Overview
Stage | Feasibility |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Longitudinal open stoping
- Longhole open stoping
- Transverse open stoping
- Paste backfill
|
Production Start | ...  |
Mine Life | 12 years (as of Jan 1, 2021) |
Source:
p. 2
Company | Interest | Ownership |
Trevali Mining Corp.
|
90 %
|
Indirect
|
Rosh Pinah Zinc Corporation (Pty) Ltd.
(operator)
|
100 %
|
Direct
|
Trevali holds a 90% interest in, and is operationally responsible for, Rosh Pinah Zinc Corporation (Pty) Ltd, the Namibian incorporated (joint venture) company, which holds a 100% interest in the Property. The remaining 10% is owned by Namibian Broad-Based Empowerment Groupings and an EEPS.
Contractors
- Subscription is required.
Summary:
Deposit types
The Rosh Pinah mine has been historically interpreted as being predominantly a reworked SEDEX type deposit comprising a primary banded sulphide exhalite, part of which was carbonatized with associated remobilization and enrichment of sulphides. The secondary carbonate mineralization carries the higher, economic, base-metal values.
The emplacement of the Spitskop Volcanic Complex and related mafic edifices at approximately 752 Ma to 741 Ma drove hydrothermal plumbing along the rift-fault system of the Rosh Pinah Graben. Hydrothermal fluids leached base metals from the basin-fill siliciclastics which were derived mainly from the erosion of a Paleoproterozoic, 2.0 Ga to 1.7 Ga, calcalkaline island arc in the hinterland (Frimmel et al. 2004).
The base-metal bearing brines were exhaled onto the sea floor from the present-day Western Fault bounding the Rosh Pinah Graben, during a period of sediment paucity and / or high sea-level. Exhalation was accompanied by silicification and hydraulic brecciation of the footwall. The primary mineralization was deposited at, or below, the sediment / seawater interface as stratiform, inter-banded, massive sulphide and cherty argillite (micro quartzite). Time between exhalative pulses determined the variation in ratio of content, of chert- exhalite and background argillitic sediment.
At some stage following primary SEDEX style mineralization deposition, the hydrothermal fluid chemistry change ........

Mining Methods
- Longitudinal open stoping
- Longhole open stoping
- Transverse open stoping
- Paste backfill
Summary:
Current mining method
Rosh Pinah is an existing operating underground mine with well-established mining methods. The current mining method is LHOS without backfill using a Primary, Secondary, and Tertiary top-down extraction sequence. Mining using this LHOS method since 1969 has resulted in significant voids within the historical and currently mined zones.
Ore is sourced from six steeply-dipping zones, with an increasing proportion sourced from the WF3 and AAB zones, as the eastern zone (EOF) and southern-central zone (SF3, SF3, and BME) are depleted.
Access to the production areas is via multiple interconnecting declines that provide fresh air intake into the mine. A new independent decline from surface to the WF3 zone is proposed.
The current mining areas use a LHOS Primary / Secondary extraction sequence with no backfill, except for WF3, which uses a LHOS Primary / Secondary / Tertiary extraction sequence with no backfill.
The current mining fleet consists of mechanized mobile and ancillary fleet including development jumbos, production drills, loaders and 30 t trucks for haulage to an underground crushing and conveying system (notionally called the Krupp). Future plans include the use of 60 t trucks to haul WF3 material directly to surface.
Current ore haulage is via a decline to the Krupp tip point comprising three ore silos in which to tip. Blending of the ore is conducted using the ore silos to maintain a cons ........

Source:

- subscription is required.
Flow Sheet:
Summary:

- subscription is required.
Reserves at March 31, 2021:
Mineral Reserves were estimated at a full breakeven NSR cut-off value of US$50 per tonne. NSR values were calculated based on average metal prices of US$1.17/lb Zn, US$0.96/lb Pb, and US$24.47/oz Ag.
Mineral Resources are reported at an ZnEq cut-off grade of 4.0% which approximates a Net Smelter Return value of US$40/t.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
6.14 Mt
|
Zinc
|
6.26 %
|
384 kt
|
Proven
|
6.14 Mt
|
Lead
|
1.5 %
|
92 kt
|
Proven
|
6.14 Mt
|
Silver
|
18.8 g/t
|
3,713 koz
|
Probable
|
6.21 Mt
|
Zinc
|
6.55 %
|
407 kt
|
Probable
|
6.21 Mt
|
Lead
|
1.22 %
|
76 kt
|
Probable
|
6.21 Mt
|
Silver
|
20.8 g/t
|
4,145 koz
|
Proven & Probable
|
12.35 Mt
|
Zinc
|
6.41 %
|
791 kt
|
Proven & Probable
|
12.35 Mt
|
Lead
|
1.36 %
|
168 kt
|
Proven & Probable
|
12.35 Mt
|
Silver
|
19.8 g/t
|
7,858 koz
|
Measured
|
10.54 Mt
|
Zinc
|
7.41 %
|
|
Measured
|
10.54 Mt
|
Lead
|
2.04 %
|
|
Measured
|
10.54 Mt
|
Silver
|
27.4 g/t
|
|
Measured
|
10.54 Mt
|
Zinc Equivalent
|
10.22 %
|
|
Indicated
|
7.92 Mt
|
Zinc
|
7.48 %
|
|
Indicated
|
7.92 Mt
|
Lead
|
1.46 %
|
|
Indicated
|
7.92 Mt
|
Silver
|
23.8 g/t
|
|
Indicated
|
7.92 Mt
|
Zinc Equivalent
|
9.6 %
|
|
Measured & Indicated
|
18.46 Mt
|
Zinc
|
7.44 %
|
|
Measured & Indicated
|
18.46 Mt
|
Lead
|
1.79 %
|
|
Measured & Indicated
|
18.46 Mt
|
Silver
|
25.8 g/t
|
|
Measured & Indicated
|
18.46 Mt
|
Zinc Equivalent
|
9.96 %
|
|
Inferred
|
1.58 Mt
|
Zinc
|
8.31 %
|
|
Inferred
|
1.58 Mt
|
Lead
|
2.19 %
|
|
Inferred
|
1.58 Mt
|
Silver
|
54.9 g/t
|
|
Inferred
|
1.58 Mt
|
Zinc Equivalent
|
12.04 %
|
|
Corporate Filings & Presentations:
- Subscription is required.
- Subscription is required.