Overview

The Muliashi Mine represents a modern addition to the Copperbelt's mining inventory, developed by China Nonferrous Mining Corporation (CNMC) to exploit oxide copper-cobalt resources near Luanshya through open pit mining and hydrometallurgical processing. Unlike the region's traditional underground sulphide operations, Muliashi employs acid leaching and solvent extraction-electrowinning (SX-EW) technology to produce refined copper cathode directly on site, bypassing the need for concentrate smelting.

The operation was developed as a complement to CNMC's nearby Luanshya underground mine, targeting the oxide and transitional ore zones that occur above and adjacent to the deeper sulphide mineralisation exploited at Luanshya. This integrated approach allows CNMC to extract value from multiple ore types within the same geological system, maximising the economic return from the Luanshya mineral endowment.

Muliashi's development represented a significant capital investment by CNMC and demonstrated the company's commitment to expanding its Zambian mining footprint beyond the original Chambishi operation. The mine's SX-EW technology is well-suited to the oxide ores found in the weathered upper portions of Copperbelt deposits, where conventional flotation is less effective. The result is a clean, efficient operation that produces high-quality copper cathode suitable for direct sale to fabricators and manufacturers.

Geology & Reserves

Muliashi's mineralisation occurs within the same Katanga Supergroup stratigraphy that hosts the broader Luanshya copper deposits. The open pit targets oxide and mixed oxide-sulphide copper-cobalt mineralisation that has formed through the weathering and oxidation of primary sulphide ores in the near-surface environment. The principal copper minerals in the oxide zone include malachite, chrysocolla, and cuprite, while cobalt occurs as heterogenite and other oxide-phase cobalt minerals.

The oxide zone at Muliashi extends from surface to depths of approximately 50-80 metres, below which transitional and then fresh sulphide mineralisation is encountered. The transition zone contains a mix of oxide and sulphide copper minerals, presenting metallurgical challenges that require careful blending and process management to maintain leach recovery rates. The distribution of oxide versus sulphide mineralisation is controlled by the depth of weathering, which varies across the deposit in response to topography and structural permeability.

Resources at Muliashi are substantial, with the oxide ore body containing tens of millions of tonnes of leachable material at copper grades of 1.0-1.5 percent. Cobalt grades, while lower, are economically significant when recovered as a by-product. The resource base supports continued open pit mining over a medium-term horizon, with the possibility of extending operations through the treatment of lower-grade material or the development of adjacent oxide zones identified through exploration.

Operations & Infrastructure

Muliashi operates as a conventional open pit mine using truck-and-shovel methods. Ore is drilled and blasted on benches of approximately 10 metres, loaded by hydraulic excavators, and hauled by rigid-body dump trucks to either the crushing circuit or the run-of-mine leach pads. Waste rock is deposited on dedicated dumps adjacent to the pit.

The hydrometallurgical processing circuit at Muliashi consists of three main stages. First, crushed ore is stacked on lined leach pads where dilute sulphuric acid solution is applied through drip irrigation. The acid dissolves copper and cobalt from the oxide minerals as it percolates through the ore stack, producing a pregnant leach solution (PLS) that is collected in lined ponds. Second, the PLS is processed through a solvent extraction (SX) plant where copper is selectively concentrated into a rich electrolyte. Third, the copper-rich electrolyte is fed to an electrowinning (EW) tankhouse where copper is plated onto cathodes through electrolysis, producing LME-grade copper cathode.

Cobalt is recovered from the SX raffinate (the copper-depleted solution) through a separate precipitation or crystallisation circuit. The cobalt product is sold as cobalt hydroxide or cobalt carbonate, depending on market requirements and processing conditions.

Process Advantages

The SX-EW process offers several advantages for oxide ore treatment at Muliashi. It produces finished copper cathode on site, eliminating the need for concentrate transport and third-party smelting. Operating costs per tonne of copper are competitive with flotation-smelting routes for oxide ores. The process has a smaller atmospheric emission footprint than pyrometallurgical processing, as it avoids the sulphur dioxide generation associated with smelting.

Production Data

Cobalt recovery from the leach circuit typically yields 500-800 tonnes per year as hydroxide product. Cobalt revenues provide a valuable supplement to the operation's economics and have become increasingly important as cobalt demand from the battery sector has elevated prices and strategic interest in cobalt supply.

