JOHANNESBURG (miningweekly.com) – London-listed North River Resources is advancing developments at its flagship Namibia-based lead/zinc/silver project following the emergence of significant historical data and the establishment of new management.

The group on Friday said rapid progress had been made over the past 18 months to reopen the Namib mine, which produced lead, zinc and silver from 1969 to 1991.

“A considerable amount of preparation work and study has been conducted at the mine and we are now in a position to roll out this project,” North River executive director Martin French said.

The company had developed a three-stage plan of appraisal drilling, resource drilling and production development, and revised recommendations to the mine’s development plan and conceptual engineering study were currently being refined, following the appointment of new project manager Dominic Claridge and the data discovery.

North River appointed geological consultants CSA Global to undertake a comprehensive review of the orebodies at Namib and to design a proof-of-concept drill programme to verify the direction, grade and depth of orebodies – both underneath the historic mine and also at the largely unmined Northern orebodies adjacent to the mine.

The study would provide detailed recommendations on appraisal drilling programmes and the development of the mine.

“The company is already well advanced in its mobilisation planning for the drill programme, which is expected to start next month and involve both surface and underground drilling,” French commented.

The group determined a maiden resource of 668 000 t of indicated and inferred ore.

The legacy information allowed North River to determine that the historic mine produced about 700 000 t of ore, producing over 100 000 t of lead and zinc concentrate, and over one-million ounces of silver.

The company calculated that this would have yielded revenues in excess of $100-million at current commodity prices after net smelter returns.

Over the past 18 months, North River had dewatered about 15-million litres of water from the mine; resurveyed the region using CMS, geological mapping and photographic surveys of underground workings; and completed the environmental cleanup of surface and underground and removed all historic debris, making the mine fully accessible and safe.

The company completed underground diamond drilling with high-grade intercepts beneath existing mine workings; a 1 572 km helicopter versatile time domain electromagnetic survey within the licence area around the mine; and a 600 m channel sampling survey on underground in-situ ore within the existing mine structure.

Further, an environmental impact assessment report was nearing completion.