• Data Access
  • Your Email  
  • Your Email  
Keep me signed in.
Forgot your password?
Close
  • Forgot Your Password?
  • Enter the email you signed up with and we'll email it to you.
  • Your Email  
Close
Back
MDO
Mining Data Solutions
  • Home
  • Database
  • Subscribe
  • Sign In
  • Sign In
Canada
Halfmile Project (Halfmile-Stratmat Project)

This page is not tailored to
devices with screen width under 750 px.
 Location:
68 km NW from Miramichi, New Brunswick, Canada

  Project Contacts:
701 West Georgia Street Suite 1450, PO Box 10089
Vancouver
British Columbia, Canada
BC V7Y 1B6
Phone  ...  Subscription required
Additional Resources for Suppliers & Investors
Drill results over 30 g/t Au
Stay on top of recent discoveries.
Search drill results by commodity and grade.
Largest mines in the Americas
Mining and mill throughput capaciites.
Full profiles of select mines and projects.
Deepest underground mines
Shaft depth and mill throughput data.
Full profiles of select mines and projects.
Heavy mobile equipment
HME type, model, size and quantity.
Full profiles of select mines and projects.
Permitting and construction projects
Projects at the permitting or construction stage. Full profiles of select projects.
Mines with remote camps
Camp size, mine location and contacts.
Full profiles of select mines and projects.
Mines & projects in Canada
A list of country's mines and projects.
Full profiles of select mines and projects.
  • Overview
  • Owners
  • Geology
  • Mining
  • Processing
  • Production
  • Reserves
  • Costs & Financials
  • Fleet
  • Personnel
  • Filings & News

Thank you for browsing through mine profiles compiled by the Mining Data Online team.

Would you like to subcribe or schedule a Demo?
  • Name:
     
  • Company:
     
  • Position:
     
  • Phone:
  • Email:
  • Message:

Overview

StatusInactive / Suspended
Mine TypeUnderground
Commodities
  • Zinc
  • Lead
  • Copper
  • Silver
  • Gold
Mining Method
  • Mechanized Cut & Fill
  • Post Pillar Cut & Fill
  • Sub-level stoping
  • Avoca
  • Sub-level Retreat
  • Longitudinal retreat
  • Cemented backfill
Mine Life13 years (as of Jan 1, 2017)
The Halfmile-Stratmat integrated project is comprised of the Halfmile mine and the advanced exploration stage Stratmat project.

On Aug. 19, 2022, Trevali Mining Corporation announced that the Company had received an Initial Order for creditor protection from the British Columbia Supreme Court under the Companies' Creditors Arrangement Act (the "CCAA").

On June 30, 2023, Trevali Mining Corporation announced that the Supreme Court granted an order in the Company's ongoing CCAA proceedings pursuant to which FTI Consulting Canada Inc., the Court appointed "Monitor", has been granted enhanced powers in the CCAA Proceedings with respect to the Company's business and affairs.

The Monitor's powers to manage the Company, the Company's remaining employees have ceased their employment with the Company.

Please note that all data presented below is sourced from 2017 technical report prepared by SRK Consulting (Canada) Inc.


Owners

Source: p. 2
CompanyInterestOwnership
Trevali Mining Corp. 100 % Indirect
The Halfmile-Stratmat integrated project is 100% held by Trevali Mining (Maritimes) Ltd., a 100% owned subsidiary of Trevali Mining Corporation.

On June 30, 2023, Trevali Mining Corporation announced that the Supreme Court of British Columbia granted an order in the Company's ongoing Companies' Creditors Arrangement Act proceedings (the "CCAAProceedings") pursuant to which FTI Consulting Canada Inc., the Court appointed "Monitor", has been granted enhanced powers in the CCAA Proceedings with respect to the Company's business and affairs.

Contractors

Subscription required - Subscription is required.


Deposit Type

  • VMS


Summary:

The Halfmile and Stratmat projectss are volcanic massive sulphide (VMS) deposits typical of the Bathurst Mining Camp (BMC). The BMC hosts 45 volcanic-sediment hosted massive sulphide deposits and 95 occurrences, including the world-class Brunswick 12 Mine. BMC deposits formed in a sediment-covered back-arc continental rift during periods when the basin was stratified with a lower anoxic water column. The basin was subsequently intensely deformed and metamorphosed during multiple collisional events related to east-dipping subduction of the basin.

