Mar 3 2011
Rambler Metals and Mining plc (TSX VENTURE:RAB)(AIM:RMM) has provided a resource update for the Lower and Upper Footwall Zones (LFZ and UFZ) at the Ming Copper-Gold Mine.
George Ogilvie, President and CEO commented:
"We believe the Footwall Zones will provide Rambler with the opportunity of organic growth, once the Ming Mine is in production. The Footwall Zone could be mined as a bulk tonnage operation to benefit from the economies of scale, due to its increased size and lower grade, compared to our current mine plan. The preliminary economic assessment for the Footwall Zones will evaluate mining scenarios between 2,000 and 4,000 mtpd and target potential production of 10,000 - 20,000 tonnes of copper metal annually. We believe an improvement in grades and metal produced may be achieved by blending massive sulphide ore with the Footwall Zone. Importantly, all ore and mineralized zones in the Ming Mine are open in multiple directions providing a good opportunity to further increase the available resources with new diamond drilling."
FUTURE PLANS
- Rambler is currently evaluating the possibility of utilizing gravity separation to improve the grade of the Lower Footwall Zone ore delivered to the mill and to also provide a source of paste backfill for the mining operation. If successful, this would significantly reduce the cost of transporting ore from the mine to the mill. This work is ongoing and is expected to be completed Q2 2011.
- An area of the Lower Footwall Zone can be accessed from the 1800 level. As the Ming Mine enters into commercial production, a larger bulk sample can be excavated from this area to further evaluate the zone's flotation kinetics and overall recovery. Preliminary bench scale testing has indicated that an overall copper recovery of 98% within a 5 minute reaction time can be achieved. The bulk sample program will provide a true representation of how the Footwall mineralization will behave in the new flotation circuit at Nugget Pond.
- The Lower and Upper Footwall Zones are open both in the up and down plunge directions. New diamond drill exploration programs are being designed to further improve the existing resource estimate.
- The current mine plan for the project does not include any of the resource from the Footwall Zones. The company has made plans to embark on a NI43-101 compliant preliminary economic assessment, which will evaluate the technical and economic feasibility of a bulk tonnage mining scenario for the Footwall Zones.
Larry Pilgrim, P.Geo. is the Qualified Person responsible for the technical content of this release and has reviewed and approved it accordingly. Mr. Pilgrim is an independent consultant contracted by Rambler Metals and Mining plc.
Lower Footwall Zone (LFZ)
The Lower Footwall Zone has been defined with a strike length of 250 meters wide, plunge length of 1,550 meters long, 200 meters thick and hosts disseminated stringer chalcopyrite and pyrrhotite. Importantly the zone is open both up and down plunge and has returned good copper grades over significant widths.
The LFZ has always been considered a potential source for a low grade, bulk tonnage mining method. While the 1.25 percent copper cut-off grade was chosen based on a long term copper price of US$2.50 /lb, when considering a copper cut-off representative of today prices it is conceivable that the amount of in-situ contained copper metal will be doubled.
Upper Footwall Zone (UFZ)
The Upper Footwall Zone is a high grade semi-massive stringer zone that sits stratigraphically between the Ming Horizon and the Lower Footwall Zone. It was first discovered in 2006 when diamond drill hole RM06-04f intersected 6.00 meters of 14.55% copper with 1.6 g/t gold.
Rambler Qualification and Methodology of Resource Estimation
Resource classification
Mineral resources for the Ming Copper-Gold Mine have been classified according to the "CIM Standards on Mineral Resources and Reserves: Definitions and Guidelines" (December, 2005) by Larry Pilgrim, P.Geo, an appropriate Qualified Person as defined by NI43-101. Since the Footwall Resource did not have a 100% or greater change to the original resource there was no requirement for an Independent technical report or evaluation.
The resource estimation is based on a 3-D geological interpretation of the mineralized zones from 85,416 meters of RMM surface drilling (2003-2008) in 86 drill holes and 22,263 meters of RMM underground drilling (2007-2009) in 167 drill holes. The geological interpretation and modeling defined six separate but intimately related ore zones namely; the 1807 zone, the 1806 zone the Main Zone (includes North and South Ming), the Upper Footwall Zone and the Lower Footwall Zone. Only the stringer mineralization related to both Footwall Zones has been included in this new resource update. The resources of the other massive sulphide zones remain the same as those published in the project feasibility report in August 26, 2010.
Density factors used to determine tonnages were 3.07 gcm3 for the semi-massive stringer Upper Footwall and 2.83 gcm3 for the stringer style Lower Footwall Zone.
The modeled resources for the Lower Footwall Zone were created using Datamine 3D modeling software with 5 x 5 x 5 m blocks. A sub-block routine was also applied with a minimum block size of 0.5x 0.5 x 0.5m. Grade estimation was conducted on data composited to 1.5 m intervals, confined within the modeled mineralized zone. Appropriate grade cappings were applied to the composited data. Block grades were estimated using inverse distance squared (ID2) grade estimation methodologies.
Datamine Studio 3 was used to generate variograms for the LFZ. Traditional experimental variograms were modelled from the composited and capped dataset for the mineralized zone for copper, gold, silver and zinc for all three modelled principle directions. A two structure spherical variogram model was applied to the LFZ and where possible variography was calculated on both raw and Gaussian (normal scores) transformed data.
Source: Rambler Metals and Mining plc