Name: Rosh Pinah mine.

Location: The mine is located in south-west Namibia.

Mine Owner/s: Trevali Mining Corporation (90%) and Namibian Broad-Based Empowerment Groupings and an Employee Empowerment Participation Scheme (EEPS).

Brief Description: Rosh Pinah is a 2 000 t/d underground mine, producing zinc and lead concentrates, with copper, silver and gold as by-products. The sulphides are concentrated in a flotation plant using separate zinc and lead circuits. The zinc and lead concentrates are transported by road to the Port of Luderitz on the Namibian coast, and then shipped to the international smelters and refineries.

Brief History: The Rosh Pinah mine has been in continuous operation since 1969.

The deposit was discovered in 1963. Drilling started in 1965. Shortly thereafter, sufficient reserves were proven to develop a mine and an operating company Imcor Zinc was formed.

Preparatory work and mine development started in 1967, with the first ore production starting in May 1969.

Mining was halted from 1993 to 1995, as a result of the mine being liquidated. In 1996, the mining rights were awarded to PE Minerals and in 1998 Rosh Pinah Zinc Corporation (RPZC) was formed through a joint venture. Glencore acquired an 80.08% interest in RPZC in June 2012. The balance was owned by Namibian Broad-Based Empowerment Groupings and an EEPS.

Trevali executed definitive agreements with Glencore and certain of its subsidiaries in August 2017, whereby Trevali acquired a portfolio of zinc assets from Glencore, including an 80.08% interest in the Rosh Pinah mine. Trevali subsequently bought an additional 10% interest taking its ownership to 90%. Trevali is operationally responsible for the management of RPZC.

Primary Metals: Zinc and lead concentrates.

Secondary Metals: Copper, silver and gold.

Geology/Mineralisation: The Rosh Pinah mine is hosted by the Rosh Pinah Formation (Hilda subgroup of the Port Nolloth group), forming part of the neoproterozoic Gariep Terrane deposited onto a palaeo-mesoproterozoic basement of granite gneisses and supracrustals.

The base metal sulphides at the Rosh Pinah mine are contained within the estimated 30-m-thick ore equivalent horizon. In the Rosh Pinah area, the Rosh Pinah Formation has been shown to be at least 1 250 m thick.

The primary mineralisation type of economic interest at the Rosh Pinah mine is a silicified, grey to dark grey, fine-grained and laminated unit locally called microquartzite mineralisation. It comprises alternating millimetre- to centimetre-wide bands of sulphide exhalites (sphalerite, pyrite and galena and minor chalcopyrite), part of which was carbonatised with associated remobilisation and enrichment of sulphides, and is believed to represent a classic reworked sedimentary-exhalative style exhalite. The secondary argillite carbonate mineralisation carries the higher, economic, base metal values. The argillite mineralisation would be similarly derived, but diluted with background benthonic argillite.

Reserves: Total proven and probable reserves as at 8.49-million tonnes grading 6.73% zinc, 1.52% lead, 21.9 g/t silver.

Resources: Total measured and indicated resources are estimated 11.32-million tonnes grading 7.82% zinc, 1.76% lead and 26.13 g/t silver. Inferred resources were estimated at 5.56-million tonnes grading 7.11%, 1.13% lead and 24.93 g/t silver.

Mining Method: Underground, using predominantly sublevel open stoping, following a primary and secondary sequencing approach.

Major Infrastructure and Equipment: Rosh Pinah’s orebodies are accessed through multiple declines. All mining is mechanised using drill rigs, scoop trams and underground haulage trucks. Waste is hauled through declines to a surface waste dump or is placed in mined-out stopes, where possible. Ore is dumped into an ore pass feeding a grizzly and primary crusher, and is subsequently conveyed to the surface process plant.

The mine includes a 2 000 t/d processing plant, a flotation recovery plant, metallurgical and geochemical laboratories and a tailings facility.

Prospects: Tevali plans to complete the RP2.0 expansion feasibility study on the Rosh Pinah mine by the end of 2020. The project is expected to increase production by 60% to 80%, reduce unit costs, and improve recoveries and concentrate grades at an initial capital cost of $60-million to $80-million.

The scope of the project includes addressing the mining method, materials handling configuration, the sizing of the processing plant and various underground and surface infrastructure. A significant portion of this investment is focused on expanding Rosh Pinah’s processing plant, but part of the RP2.0 expansion will also focus on modernising the underground operation.

Contact Details:
Trevali Mining Corporation
Tel +1 604 488 1661
Email info@trevali.com
Website https://www.trevali.com