The VMS deposits typically form lenses of polymetallic massive sulphide. Most deposits are zoned vertically and laterally from a high temperature, vent-proximal, copper-polonium bismuth-rich veined and brecciated core to vent-distal zinc-lead-silver-rich hydrothermal sediments. The vent complex is commonly underlain by a highly deformed sulphide stringer zone that extends hundreds of metres beneath deposits and consists of veins and impregnations of sulphides, silicates, and carbonates that cut chloritized and sericitized volcanic and sedimentary rocks.

The Halfmile project is underlain predominantly felsic volcanic rocks and lesser sedimentary rocks which are host to all massive sulphide deposits on the property. Provincial Government regional
mapping projects have classified the rocks as belonging to the Flat Landing Brook formation of the Middle Ordovician Tetagouche group and Nepisiguit Falls formation. ........


Mining Methods

  • Mechanized Cut & Fill
  • Post Pillar Cut & Fill
  • Sub-level stoping
  • Avoca
  • Sub-level Retreat
  • Longitudinal retreat
  • Cemented backfill


Summary:

At Halfmile, all run-of-mine (RoM) material will be mined by underground mining method. Sublevel open stoping (SLOS) and Sublevel Retreat (SLR) will be the main mining methods planned, supplemented by post pillar cut and fill (PPCF) and mechanized cut and fill (MCF) mining for Upper zone where mineralization dip angle is approximately at 39 degrees. All mining methods will employ either cemented or unconsolidated waste rock as backfill. The mine plan includes 92% of RoM tonnes from SLOS/SLR with down holes (up holes for sill pillar recovery) on 20 m sublevels and cemented or unconsolidated waste rock fill, and 8% of RoM tonnes from PPCF/MCF with unconsolidated waste rock and cemented waste rock (sill level stopes only). There is no permanent sill or rib pillar considered for the SLOS/SLR mining. Limited sill pillars were planned only for the two trial mining opened mining fronts.

Access to the underground mine will be by an existing portal and ramp system developed previously to a depth of 170 m below surface. The ramp will be extended down to the mine bottom approximately 1,020 m below surface at a maximum gradient of -15% with dimensions of 5.0 m width by 5.0 m height, the same as the existing ramp.

Stope sequencing will generally be top-down block by block, and bottom-up within the mining block. On a mining level scale, both transverse primary-secondary stope sequence and longitudinal retreat mining will be employed, dependent on mineralization thickn ........


Crushing and Grinding
Flow Sheet: Source

The RoM production will initially be subjected to primary and secondary crushing at the Stratmat mine site to reduce the rock size to a suitable feed for a dense media separation plant (DMS). This operation will reject barren material from the +3 mm size from the mill feed effectively increasing the mill head grade and reducing the overall operating costs of the concentrator. A Barely Autogenous Grinding (BAG) mill will be used for primary grinding followed by a conventional ball mill for secondary grinding to liberate the minerals to allow flotation to concentrate the metals to saleable concentrates.

Primary crushing, secondary crushing and screening will be contracted out. The crushed product will be fed to a covered stockpile with a live content of 4,000 tonnes and the DMS plant will be fed using two apron feeders in a tunnel under the stockpile at 175 tonnes per hour. The dense media process is expected to reject 22% of the mass of RoM material in a reject which will be suitable for producing backfill with the addition of the required amount of cement. As only the +3 mm fraction of the RoM material can be upgraded, the -3 mm fraction will be screened out on a wet screen, thickened and the thickener underflow pumped to the ball mill discharge pump box or to a lagoon if the DMS plant is operating and the main plant is down. DMS upgraded material will be conveyed to a second stockpile with a live content of 3,000 tonnes.

Design feed tonnage to the grinding circuit is 145 tonnes per hour. The BAG mill will operate in closed circuit with a vibrating screen recycling the +5 mm fraction back to the BAG mill. Screen undersize will flow to a secondary ball mill which will operate in closed circuit with 15-inch diameter cyclones and will grind the material to a P80 of 72 microns.

The upgraded mineralization stockpile will be an insulated structure with 3,000 tonnes of live capacity to allow for operation of the mill during maintenance of the DMS plant or vice versa. A dump point will allow crushed mineralization to be added to this stockpile to completely decouple the operation of the mill from the DMS plant

Primary grinding will be in a BAG mill with a 950 kW motor. A BAG mill is required as the -65 mm maximum size of the mineralization means that there will be no lumps that are large enough to act as media for a semi-autogenous grinding (SAG) mill. A ball mill will not be used because a higher aspect ratio mill is required to ensure that the balls have sufficient energy to break the largest particles at a size that will also provide highly efficient grinding. A double-deck vibrating screen in closed circuit with the BAG mill is included with a designed opening of 5 mm on the lower screen.

