Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
|
Mine Life | 16.5 years (as of Jan 1, 2008) |
Ecuador’s first large-scale open pit mining operation Mirador copper mine, in which Chinese copper smelter Tongling Non-ferrous owns a 70% stake, has been commissioned as of July 18, 2019. |
On December 28, 2009, Corriente Resources Inc. announced that it had signed a definitive agreement (the “Support Agreement”) with CRCC-Tongguan Investment Co., Ltd. (the “Offeror”), Tongling Nonferrous Metals Group Holdings Co., Ltd. ("Tongling") and China Railway Construction Corporation Limited ("CRCC"), under which the Offeror has agreed to make an offer to acquire all of the company’s outstanding shares (the “Offer”) for $8.60 per share in cash, equivalent to approximately $679 million on a fully-diluted basis. On May 31, 2010, the Offeror pursuant to its offer dated February 1, 2010 to purchase all of the issued and outstanding common shares (the "Common Shares") of the Corporation, acquired 76,478,495 Common Shares representing approximately 96.9% of the issued and outstanding Common Shares on a fully diluted basis. On August 4, 2010, the Offeror acquired an additional 2,443,898 Common Shares.
Summary:
The host rock, alteration, and mineralization at the Mirador deposit are characteristic of a calcalkaline porphyry copper system. Copper deposits of a similar style are widespread in the Cordilleras of North and South America.
Most of the Mirador mineralization is exposed as weathered, leached laterite in the numerous drill trail and road exposures. Unevenly developed zones of supergene copper (and possibly silver) enrichment lie beneath a leached, lateritic “cap” with a relatively flat lower boundary. Thus this leached zone is thickest under ridge crests and nonexistent in any significant drainage bottom. Primary and supergene mineralization are only preserved in creek bottom outcrops, where the drainages have cut down through the overlying laterite.
The copper-gold-silver mineralization of the Mirador deposit is present mostly as disseminations and fine fracture-fillings of chalcopyrite, secondary chalcocite, and pyrite. Gold occurs as fine inclusions in chalcopyrite and pyrite, as well as native. Molybdenite is present in systems of early-stage quartz veins that have a preferred east-west orientation. These veins occur as stockwork in both Zamora granite and early porphyry dikes.
The sequence of mineral deposition at Mirador has been divided into early-stage molybdenum, early- stage copper ± gold, and late-stage copper-gold events, with a final weak polymetallic vein stage.
Summary:
The feasibility study is based on conventional open pit mining of the porphyry copper deposit. The deposit is covered by an average 22 m depth of overburden and a leached cap, a portion of which must be pre-stripped to access the orebody. The sulphide ore body is relatively homogenous, consisting dominantly of primary copper sulphides and is open at depth. Secondary enrichment is thinly developed in places over the primary sulphide mineralization.
Flow Sheet:
Flow Sheet:
Summary:
Run-of-mine ore will be crushed in a gyratory crusher. The mill flow sheet selected for Mirador will be a conventional copper-gold porphyry flowsheet, with relatively coarse primary semiautogenous and ball mill grinding to about 150 µm followed by copper rougher flotation, concentrate regrind to 30 µm, and cleaner flotation and dewatering. Concentrates produced are predicted to average 29.8% copper at a recovery of 91%. Gold recovery is expected to average 47%. A laboratory analysis of concentrates indicated that no significant deleterious penalty element impurities are present. The concentrate will be trucked via the existing road network in the area to a port facility in Machala for shipment to smelters. Tailings from the process will be impounded in a zero discharge tailings pond; water will be reclaimed from the tailings pond and reused in the process.
Commodity | Parameter |
Gold
|
Recovery Rate, %
|
Gold
|
Head Grade, g/t
|
Gold
|
Concentrate Grade, g/t
|
Silver
|
Recovery Rate, %
|
Silver
|
Head Grade, g/t
|
Silver
|
Concentrate Grade, g/t
|
Production:
Commodity | Product | Units | Avg. Annual (Projected) | LOM (Projected) |
Copper
|
Payable metal
|
M lbs
| | 2,208 |
Copper
|
Concentrate
|
kt
| 205 | 3,395 |
Gold
|
Payable metal
|
koz
| | ......  |
Silver
|
Payable metal
|
koz
| | ......  |
Copper
|
Metal in concentrate
|
M lbs
| 137 | |
Gold
|
Metal in concentrate
|
koz
| ......  | |
Silver
|
Metal in concentrate
|
koz
| ......  | |
* Projected daily production according to 2008 company report.
Reserves at December 31, 2009:
Category | Tonnage | Commodity | Grade | Contained Metal |
Measured
|
52,610,000 t
|
Copper
|
0.65 %
|
753 M lbs
|
Measured
|
52,610,000 t
|
Gold
|
0.21 g/t
|
360 koz
|
Measured
|
52,610,000 t
|
Silver
|
1.6 g/t
|
2,770 koz
|
Indicated
|
385,060,000 t
|
Copper
|
0.6 %
|
5,134 M lbs
|
Indicated
|
385,060,000 t
|
Gold
|
0.19 g/t
|
2,380 koz
|
Indicated
|
385,060,000 t
|
Silver
|
1.5 g/t
|
18,760 koz
|
Measured & Indicated
|
437,670,000 t
|
Copper
|
0.61 %
|
5,887 M lbs
|
Measured & Indicated
|
437,670,000 t
|
Gold
|
0.2 g/t
|
2,740 koz
|
Measured & Indicated
|
437,670,000 t
|
Silver
|
1.5 g/t
|
21,530 koz
|
Inferred
|
235,400,000 t
|
Copper
|
0.52 %
|
2,708 M lbs
|
Inferred
|
235,400,000 t
|
Gold
|
0.17 g/t
|
1,250 koz
|
Inferred
|
235,400,000 t
|
Silver
|
1.3 g/t
|
9,900 koz
|
Corporate Filings & Presentations:
- Subscription is required.
Aerial view:
- Subscription is required.