Ivanhoe Mines updates ongoing exploration and development
work at its Kamoa copper discovery in the Democratic Republic
of Congo's southern province of Katanga
Recent drill hole intercepted 15.7 metres true thickness
of 7.04% copper in Kansoko Sud high-grade area
that will be the focus of initial mining
Mr. Friedland said the work has further confirmed that the focus of the company’s initial mine development at Kamoa will be on the high-grade Kansoko Sud area, where ongoing infill drilling since the last resource estimate was produced in 2012 has defined a thick, near-surface zone of high-grade copper sulphide mineralization that would be amenable to treatment by a conventional copper flotation plant.
One of the 101 infill holes drilled in this area, for which assays were received in April 2014, intercepted 15.7 metres (true width) of 7.04% copper at a 1.5% total copper cut-off.
Infill drilling confirms overall grade and thickness of 2012 resource estimate
Since issuing an updated, independent preliminary economic assessment (PEA) for the Kamoa Project in November 2013, Ivanhoe has concentrated its exploration drilling activities on the acquisition of samples for metallurgical testing, as well as undertaking drilling on 200-metre close-spaced sections in the Kansoko Sud area. Exploration drilling has been directed at infilling those areas identified as primary mining targets in the PEA.
A total of 60 of the 101 holes with assays returned since the release of the updated PEA six months ago were drilled in the Kansoko Sud area, 29 were in Kansoko Centrale, one in Kansoko Nord, nine in Kamoa Sud and two in Makalu. The final composited assay results are included at the end of this news release.
Infill drilling of the initial mining area has confirmed the overall grade and thickness of the December 2012 resource estimate in these areas and has provided invaluable refinement within localized areas. While traditionally modelled on a 1% total copper cut-off to define a selective mineralized zone, the deposit has shown that grade continuity also exists at an elevated 1.5% total copper vertical cut-off, and that a 2.0% vertical total copper cut-off may be feasible in certain areas.
Figure 1. Location of holes with assays returned on Kamoa Copper Project from October 2013 to May 2014.
Initial mine economics should benefit from narrower, higher-grade intervals
Recent work defining the selective mineralized zone (SMZ) at higher vertical cut-offs has shown that narrower, higher-grade intervals create more expansive, contiguous zones, which should improve initial mine economics.
A new base case for future engineering studies is being developed using a 1.5% total copper cut-off with a minimum three-metre mining height and a maximum mining constraint of six metres (a single mining cut); incremental mineralization above six metres will be included only if the grade of the incremental mineralization exceeds 2%. This approach was introduced for thicker intercepts, to ensure initial mining cuts would extract only higher-grade material.
Encouraging results of Kansoko Sud infill drilling and Hole DKMC DD860
The initial mine plan produced in the PEA focused initial mining in the shallower portion of Kansoko Sud, an area previously drilled on 400-metre spacings. Since completion of the PEA, Ivanhoe has concentrated on substantially closing the distances to 100-metre spacings on 200-metre-spaced, east-west lines, with the goal of demonstrating grade and structural continuity of this high-grade zone at potentially elevated cut-offs. Drilling is continuing in this area; results to date are extremely encouraging and have confirmed — and in some locations exceeded — the initial results based on holes spaced 400 metres apart.
Included in the new drill results is Hole DD860, which is a PQ-sized parent hole of a series of wedges drilled for comminution. Assay results received for Hole DD860 show a remarkable combination of grade and thickness, with a copper grade of 6.88% over 17.3 metres (16.2 metres true thickness) at a 1% total copper composite cut-off. Using a higher cut-off of 1.5% total copper, the intercept returned 7.04% total copper over 16.8 metres (15.7 metres true thickness). Sections through Hole 860 displayed good continuity of grade and thickness in the north-south and east-west orientations, as shown in the accompanying sections — which also report the elevated, 1.5% total copper composites.
Exploration continuing in 2014
During the remainder of 2014, Ivanhoe intends to continue its detailed infill program in the initial mining area to cover an area of approximately one square kilometre with a 100-metre detailed grid.
