Name of the Project
Uis tin mine Phase 1 expansion project.

Location
Namibia.

Project Owner/s
Tin mining company AfriTin Mining.

Project Description
A definitive feasibility study (DFS) has confirmed the feasibility of expanding the current Phase 1 processing plant, resulting in a 67% increase in tin concentrate production from 720 t/y to 1 200 t/y.

The DFS proposes enhancements to the current processing plant, which will result in a modular expansion of the existing crushing circuit to increase ore throughput by 50%. It also proposes the upgrade of the existing concentrator circuit to accommodate the increased crushed ore feed tonnage and increase the projected overall tin recovery target from the current 60% to 64%.

The detailed upgrades include:

• the addition of a crusher and screen between the primary jaw crusher and the fines crushing section;

• the addition of a buffer stockpile between the crushing and concentrating sections;

• the increase of the water rejection capacity in the dense-medium separation (DMS) 1 section;

• combining the dense-medium circuits of DMS 2 and DMS 3 to improve operability and stability;

• converting the DMS 2 floats recrush circuit into a closed circuit by adding a classification screen;

• additional spirals to reprocess middlings; and

• the relocation of product handling infrastructure and the installation of an additional shaking table for improved processing capacity. The existing shaking tables will be replaced with Holman tables for higher separation efficiency.

The DFS is based on a tin-only basis and currently excludes tantalum and lithium concentrate as potential by-products – these commodities are being investigated by AfriTin’s metallurgical testwork programme.

The Uis mine has proven and probable reserves of 15.61-million tonnes grading 0.14% tin for 21 536 t of contained metal.

Potential Job Creation
The project will be complemented by the appoint­ment of a skilled and experienced project management and construction management team to reduce implementation time and limit project implementation risks.

Net Present Value/Internal Rate of Return
The project has a net present value of $12.1-million and an internal rate of return of 54%, with a payback of 2.4 years.

Capital Expenditure
The project is estimated at $5.7-million.

Planned Start/End Date
The company aims to complete the expansion by the second quarter of 2022.

Latest Developments
An engineering, procurement and construction management (EPCM) contractor has been appointed to design and construct a lithium pilot processing plant at the Uis mine.

This follows metallurgical test work results showing the successful production of a petalite lithium concentrate, indicating the potential for a lithium by-product at the Uis mine.

Consulmet (South Africa) has been appointed EPCM contractor for a 20 t/h pilot plant with a target commissioning date in the fourth quarter of 2022.

The pilot plant is intended as a proof of concept for a full-scale, integrated lithium beneficiation circuit, which will be added to the existing processing plant, AfriTin has stated.

Petalite lithium concentrate, with a purity of up to 94%, has been produced from bulk ore samples by independent test facilities.

The concentrate is expected to meet demand from premium glass and ceramics manufacturers, and be suitable feedstock for battery-grade lithium carbonate or lithium hydroxide converters.

The lithium resource is contained within the currently mined orebody, and the lithium concentrate will be a by-product to existing tin concentrate.

The potential of sensor-based ore sorting technology to produce a lithium preconcentrate prior to concentration is being investigated.

Initial test work by Steinert of Germany has demonstrated a hyperspectral signature for petalite using a near-infrared and laser sensor. This has the potential of achieving waste rejection early in the beneficiation process.

Key Contracts, Suppliers and Consultants
Minxcon (DFS) and Consulmet (EPCM contractor – pilot plant).

Contact Details for Project Information
AfriTin Mining, tel +27 11 268 6555.