London-listed magnet metals miner Pensana chairperson Paul Atherley has lauded the ongoing support from the government of Angola, the sovereign wealth fund of Angola – Fundo Soberano de Angola (FSDEA), financial services provider Absa, and others, for their assistance in the development of the Longonjo rare earths project in Angola.

The Longonjo project, located near the city of Longonjo, is a significant and undeveloped rare earths project which benefits from a high-grade near-surface orebody, with the ability to be powered using low-cost hydroelectricity and direct access to the Lobito Corridor rail and port infrastructure.

The engineering review and the staged development has resulted in a significantly lower upfront capital cost, which greatly enhances the projects’ potential to be financed.

This immediate funding from FSDEA will allow Pensana CEO Tim George, and the company’s team, to accelerate the work on the ground with an intention to starting main construction later in the year with a view to achieving first production in 2025.

The Longonjo deposit has an initial 20-year mine life and considerable exploration potential to extend the resource base both immediately below the existing orebody as well as at the recent discovery on the Coola exploration licence.

The near-surface, deeply weathered orebody, has an average depth of less than 30 m, with an average mine grade of 3.73% total rare earth oxide (TREO), and 0.79% neodymium-praseodymium (NdPr) over the first five years.

The process routes and key equipment required for beneficiation of the mined material at Longonjo are those commonly used in the broader minerals processing industry, and should be easy to access as a result.

Following comminution and flotation, the rare earth mineral concentrate is subjected to acid roast, leaching and selective precipitation to produce a mixed rare earth double sulphate (MREDS), or mixed rare earth carbonate (MREC), providing customers with a clean, radionuclide-free product available for export through the recently refurbished Port of Lobito.

The Longonjo operation is located close to major existing infrastructure in the form of the recently upgraded Benguela railway line, linking the project to the Atlantic seaboard Port of Lobito, commonly referred to as the Lobito Corridor, and hydro-power infrastructure.

The US International Development Finance Corporation is currently performing due diligence for a potential $250-million investment to finance the Lobito Atlantic Railway Corridor to connect the Democratic Republic of Congo’s (DRC’s) Copperbelt region with the Port of Lobito.

The Lobito Corridor is anticipated to become one of the most important rail transport infrastructure systems within the Southern African Development Community (SADC) region over the next 25 years.

This follows the award of a $450-million contract by the Angolan Ministry of Transport to a consortium of mining company Trafigura, construction company Mota-Engil and rail developer Vecturis, to operate and maintain the Benguela railway through to the DRC Copperbelt on a private concession basis, as part of the Lobito Corridor development.

This is expected to have a positive impact on the transport logistics during the construction period and for reagent and product transport during operations.

After completing the phased development, the mine, at full production, will target production of up to 3 000 t/y of MREDS or MREC containing 14 000 t of TREO and up to 4 400 t of NdPr oxide. This equates to about 5% of the global yearly production of NdPr oxides for downstream processing or to be sold on the international market.

The Longonjo ore reserve estimate was prepared by mining group Snowden Optiro in August 2022 as part of the Longonjo project feasibility study, using the guidelines of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves.

Following discussions with its major shareholders – FSDEA and investment management firm M&G, supported by Angola’s Ministry of Mineral Resources, Petroleum & Gas – a detailed review was undertaken by the Longonjo engineering team to reflect the strong desire of all parties to bring the Longonjo operation into production as soon as practical.

The revised execution plan is based on a staged development of the mine and processing facilities with a reduced upfront capital cost of $200-million, with about $105-million related largely to the national power grid connection, rail spur and subsequent expansion costs, deferred until year three following commissioning.

Subsequent to the engineering redesign, the Angolan government has announced an $83.6-million funding package for the extension of the hydroelectric power line to Huambo. This has the potential to reduce the capital funding requirement for the project by $36-million, thereby potentially reducing the capex in year three to about $70-million.

FSDEA has also agreed to provide an initial $15-million loan facility as part of an $80-million investment, subject to due diligence and the finalisation of investment terms, and which will be repaid out of the larger facility for the $200-million staged development.