Overview
Stage | Pre-Feasibility |
Mine Type | Underground |
Commodities |
- Copper
- Gold
- Silver
- Molybdenum
|
Mining Method |
|
Processing |
|
Mine Life | 23 years (as of Jan 1, 2019) |
Summary:
Five main targets have been identified, namely Nuevo Chaquiro, Aurora, Tenedor, Isabela and La Sola. The most advanced of the targets, Nuevo Chaquiro, a significant copper-gold porphyry-style mineralised system, is one of five known porphyry centres on the property.
Nuevo Chaquiro is a porphyry type deposit. The host rock composes a volcaniclastic sequence of the Combia Formation which is intruded by diorite dykes.
The intrusions are by various pulses of diorites with the primary intrusive being a fine to medium grainedquartz diorite. Most of the intrusives do not outcrop. These intrusives are categorised into pre-mineral, early, intra-mineral and late, according to cross cutting relations, locality and copper-gold values. The developed alteration follows a well zoned porphyry type alteration system ranging from a high temperature, potassium silicate central zone (biotite, magnetite, chalcopyrite, and molybdenite), which trends into an overlying sericitic alteration zone (muscovite, chlorite, quartz, pyrite,+-tourmaline) surrounded by more distal propylitic alteration (chlorite, epidote, illite, carbonate). There is also an inner core of calcic-potassic alteration featuring biotite, actinolite, epidote, and anhydrite with lesser copper, gold and molybdenum values.
The mineralised zone is characterised by fine stock works, disseminations and veinlets of quartz, magnetite, pyrite, chalcopyrite and molybdenite.
Summary:
The Quebradona Project is a Greenfields project. Sub-Level-Caving (SLC) is the preferred mining method. The Nuevo Chaquiro deposit is considered to be medium to large, steep dipping, competent rock mass with highergrade material located at the top of the deposit which is approximately 200 m below surface. The grade profile reduces with depth, thus making exploitation of the deposit amendable to SLC being a top down mining method. Drill and blast methods will be used to fracture the orebody commencing at the top and sequentially moving downwards with an inter-level spacing of 27.5m from 425m below surface to 975m below surface.
The planned underground infrastructure consists of an adit to access the orebody andnumber of internal vertical ore passes that gravity feeds to the main ore transfer level. The material will betransferred to the main internal crusher by load and haul dump vehicles. Crushed material will then be transferred horizontally to surface via a 6km conveyor, in a dedicated adit to a single Coarse Ore Stockpile.
Minera Quebradona Colombia (MQC) ore deposit will have two independent mine access portals located in the Cauca valley at the surface processing facility approximately 6 km away from the ore body. Twin tunnels will be developed in parallel for the first 2 km, then the twin tunnels will be developed upwards the SLC undercut level located 425meters below surface. One of the twin tunnels is extended for the Material handling system located at the base of the SLC approximately 950 to 1000 meters below surface.
The production level designs are based on the following design parameters:
- 2.6 m burden spacing,
- 15 m drill drive spacing,
- 27.5 m inter-level spacing,
- Transverse layout,
- Hydraulic radius of 39 (155 x 155) required to create the unstable span to initiate caving.
The material handling system (MHS) will consist of:
- 5 internal ore pass from the SLC production levels 500m long,
- 6.2 Mtpa Ore transfer level with 3 tramming drives and 5 orepass drawpoints,
- 3 way tipping station,
- Underground Crusher 1,500 t/h peak capacity,
- 6.1 Km Belt conveyor 1,011 t/h design capacity.
Production scheduling were based on the following drivers:
- 3 active production levels,
- 2 active development levels ,
- 4 production drill rigs capable of drilling 1.5Mtpa/rig,
- 6 SLC production loaders with a load capacity of 21t LHD (maximum 2 per production level),
- SLC Short haul tram - 3,500 to 4,500t per day,
- SLC Medium haul -tram 2,500 to 3,500t per day,
- SLC Long haul tram - 1,500 to 2,500 t per day.
- 3 x 17t ore transfer loaders
- 6.2Mtpa Underground crush and Convey system.
Source:
Summary:
The ore can be treated by a typical porphyry copper flotation circuit producing a copper/gold concentrate. The concentrate is clean and free of deleterious elements which would attract smelter penalties. The processing circuit includes primary crushing underground, secondary crushing, high pressure grinding rolls, ball milling, rougher-scavenger flotation for all elements(Cu, Au, Ag), followed byregrinding the concentrate and cleaning,firstly in conventional cellsandthen in columns. A further flotation stage removes pyrite to leave a non-acid producing flotation tails and a pyrite concentrate that can be stored in a lined and eventually sealed impoundment within the Tailings Storage Facility (TSF). Molybdenum, at present, is not planned for recovery.The Quebradona process plant will be designed to treat approximately 6.2 Mtpa underground ore to produce copper concentrate overa 23 year mine lifewith provision of space for a Molybdenum plant in the future.
The process flowshe ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Copper
|
Recovery Rate, %
| ......  |
Copper
|
Concentrate Grade, %
| ......  |
Gold
|
Recovery Rate, %
| ......  |
Silver
|
Recovery Rate, %
| ......  |
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Projected Production:
Commodity | Units | LOM |
Copper
|
M lbs
| 2,900 |
Gold
|
M oz
| ......  |
Silver
|
M oz
| ......  |
All production numbers are expressed as metal in concentrate.
Operational Metrics:
Metrics | |
Annual mining capacity
| ......  |
Annual processing capacity
| ......  |
* According to 2019 study.
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Reserves at December 31, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven & Probable
|
111.24 Mt
|
Copper
|
1.25 %
|
3,068 M lbs
|
Proven & Probable
|
111.24 Mt
|
Gold
|
0.71 g/t
|
2.53 M oz
|
Proven & Probable
|
111.24 Mt
|
Silver
|
7.25 g/t
|
25.95 M oz
|
Total Resource
|
602.1 Mt
|
Copper
|
0.73 %
|
9,677 M lbs
|
Total Resource
|
602.1 Mt
|
Gold
|
0.37 g/t
|
7.13 M oz
|
Total Resource
|
602.1 Mt
|
Silver
|
4.8 g/t
|
92.95 M oz
|
Corporate Filings & Presentations:
Document | Year |
...................................
|
2019
|
...................................
|
2019
|
...................................
|
2019
|
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Aerial view:
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