How Prospect Resources’ Flotation Breakthrough Could Slash Mumbezhi Costs

Flotation Testwork Delivers High-Grade Copper Concentrates

Prospect Resources Limited has announced compelling metallurgical testwork results from sulphide materials at its Nyungu Central deposit, part of the Mumbezhi Copper Project in Zambia's prolific Central African Copperbelt. Independent consultants Core Metallurgy Pty Ltd conducted flotation tests that yielded copper concentrates grading up to 33.3% copper with recoveries exceeding 90%, demonstrating the deposit’s amenability to conventional processing methods.

The standout result was a fresh composite sample producing a concentrate grading 24.6% copper and 9,000 ppm cobalt at a remarkable 96.2% copper recovery after just one cleaning stage. These figures not only affirm the quality of the mineralisation but also suggest strong commercial potential for the project.

Grinding Size Optimization Points to Cost Efficiencies

A key highlight from the testwork is the ability to coarsen the primary grind size from the previously used 150 microns to approximately 250 microns with only a marginal 0.4% reduction in copper recovery. This shift is significant because coarser grinding typically reduces both capital expenditure and operating costs for processing plants, potentially enhancing the project's economic viability.

In addition, the presence of relatively high graphitic carbon levels, up to 4.8% total graphitic carbon, was found not to impede the production of high-quality copper concentrates when an appropriate reagent scheme is applied. This finding alleviates a common metallurgical challenge and further supports the simplicity of the processing flowsheet.

Ongoing Testwork and Strategic Developments

Prospect is currently advancing testwork on transitional materials from Nyungu Central and fresh sulphide samples from the nearby Kabikupa deposit, with results expected by the end of the second quarter of 2025. These studies will provide a more comprehensive understanding of the project’s metallurgical characteristics and help refine processing strategies.

These metallurgical advances come on the back of Prospect’s maiden Mineral Resource Estimate for Mumbezhi, released in March 2025, which reported a substantial resource of 107.2 million tonnes at 0.5% copper, containing over 500,000 tonnes of copper. The company’s recent strategic placement and technical alliance with copper giant First Quantum have bolstered its financial position, enabling an aggressive exploration and development program, including the commencement of Phase 2 drilling earlier this month.

Implications for Mumbezhi’s Future

Managing Director Sam Hosack emphasised the company’s focus on de-risking and enhancing the commercial viability of Mumbezhi through rigorous metallurgical evaluation. The positive flotation results and grind size optimization underscore the potential for a streamlined, cost-effective processing plant, which could translate into improved project economics and investor confidence.

As Prospect continues to unlock the full potential of its copper assets in Zambia, the Mumbezhi Copper Project is shaping up as a promising contributor to the global copper supply, particularly in the context of rising demand driven by electrification and green energy technologies.