Progress on pre-feasibility study, with initial mining at Kansoko Sud
In line with the phased approach to project development outlined in the 2013 updated Kamoa PEA, the Kamoa pre-feasibility study (PFS) is progressing on the basis of an initial three-million-tonne-per-annum (3Mtpa) mine and concentrator.
Reviews of the resource model, combined with results from recent infill drilling at Kansoko Sud, have confirmed grade continuity, which allows the resource model to be constrained at a higher cut-off grade. The focus in planning the early years of mine production continues to be on the near-surface and high-grade material from Kansoko Sud to maximize margins. The 3Mpta mine and concentrator can be split into modules to potentially better match the underground ramp-up and further reduce the pre-production development capital. This will be examined in more detail as part of the pre-feasibility study to provide flexibility to the development of the Kamoa Project.
Work to begin this year on decline to access the Kamoa underground
Preparations are underway to start the first mine-access decline at Kamoa’s Kansoko Sud area. The decline is designed to provide access to the high-grade copper resources that would be targeted for the planned first phase of production using the room-and-pillar mining method.
Figure 2. New holes drilled in the Kansoko Sud and Kansoko Centrale area showing north-south and east-west section lines through Hole DKMC DD860, superimposed on Cu% x true thickness contours.
Figure 3. Kansoko Sud Section Line looking west, showing 1.5% copper cut-off composites.
Figure 4. Kansoko Sud Section Line looking north, showing 1.5% copper cut-off composites.
Large-scale underground mining to use room-and-pillar and drift-and-fill methods
Kamoa is considered amenable to large-scale, mechanized mining using a combination of room-and-pillar and drift-and-fill methods, given the deposit’s favourable mining characteristics as derived from the December 2012 mineral resource — including its relatively undeformed, continuous mineralization, local continuity between closely-spaced drill holes and flat-to-moderate dips. The low dip and the flat geometry of the resource make it conducive to room-and-pillar mining in the shallow portions of the deposit, which would transition to drift-and-fill mining in the deeper sections. These conventional mining methods are the accepted industry standards for deposits such as Kamoa.
A minimum mining thickness of 3.5 metres was used for the PEA; any thinner blocks were diluted to 3.5 metres using the average grade of the adjacent hanging wall and footwall blocks. Room-and-pillar panels are designed to be 80 metres wide and 500 metres long, with in-panel extraction ratios ranging from 60% to 80%, depending on the panel depth below surface. Partial extraction of the barrier pillars (up to 50%) is planned at the end of the mining of each section.
The overall extraction ratio in the room-and-pillar areas is expected to be between 56% and 82%, depending on the depth below surface. Higher in-panel extraction ratios of up to 95% are expected within the drift-and-fill areas, with an overall extraction ratio of 85% after partial extraction of barrier pillars.
Kamoa Project description
The Kamoa Project is a newly discovered, very large, stratiform copper deposit with adjacent prospective exploration areas within the Central African Copperbelt, approximately 25 kilometres west of the town of Kolwezi and about 270 kilometres west of the provincial capital of Lubumbashi. Ivanhoe Mines holds its 95% interest in the Kamoa Project through a subsidiary company, Kamoa Copper SPRL. A 5%, non-dilutable interest in Kamoa Copper SPRL was transferred to the DRC government on September 11, 2012, for no consideration, pursuant to the DRC Mining Code. Ivanhoe also has offered to sell an additional 15% interest to the DRC on commercial terms, to be negotiated.
In December 2012, a new, independent mineral resource estimate was prepared for the Kamoa Copper Discovery by AMEC E&C Services, of Reno, Nevada. The new estimate ranked Kamoa as Africa’s largest, high-grade copper discovery and the world’s largest, undeveloped high-grade copper discovery.
