Vault Minerals Limited (ASX: VAU) announced on 26 Mar 2026 that Stage 1 of the King of the Hills plant upgrade has progressed on time and on budget and is now in the final stages of commissioning. The upgrade, focused on increasing plant throughput capacity to approximately 6.0 million tonnes per annum (Mtpa), marks a significant step in the Company’s Vault Minerals Leonora expansion strategy at its flagship Western Australian gold operation.
Figure 1: Vault Minerals Limited logo representing the Australian gold producer [Courtesy: Business News]
The King of the Hills throughput upgrade will increase overall processing capacity by approximately 50% at a capital intensity of A$57 per tonne of increased annual throughput capacity. With a substantial ore stockpile buffer already in place and Stage 2 progressing in parallel, the Company is advancing toward a clear production growth pathway at KoTH.
Stage 1 Construction Hits All Key Milestones
The KoTH plant upgrade Stage 1 commissioning has reached completion across all major construction activities ahead of the first ore feed. Vault Minerals confirmed the new primary crusher installation is complete, the conveyor belt extension tying the new crushing facility into the existing plant is complete, and the Stage 1 power station upgrade has been finalised with the commissioning of two additional gas-fired gensets.
Figure 2: New primary crusher installation at the King of the Hills processing facility [Courtesy: Vault Minerals]
Wet Plant Upgrades and Power Infrastructure Now Operational
The wet plant component of the Stage 1 upgrade has also been completed and is performing well. Tie-in of the wet plant upgrades included four additional carbon-in-leach (CIL) tanks, a larger regeneration kiln and a new tailings booster pump. The KoTH power station operates on gas, supported by a three-year gas supply agreement at a CPI-linked fixed price that commenced in January 2026, providing meaningful cost certainty across the upgrade period.
Figure 3: Stage 1 wet plant upgrade at KoTH showing four additional CIL tanks now online [Courtesy: Vault Minerals]
Crushed Ore Stockpile Ensures Uninterrupted Mill Feed Through Commissioning
To ensure continuity of operations through the crusher transition, Vault Minerals managed the cutover carefully. The existing crusher was taken offline on 24 Mar 2026, with crushed stocks of approximately 90,000 tonnes on the ground. These stocks are expected to provide uninterrupted mill feed prior to crusher ore commissioning, with first ore to the new crusher expected on 31 Mar 2026.
A 15 Million Tonne Stockpile Keeps Mill Feed Running Smoothly
Beyond the commissioning buffer, Vault Minerals holds a significant strategic inventory at the KoTH site. As at 28 Feb 2026, the Company had stockpiles of approximately 15 million metric tons (Mt) at KoTH containing approximately 180,000 ounces of gold. These stockpiles are located adjacent to the processing facility.
Figure 4: Aerial view of the crusher area showing the new crusher, retiring crusher, ROM pad, ore stockpiles and crushed ore stockpile at KoTH [Courtesy: Vault Minerals]
The Company noted that this inventory provides significant operational flexibility to maintain base load mill feed under a range of operating scenarios. This flexibility is particularly relevant given the potential for supply disruptions of key operational inputs arising from ongoing tensions in the Middle East.
Stage 2 Remains on Track for Higher Capacity in FY27
The Vault Minerals Leonora expansion does not stop at Stage 1. Stage 2 of the KoTH plant upgrade is progressing on time and on budget, with completion and tie-in remaining on schedule for Q2 FY27. Stage 2 will deliver increased plant capacity of 7.5 to 8.0 Mtpa throughout the second half of FY27, taking the King of the Hills throughput to a materially higher base than the current operation.
Stage 2 works currently underway include a tailings thickener and powerhouse extension, both of which were visible and progressing well at the time of the announcement. Together, Stages 1 and 2 represent a coordinated, capital-efficient pathway to significantly higher annual gold production volumes from the KoTH operation.
Vault Minerals Share Price
Vault Minerals Limited (ASX: VAU) is currently trading at A$4.020 per share, with a market capitalisation of A$4.18 billion. The 52-week range stands at A$2.340 to A$6.300 per share.
Figure 5: Vault Minerals share price performance over the past year [Courtesy: ASX]
Industry Outlook
The Australian gold mining sector continues to attract strong investor interest, underpinned by elevated gold prices and increasing demand for domestically produced precious metals. Processing plant expansions of the kind being executed at King of the Hills represent a capital-efficient method of growing output without the lead times associated with greenfield development.
For ASX-listed gold producers, throughput expansion at existing operations remains one of the most direct pathways to improved free cash flow generation and earnings growth.
Future Direction and Impact on Production and Shareholders
The completion of the KoTH plant upgrade commissioning across Stages 1 and 2 is expected to have a direct and material impact on Vault Minerals’ annual gold production volumes. With Stage 1 delivering 6.0 Mtpa capacity and Stage 2 targeting 7.5 to 8.0 Mtpa, the King of the Hills throughput profile will be substantially transformed by the second half of FY27. The capital intensity of A$57 per tonne of increased annual throughput capacity positions this as a highly competitive expansion relative to industry benchmarks.
For investors tracking the Vault Minerals Leonora expansion, the on-time and on-budget delivery of Stage 1 commissioning, supported by a large ore stockpile and a secured gas supply contract, provides a strong operational foundation as the Company advances toward full Stage 2 delivery.
ALSO READ: Asian Battery Metals: A Copper Explorer Positioned for the Copper Supercycle
Frequently Asked Questions
Q1. What is the KoTH plant upgrade?
Ans. The King of the Hills plant upgrade is a two-stage expansion of the processing facility at Vault Minerals’ flagship gold operation in Western Australia, targeting throughput capacity of 7.5 to 8.0 Mtpa upon full completion.
Q2. What does Stage 1 of the KoTH plant upgrade commissioning deliver?
Ans. Stage 1 increases plant throughput capacity to approximately 6.0 Mtpa. Key works include a new primary crusher, conveyor belt extension, four additional CIL tanks, a larger regeneration kiln and a power station upgrade with two additional gas-fired gensets.
Q3. When will Stage 2 of the KoTH plant upgrade be complete?
Ans. Stage 2 is on schedule for completion and tie-in in Q2 FY27, with the increased capacity of 7.5 to 8.0 Mtpa to be operational throughout H2 FY27.
Q4. How does the stockpile support the Vault Minerals Leonora expansion?
Ans. As at 28 Feb 2026, the Company held approximately 15 million metric tons of stockpiles at KoTH containing approximately 180,000 ounces, providing base load mill feed flexibility during commissioning and under potential supply disruption scenarios.
Q5. What is the capital intensity of the upgrade?
Ans. The King of the Hills throughput upgrade is being delivered at a capital intensity of A$57 per tonne of increased annual throughput capacity, which the Company describes as highly competitive.
Disclaimer
This article is intended for informational purposes only and does not constitute financial or investment advice. All content is based on the ASX announcement issued by Vault Minerals Limited (ASX: VAU) on 26 Mar 2026. Share price and market capitalisation data reflect figures provided at the time of publication. Investing in securities involves risk. Readers should conduct their own research and seek independent financial advice before making any investment decisions. Colitco does not hold any position in the companies or organisations mentioned.
Sources
https://www.fool.com.au/2026/03/26/vault-minerals-koth-plant-upgrade-commissioning-kicks-off/
https://www.asx.com.au/markets/company/VAU
Last modified: March 26, 2026
