Source:
p. 83
Rambler Metals and Mining plc has a 100 per cent ownership in the Ming Copper-Gold Mine.
Summary:
The Property is a Noranda-type VMS (Volcanogenic massive sulfide) hosted by Cambrian-Ordovician metavolcanic and metasedimentary rocks of the Pacquet Harbour Group. The style of mineralization, alteration, host rock, and tectonism most closely resembles other VMS deposits throughout the world. This deposit type is referred to as type G06 by the British Columbia Ministry of Energy, Mines and Petroleum Resources Deposit Profiles.
The polymetallic sulphide deposits in the Ming Mine area are known to contain copper, zinc and minor lead, gold and silver along with traces of other metals. Mineralization in the deposits has been classified in the past as either massive sulphide, footwall stringer, or disseminated ore.
More recent exploration on the Ming deposit has identified distinct zones of sulphide mineralization. This, in conjunction with ongoing academic studies, imply a somewhat greater complexity in orogeny of the Ming Mine and other deposits in the area based on distinct alteration and sulphide assemblages, mineralogical and textural variations and the structural setting of mineralization. For the current documentation there remain two dominant types of mineralization in the Ming deposit:
- Stratiform volcanogenic massive sulphide (MMS); and
- Disseminated stringers of sulphides (LFZ).
The MMS is recognized as a horizon which is open at depth, locally up to three metres in thickness with a strike length of at least 100 metres. Like other deposits in the area, it follows D2 planar fabric and is roughly parallel to the D2 extension lineation plunging 30 to 35 degrees northeast to a vertical depth of at least 1,000 metres. Several textural varieties of mineralization are recognized in the MMS horizon including massive pyrite ore, banded ore, massive chalcopyrite-pyrrhotite ore, and breccia ore.
The MMS has three different ore types. Massive pyrite ore, which is less than 70% pyrite, with chalcopyrite and minor amounts of galena, sphalerite, and silicate minerals. Banded ore consists of alternating bands of pyrite and chalcopyrite-quartz-actinolite-biotite. Massive chalcopyrite-pyrrhotite ore occurs as lenses and layers with up to 80% chalcopyrite. Minor amounts of arsenopyrite, galena, tetrahedrite, native gold, tennantite, and cubanite occur locally. There is up to 10% disseminated pyrite in the immediate footwall.
The LFZ is another mineralized horizon that lies approximately 100 metres below the MMS horizon. The LFZ strike length is approximately 1,700 metres and has a thickness that varies from 200 metres to 290 metres. Base metal assays from drilling are variable indicating that there are clusters of chalcopyrite and pyrite / pyrrhotite stringers which are separated by less mineralized rock. Gold values in the LFZ are generally less than 0.5 g/t and only trace amounts of zinc have been reported. The LFZ is transected by fine to medium grained basic dykes interpreted as feeder dykes to a mafic sequence in the hanging wall above the MMS.
The LFZ is an alteration zone consisting dominantly of chloritic schist that contains varying percentages of chalcopyrite and pyrite which occur as stringers with lesser amounts of pyrrhotite and sphalerite. The LFZ is parallel to the D2 planar fabric and extension lineation, appears to be conformable to the overlying MMS and as such, can be interpreted as the feeder or stockwork alteration zone to the MMS a relationship consistent with the VMS model. The exact location of the hydrothermal conduit responsible for alteration in the LFZ and mineralization in the overlying MMS has been obscured through deformation; however in its plunge direction the LFZ itself may represent a structural conduit that allowed the ascent of hydrothermal fluid. The extent of the LFZ is unknown as it is open both up and down plunge. Recent drilling has traced mineralization 1,500 metres down plunge.
Mining Methods
- Post Pillar Cut & Fill
- Longhole stoping
- Backfill
Summary:
The Ming Mine is an underground, copper and gold rich massive sulphide deposit consisting of six mineralised zones. These are identified as the 1806 Zone, 1807 Zone, Ming North Zone (MNZ), Ming South Zone (MSZ), Lower Footwall Zone (LFZ) and Upper Footwall Zone (UFZ).
