 |
|
Property |
Location |
Deposit Type |
Interest |
Status |
|
Braúna Diamonds |
Brazil |
Kimberlite and Alluvial Diamond Deposits |
51% interest, subject to meeting certain
conditions |
4 diamondiferous kimberlites, 22 kimberlite
occurrences discovered along a 15 km long
fissure system. |
|
Braúna Gold |
Brazil |
Lode Gold |
100% |
800 metre long quartz vein system with
grab-sample gold grades ranging between 0.19
oz/t and 0.68 oz/t. |
Braúna Diamonds
Vaaldiam has a 51% interest, subject to satisfying
certain conditions, in the Braúna diamond project in the
state of Bahia, Brazil. This is Vaaldiam’s most advanced
exploration project. The Braúna property is 7km south of the town of Nordestina in the Rio Itapicuru basin on the São Francisco Craton. The property is situated approximately 350km from the city of Salvador, the state capital, and is easily accessible by road on a year-round basis. Skilled labour and complete infrastructure including power and water are readily available in the area.
The Braúna project is comprised of three exploration concessions which encompass four diamondiferous kimberlite pipes or blows that are associated with a system of 22 kimberlite occurrences that have been traced over a distance of 15km. The exploration licenses cover an area of 50km² (5,000 hectares).
Highlights of the study, for 100% of
the project on an equity basis, are as follows:
-
Using a 10% discount rate and an
independent diamond value of US$338/carat:
- Base case pre-tax Net Present Value (‘NPV’) of
US$33.6 million and Internal Rate of Return (‘IRR’)
of 42%, using Coffey’s NI43-101 Mineral Resource
with base case diamond grade of 16.8 carats per 100 tonnes (‘cpht’); and
- Second
scenario pre-tax NPV of US$101.0 million and IRR of
107% using the Howe NI43-101 Mineral Resource
diamond grade of 24.58 cpht.
-
A conceptual open pit mine life of 5 years based on
a production rate of 720,000 t/year, waste stripping
ratio of 4.45 and a total open pit diamond
production of 573,000 carats for Coffey’s Mineral
Resource and 839,000 carats for Howe’s Mineral
Resource. This excludes any potential below
200 metres at B3 or from other nearby kimberlites.
-
Project capital cost of US$25 million (including 15%
contingency) and average open pit life of mine
operating cost of US$31/t run of mine production
(‘ROM’) in a conceptual mine plan using open pit
mining to a depth of approximately 200 metres below
surface.
B3 Resources – Howe
Vaaldiam reported on January 20, 2011 that Howe prepared
an initial NI43-101 Mineral Resource and defined
Indicated Resources to a depth of approximately 40
metres of 0.63 million tonnes at a grade of 24.58 cpht
in the South Lobe, and 0.67 million tonnes at a grade of
4.72 cpht in the North Lobe of the B3 kimberlite.
Howe also reported Inferred Resources to a depth of
approximately 200 metres containing 3.75 million tonnes
at a grade of 24.6 cpht in the South Lobe and 1.04
million tonnes at a grade of 4.7 cpht in the North Lobe,
at diamond valuations of US$338/carat and US$100/carat
respectively.
|
Braúna 3 Global Resource Statement, North and South Lobes – Howe |
|
Mineral Resource |
Classification |
Volume (m3) |
Density (t/m3) |
Tonnes |
Diluted Grade (cpht) |
Carats
|
|
North Lobe |
Indicated
Inferred |
247,000
386,000
|
2.7
2.7 |
667,000
1,042,000 |
4.72
4.72 |
31,000
49,000 |
|
South Lobe |
Indicated
Inferred |
233,000
1,390,000 |
2.7
2.7 |
629,000
3,753,000 |
24.58
24.58 |
155,000
922,000 |
B3 Resources – Coffey
Coffey reviewed the Howe Mineral Resource Statement and
adjusted the diamond grade so that it is based on volume
(ct/100m3) using density data acquired from the surface
bulk samples and drilling programs, to account for a
difference in density between the saprolitic samples
excavated at surface and the harder, fresh kimberlite at
depth. Coffey estimated an average resource
diamond grade of 16.8 cpht for their base case scenario
for the South Lobe of the B3 kimberlite, and a diamond
valuation of US$338/carat. Coffey did not consider the
North Lobe in the PA because the diamond grade based on
the surface sampling completed to date was too low to be
declared a Resource at a value of US$100/carat.
