Orca Gold Inc. ("Orca" or the "Company") is pleased to provide an update on the ongoing Pre-Feasibility Study (the "PFS") on its Block 14 Gold Project ("Block 14" or the "Project") in the Republic of the Sudan.
The PFS is progressing well with most of the component parts completed. However, due to the delay in receipt of laboratory test results, the PFS is now expected to be finished and reported by June, 2017.
- Water Exploration: testing in four production scale boreholes has confirmed that the aquifer can accommodate the 1.8 Mtpa throughput scenario used in the Preliminary Economic Assessment (the "PEA"), dated July 26, 2016. A second geophysical survey to expand the footprint of the current water resource will begin by mid-March to provide for production expansion.
- Geotechnical Assessment: analysis of logging and test work from a 1,420m diamond core drilling programme supports an increase in the overall slope angle of the pits by at least 8° (from 43° to 51°), which will result in the reduction of waste stripping.
- Mineral Resource Update: a 7,062m infill drill programme has successfully confirmed and expanded the PEA resource estimate, with Indicated Resources going up by 10%. Inferred Resources within the PEA design pit shells have been reduced to less than 3% of the total material.
As part of the PFS, a series of four production scale boreholes have been drilled across the HA8 aquifer, 55km north of the proposed process plant location. Pump testing of these boreholes, as supervised by the Company's consultants, GCS Water and Environmental Consultants, has confirmed that the aquifer is able to accommodate the 1.8 Mtpa throughput scenario used in the PEA, dated July 26, 2016.
Part of the PFS involves the investigation of employing alternative tailings disposal methods to maximize water recovery towards achieving a process plant throughput of up to 2.4 Mtpa. At the same time, the Company is mobilizing a second geophysical survey towards expanding the footprint of the current water resource with the aim of identifying additional water for the Project and the region as a whole. PFS work to date suggests that a throughput level of 2.4 Mtpa optimizes project economics. A filtered tailings option and/or the discovery of more water gives optionality in achieving that throughput level.
Based on results from a 1,420m diamond core drilling programme designed by SRK Consulting (UK) Ltd., and subsequent analysis of geotechnical logging and laboratory test work, the pit slope design criteria has been revised from that employed in the PEA. The geotechnical work now supports an increase in the overall slope angle of the pits by at least 8° (from 43° to 51°), with a concomitant reduction in waste stripping.
Mineral Resource Estimate
As detailed in the February 2, 2017 news release, MPR Geological Consultants have completed an updated Mineral Resource Estimate for the Project following the completion of 7,062m of infill drilling conducted as part of the PFS. The updated Mineral Resource Estimate, using a cut-off grade of 1.0 g/t, comprises an Indicated Resource of 30.6 Mt grading 1.82g/t for 1.792 Moz of gold and an Inferred Resource of 9.7 Mt grading 1.7g/t for an additional 0.536 Moz. In comparison to the previous estimate (July 2016), Indicated Resources have increased by 10% or 159 koz and Inferred Resources have decreased by 15% or 98 koz. The drilling was directed within the PEA design shells and has reduced the Inferred Resources within those shells to less than 3% of total material. Accordingly, the infill programme has successfully confirmed and expanded the PEA resource estimate.
Metallurgical Test work
Metallurgical test work is running behind schedule due to internal, analytical issues at the metallurgical laboratory. The consultant, SGS, has assured the Company that all test work is now scheduled for completion by the end of March 2017.
Commenting on these updates at Block 14, Rick Clark, CEO and Director of Orca, said, "The confirmation of the project water supply at HA8 is a critical tick on the path to production for Block 14. Further, we expect the project to be materially enhanced by the ability to increase the production throughput rate. The geotechnical results will also improve the economics of the project by reducing the strip ratio. The delay in the completion of the PFS is unfortunate but it is important that we have complete confidence in the metallurgical data forming the basis of the PFS."