The technical report 2018 update is based on an optimization of the current massive sulphide (Phase 1) operation by gradually increasing the proportion of Lower Footwall Zone (LFZ) ore with Massive Sulphide (MMS) to achieve a total mine production rate of 1,250 mtpd.
Current planned production at the operation is 1,250 mtpd of MMS and LFZ Block 1 post pillar material. LFZ production presently comes entirely from post pillar cut and fill mining in Block 1, whereas all subsequent Blocks (2 to 6) will be mined using a longhole method. Primary backfilling will utilize paste backfill augmented with waste rock produced during underground development and stope preparation activities.
Access to the LFZ blocks will be through new development and extension of the existing ramps and raises.
The mine ventilation system is presently being reconfigured to supply additional air to the underground workings as well as to allow development and production blasting to occur during work shifts, which will allow longer work shifts.
LONGHOLE (TRANSVERSE) WITH A DIP OVER 50 DEGREES
The LFZ has been divided into six blocks for design purposes. Blocks 2 to 6 will utilize longhole transverse mining methods, whereas Block 1 will be mined entirely with a post pillar method.
Mining sublevels will be spaced 25 vertical metres apart. Transverse stope accesses / crosscuts will be driven 4 m wide by 4.5 m high every 20 m along strike to the hanging wall contact. Drop raises, driven 2.4 m x 2.4 m, will be used as slots to facilitate stope using 76.2 mm (3-inch) production. Stopes will be mucked until the brow is opened up, upon which time they will be mucked remotely. Mine waste rock will be placed in the mucking horizon brows to act as fill barricades. Primary stopes will be filled with straight pastefill, whereas secondary stopes will be filled with straight waste rock (refer to Figures 16.5 to 16.7); waste rock may also be used to displace some of the pastefill requirements in primary stopes, albeit under strict engineering control to ensure that the final cured backfill strength is sufficient.
Mine designs have been standardized to maintain drift sizes to a minimum while optimizing production rates. Remote mucking of stopes will be employed where necessary.
LONGHOLE ADAPTED WITH A DIP UNDER 50 DEGREES
In the MMS, an undercut or bottom sill will be driven to a maximum of 8 m wide. Wider ore intersections will require pillars which will be recovered during primary blasting activities. A drift will be developed parallel to the orebody in the footwall waste which will be used to create an artificial footwall to achieve a minimum ore draw angle of 50 degrees. Waste will be blasted using upholes from this drift. A top sill will be developed to a maximum width of 8 m, followed by a 2.4 m x 2.4 m drop raise, excavated using with 64 mm (2.5 inch) diameter production holes. Production blasting will utilize a slot slash technique where blastholes will be broken into the previously created slot opening. Stopes will be mucked using LHDs. When the brow becomes open, the remainder of the broken stope material will be mucked remotely.
POST PILLAR CUT AND FILL MINING
The LFZ Block 1 zone utilizes a post pillar cut and fill mining method. An access ramp driven at -18% grade off the main ramp is driven down to the mining first lift in the ore zone where a 5 m high by up to 8 m wide sill cut is driven the full width of the ore zone. Post pillars (5 m by 5 m) are left where the ore zone exceeds 8 m in width. Mine waste rock is used to backfill completed sill cuts to the height required to downbreak the next higher lift. Subsequent sill cuts will be accessed by slashing down the ramp access back to achieve a 5 m face height at the footwall ore contact which will be used to drive the next higher sill drifts to the end of the ore zone, after which it will be backfilled and the general process repeated. New access ramps will be driven when required to access higher mining panels at acceptable incline grades which typically are +/- 18%.
UNDERGROUND MINE ACCESS
Primary underground access will be through the existing mine portal using the existing MMS ramp.
