Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Cut & Fill
- Longhole stoping
- Shrinkage stoping
- Paste backfill
|
Processing |
- Gravity separation
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in pulp (CIP)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Starting from 2016 mine production is included into Porcupine Operation production. |
Summary:
The Hoyle Pond Main Zone and 1060 Zone deposits occur on opposite limbs of an open, northeast-plunging antiformal structure, hosted within carbonatized north-dipping tholeiitic basalts. The 7 Vein System occurs as a series of stacked, flat to gently northeast-dipping veins in the nose of the antiformal structure.
The Hoyle Pond Main Zone includes a series of generally northeast-striking, linked, quartz vein zones folded on a small scale with moderate west- and northeast-plunging axes.
The 1060 Zone consists of at least five main vein structures (1060 B1, B2 and B3 zones, A zone and Porphyry zone) with orientations ranging from north to northeast and a generally subvertical dip. The veins are strongly boudinaged, with the long axis of the boudin oriented from subhorizontal to shallow west–southwest plunging.
Alteration
The mineralization at Hoyle Pond occurs as coarse free gold in white to grey–white quartz veins with a variable ankerite, tourmaline, pyrite, and locally arsenopyrite, content. Alteration halos are generally narrow, consisting of mainly grey zones (carbon, carbonate, sericite, cubic pyrite) in the Hoyle Pond system and carbonate–sericite, plus fuchsite with pyrite, arsenopyrite and trace amounts of chalcopyrite and sphalerite within the 1060 structure.
Gold at the Hoyle Pond Mine predominantly occurs as coarse free gold in white to greyishwhite quartz veins with variable ankerite, tourmaline, pyrite, pyrrhotite and local arsenopyrite. Trace amounts of chalcopyrite and sphalerite have also been noted.
The Hoyle Pond Main Zone includes a series of generally northeast-striking, linked quartz vein zones. There are at least 11 veins of economic significance. These veins are folded on a small scale with moderate west and northeast plunging axes. The 1060 zone consists of at least five main vein structures with orientations ranging from north to northeast, are strongly boudinaged, and generally have a subvertical dip.
A series of auriferous zones occurs along what is termed the “South Trend”, stretching from the Bell Creek deposit (to the west of Hoyle Pond) for 6.4 km to the 1060 zone (includes Blackhawk–Vogel deposit, Owl Creek West, Owl Creek, Owl Creek East and the 950 zone). Mineralization in these zones consists of quartz–ankerite veining with varying amounts of pyrite, pyrrhotite and free gold.
Mining Methods
- Cut & Fill
- Longhole stoping
- Shrinkage stoping
- Paste backfill
Summary:
The Hoyle Pond mine hosts a variety of ore shapes. In order to maximize the stoping efficiency, numerous stoping methods are used.
Conventional cut and fill, shrinkage and panel mining methods are typically employed by the PJV to excavate the narrower gold bearing vein structures. Each of the preceding mining methods is used to extract vein structures with vertical and/or near horizontal attitudes. Veins mined by these methods typically range from 0.20 meters to 2.0 meters thick and are usually higher grade material. Mucking is accomplished using appropriately sized slushers.
Longhole methods with paste backfilling are used in wider stoping areas. Longhole levels are advanced at 60 meter intervals with sub levels at a 20 m interval. Haulage drifts are driven in the footwall about 12 meters offset from the ore zone. Backfilling methods were traditionally a combination of rock fill and cemented slag but these methods have been replaced with high quality paste backfill delivered through holes from surface and distributed with a network of underground piping.
Processing
- Gravity separation
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in pulp (CIP)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Source:
Summary:
Gold is recovered using a combination of gravity concentration and cyanidation techniques. The circuit consists of primary, secondary and tertiary crushing, rod/ball mill grinding, gravity concentration, cyanide leaching, carbon-in-pulp gold recovery, stripping, electro winning and refining.
Combined production numbers are reported under
Porcupine Operation
Operational Metrics:
Metrics | 2015 | 2014 |
Tonnes milled
| 362,300 t | 321,500 t |
Corporate Filings & Presentations:
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