As of January 2013, Ivanhoe Mines had discovered Indicated Mineral Resources of 739 million tonnes grading 2.67% copper, containing 43.5 billion pounds of copper, and Inferred Mineral Resources of 227 million tonnes grading 1.96% copper, containing 9.8 billion pounds of copper. A 1% copper cut-off grade and a minimum vertical mining thickness of three metres were applied in each classification.
Kamoa Mineral Resources December 2012
|Copper cut-off||Tonnage (Mt)||Copper Grade||Contained Copper (billion lbs)|
Note: Mineral Resources have an effective date of December 10, 2012. Harry M. Parker and Gordon Seibel, both SME Registered Members, are the Qualified Persons responsible for the Mineral Resource estimate, which was prepared by Mr. Seibel. Mineral Resources are reported using a total copper cut-off grade of 1% copper and a minimum assumed mining thickness of three metres. A 1% copper cut-off grade is typical of analogue deposits in neighbouring Zambia.
Qualified Person and Quality Control and Assurance
The scientific and technical information in this release has been reviewed and approved by Stephen Torr, P.Geo., Ivanhoe Mines’ Vice President, Project Geology and Evaluation, a Qualified Person under the terms of National Instrument 43-101. Mr. Torr has verified the technical data disclosed in this news release.
Copper assays were determined by mixed-acid digestion with ICP finish at Ultra Trace Geoanalytical Laboratories in Perth, Australia, an ISO 17025-accredited laboratory. Ivanhoe Mines utilized a well-documented system of inserting blanks and standards into the assay stream and has a strict chain of custody and independent laboratory re-check system for quality control. For detailed information about assay methods and data verification measures used to support the scientific and technical information, please refer to the current technical report on the Kamoa Copper Project on the SEDAR profile of Ivanhoe Mines at www.sedar.com.
About Ivanhoe Mines
Ivanhoe Mines, with offices in Canada, the United Kingdom and South Africa, is advancing and developing its three principal projects:
- The Kamoa copper discovery in a previously unknown extension of the Central African Copperbelt in the DRC’s Province of Katanga.
- The Platreef Discovery of platinum, palladium, nickel, copper, gold and rhodium on the Northern Limb of the Bushveld Complex in South Africa.
- The historic, high-grade Kipushi zinc, copper and germanium mine, also on the Copperbelt in the DRC, now being drilled and upgraded following an 18-year care-and-maintenance program that ended when Ivanhoe acquired its majority interest in the mine in 2011.
Bill Trenaman +1.604.331.9834
North America: Bob Williamson +1.604.512.4856
South Africa: Jeremy Michaels +27.11.088.4300
Cautionary statement on forward-looking information
Certain statements in this release constitute “forward-looking statements” or “forward-looking information” within the meaning of applicable securities laws, including without limitation, the timing and results of: (i) a pre-feasibility study at the Kamoa Project which contemplates the declaration of a mineral reserve estimate; (ii) plans to start the first underground mine-access decline at the Kamoa Project in 2014; (iii) potential mining plans; and (iv) completion of an infill drill program in 2014 to cover an area of approximately one square kilometre with a 100-metre detailed grid. Such statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the company, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements or information. Such statements can be identified by the use of words such as “may”, “would”, “could”, “will”, “intend”, “expect”, “believe”, “plan”, “anticipate”, “estimate”, “scheduled”, “forecast”, “predict” and other similar terminology, or state that certain actions, events or results “may”, “could”, “would”, “might” or “will” be taken, occur or be achieved. These statements reflect the company’s current expectations regarding future events, performance and results and speak only as of the date of this release.