The life-of-mine plan is to extend the ramp from its current depth to -810 m elevation. The LFZ will accessed via a 5 m wide by 5 m high ramp driven at a -15% grade from the existing ramp system to the bottom of Block 2 at -537 m elevation.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
SAG mill
|
|
|
|
1
|
Ball mill
|
|
|
|
1
|
Summary:
Run-of-mine (ROM) mill feed from the Ming Mine is stored on an outdoor pad at the Nugget Pond site. It is fed through a two-stage crushing plant by front-end loader and the crushed material is conveyed into the crushed ore silo.
The grinding circuit consists of a semi-autogenous grinding (SAG) mill and a ball mill. The mill feed is conveyed to the SAG mill which operates in open circuit. A minimal amount of oversize material discharging from the SAG mill trommel screen is collected in a bin that is periodically dumped back on the mill feed stockpile. The ball mill operates in closed circuit with hydrocyclones for classification. Lime is added to the mill discharge pump box. The cyclone overflow is directed to the flotation circuit.
Flow Sheet:
Summary:
The recovery of a copper-gold concentrate is based on using the existing copper concentrator located at Nugget Pond. The existing grinding and flotation circuits, and concentrate dewatering equipment will be used as-is without any modifications. Upgrades will be required for pumping tailings to new impoundment areas and for pumping reclaim water from the new tailings impoundment areas back to the concentrator.
The copper-gold flotation circuit is arranged in a conventional configuration and consists of rougher, rougher-scavenger, primary cleaner, cleaner-scavenger, secondary cleaner, and tertiary cleaner flotation cell banks.
Ground mill feed is received from the grinding circuit in the flotation feed holding tank, which provides some storage capacity for feed to the flotation circuit and allows the downstream processes to continue operating during short-term interruptions of the grinding circuit operation. Flotation collector (Aerophine 3418A) and additional lim ........

Recoveries & Grades:
Commodity | Parameter | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Copper
|
Recovery Rate, %
| ......  | ......  | ......  | 96.3 | 95.6 | 95.6 | 96.9 |
Copper
|
Head Grade, %
| ......  | ......  | ......  | 1.24 | 1.27 | 2.12 | 2.53 |
Copper
|
Concentrate Grade, %
| ......  | ......  | ......  | 28.1 | 27.7 | 26.9 | 27.3 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | 70.7 | 60.7 | 68.7 | 69.8 |
Gold
|
Head Grade, %
| ......  | ......  | ......  | 0.57 | 0.58 | 1.4 | 1.18 |
Gold
|
Concentrate Grade, %
| ......  | ......  | ......  | 9.4 | 8 | 13.8 | 9.87 |
Silver
|
Recovery Rate, %
| ......  | ......  | ......  | | | 71.8 | 73.7 |
Silver
|
Head Grade, g/t
| ......  | ......  | ......  | | | 9.97 | 8.68 |
Silver
|
Concentrate Grade, g/t
| ......  | ......  | ......  | | | 98.1 | 73.2 |
Reserves at March 31, 2022:
Mineral Resources cut-off grades of 1.0 % copper for the massive sulphides, 1.25 grammes per tonne gold for any gold zones and 1.0 % copper for the stringer sulphides.
The NSR for the reserve material was calculated using an all-in cost of USD$72 per tonne of ore milled.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven & Probable
|
7,413 kt
|
Copper
|
1.74 %
|
289,851 k lbs
|
Proven & Probable
|
7,413 kt
|
Gold
|
0.38 g/t
|
94 koz
|
Proven & Probable
|
7,413 kt
|
Silver
|
2.53 g/t
|
645 koz
|
Measured & Indicated
|
23,755 kt
|
Copper
|
1.8 %
|
944,538 k lbs
|
Measured & Indicated
|
23,755 kt
|
Gold
|
0.35 g/t
|
271 koz
|
Measured & Indicated
|
23,755 kt
|
Silver
|
2.78 g/t
|
2,124 koz
|
Inferred
|
6,430 kt
|
Copper
|
1.86 %
|
263,546 k lbs
|
Inferred
|
6,430 kt
|
Gold
|
0.38 g/t
|
78 koz
|
Inferred
|
6,430 kt
|
Silver
|
2.6 g/t
|
538 koz
|
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