higher than 0.21% CuEq especially at the beginning of project |
|
Block Cave Dimensions |
|
|
|
Maximum Height of Draw |
500m |
|
|
Minimum Width |
150m |
|
|
Rates |
|
|
|
Decline Vertical Advance |
240m per year |
Reduced from 300m per year in the previous study based on recent experience of developing a twin access/conveyor decline |
|
Footprint Access/Setup time |
1 year |
Set-up footprint, before starting undercutting |
|
BC Undercut Rate |
6,000m2 per month |
Typical scheduled undercut rate for a large block caving project |
|
BC Rate of Vertical Draw |
Up to 70m per year |
Typical height of draw rate for a block caving project. |
|
SLC Sink Rate |
70m per year |
Mining Plus Estimate |
|
SLC Lateral Advance |
180m per year |
Mining Plus Estimate, equivalent to 500t/d/drawpoint (15m spacing) |
Summary of Revenue Parameters
|
|
Cu |
Au |
|
Metal Price |
$3/lb |
$1,250/oz |
|
Metallurgical Recovery |
94% |
74% |
|
Metal units |
2,205 lb/t |
31.103 g/oz |
|
Equivalent Factor % to g/t |
|
0.478 |
|
Concentrate Grade |
30% |
|
|
Concentrate Shipping Cost |
$30/con tonne |
|
|
Smelting Cost |
$70/con tonne |
|
|
as a % of gross value |
5% |
|
|
Smelter Deductions |
5% |
2% |
|
Refining Charge |
$0.07/lb metal |
$1.5/oz metal |
|
as a % of gross value |
2% |
0.1% |
|
Gross value per grade unit (% or g/t) |
$66.2 |
$40.2 |
|
NSR per milled grade unit (% or g/t) |
$58.1 |
$39.3 |
|
NSR per mined grade unit (% or g/t) |
$54.6 |
$29.1 |
Royalty and tax excluded
A full financial analysis was not undertaken and, due to the current uncertainty surrounding the Philippine tax/royalty rates, tax and royalty were not included in the comparison. Inclusion of tax and royalty would reduce the NPV and IRR, but it is expected that the relative economic merits of each scenario would not change significantly.
Recommendation
Mining Plus recommends that the respective options are studied in more detail as part of a future multi-disciplinary pre-feasibility study to include updating of the parameters/cost data which were taken from the 2011 conceptual study.
Historic Resource Estimate
The study was based on a JORC (2004) resource estimate from Snowden reported in July 2009 as set out below:
|
JORC (2004) Resource Category |
Tonnes (Mt) |
Copper (CU)% |
Gold (Au) g/t |
Contained Copper Tonnes (Million) |
Contained Gold Ounces (Million) |
|
Indicated |
221.6 |
0.49 |
0.52 |
1.10 |
3.7 |
|
Inferred |
36.2 |
0.44 |
0.48 |
0.20 |
0.6 |
The model also included mineralisation that sits outside of the stated JORC resources presented within the geological block model.
Data room and access to full report
Full access to the Company's established data room on its Mankayan Project and the full Mining Plus study can be granted to interested industrial or professional groups on application to the Company: lread@bezantresources.com.
Dr Evan Kirby has reviewed and approved the technical information contained within this announcement in his capacity as a qualified person as required under the AIM rules. Dr Kirby is a Non-Executive Director of the Company and a Member of the Australian Institute of Mining and Metallurgy.
For further information, please contact:
|
Bezant Resources Plc Laurence Read Chief Executive Officer Colin Bird Executive Chairman |
Tel: +44 (0)20 3289 9923
|
|
Strand Hanson Limited (Nomad) James Harris / Matthew Chandler / James Dance |
Tel: +44 (0)20 7409 3494 |
|
Novum Securities Limited (Broker) Jon Belliss |
Tel: +44 (0)20 7399 9400 |
|
or visit http://www.bezantresources.com |
|
The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulation (EU) No. 596/2014.
Notes to Editors:
Mining Plus
Mining Plus (www.mining-plus.com) is an international mining services provider specialising in geology, mining engineering and geotechnical engineering, covering a broad range of mineral commodities and project types, enhanced by strategic alliances in other core disciplines. Mining Plus has advised on over 1,850 projects for 630 customers in 40 countries over a range of different commodities.
Bezant's Copper-Gold Project Portfolio
The Mankayan Project, Philippines
The deposit is principally hosted by a 900m long by 400m wide north-south striking intrusive stock complex composed largely of quartz diorite porphyry. The igneous rocks have intruded a thick sequence of andesitic volcanics and a basement of biotitequartz schists and mafic flows. The size, grade and mineralogy of the Guinaoang deposit are typical of porphyry copper deposits.
From October 2011 to January 2014, the Mankayan Project was held under option by Gold Fields Netherlands Services BV ("Gold Fields") for a total exercise price of US$70m (of which US$9.5m was received by the Company by way of initial non-refundable option payments). The option ultimately lapsed, as Gold Fields began new operations in Australia, and all exploration data, including the results of the high-grade BR 60 drill hole completed by Gold Field during the option period, was transferred to Bezant.
Eureka Project, Argentina
The Eureka project covers in excess of 10 thousand hectares and is located in the north-west corner of the Jujuy province in northern Argentina, adjacent to the border with Bolivia and at an altitude of approximately 3,600 to 4,400 metres (above sea level). The tenements are situated within the Argentinean portion of the regionally extensive Bolivian-Argentinean Tertiary Belt (Puna-Altiplano high-plateau) and there are two major metallogenic associations present.
The property hosts the historical "Eureka Mine", which had been exploited by the Jesuits since the 17th century, with an artificial dam having been constructed for washing the gold extracted. Further industrial-style gold exploitation commenced in circa 1885 (Novarese 1893), alongside exploitation of the "La Perdida" (now called "El Torno") and the "San Francisco" mines. The most recent copper extraction occurred in circa 1949 and continued in sporadic form to 1975 (Coira et al 2002). The latest exploration activities in the area (1980-2001), were carried out by Mantos Blancos, Paramount Ventures and Finances and most recently, by Minera Penoles and Codelco. The Company is interested in 11 exploration licences covering the tenements.
Historic exploration resulted in non-compliant resource estimates from Minera Penoles in the order of 62 million tonnes grading at approximately 1% for copper (620,000 tonnes of copper) and from Mantos Blancos, of 600,000 tonnes grading at approximately 2.7 g/t of gold (52,000 ounces of gold).
The Company is currently developing and pursuing potential Joint Venture options for the project.
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