As well, the results of the preliminary economic assessment of the Kamoa Project constitute forward-looking information, including estimates of internal rates of return, net present value, future production, estimates of cash cost, proposed mining plans and methods, mine life estimates, cash flow forecasts, metal recoveries, and estimates of capital and operating costs. Furthermore, with respect to this specific forward-looking information concerning the development of the Kamoa Project, the company has based its assumptions and analysis on certain factors that are inherently uncertain. Uncertainties include among others: (i) the adequacy of infrastructure; (ii) geological characteristics; (iii) metallurgical characteristics of the mineralization; (iv) the ability to develop adequate processing capacity; (v) the price of copper; (vi) the availability of equipment and facilities necessary to complete development, (vii) the cost of consumables and mining and processing equipment; (viii) unforeseen technological and engineering problems; (ix) accidents or acts of sabotage or terrorism; (x) currency fluctuations; (xi) changes in regulations; (xii) the availability and productivity of skilled labour; (xiii) the regulation of the mining industry by various governmental agencies; and (xiv) political factors.
This release also contains references to estimates of Mineral Resources. The estimation of Mineral Resources is inherently uncertain and involves subjective judgments about many relevant factors. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. The accuracy of any such estimates is a function of the quantity and quality of available data, and of the assumptions made and judgments used in engineering and geological interpretation (including estimated future production from the Kamoa Project, the anticipated tonnages and grades that will be mined and the estimated level of recovery that will be realized), which may prove to be unreliable and depend, to a certain extent, upon the analysis of drilling results and statistical inferences that may ultimately prove to be inaccurate. Mineral Resource estimates may have to be re-estimated based on: (i) fluctuations in copper price; (ii) results of drilling, (iii) metallurgical testing and other studies; (iv) proposed mining operations, including dilution; (v) the evaluation of mine plans subsequent to the date of any estimates; and (vi) the possible failure to receive required permits, approvals and licenses.
Forward-looking statements involve significant risks and uncertainties, should not be read as guarantees of future performance or results, and will not necessarily be accurate indicators of whether or not such results will be achieved. A number of factors could cause actual results to differ materially from the results discussed in the forward-looking statements, including, but not limited to, the factors discussed here, as well as unexpected changes in laws, rules or regulations, or their enforcement by applicable authorities; the failure of parties to contracts with the company to perform as agreed; social or labour unrest; changes in commodity prices; and the failure of exploration programs or studies to deliver anticipated results or results that would justify and support continued exploration, studies, development or operations.
Although the forward-looking statements contained in this release are based upon what management of the company believes are reasonable assumptions, the company cannot assure investors that actual results will be consistent with these forward-looking statements. These forward-looking statements are made as of the date of this release and are expressly qualified in their entirety by this cautionary statement. Subject to applicable securities laws, the company does not assume any obligation to update or revise the forward-looking statements contained herein to reflect events or circumstances occurring after the date of this release.
The company’s actual results could differ materially from those anticipated in these forward-looking statements as a result of the factors set forth in the “Risk Factors” section and elsewhere in the company’s most recent Management’s Discussion and Analysis report and Annual Information Form, available at www.sedar.com.
Collar Co-Ordinates for Holes with Assays Received October 1, 2013, to April 12, 2014
Collar Co-Ordinates for Holes with Assays Received October 1, 2013, to May 12, 2014
Drill Hole Composite Results for Assays Received October 1, 2013, to May 12, 2014
||1% Total Copper 3m Composites||
||1.5% Total Copper 3m - 6m Composites|
|BHID||From||To||Length||Total Copper||True Thickness||
||From||To||Length||Total Copper||True Thickness|
|DKMC_DD798||No Mineralization - On Dome||
||No Mineralization - On Dome|
|DKMC_DD815||In Zone of Leaching||
||In Zone of Leaching|
Drill Hole Composite Results for Assays Received October 1, 2013, to May 12, 2014
|1% Total Copper 3m Composites||1.5% Total Copper 3m - 6m Composites|
|BHID||From||To||Length||Total Copper||True Thickness||From||To||Length||Total Copper||True Thickness|
|DKMC_DD850||No Mineralization||No Mineralization|
|DKMC_DD852||No Mineralization||No Mineralization|
|DKMC_DD853||In Zone of Leaching||In Zone of Leaching|
|DKMC_DD865||No Mineralization||No Mineralization|
|DKMC_DD886||No Mineralization||No Mineralization|