Ownership & Corporate Structure

Muliashi is operated by Sino Metals Leach Zambia Limited, a subsidiary of CNMC. The operation sits within CNMC's broader Zambian portfolio that includes Chambishi and Luanshya, forming an integrated mining complex that spans underground sulphide mining, open pit oxide mining, concentrate production, leach cathode production, and smelting.

CNMC's centralised management of its Zambian operations allows for coordination of ore flows, shared procurement, and integrated marketing of copper and cobalt products. The Muliashi SX-EW plant also processes acid-soluble material from other CNMC operations when available, contributing to overall portfolio optimisation.

ZCCM-Investments Holdings holds a minority interest in the Muliashi operation, consistent with the standard Zambian government participation framework across the mining sector. The relationship between CNMC and the Zambian government has been broadly constructive, with CNMC among the more stable and consistent Chinese mining investors in the country.

ESG Considerations

Environmental Management

Muliashi's environmental profile is shaped by the characteristics of open pit mining and hydrometallurgical processing. The primary environmental management focus areas include acid management (preventing uncontrolled release of sulphuric acid to the environment), leach pad liner integrity (preventing pregnant leach solution from infiltrating groundwater), dust management from open pit operations, and progressive rehabilitation of exhausted pit areas and waste dumps.

The SX-EW process has a lower atmospheric emission profile compared to smelting operations, as it does not generate sulphur dioxide or other smelter-related emissions. However, the use of large volumes of sulphuric acid creates its own environmental risks, and the management of spent leach solutions and residual acidified material requires careful long-term planning. The lined leach pads and solution ponds represent engineered containment systems whose integrity must be maintained throughout the mine's operating life and beyond.

Water Management

Water management is critical at Muliashi due to the mine's proximity to local watercourses and the water-intensive nature of the leach process. The operation recirculates process water to the maximum extent practical, but net water consumption from the leach circuit is significant. Groundwater monitoring wells surrounding the leach pads and solution storage ponds provide early warning of any seepage, and interceptor systems are in place to capture and return any escaped solution to the process circuit.

Social Impact

Muliashi's development created employment opportunities for the Luanshya community at a time when the town's historic underground mine was in decline. The open pit operation employs approximately 1,500 people directly and through contractors, providing an economic supplement to the nearby underground mining activity. Community relations have been generally stable, though concerns about dust, noise, and visual impact from the open pit have been raised by residents in adjacent areas.

Corridor Relevance

Muliashi's strategic value in the context of the Lobito Corridor is enhanced by the fact that it produces finished copper cathode rather than concentrate. Cathode is a higher-value, easier-to-transport product that can be shipped directly to end users without the need for intermediate smelting and refining. This means that improved export logistics via the corridor extension would translate more directly into cost savings, as there is no intermediate processing step between mine gate and market.

The mine's position near Luanshya places it within the central Copperbelt, well situated to access any eastward rail connection linking the Zambian Copperbelt to the Lobito Corridor's DRC segment or a direct westward route through North-Western Province. For Muliashi's approximately 20,000 tonnes of annual cathode output, reduced transport costs of even USD 20-30 per tonne would yield meaningful annual savings.

Additionally, improved logistics infrastructure would facilitate the import of sulphuric acid, which is a critical and cost-sensitive input for the leach operation. Currently, acid is sourced from local smelters and supplemented by imports; an alternative import route via the Atlantic coast could provide competitive acid supply options and reduce the operation's vulnerability to domestic acid supply disruptions.

Outlook

Muliashi's outlook is positive, supported by a resource base that sustains continued open pit mining and leaching for the medium term. The operation has reached design capacity and is focused on maintaining production rates while managing ore grade variability as the pit advances into different zones of the deposit. CNMC has demonstrated commitment to its Zambian operations, and Muliashi benefits from integration with the broader CNMC portfolio.

Key variables include copper and cobalt price trends, sulphuric acid supply and pricing, and Zambian power supply reliability. The SX-EW process is electricity-intensive, particularly the electrowinning stage, making the operation sensitive to power costs and availability. Zambia's ongoing power challenges, driven by reduced hydroelectric generation during drought years, present a risk that CNMC has partially mitigated through on-site backup generation capacity.

Longer-term, the depletion of oxide ore reserves will eventually transition Muliashi from leaching back to conventional sulphide processing or closure, unless additional oxide resources are identified through exploration. The timing of this transition — likely a decade or more away at current mining rates — provides a planning horizon for either resource extension or integration of Muliashi's output into other CNMC operations in the area.

Timeline

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