Vault Minerals (ASX:VAU) said that its King of the Hills open pit, part of the firm's Leonora operation in Western Australia, recorded ore reserves of 110 million tonnes at 0.6 grams per tonne (g/t) grade of gold for 2.2 million ounces, a 33% increase in ore reserves from the open pit reserve as of June 30, 2024, before mine depletion of 97,065 ounces as of April 30, according to a Monday Australian bourse filing.

The company added that the stage two plant upgrade will dovetail with the stage one upgrade, which will deliver 6 million tonnes-per-annum throughput rates from the middle of the fourth quarter of fiscal 2026 and 7.5 million tonnes per annum during the second quarter of fiscal 2027.

The upgrades will deliver a 50% increase to current processing throughput during the second quarter of fiscal 2027 for a stage two capital cost of AU$92 million.

The company's gold production is expected to average 215,000 ounces over the next five years, jumping to 235,000 ounces after the stage two upgrade on a mill feed grade profile, reflecting ore production from the firm's three existing mines, per the filing.

Vault Minerals' shares were up almost 2% in recent Monday trade.