Source:
In May 2014 Highland completed the interim closing of the acquisition of the White Pine copper project (now White Pine North) from Copper Range Company ("CRC"), a subsidiary of First Quantum Minerals Ltd. The final closing of the acquisition is subject to certain conditions including Highland releasing CRC from certain environmental obligations associated with the remediation and closure plan of the historical White Pine mine site and replacing the related environmental bond.
In April 2015, Highland entered into a 20-year lease agreement over certain mineral rights located within the White Pine North project area. The leased mineral rights cover an area of approximately 1,816 acres.
April 13, 2021 – Highland Copper Company Inc. announced today that the deadline to complete the acquisition of the White Pine North Project from Copper Range Company (“CRC”), a wholly owned subsidiary of First Quantum Minerals Ltd., was extended to June 30, 2021.
Summary:
The mineralization of the White Pine North Project is classified as a reduced facies stratiform sediment-hosted copper deposit.
Copper mineralization at the White Pine deposit occurs in two modes - as very fine-grained sulfide (chalcocite) and as native copper. Sulfide mineralization is estimated to account for 85-90% of the copper in the deposit, but both modes of copper are intimately associated throughout the deposit. The copper mineralization at White Pine is unusually consistent. All drill holes within the deposit intercepted mineralized strata. Within the deposit, the grades of the mineralization are usually above cut-off grade over normal mining configurations. Most of the beds in the mineralized horizon are continuous over the entire deposit. The beds comprising the Parting Shale pinch out in the southwest part of the historic mine. The variation of the thickness of mineralized beds is also low from drill hole to drill hole.
Sulfide Mineralization: The dominant copper mineral in the White Pine deposit is chalcocite (Cu2S). It occurs as fine-grained lamellae in laminites and partings in interbedded sandstone and shale, very-fine grained disseminations and discrete clots in siltstone, and in veinlets and veins. The top of the copper mineralization is identified as the Top of Mineralization (“TOM”) Line or “fringe,” a narrow transition zone between cupriferous and pyritic zones. The fringe is typically very narrow (a few inches) and is identified by the sequence: chalcocite, digenite, bornite, chalcopyrite, and pyrite. Immediately above the cupriferous zone is a narrow zone containing disseminated greenockite, galena, and wurtzite. The yellow color of greenockite is easily spotted in drill core. The TOM Line cross-cuts stratigraphy. In the shallow areas of the mine to the west near the portal, the TOM Line is typically 9.5 m (30 ft) above the Lower Sand while to the east the TOM Line descends through the otherwise normally mineralized beds.
Native Copper: Native copper mineralization occurs throughout the deposit. The most significant occurrences are as sheet copper and mineralized sandstone. Sheet copper forms along thrust surfaces in the southwest mine. The sheet copper in thrust surfaces is bedding parallel as well as cross-cutting stratigraphy. Sheets can reach spectacular size. It was observed that some sheets could be traced through entire pillars. Mineralized sandstone occurs in the uppermost part of the Copper Harbor Conglomerate and is invariably associated with trapped hydrocarbons. The greatest amounts of mineralized sandstone were found in areas adjacent to the White Pine fault.
Mixed Sulfide and Native Copper Mineralization: Native copper and chalcocite are found throughout the deposit. Native copper is found in close relationship to copper sulfide in sandy lenses and pods (load casts) in the Lower Transition. Native copper in the Lower Transition is more common in channels incised into the top of the CHC. Both chalcocite and native copper mineralization are ubiquitous features of the mineralization of the Dark Gray Massive bed as well; chalcocite occurs as very-fine grained disseminations; and native copper, as discrete blebs.
Structural Relationship: Structure imposes a significant control on the distribution and grade of mineralization. Higher-grade ore is spatially associated with the White Pine fault and thrust and strike-slip faults in the Southwest mine. Part of the increase in grade is due to the presence of mineralized sandstone and/or sheet copper. In addition, chalcocite mineralization is also enhanced as wider lamellae and crosscutting veins and veinlets in the laminites.
Formation Water: The formation water encountered in the CHC is an alkaline brine (Table 7.1) with a chloride and TDS content approximately twice that of seawater. These compositions are thought to represent an approximate original composition of the depositional lake water and ore bearing fluid. Further support for alkaline brines existing during Nonesuch times is the abundance of carbonate throughout the CHC and Nonesuch Formation.
Hydrocarbons: The White Pine Mine is famous for its hydrocarbon seeps. In many areas near the White Pine fault, hydrocarbons seep out of the back, drip, and form puddles of “oil” on the floor. The most prolific seeps were noted in the northwest portion of the mine near and beneath the North Number One tailings dam.
Summary:
Based on geotechnical information, White Pine mine history and mineralization geometry, an underground room-and-pillar method is selected for the White Pine North deposit. This mining method allows for both a good ore selectivity and productivity. However, a series of pillars are left in place to provide roof stability. The mining design was based on a mining rate of approximatively 5.4 Mt/yr. Historically the old White Pine Mine has reached the proposed mining rate. In addition, many assumptions are based on historical data from the old White Pine Mine.
The main conclusions on the mining and mineral reserve estimation are as follows:
- The production schedule is based on mining a fixed target of 5.4 Mt/yr. To achieve this annual production, seven to fourteen production panels must be in production simultaneously;
- The mining method consists of the extraction of a series of entries and cross cuts in the ore leaving pillars in place to support the back. The entries, cross cuts and pillars are sized using a geotechnical analysis of the rock, and experience from the old White Pine Mine with similar ground conditions.
