Bisha Mine

Bisha Mine (also known as Bisha Copper-Zinc Mine) is Eritrea's flagship and largest modern mining operation. It is a volcanogenic massive sulfide (VMS) deposit located in the Gash-Barka region, approximately 150 km west of Asmara and 40 km west of Akordat.

Ownership and History

• Current ownership: Zijin Mining Group (China) holds 55%, and the state-owned Eritrean National Mining Corporation (ENAMCO) holds 45%. Zijin acquired its stake (initially 60%) from the Canadian company Nevsun Resources in 2019.
• Operator: Bisha Mining Share Company (BMSC).
• Development: Discovered in the early 1990s and developed by Nevsun. It was Eritrea's first large-scale industrial mine. Construction began around 2008–2010, with commercial production starting in February 2011.

Phased Production

• 2011–early 2013: Primarily high-grade gold from oxide ore.
• Late 2013 onward: Transition to copper concentrate.
• 2016 onward: Zinc production added via plant expansion (copper and zinc concentrates now produced).

The mine has cumulatively produced over 1 million ounces of gold across its phases, along with significant copper and zinc.

Geology and Resources

Bisha is a high-grade polymetallic VMS deposit rich in zinc, copper, gold, and silver. It includes the main Bisha pit and satellite deposits like Harena (and the developing Hambok pit).

Recent estimates (around 2023–2024):

• Proven & Probable Reserves: Approximately 3.09 million tonnes of zinc (at ~3.75% grade) and 800,000 tonnes of copper (at ~0.97% grade). Other figures cite contained zinc around 693 kt at 5.3% and copper 119 kt at 0.91% in reserves.
• Mineral Resources (inclusive of reserves, measured/indicated/inferred): Higher contained metals, e.g., ~2.74–3 Mt zinc and ~638–759 kt copper at average grades around 3.7–4.8% Zn and 1.0–1.02% Cu.

Remaining open-pit mine life was previously estimated at around six years (as of ~2024), but extensions via the Hambok pit and potential underground development could extend operations.

Mining and Processing

• Mining method: Conventional open-pit (truck-and-shovel/loader) with flotation processing.
• Throughput: The processing plant handles roughly 2.4–2.9 million tonnes of ore per annum. Capacity has been increased through debottlenecking.
• Products: Copper concentrate, zinc concentrate, with by-product gold and silver. Some gold doré was produced in the oxide phase.

Recent Production (100% basis)

• 2024: Zinc 121.4 kt, Copper 20 kt, Silver 65 t (gold production is lower in the current sulfide phase but remains a by-product).
• Earlier years showed zinc output often in the 100–120+ kt range annually at peak, with copper in the 16–20+ kt range. Historical peaks included higher copper during the supergene phase.

The mine is one of Africa's notable polymetallic operations and Eritrea's largest zinc producer.

Expansions and Future Plans

• Hambok open pit: Waste rock stripping and infrastructure work began in 2024. Ore extraction is scheduled to start in Q1 2026, providing additional feed to extend operations and maintain throughput.
• Debottlenecking and plant upgrades have increased capacity and efficiency.
• Innovations reported in 2025–2026 include automation (remote-controlled equipment, autonomous drilling), high water recycling (>80%), digital operations, and workforce nationalization (reportedly reaching ~90% Eritrean nationals).
• Potential for underground mining has been studied in the past (e.g., below the Bisha and Harena pits), though open-pit remains the focus with Hambok.

Economic and Operational Context

Bisha has been a major contributor to Eritrea's export earnings and GDP since startup. It employs thousands (with high nationalization rates) and has included infrastructure like power, water, and processing facilities. Operations emphasize safety and environmental measures, including tailings management and rehabilitation programs, though the arid setting requires careful water management.

Like other Eritrean mining projects, it operates under the government's joint-venture model with ENAMCO holding a substantial stake. Past controversies (under Nevsun) involved allegations related to labor practices tied to national service, but current reports focus more on production, expansions, and Chinese operational involvement.

For the most current figures (e.g., 2025 full-year production or updated reserves), company reports from Zijin Mining or Eritrean official sources provide the latest data, as outputs fluctuate with ore grades, metal prices, and mine sequencing. The Hambok addition in 2026 is expected to help sustain output into the late 2020s and beyond.