Huckleberry is an open pit copper/molybdenum mine located in west-central British Columbia, owned by Huckleberry Mines Ltd. Imperial holds a 50% interest in Huckleberry Mines Ltd. and the other 50% is held by the Japan Group (Mitsubishi Materials Corporation, Furukawa Co. and Dowa Mining Co. Ltd.).
(1) represents Huckleberry mine total production of which 50% is allocable to Imperial
Huckleberry Annual Production(1)Huckleberry recoveries continued to be excellent throughout 2012. Annual copper production of 35.1 million pounds exceeded the 2012 forecast by 6.4%. In 2013 copper production is estimated to be 40.0 million pounds, of which 50% is allocable to Imperial.
|Copper - lbs||40,000,000||35,112,000||42,830,000||45,510,000|
|Gold - oz||3,200||2,578||3,520||3,195|
|Silver - oz||190,000||191,787||218,150||223,557|
|Molybdenum - lbs||-||4,556||6,929||84,027|
Construction of a new tailings storage facility (TMF3) began in early 2012. The new starter dam was completed to the 924 metre level by the end of the construction season. The main diversion ditch and seepage collection systems related to this new facility were also completed in 2012. Approximately 1.2 million cubic metres of earthworks will be required to complete the TMF3 starter dam to the 945 metre level. This work is expected to begin in April 2013 and to be completed by July 2013. The TMF3 will then be used for storage of tailings and potentially acid generating (PAG) waste, generated by the operation.
Exploration at HuckleberryIn 2013 Huckleberry plans to continue with a strategy of drilling both deep and shallow targets in the mine site area, using historical drilling and geophysical data as guides.
In February 2013 a comprehensive geophysical model of the mine site area was completed, incorporating data from historical magnetometer and IP surveys with data from Titan-24 DC-IP/MT surveys conducted in 2011 and 2012.
Regional work in 2013 will include a soil sampling program on the Huckleberry North claims, directed towards developing new geophysical or drill targets for 2014/2015.
In 2012 Huckleberry completed 15 diamond drill holes totalling 5,141 metres. Drilling was divided between deep and near-surface targets located adjacent to the MZO pit. Near-surface drilling focused primarily on the abandoned NAG quarry targeted in 2011. This work added a significant low-grade resource to the deposit. Deep drilling tested for the extension of ore-grade material along the eastern portions of the Main zone ore body. Drilling of a coincident moderate chargeability/resistivity anomaly resulted in the discovery of the MZ Deep target, an extensive zone located between the Main zone and East zone ore bodies. The correlation between this type of anomaly and copper mineralization led to an expanded Titan-24 DC-IP/MT survey, comprising 10 line km designed to build on survey data from 2011 and seek new targets.
Geological SettingThe Huckleberry mine is a typical porphyry copper/molybdenum deposit. It is characterized as a calc-alkalic copper/molybdenum type mineralization. These deposits are typically hosted in intrusive rocks, usually of granodioritic or quartz monzonitic composition, and in volcanic rocks surrounding intrusives.
Huckleberry Mill InfrastructureOre from the pit is delivered to a 42"x 65" gyratory crusher and after crushing is conveyed to a stockpile. Ore from the stockpile is ground in two stages prior to flotation, firstly in a single 10,000hp semi-autogenous (SAG) mill, and secondly in two 5,000hp ball mills. A bulk copper concentrate is floated from the ball mill product. The bulk copper concentrate is then reground in a 1,500hp regrind mill, and then floated again to produce a final copper concentrate grading approximately 27% copper. Molybdenum concentrate is floated out of the copper concentrate.
Both final concentrates are thickened and dewatered prior to shipment. A Grinding Improvement Project (SAG pebble circuit) was completed by mid-2000. This circuit consists of a vibrating screen that removes critical size rocks from the SAG mill discharge conveyors then transports this material to a pebble crusher where the rocks are crushed and then returned to the SAG mill. Final copper concentrate is trucked to the Port of Stewart, British Columbia and then shipped by bulk carrier to Asia. The molybdenum concentrate is trucked to and sold in Vancouver under long term contract.
For additional information refer to the Company's Quarter Reports & Annual Information Form.
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