Chile

Los Helados Project

Click for more information

Categories

Overview

Mine TypeUnderground
StagePreliminary Economic Assessment
Commodities
  • Copper
  • Gold
  • Silver
Mining Method
  • Block caving
Mine Life... Lock
SnapshotLos Helados is one of the largest undeveloped copper-gold-silver deposits in the world.

Owners

SourceSource
CompanyInterestOwnership
Nippon Caserones Resources Co., Ltd 36.2 % Indirect
NGEX Minerals Ltd. (operator) 63.8 % Indirect
As of March 31 2020, NGEX Minerals Ltd. holds an approximately 63.8% interest in Los Helados subject to a Joint Exploration Agreement with Nippon Caserones Resources which holds the remaining approximately 36.2%. NGEx is the operator of the Los Helados Project.

NGEx has a life-of-project lease agreement with the owners of the surface rights covering 20,000 hectares over the Los Helados Project area. This agreement secures the surface rights needed for all future exploration, development and mining.

The Los Helados deposit is held by Minera Frontera del Oro (MFDO), an indirectly wholly-owned Chilean subsidiary of NGEx.

Contractors

Lock

- subscription is required.

Deposit type

  • Porphyry
  • Breccia pipe / Stockwork
  • Hydrothermal

Summary:

Based on geological features and location, the Los Helados deposit is classified as a porphyry Cu–Au system. Porphyries are well documented along the Andes and represent a widespread type of deposit in Chile.

The Los Helados project area is underlain most extensively by Permo-Triassic rocks assigned to the Choiyoi Group that form the Andean basement in the region.

The Los Helados porphyry Cu-Au system is exposed in a high-elevation, northwestfacing cirque with high topographic relief. The bottom of the elongated cirque, where the uppermost part of the deposit is exposed at surface, is at 4500 metres above sea level, while the sides of the valley rise steeply above to 5300 metres on the eastern side: a difference of at least 800 metres. The abundant rock exposures on this steep eastern slope provide the best outcrop for mapping geological relationships at surface, including excellent alteration vectors towards the largely covered deposit in the cirque bottom.

The host rocks to the deposit are largely Permo-Triassic in age. Granite is the oldest, and most regionally extensive unit. It is intruded by a tonalitic- to dioritic intrusive complex as well as fine-grained andesite dykes, typical of the Permo-Triassic in the region. A rhyodacitic to rhyolitic feldspar-phyric intrusion has previously been interpreted to pre-date the mafic units, however recent work suggest that the rhyodacitic intrusion is a pre-mineral porphyry of Eocene to Late Oligocene age (Martinez et al., 2015).

The deposit occurs in the upper part of a mid-Miocene porphyry/breccia system that was emplaced into basement rocks and the pre-mineral rhyodacitic intrusion. Copper-gold mineralization is predominantly hosted within the magmatic-hydrothermal breccias and contemporaneous dacitic porphyries, with some peripheral mineralization also within the immediate country rock although grades rapidly decline away from the breccia and porphyry intrusive contacts.

Four mineral zones are recognized within the deposit based on sulphide occurrence. Zone definition does not include late pyrite veinlets or the total volume of sulphides present in the rock. In order of increasing depth, the zones are: Pyrite-only (Py); pyrite>chalcopyrite (Py>Cpy); chalcopyrite>pyrite (Cpy>Py); and chalcopyrite-only (Cpy). This sulphide zoning sequence reflects a progressive downward increase in the amount of chalcopyrite relative to pyrite.

The copper–gold mineralization at Los Helados is primarily hosted within the Miocene magmatic–hydrothermal breccia which forms a roughly circular, pipe-like body with minimum dimensions of 1,100 m east–west, 1,200 m north–south and at least 1,500 m vertically. The breccia body is surrounded by a broad halo of moderate to low grade Cu–Au mineralization which diminishes in grade with increasing distance from the breccia contact.

The breccia limits have been established by drilling to the west, east and south; however, the northern limit of the breccia body has not yet been identified. The system also remains open at depth, and the lateral extent of the breccia at depth is also poorly constrained by the current drilling. The eastern contact appears to be subvertical, whereas the western contact dips outwards at roughly 70°, hence the width of the breccia body increases progressively downwards.

Copper grade increases downwards, either in the lower parts of the sericitic zone or in the underlying chlorite–sericite alteration zone, and elevated grades are maintained into the potassic alteration zone. Within the central part of the breccia body, consistent grades on the order of 0.5% Cu and 0.2-0.3 g/t Au in the core zone are flanked by domains of ~0.3-0.4 % Cu and 0.1-0.2 g/t Au. High grade zones exceeding 1% Cu and 1.5 g/t Au are found locally. Although Cu grades typically diminish towards the bottoms of the deepest holes drilled to date, there is an exception in that drill hole LHDH34 encountered some of the better grades of the deposit (>1%Cu and >1.5 g/t Au) in a breccia body at 900 metres.

Reserves

Lock

- subscription is required.

Mining Methods

Lock

- subscription is required.

Comminution

Crushers and Mills

Lock

- subscription is required.

Processing

Lock

- subscription is required.

Production

CommodityUnitsLOM
Gold koz 5,509
Silver koz 43,147
All production numbers are expressed as metal in concentrate.

Operational metrics

Metrics
Daily ore mining rate 120,000 t *
Daily milling capacity 120,000 t *
Annual ore mining rate 43,800 kt *
Ore tonnes mined, LOM 1,557,279 kt *
* According to 2016 study.

Production Costs

CommodityUnitsEstimated
Assumed price Copper USD 3 / lb *  USD
Assumed price Silver USD 20 / oz *  USD
Assumed price Gold USD 1,275 / oz *  USD
* According to 2016 study / presentation.

Operating Costs

Currency2016
UG mining costs ($/t milled) USD 4.43 *  
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2016 study.

Project Costs

MetricsUnitsLOM Total
Closure costs $M USD  ......  Subscribe
UG OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 6,635
Refining costs $M USD  ......  Subscribe
G&A costs $M USD 1,246
Total OpEx $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe

Heavy Mobile Equipment

Lock

- subscription is required.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Feb 22, 2016
....................... Subscription required ....................... Subscription required Subscription required Sep 8, 2023
....................... Subscription required ....................... Subscription required Subscription required Sep 8, 2023

Total WorkforceYear
...... Subscription required 2016

Aerial view:

Lock

- subscription is required.