Sodium carbonate (soda ash) for pH control and depressants (sodium cyanide and zinc sulfate) will be added to the BAG mill feed to ensure that depression of sphalerite and pyrite occurs as soon as the surfaces are exposed.

A conventional ball mill with a 2 MW motor in closed circuit with a cyclopac having eight 12-inch cyclones will take the BAG mill screen undersize at a P80 in the order of 750 microns and reduce it to the size noted above (P80 of 72 microns) for flotation feed.

Regrinding of the lead/copper rougher and scavenger concentrates and the lead/copper first cleaner scavenger concentrate will be in a M4 (1MW) Isamill.

The zinc regrind mill will be an M4 (1MW) Isamill operated in closed circuit with a cyclopac having 10 five-inch diameter cyclones.


Processing

Flow Sheet: Subscription required

Summary:

- subscription is required.


Projected Production:

CommodityUnitsLOM
Zinc dmt 0
Lead dmt  ......  Subscription required
Copper dmt  ......  Subscription required
Silver oz  ......  Subscription required
Gold oz  ......  Subscription required

Operational Metrics:

Metrics
Daily ore mining rate 2,600 t *
Annual mining rate 910,000 t of ore *
Waste tonnes, LOM 2,472 kt *
Ore tonnes mined, LOM 9,376 kt *
Tonnes milled, LOM 9,376 kt *
* According to 2017 study.

Reserves at June 23, 2016:
Mineral Resource estimate is reported based on zinc equivalent cut off grade of 5% ZnEq.

CategoryTonnage CommodityGradeContained Metal
Measured 0.4 Mt Zinc 5.92 % 54 M lbs
Measured 0.4 Mt Lead 1.99 % 18 M lbs
Measured 0.4 Mt Copper 0.46 % 4 M lbs
Measured 0.4 Mt Silver 40 g/t 520 koz
Measured 0.4 Mt Gold 0.6 g/t 10 koz
Indicated 7.4 Mt Zinc 7 % 1,146 M lbs
Indicated 7.4 Mt Lead 2.37 % 389 M lbs
Indicated 7.4 Mt Copper 0.16 % 26 M lbs
Indicated 7.4 Mt Silver 35 g/t 8,450 koz
Indicated 7.4 Mt Gold 0.29 g/t 70 koz
Measured & Indicated 7.8 Mt Zinc 6.94 % 1,199 M lbs
Measured & Indicated 7.8 Mt Lead 2.35 % 407 M lbs
Measured & Indicated 7.8 Mt Copper 0.18 % 31 M lbs
Measured & Indicated 7.8 Mt Silver 36 g/t 8,980 koz
Measured & Indicated 7.8 Mt Gold 0.3 g/t 80 koz
Inferred 6.5 Mt Zinc 5.62 % 806 M lbs
Inferred 6.5 Mt Lead 1.51 % 216 M lbs
Inferred 6.5 Mt Copper 0.15 % 21 M lbs
Inferred 6.5 Mt Silver 23 g/t 4,720 koz
Inferred 6.5 Mt Gold 0.1 g/t 20 koz

Operating Costs:

Units2017
UG mining costs ($/t mined) CAD 38.2 *  
* According to 2017 study.

2017 Study Costs and Valuation Metrics :

MetricsUnitsLOM Total
Pre-Production capital costs $M CAD  ......  Subscription required
Sustaining CapEx $M CAD  ......  Subscription required
Subscription required - Subscription is required.

Water Supply
Source: Subscription required

- subscription is required.


Proposed Heavy Mobile Equipment as of October 26, 2017:
HME TypeModelSizeQuantityLeased or
Contractor
ANFO Loader ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
Subscription required - Subscription is required.

Mine Management:

Job TitleNamePhoneEmailProfileRef. Date
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required Subscription required Aug 28, 2023
Subscription required - Subscription is required.


Corporate Filings & Presentations:

DocumentYear
Press Release 2023
Press Release 2023
Management Discussion & Analysis 2022
Press Release 2022
................................... Subscription required 2021
................................... Subscription required 2021
................................... Subscription required 2020
................................... Subscription required 2020
................................... Subscription required 2019
................................... Subscription required 2019
Annual Information Form 2018
Management Discussion & Analysis 2018
Press Release 2018
Management Discussion & Analysis 2017
Preliminary Economic Assessment 2017
Management Discussion & Analysis 2016
Management Discussion & Analysis 2015
Technical Report 2010
Subscription required - Subscription is required.

Subscription required - Subscription is required.

Terms of Use Privacy Policy © 2017-2023 MDO Data Online Inc.