Source:
p. 57
Deposit Type
- Breccia pipe / Stockwork
- Vein / narrow vein
Summary:
The mineralized deposits at the Manantial Espejo mine are predominantly veins with short strike slip and larger down dip displacement. The styles of mineralization include massive quartz veins, vein breccias, sheeted and stockwork veining, and minor dissemination. Gold occurs mainly as electrum in pyrite while the silver occurs in a number of forms including argentiferous galena and silver sulphosalts. Sulphides account for up to 3% to 5% ocount for up to 3% to 5% of the rock mass as veinlets and dissemination.
Mineralization at Manantial Espejo is hosted in four main veins known as Maria, Karina/Union, Melissa, and Concepcion. The majority of the mineralization out lined to date is in the Maria Vein. The vein is a thick silica vein exposed on surface fot more than one kilometre and has been intersected at a depth of up to 275 metres. This vein averages 7.8 metres in true wight and ranges from 0.63 metres to 20 metres and is open to the east and at depth. Economic grade mineralization of the vein is less continuous. Open pit economic grade zones measure tens to hundreds of metres in longitudinal dimention, with over 100 metres of vertical extent in the Maria West area.
The Karina/Union Vein is exposed on surface for a distance of 850 metres and has been drilled to a depth of 150 metres. Several interconnected high grade silver-gold epithermal veins in excess of 20 metres true wights have been observed in drillhole intersections.
The Melissa vein is thought to be the extensional component to the Maria shear system. The Melissa Vein has been defined by drill hole along a 300 metres strike lenght and 200 metres down dip and averages from between 1.5 and 2.5 metres wide.
The Concepción Vein is a single quartz vein. Mineralization occurs over a strike lenght of 600 metres and is open at depth and at both ends. The host rocks mineralogy and alteration are similar to the other veins on the property.
Mining Methods
- Mechanized Cut & Fill
- Longhole stoping
Summary:
Ore was mined at Manantial Espejo using a combination of conventional open pit and underground mining methods until October 2017, when open pit mining ceased. All production now is from the underground mine and surface stockpiles. The underground mining operations consist primarily of long-hole and mechanized cut and fill mining methods utilizing development waste as backfill. The underground mine is expected to operate into 2021.
Processing
- Gravity separation
- Agitated tank (VAT) leaching
- Counter current decantation (CCD)
- Concentrate leach
- Merrill–Crowe
- Cyanide (reagent)
Source:
Summary:
Ore is treated by conventional crushing, semi- autogenous/ball mill grinding, bulk gravity concentration, intensive gravity concentrate agitation leaching, thickening, agitated cyanide leaching of the gravity tailings slurry, counter current decantation thickening, Merrill Crowe zinc precipitation, sulphur dioxide cyanide neutralization, conventional pulp tailings disposal, and conventional silver and gold doré bar production from melting of the Merrill Crowe precipitate. The nominal treatment rate at design capacity is 2,000 tpd of ore.
Recoveries & Grades:
Commodity | Parameter | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 |
Silver
|
Head Grade, g/t
| 127 | 135 | 134 | 143 | 158 | 157 | 150 |
Gold
|
Head Grade, g/t
| 1.08 | 1.42 | 1.88 | 2.94 | 3.31 | 2.82 | 2.81 |
Silver
|
Recovery Rate, %
| | ......  | ......  | ......  | ......  | ......  | ......  |
Gold
|
Recovery Rate, %
| | ......  | ......  | ......  | ......  | ......  | ......  |
- Subscription is required.
Reserves at June 30, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
0.8 Mt
|
Silver
|
170 g/t
|
4.6 M oz
|
Proven
|
0.8 Mt
|
Gold
|
1.35 g/t
|
36.2 koz
|
Probable
|
0.1 Mt
|
Silver
|
204 g/t
|
0.9 M oz
|
Probable
|
0.1 Mt
|
Gold
|
3.64 g/t
|
16 koz
|
Measured
|
0.1 Mt
|
Silver
|
164 g/t
|
0.7 M oz
|
Measured
|
0.1 Mt
|
Gold
|
1.65 g/t
|
7.1 koz
|
Indicated
|
0.2 Mt
|
Silver
|
241 g/t
|
1.4 M oz
|
Indicated
|
0.2 Mt
|
Gold
|
2.86 g/t
|
16.5 koz
|
Inferred
|
0.5 Mt
|
Silver
|
194 g/t
|
3 M oz
|
Inferred
|
0.5 Mt
|
Gold
|
2.71 g/t
|
41.4 koz
|
Corporate Filings & Presentations:
- Subscription is required.
News:
Aerial view:
- Subscription is required.