- No geotechnical investigation has been conducted on the underground operations at White Pine North since the closure of the former White Pine Mine. The previous geotechnical work carried out during the operation of the old white pine mine was analyzed and it was used to produce this preliminary study. In addition, a back analysis of the old White Pine was done by Itasca at the beginning of the project;
- The Mineral Resource included in the mine plan comprises 122 Mt at a copper grade of 0.98%Cu and 11.8 g/t of silver and containing 2.67 billion pounds of copper and 46 M oz of silver;
- Mine equipment selection requires low-profile equipment. Drilling will be done with a low-profile hydraulic-electric jumbo with 2 booms, mucking with 10 t and ground support installed with 1-boom electric-hydraulic bolters. Material handling consists of twelve rock breaker loading stations that feed onto 42 in secondary conveyors located in the stopes which transfer to the main conveyors which transport the ore to the ore storage bins at surface;
- The mine will be accessed via an open box-cut to establish a portal at the mine entrance from surface. Only two drift are excavated from the portal for the first 35 m deep. Then 4 drift are excavated until the first ventilation raise located at a depth of 189 m. From this ventilation raise to the beginning of the West mine section, 6 parallel drift will be excavated to allow a high ventilation flow rate to the Mine. All drifts are set at a width of 6.1 m, and their height varies from a minimum of 3.5 m to a maximum of 6.1 m;
- To achieve and maintain an adequate level of production, the panel must contain at least 12 rooms (headings) in operation simultaneously. The mining cycle includes drilling, blasting, ore mucking, ore transportation to a rock breaker and the stope conveyor, scaling and finally ground support. The mining of the room will be done in two pass approach. In the first pass, larger pillars are left in place. Mining recovery of the first pass is 40%. Once the first is completed, the size of the pillars is reduced to an average mining recovery of 57%.
Crusher / Mill Type | Model | Size | Power | Quantity |
Ball mill
|
|
5.8m x 9.86m
|
5500 kW
|
1
|
Vertical mill / Tower
|
|
|
|
1
|
Summary:
Crushed Ore Reclaim
Ore from the underground mine will be crushed down to 150 mm in order to be conveyed to a transfer conveyor equipped with a weightometer. Ore is received on surface into two 1,500 live ton coarse ore bins. Initial processing plant will include a Crushing Circuit to reduce ore size from 150 millimeters (“mm”) to P80 = 16 mm. To achieve these results, there is a series of scalping screens and crushers to process ore. The ore is first screened over double deck scalping screens. Screen oversize is fed to a standard crusher operating at about 30 mm closed-side setting. Scalping screen undersize is sent directly to the fine ore bin while the intermediate screen product is combined with the standard crusher discharge and conveyed a 1,500 live ton feed bin. Shorthead feed is processed through screening and crushing line including double deck screens and a shorthead crusher which are set at a 6 mm closed-side setting and operate in open circuit. Crushing plant product is nominally minus 19 mm with an 80% passing size of 16 mm.
Grinding and Classification Circuit
The grinding circuit will receive ore at a nominal top size of 19 mm with an 80% passing size of 16 mm. The circuit will consist of a Ball mill in closed circuit with a cyclone cluster. The grinding line is fed from a dedicated 1,500 live ton fine ore bin and consists of one Ball mill. The Ball mill will be a 5.80 m diameter x 9.86 m EGL overflow mill, with a 5,500 kW fixed speed motor. The mill will operate with between 30 and 35% ball charge. The cyclone feed pumps will deliver slurry to the cyclone cluster where will be classified. Cyclone underflow will be directed to the ball mill, while cyclone overflow will gravitate back to the flotation conditioning tank. Product from the ball mill will discharge over the cyclone feed pump box. again. Product size is set to feed the flotation circuit at 80% passing size of 106 microns.
Two vertical spindle sump pumps will service the grinding and classification area. The concrete floor under the mill area will slope to the sumps to facilitate cleanup. Grinding media for the mills will be introduced by use of a dedicated kibble.
Processing
- Crush & Screen plant
- Filter press plant
- Flotation
Flow Sheet:
Summary:
The process plant has been designed for a throughput of 15,000 tpd (dry). The overall flowsheet includes the following steps:
• Crushing, grinding and classification;
• Rougher flotation;
• Rougher concentrate regrinding;
• Cleaner flotation, using two stages of cleaning with flotation cells and columns;
• Concentrate thickening and filtration;
• Tailings pumping and disposal in the common Tailings Disposal Facility.
Rougher Flotation
Flotation feed will pass through the trash screen designed to remove foreign material prior to flotation. Trash will report to the trash bin which will be periodically emptied. Screen undersize will gravitate to the rougher conditioner tank. A sampler will be installed on the screen underflow line to take a sample to the On-stream Analyzer (“OSA”) for metallurgical, process control and particle size measurement purposes.
Frother and other flotation reagents will be added into the rougher conditione ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Copper
|
Recovery Rate, %
| 88 |
Copper
|
Head Grade, %
| 0.98 |
Silver
|
Recovery Rate, %
| 76 |
Silver
|
Head Grade, g/t
| 11.8 |
Reserves at August 30, 2019:
A cut-off grade of 0.9% Cu was used based on an underground “room and pillar” mining scenario.
Category | Tonnage | Commodity | Grade | Contained Metal |
Indicated
|
133.4 Mt
|
Copper
|
1.07 %
|
3,154 M lbs
|
Indicated
|
133.4 Mt
|
Silver
|
14.9 g/t
|
63.8 M oz
|
Inferred
|
97.2 Mt
|
Silver
|
8.7 g/t
|
27.2 M oz
|
Inferred
|
97.2 Mt
|
Copper
|
1.03 %
|
2,210 M lbs
|
Corporate Filings & Presentations:
Document | Year |
...................................
|
2019
|
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