Name of the Project
King of the Hills (KOTH) processing facility expansion.

Location
Leonora Operations, in the Eastern Goldfields region of Western Australia.

Project Owner/s
Intermediate gold producer Vault Minerals.

Project Description
The KOTH openpit and underground gold mines, the Darlot satellite underground gold mine and the KOTH processing facility form part of the Leonora Operations.

The expansion will increase KOTH’s processing facility capacity to six-million tonnes a year. Stage 1 includes the installation of a new, fit-for-purpose crushing circuit delivering increased throughput capacity and reduced unit operating costs.

Stage 1 also significantly increases wet plant and classification circuit capacity to cater for throughput exceeding seven-million tonnes a year.

Stage 2 mill expansion will focus on the addition of a regrind ball mill, a thickener, increased elution and gravity circuit capacity, and increased tailings discharge capacity.

The upgrade will introduce opportunities for further and ongoing debottlenecking and optimisation to increase throughput to between seven- and eight-million tonnes per annum.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
Not stated.

Capital Expenditure
Stage 1 project capital expenditure is expected to be $80-million (inclusive of owner’s costs), with an estimated $8-million forecast to be spent in the 2025 financial year. Preliminary capital for Stage 2 is estimated at between $65-million and $80-million.

Planned Start/End Date
The project was approved in February 2025. Work is expected to be completed within 15 months from April 2025, with commissioning scheduled for the fourth quarter of 2026.

Latest Developments
Vault Minerals will transition load-and-haul operations at KOTH to an owner-operator model from January 1, 2027, following the expiry of its current mining services contract at the end of 2026.

The decision comes after a comprehensive tender process and assessment of operating models, with Vault concluding that owner mining will deliver greater long-term value and operational control. The model will also provide “superior cost efficiency” and “enhanced cost control” by allowing for direct management of mine operations. 

The company has also cited “operational agility”, “workforce stability” and “strategic alignment” among the key advantages of the owner-operator model.

“Owner operation is materially more cost-effective over the life-of-mine,” Vault has stated, adding that owning equipment also creates “enduring value, with potential for resale or redeployment”.

The transition follows a significant increase in KOTH openpit ore reserves announced in May 2025, extending the mine’s life to 13 years. Stockpiles generated during that period will also provide baseload mill feed for Vault’s Leonora Operations for an additional five years.

To support increased activity – forecast to increase by about 35% – Vault plans to deploy a larger and more productive fleet, including two 360 t excavators and one 260 t excavator, supported by 190 t haul trucks and ancillary equipment. Average material movements are expected to reach about 14-million bank cubic metres a year over the life of the ore reserve.

A transition plan will be implemented throughout the 2026 financial year and the first half of the 2027 financial year to ensure a seamless start to owner mining.

Vault will retain contract drill-and-blast services at KOTH, with a preferred contractor selected for a five-year term starting in January 2027, subject to final contractual agreements.

The company has also confirmed that there will not be changes to its Leonora Operations production, its all-in sustaining cost guidance for 2026 or its 2027 and 2028 outlook. 

Deposits of about A$2-million for long-lead fleet items are expected to be paid in the second quarter of 2026, with equipment financing and hybrid funding options under review.

Key Contracts, Suppliers and Consultants
GR Engineering Services (project design, scope of work and costing).

Contact Details for Project Information
Vault Minerals, tel +61 8 6313 3800 or email info@vaultminerals.com.