お知らせ • Sep 10
Osino Resources Corp. Provides Update on Development Studies At Twin Hills Gold Project, Namibia
Osino Resources Corp. provided an update on the technical and development studies which are ongoing at its Twin Hills Gold Project in Namibia. The Company released a Preliminary Economic Assessment (“PEA”) on Twin Hills earlier in 2021, which described an open-pit gold mine producing an average of 99,000 ounces of gold per annum over a 16-year life-of-mine with 124,000 ounces produced per annum for years two to six. Osino’s technical team and specialist consultants are presently engaged in optimizing and improving the technical studies with the aim of further improving the annual gold production rate and overall economics of the Twin Hills gold project. Three areas of significant potential growth that have been identified by Osino are as follows: Mineral resource improvement due to extra drilling and enhanced resource estimation, Optimized mine plan incorporating higher mining rates, pre-stripping and improved pit slopes, Increased processing plant throughput and potentially improved recovery. The Twin Hills project is in an infrastructure-rich part of Namibia, only 25km from the producing Navachab gold mine and the local mining town of Karibib. Navachab is a currently producing open-pit mine with approximately 1.8 million tonnes per annum (“mtpa”) name-plate processing capacity and is supplied with power and water through the national grid. Osino has appointed George Fainsinger & Associates (“GSFA”), a respected Namibian electrical engineering consultancy and contractor to undertake a trade-off and engineering analysis to define and cost the most feasible power supply options for Twin Hills. This will include an assessment of adding self-generation and possible grid-feed-in via solar-photovoltaic power, as is presently being implemented by GSFA at B2Gold’s Otjikoto gold mine further north in Namibia. Namibia Power Corporation (Pty) Ltd., Namibia’s parastatal electricity supply utility, has provided a formal offer to supply power to Twin Hills via a dedicated 66kV line from the Erongo sub-station, which is under development by NamPower near the local town of Karibib. The offer currently allows for 16MVA to cater for the process plant capacity of 3.5mtpa as envisaged in the current PEA, however the 66kV line would also cater for a likely increase in the metallurgical processing rate at an estimated 20MVA. As Twin Hills is located in an arid part of Namibia, with limited ground and surface water, the availability of bulk water is considered to be one of the key project risks. Osino is mitigating this risk by evaluating various water supply options, ranging from bulk water supplied by the national grid to sustainable own production of ground water from local aquifers. Application has been made to Namwater, Namibia’s parastatal water utility, to determine the bulk water supply capacity which may be available from existing sources such as the Swakoppoort storage dam and pipeline which currently supplies Navachab gold mine. Osino has also commenced with drilling and hydrological modelling to determine the sustainable yield of local groundwater sources. 14 reconnaissance boreholes have been drilled to-date and based on preliminary blow-yields already have the potential to supply a significant portion of the project’s future water demand. Pump-testing of these holes is near completion and hydrological modelling to determine sustainable yield will be undertaken next. A strategy successfully employed on other Namibian mines, is to store water in sand aquifers contained in dry river courses. A study is currently underway to determine the potential carrying capacity of the Khan River which lies on the project’s northern boundary as a backup supply source of water. Column leach test work was commissioned in July 2021 to determine the whole-rock geochemistry and kinetic properties of the planned waste as well as process plant tailings material. This work will optimize the TSF design with a primary focus on dry stacked tailings through filtering tailings and recycling water in the plant. Dry stacked tailings as a standalone, or potentially as co-disposal with mine waste, will substantially lower the project water consumption. PEA whole ore leach metallurgical tests identified a 53um grind to be optimal and samples have been submitted for confirmation work as well as to determine detailed plant design parameters. Testwork results received since the completion of the PEA also indicated that adding a sulphide flotation component may result in a more optimised process layout (finer grinding of sulphide float concentrate only) and potentially a further improvement in gold recovery. Testwork to quantify this potential gold recovery improvement is underway in conjunction with the whole ore leach program. Infill drilling at Bulge, Twin Hills Central and Clouds is nearing completion. All drill and assays results received since the last mineral resource update are in process of being updated and incorporated. Geological modelling and resource estimation is ongoing and will be completed once all drilling is completed and assay results received later in 2021. Drill spacing over most of the deposit was done on a 25m x 25m offset basis and was designed to convert most of the existing mineral resource to the Indicated status. This drill spacing should also be sufficient to allow for advanced resource estimation techniques, such as multiple indicator kriging (“MIK”) or localized uniform conditioning (“LUC”). These methods estimate the tonnage and grade of mineralization which can be extracted as small selectively minable blocks from large blocks (panels), whose grade is modelled by Ordinary Kriging (“OK”) and generate a so-called recoverable resource model. In layman’s terms, these techniques allow modelling of selective mining and could potentially result in a higher recoverable resource grade offset by potentially slightly lower total contained ounces. Approximately 90,000m drilling has been completed year-to-date, comprising 12,000m of resource drilling up to February 2021 (included in the PEA mineral resource), 41,000m (mostly infill) of subsequent resource drilling (not yet included in the mineral resource), 24,000m of brownfields exploration drilling and 13,000m of feasibility drilling (geotech, hydrology, met testwork, grade control and regional exploration). Assay results for approximately 8,000m of this drilling have not yet been received or reported.
