Castle Hill

Castle Hill is situated in the Kunanalling district, within the Goldfields-Esperance region of Western Australia, approximately 50 km northwest of Kalgoorlie. The terrain is characterised by flat to gently undulating semi-arid landscape, typical of the Eastern Goldfields greenstone belt. Elevation is low, with minimal topographic relief. The site operates within Evolution Mining's broader Mungari Gold Operations tenement package, sharing infrastructure corridors with adjacent pits across a consolidated land position.

The Kunanalling zone experiences extreme thermal stress, with summer ambient temperatures regularly exceeding 42°C. This imposes critical thermal loads on hydraulic systems, engine cooling circuits, and haul truck powertrains. Operators must implement:

• Enhanced radiator and coolant circuit inspections on daily pre-start cycles
• Scheduled shade-down protocols during peak heat windows (11:00–15:00 AWST)
• Hydraulic fluid viscosity grade adjustments for high-ambient conditions
• Real-time engine temperature telemetry on NRW fleet assets

With NRW Holdings managing surface fleet operations, unplanned downtime at Castle Hill directly impacts ore delivery to the Mungari processing plant. The absence of on-site heavy maintenance infrastructure makes proximity to Kalgoorlie-based mechanical workshops a tier-one procurement priority. Key B2B service requirements include:

• Mobile field service units for GET (Ground Engaging Tools) replacement
• Hydraulic hose and cylinder repair with sub-4-hour response SLA
• Tyre management contracts for large-format mining truck fleets
• OEM parts supply chains for Caterpillar or Komatsu surface fleet assets

Castle Hill ore is processed through Evolution Mining's Mungari processing facility, which operates a conventional CIL (Carbon-in-Leach) circuit. The primary grinding circuit imposes stringent physico-chemical requirements on feed material, including controlled particle size distribution and reagent dosing precision. Critical engineering nodes include:

• Primary crushing and SAG/ball mill grinding circuit
• Gravity concentration ahead of leach for coarse gold recovery
• Cyanide leach and CIL adsorption train
• Tailings storage facility (TSF) management under DMIRS regulatory framework

Evolution Mining has committed to net-zero Scope 1 and 2 emissions by 2050, with interim 2030 reduction targets embedded across all operating assets including Mungari. Castle Hill's open pit operations are subject to this group-wide ESG framework. Active decarbonisation initiatives relevant to this asset include:

• Evaluation of solar-hybrid power integration for Mungari site energy supply
• Diesel consumption reduction targets applied to NRW contractor fleet
• Water recycling mandates within the CIL processing circuit
• Biodiversity offset and land rehabilitation obligations under WA Mining Act tenure conditions