|
Braúna 3 Global Resource Statement, South Lobe Only – Coffey |
|
Mineral Resource |
Classification |
Volume (m3) |
Tonnes |
Grade cpht |
Total Carats |
US$/ct |
|
Saprolite |
Indicated |
14,700 |
24,200 |
27.7 |
6,700 |
338 |
|
Fresh Rock |
Inferred |
1,606,100 |
4,410,100 |
16.6 |
733,000 |
338 |
Preliminary Assessment
Coffey prepared a conceptual mine plan, process plant
design, capital cost and operating cost parameters, and
a preliminary economic assessment based on the mineral
resource block model prepared by Howe.
Coffey based their economic assessment on two open pit
mining scenarios focused only on the South Lobe of the
B3 kimberlite. Coffey’s ‘Base Case’ scenario is
based on 3.49 million tonnes (‘Mt’) of Coffey’s Mineral
Resource. The Base Case financial model uses a
diamond price of US$338/ct, which is the average value
of 1,013.75 carats of diamonds recovered from the South
Lobe of B3, independently valued by Diamond Counsellors
International of London, U.K. and International Economic
Strategies of Antwerp, Belgium in November 2010 (as
reported by Vaaldiam on December 2, 2010).
The
second scenario prepared by Coffey is based on 3.49Mt of
Howe’s South Lobe Mineral Resource.
Conceptual Mine Plan
The conceptual mine plan
envisions open pit mining of the South Lobe of the B3
kimberlite to a depth of approximately 200 metres.
The mining sequence and design was determined by
optimizing the pit depth to achieve a production rate of
720,000 t/year to support a processing rate of 100 t/hr.
The pit designs were finalized using the Whittle pit
optimization software on both the Coffey Base Case and
Howe Resource models, with a stripping ratio of 4.45:1.
The plan assumes that contract mining will be employed
for all mining operations.
Diamond
Processing Plant
Coffey proposed a diamond
processing plant capable of processing 720,000 t/year of
kimberlite ore. Ore preparation will include
initial jaw and cone crushing followed by tertiary
crushing, scrubbing and screening with vibrating
screens. Ore is concentrated in a Dense Media
Separation plant and the diamonds separated from the
heavy mineral concentrate using X-ray sorting and
grease-table technology. Diamond recovery is
estimated at 98% of the resource grade based on a bottom
screen size cut-off of 1.0mm, and an upper-screen size
cut-off of 30mm to allow the recovery of large diamonds.
Capital Cost
Coffey has estimated a
capital cost, for the mining, diamond processing plant
and infrastructure of US$25 million, including a 15%
contingency. It is envisioned that
contractors will be used for site infrastructure
construction. Coffey based its estimate of the
capital cost on factored costs from previous project
equipment capital cost information.
|
Scoping Study Plant Capital Cost Estimate |
|
Discipline |
US$
|
% of Total |
|
Earthworks & Roads, Civils, Building Works |
5,160,098 |
23.9% |
|
Mechanical Equipment Supply & Erection |
3,971,066 |
18.4% |
|
Piping, Steel and Erection |
2,640,859 |
12.2% |
|
Electrical Equipment & Instrumentation |
2,263,593 |
10.5% |
|
Indirect & Owners Costs |
2,452,226 |
11.4% |
|
Pre-Production Costs |
282,949 |
1.3% |
|
EPCM |
1,509,062 |
7.0% |
|
Transport |
100,000 |
0.5% |
|
Contingency |
3,187,623 |
14.8% |
|
Total |
21,567,476 |
100%
|
Operating Cost
Coffey has
considered a processing rate of 720,000 t/year ROM and
an average waste stripping ratio of 4.45:1. The
mining operation is envisioned to mine and transport an
average of 3.9Mt per annum (‘Mtpa’) ore and waste and a
total of 19.0Mt over the expected 5-year open pit life
of mine, excluding any potential below 200 metres and
from other nearby kimberlites.
