The Development of AK6 SAIMM Source to use Conference Feb 2010

1. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
The Development of AK6
James AH Campbell
Jeremy Clarke
William Lamb
Dr Kurt Petersen

2. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Agenda
• Introduction
• Location & History
• Terms & Conditions of the Mining License
• The Resource
• Value Engineering Study
• Social & Environmental Responsibility
• Conclusion

3. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Introduction
• Evolution of project from a poorly known
kimberlite to a world class kimberlite diamond
mining project
• Benefit of significant data procured during the
resource development phase
• Focus on reducing upfront capital costs and
designing an operation that is technically fit
for the ore body and economically flexible

4. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Location & History
• AK6 is a Cretaceous age
kimberlite located in NE
Botswana
• Discovered in 1969 by Debot
• Re-assessed in 2003 by Debot
– New geophysics & drilling
technology
• AFD, Debot JV (Boteti) signed in
2005
• Mining License approved by GRB
in 2008
• Debot sold their share in Boteti
to Lucara in 2009

5. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
The Resource
- Sampling Programme
• 44, 6.5” percussion holes
• 23 pilot (core) holes
• 31 LDD (23”) holes
– Most down to 400m
– Two down to 756m
• 51 delineation (core) holes
• 3 bulk samples
• Main challenges:
– Diamond breakage
– Estimation of large stone
content

6. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
The Resource
- Results of Sampling Programme
• Indicated Resource to 372m:
– 8.9M cts in 40M tonnes
• Inferred Resource from
372-758m:
– 6M cts in 31M tonnes
• Average grade (+1mm) of 22cpht
• Modelled diamond value of
USD162/ct (+1mm), though
production value expected to be
in the USD200/ct region
– High proportion of Type II
diamonds

7. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Terms & Conditions of Mining License
• Mining License granted for 15-years from
10 October 2008
• Taxed under the twelfth schedule of the
Income Tax Act, including a variable rate of
Income tax
• Can offset withholding taxes against
income tax
• Normal royalty specified in the Botswana
Mines and Minerals Act
• Arrangements for the marketing of AK6
diamonds to be finalised with the
government
– Originally with the DTC
– Tender systems currently being investigated
• No government equity in the project
• Waiving of road levy on diesel if used for on
site power generation

8. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Introduction & Concepts
VES designed to reduce both capex and opex
from original Debot mine design
• Review all previous information from the
previous Debot studies
• Previous PPM pre-feasibility study indicated
that a phased approach to the project lowers
risk and can improve ROI
• Very different plant flowsheet
• Contract out as much as possible

9. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Mining
• Phased approach to project
– Phase 1: 2.5-3M tpa
– Phase 2: 4M tpa
• Used Debot data for new Whittle
model
• Split shell design
• LOM
– Kimberlite mined: 36 Mt
– Waste stripped: 90 Mt
• Detailed mine design expected to
reduce waste to c.70 Mt
• Conventional drill, blast, load and
haul mining systems
• Mining contractor: wet rate contract
NLobe CLobe SLobe
5 Year
Shell
96m deep
LOM Shell
288m deep
Clearancebetween the
2shells in this area
wouldneed to be
re-engineered
inthe next phase

10. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Treatment
• Review of “standard” flowsheet
• Break down flowsheet and derive
business case for each unit process
(including recycle loads)
• Determine areas of real value add
• Prioritise unit processes
• Simplification where possible
• Consider alternative technologies
• Review need for plant infrastructure:
buildings, maintenance cranage and
access; etc.
• Contract out operations
• Optimise the generation of net
revenue

11. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Treatment
Traditional approach to plant design based on
• Upfront size preparation
• Mass balance management: circulating loads
• Maximising liberation potential through slimes generation
• Asset efficiency: multiple tasks for equipment
Autogenous Milling
• Contains compressive, shear and abrasive forces in a single
unit process
• Contains internal classification and recycling of material
• Selectively reduces softer ore to fine sizes
• Mill can be “tuned” to comminution and diamond
liberation requirements: very flexible

12. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Treatment
Autogenous milling a viable option
• Does same job as 2° crushing,
scrubbing and screening, HPGR
crushing and disagglomeration
• Can treat highly weathered kimberlite
• Reduces DMS capacity
• Removes the need for internal water
circuits
• Reduces capex
• Reduces opex
• Reduces manpower
• Better availability and utilisation
• Very flexible flowsheet: tph/tcos/bcos

13. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Treatment
Phased project development
• Equipment sizing caters for double up
• Very different material characteristics over LOM
– Soft ore in the beginning, getting harder
– Very high DMS yields in later years: up to 25% for
Unit 13
• Limited Ore Dressing Study (‘ODS’) data,
flexibility built in process facility
• Ability to bulk sample during operations
• Learn about the resource as you mine
• Flexibility of plant operations

14. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Treatment
VES Flowsheet
• Primary mineral sizer
• Mill
• Pebble crushing
• Spiral classifier and screen
• DMS
• Magnetic separation
• X-ray machines
• Grease belts
• Handsorting
One recycle load only

15. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Infrastructure
Minimal infrastructure on site
• Gravel access road
• Power supply from Orapa substation: 33kV
• Adequate process and potable water from pit
dewatering well ring
• Contractors to provide own infrastructure
• Central maintenance facility for plant and infrastructure
• Housing of personnel in Letlhakane
• Clean wage system
• On site emergency medical facilities
• Construction camp to be provided by contractor: rented?

16. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Value Engineering Study
- Capex & Opex
VES Financials
• Capex
Phase 1: US$64 million
Phase 2: US$25 million
• Opex
Phase 1: US$14.5 per tonne treated
Phase 2: US$13.8 per tonne treated

17. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Social & Environmental Responsibility
Great deal of emphasis has been placed on the
Social and environmental aspects of the project
• Preliminary EIA
• Scoping study stage
• Detailed EIA
• EMP
EIA and EMP approved in 2008
Extensive public participation ongoing after recent
change of ownership of the project

18. SAIMM Colloquium
Diamonds – Source to Use 2010
SAIMM Colloquium
Diamonds – Source to Use 2010
Gaborone, Botswana
Conclusions
• VES indicates a viable, low cost, high efficiency
approach to the development of the AK6 Mine
• Autogenous milling provides major benefits in
the treatment of kimberlites
• Phased approach to project reduces risks
• Feasibility Study update ongoing based on the
VES: completion by May 2010