Hidden Valley

  • JSE: R322.20 -2.48%
  • NYSE:$19.14 +0.47%
  • GOLD:$4 206/oz -0.06%
  • GOLD:R2 295 993/kg -0.12%
  • USD:ZARR16.98 -0.09%
  • At 04:59am, 05 Dec 2025

Overview

The Hidden Valley mine is an open-pit gold and silver operation in Morobe Province, Papua New Guinea, some 210km north-west of Port Moresby. The mine is located at elevations of 1 700m to 2 800m above sea level in steep mountainous and forested terrain with high annual rainfall. The major gold and silver deposits of Hidden Valley are in the Morobe Granodiorite of the Wau Graben.

Crushed ore is conveyed from the pit via a 5.5km overland pipe conveyor and treated at the Hidden Valley processing plant using a two-stage crushing circuit followed by a semi-autogenous grinding mill, gravity, counter current decantation/Merril Crowe circuit for silver and a carbon-in-leach circuit for gold.

As at 30 June 2024

  • Gold Resource (inclusive): 2.16Moz
  • Gold Reserve: 0.869Moz
  • Silver Resource (inclusive): 30Moz
  • Silver Reserve: 13.52Moz
  • LoM: 5 years

Operating statistics FY24

Production

5 101kg / 164 000oz

Grade

1.52g/t

Workforce

2 083

All-in sustaining cost

US$1 352/oz

Operating performance FY24

Hidden Valley benefited greatly from mining through higher grade areas of Kaveroi and Big Red during the first six months of the financial year and subsequently recorded a 33% increase in the recovered grade to 1.52g/t (FY23 1.14g/t). Total volumes of ore milled, however, decreased 13% to 3.36 million tonnes (FY23: 3.85 million tonnes) partially offsetting the improvement in grade. This was mainly as a result of the overland conveyor failure early in January resulting in approximately 22 milling days lost during this period. As a result, gold production increased 17% to 5 101kg (164 000oz) from 4 370kg (140 498oz) in FY23.

Revenue increased 39% to R6 181 million (FY23: R4 440 million) mainly due to the higher gold production as well as an increase in the gold price received. The average gold price received increased 16% to R1 223 409/kg (FY23: R1 053 611/kg). All-in sustaining cost for FY24 improved significantly to R814 375/kg (FY23: R1 014 228/kg), a 20% improvement that was mainly due to the increase in gold production.

Hidden Valley was the second largest individual mine contributor to operating free cash flow at R2 188 million in FY24, a marked improvement over the R615 million recorded for FY23.

Capital expenditure decreased by 11% to R1 541 million from R1 737 million in FY23, mainly for capitalised stripping and replacing of equipment.

Our focus area in FY25

Our focus is on safe, sustainable, margin-focused production against plan and progressing of project studies for life-of-mine extension.

ESG statistics

Lost time injury frequency rate

0.34 per million hours worked (FY23: 0.35)

Water intensity (/tonne treated)

0.63Ml (FY23: 0.57Ml)

Energy intensity (/tonne treated)

0.04GWh (FY23: 0.01GWh)

GHG intensity
(/tonne treated)

0.05t CO2e (FY23: 0.05t CO2e)

Harmony South East Asia

Tel: +61 7 3320 3700
Fax: +61 7 3320 3740

Address

Level 2, 189 Coronation Drive
Milton, Queensland 4064
Australia

PO Box 1562
Milton, Queensland 4064 Australia