Highlights

• Mount Burgess Mining NL (ASX:MTB) shares rose 25% to AUD 0.005 on in early Monday trading.
• The recent hydrometallurgical test work has revealed impressive metal recovery rates at the Nxuu Deposit.
• Zinc recovery exceeded 96%, while vanadium recovery reached 91.1%.
• MTB continues process development to enhance the recovery of key elements including gallium (Ga), germanium (Ge), and rare earth elements (REEs).

Mount Burgess Mining NL (ASX:MTB) has released encouraging interim results from recent hydrometallurgical test work aimed at optimising on-site metal recovery. The latest findings from the Nxuu Deposit have revealed impressive recovery rates for key economic metals including zinc (Zn), vanadium (V), germanium (Ge), gallium (Ga), and several rare earth elements (REEs).  

As per the company, these encouraging results will contribute to a forthcoming scoping study, which is expected to be completed in late 2025.

Interim Recovery Results

The hydrometallurgical testing yielded the following metal recoveries into solution:

• Zn : >96%
• Pb :79.4.0%
• V : 91.1%
• Ga : 59.3%
• Ge : 77.3%

Lead Recovery Potential and Process Optimisation

MTB’s Chairman and Managing Director, Mr. Nigel Forrester, highlighted that while the latest hydrometallurgical test work demonstrated lead (Pb) recovery of 79.4%, previous flotation test work had shown even higher efficiency, achieving a 93% recovery of lead in a concentrate containing cassiterite mineral. This comparison underscores the potential for further optimisation in recovery processes moving forward.

Leaching Process Insights

The aim of the recent test work was to enhance leaching kinetics through a hydrometallurgical approach, where process parameters such as pressure, temperature, and pH were adjusted to assess their individual impacts on the extraction of key economic elements.

In March 2025, four leach tests were conducted on a master composite sample from the Nxuu deposit.

Through the use of a dual leaching process, over 96% zinc dissolution and 91.1% vanadium recovery were achieved. This represents an ongoing evaluation of process development for the Nxuu Deposit.

Rare Earth Element Recovery

Additionally, the extraction percentages for several key rare earth elements (REEs) are detailed below:

• Lanthanum (La) 69.1%
• Neodymium (Nd) 68%
• Praseodymium (Pr) 70.1%
• Cerium (Ce) 63.3%
• Samarium (Sm) 63.6%
• Europium (Eu) 90.3%

The highly oxidised nature of the Nxuu deposit led to a significant dissolution of aluminum (Al), silicon (Si), and potassium (K), which is attributed to the presence of aluminum silicate minerals in the ore, where REEs are also associated. The dissolution rates for Al, Si, and K exceeded 70%.

The company is continuing further test work to enhance the recovery of gallium (Ga), germanium (Ge), and other REE elements.

Shares of MTB surged by 25.00%, reaching AUD 0.005 on Monday early trading hours.