Coffey’s base
case operating costs have been derived from first
principles and from reference to contract mining costs
at comparable-sized mining operations in Brazil.
In summary, mining costs are estimated at US$4.25/t
mined. Costs for processing and general and
admnistration are estimated at US$6.23/t and US$1.72/t
respectively.
Project Overview
The two-hectare B3 pipe is open vertically and laterally
and is located in easily accessible terrain just 7 km
south of the town of Nordestina. Nordestina has
excellent infrastructure, grid power, services and a
pool of skilled labour.
Vaaldiam has
performed exploration work elsewhere on the property,
including the Braúna 8 (‘B8’) kimberlite dike situated 5
km north of the B3 pipe. Mini-bulk samples from
this 4.5 metre-wide dike produced 170 diamonds weighing
19.37 carats, including a 7.97 carat white octahedron
stone, from approximately 46 dry tonnes, inferring a
recovered grade of 42 cpht. The B8 occurrence is a
vertically oriented kimberlite dike forming a 1,000
metre-long section of the northwest trending dike
system. Recent exploration conducted in the
vicinity of the B8 dike has confirmed that this dike is
linked to the Braúna 21 occurrence. Mini-bulk
sampling of the one hectare Braúna 7 pipe, situated 1 km
to the east of the B3 pipe, resulted in the recovery of
30 diamonds with a total weight of 3.87 carats from
approximately 87 tonnes of kimberlite with an estimated
recovered diamond grade of 4.5 cpht.
A.C.A. Howe NI 43-101 Resource
A.C.A. Howe International Limited NI
43-101 Technical Report A National Instrument 43-101 (“NI 43-101”) report,
completed at the end of December 2010, provided
estimates of Indicated Resources at Braúna 3 to a depth
of approximately 40 metres of 0.63 million tonnes at a
grade of 24.58 carats per hundred tonnes (“cpht”) in the
south lobe and 0.67 million tonnes at a grade of 4.72
cpht in the north lobe of the kimberlite. Inferred
Resources to a depth of approximately 200 metres are
estimated to contain 3.75 million tonnes at a grade of
24.58 cpht in the south lobe and 1.04 million tonnes at
a grade of 4.72 cpht in the north lobe. The diamonds
from the north and south lobes were valued at US$98 per
carat (“ct”) and US$339 per ct, respectively, using the
average estimated sales price of two independent diamond
valuations. The average value of the resources is US$338
per ct.
Braúna Gold Occurrence (100% interest)
Vaaldiam’s Braúna claims are located
within an important gold producing Rio Itapicuru
Greenstone Belt, which hosts Yamana Gold’s Fazenda
Brasiliero Mine and several advanced exploration
projects where both open pit and underground gold
reserves and resources have been delineated. Gold
occurrences within the Rio Itapicuru Greenstone Belt are
associated with hydrothermally altered shear zones that
occur within supracrustal rocks at the margins of
granitic intrusions. Mapping on the Braúna property has
outlined several intrusive units and it is along their
sheared margins in complex networks of quartz fault-fill
veins that gold mineralization has occurred. In 2010,
Vaaldiam will engage in further geochemical sampling,
geological mapping and trenching in order to assess the
potential of known gold anomalies within the Braúna
property and evaluate other potential regional targets.
Results from these efforts will be used to identify
priority drill targets on the property.
Historically, along with artisanal
diamond mining and intense exploration activities, the
area has been the target of small-scale gold production
by garimpeiro operators; however, the gold occurrences
on the Braúna claims remain untested by modern methods.
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