Overview
| Stage | Production |
| Mine Type | Underground |
| Commodities |
|
| Mining Method |
- Cut & Fill
- Sub-level stoping
- Bench stoping
|
| Processing |
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
|
| Mine Life | 6 years (as of Jan 1, 2014) |
No production data has been publicly available since Eldorado Gold sold its respective interest in White Mountain mine to an affiliate of Yintai Resources Co. Ltd in 2016. |
Source:
p. 27, 195
On May 16, 2016 Eldorado announced it had reached an agreement to sell its respective interest in White Mountain mine to an affiliate of Yintai Resources Co. Ltd (“Yintai”) for $600M in cash, subject to certain closing adjustments. The sale was completed on November 22, 2016.
Contractors
- Subscription is required.
Deposit Type
- Breccia pipe / Stockwork
- Orogenic
Summary:
The White Mountain deposit is hosted by a silica-rich breccia within a 40° to 45° south east dipping regional fault (locally named the F100). The F100 occurs near the contact of Proterozoic quartzite and marl dominated sequences. The higher gold grades are hosted by breccia within the F100 fault, however not all of the breccias are strongly mineralised or have the same thickness of mineralisation.
The F100 is overprinted by a steeply dipping fault (locally named the F102), such that the F100 occurs only in the hanging wall of the F102.
There are four stages of mineralisation at White Mountain, all of which are associated with elevated gold grades.
In September 2007 the known mineralisation at White Mountain extended over 1400m horizontally, the depth extent ranged from 100m down dip to 600m down dip, i.e. in the plane of the F100 and intersecting F102 faults and the average thickness was in the range of 10m to 12m.
Mineralisation at White Mountain is contained within a major north-east trending regional fault zone dipping approximately 45° to 50° to the southeast. Gold mineralisation is associated with silica, pyrite and barite in a silicified breccia in the fault zone that overprints an iron-rich unconformity between a hanging wall quartzite and a foot wall silicified dolomite or marl.
Geological continuity is well demonstrated by the extent of the main controlling F100 fault and its intersection with the F102 fault.
Mining Methods
- Cut & Fill
- Sub-level stoping
- Bench stoping
Summary:
The mining methods selected for White Mountain and the proposed stope dimensions are:
1. Cut-And-Fill stopes: 5m x 5m, minimum mining width of 2.5m
2. Bench stopes: width range from 2.5 to 15m, Dip>=45 degrees, Sublevel interval = 15m, minimum sill width=4m, and 2m x2m x 2m recess for remote mucking at 50m interval along strike 3. Sub-Level Open Stopes: Dip>=50 degrees, Length = 20m, Width <=~25m, Sublevel= 30m, stope height=30, 60 or 90m
Mine planning has taken consideration of mine design, proposed mining methods, dilution and ore losses. Three mining methods have been selected to minimise ore loss and dilution in those locations and to maximise ore recovery and grade while maintaining stable stopes.
Processing
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
Source:
Summary:
The metallurgy work completed to date on the gold association at White Mountain indicates the bulk of the gold is very fine grained and associated with pyrite and marcasite with small amounts of chalcopyrite, sphalerite and galena in quartz, and associated with quartz + sericite alteration. Barite overprints the silicification and is commonly observed to be late (observed readily in the core). Limonite and other ironoxides overprint the barite and may be related to fracture oxidation (from surface).
Initial metallurgical testing has returned encouraging results for most of the different styles of mineralisation hosted by the F100 fault.
Metallurgical testing has identified two metallurgical ore types, refractory and non refractory. Recoveries are nominally 84% for the non-refractory ore and 65% for the refractory ore. The production schedule is based on 23% of the ore being refractory. More recent geological modelling indicates that as little as 9% of the ore may be refractory.
Recoveries & Grades:
| Commodity | Parameter | 2016 | 2015 | 2014 |
|
Gold
|
Recovery Rate, %
| 86.1 | 86.5 | 86.9 |
|
Gold
|
Head Grade, g/t
| 2.78 | 3.3 | 3.47 |
Production:
| Commodity | Units | 2016 | 2015 | 2014 |
|
Gold
|
oz
| 56,265 | 78,156 | 85,308 |
All production numbers are expressed as metal in doré.
Operational Metrics:
| Metrics | 2016 | 2015 | 2014 |
|
Tonnes milled
| 717,145 t | 849,335 t | 850,782 t |
|
Annual milling capacity
| | 800 kt | |
Reserves at December 31, 2015:
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Proven
|
3,510 kt
|
Gold
|
3.26 g/t
|
368 koz
|
|
Probable
|
2,446 kt
|
Gold
|
3.1 g/t
|
244 koz
|
|
Proven & Probable
|
5,956 kt
|
Gold
|
3.2 g/t
|
612 koz
|
|
Measured
|
4,206 kt
|
Gold
|
3.64 g/t
|
491 koz
|
|
Indicated
|
2,678 kt
|
Gold
|
3.45 g/t
|
297 koz
|
|
Measured & Indicated
|
6,884 kt
|
Gold
|
3.56 g/t
|
788 koz
|
|
Inferred
|
1,685 kt
|
Gold
|
6.98 g/t
|
378 koz
|
Commodity Production Costs:
| | Commodity | Units | 2016 | 2015 |
|
Cash costs
|
Gold
|
USD
|
731 / oz
|
653 / oz
|
|
Total cash costs
|
Gold
|
USD
|
773 / oz
|
691 / oz
|
Financials:
| | Units | 2016 |
|
Sustaining costs
|
M USD
|
9.9
|
|
Revenue
|
M USD
|
70.8
|
|
Gross profit
|
M USD
|
18.6
|
- Subscription is required.
Staff:
| Employees | Year |
|
|
2015
|
Corporate Filings & Presentations:
- Subscription is required.
Aerial view:
- Subscription is required.