OUR TRACK RECORD
NORTHERN STAR - KCGM MILL EXPANSION PROJECT
The Details
TIMEFRAME: 2021– 2022
CLIENT: Northern Star Resources
LOCATION: Western Australia
COMMODITY: Gold
SERVICES: Subject Matter Expert
GOLD OUTPUT
900koz/a target
PROCESSING THROUGHPUT
Upgrade from 13 to 27 Mt/a
KEY OUTCOMES
Will be one of the world's top 10 gold mines
Project Background
In 2021, Northern Star engaged Chemech to provide technical support with their KCGM Mill Expansion Study, which was targeting an increase in throughput to 27Mt/a. The proposed upgrade was complex, with a mixture of existing and new equipment requiring integration into a plant built in 1989 and significantly expanded in 1995. Northern Star recognised the risks associated with such a complex upgrade and adopted a hands-on approach, with a strong owner’s team providing significant up-front process design definition prior to engaging an engineering consultant. Northern Star engaged Chemech to supplement the owner’s team due to their proven design experience with other large-scale processing plants such as Cadia, Telfer and Boddington.
Chemech's Contribution
Chemech initially completed an independent review of the study design documentation focussing on the process design risks and opportunities. Since the review highlighted a number of significant design-related issues, Chemech were subsequently engaged to develop technical documentation required for the upcoming Early Contractor Involvement (ECI) and Front-End Engineering Design (FEED) phases.
Chemech devised and developed a unique stage-gate type review system for Northern Star to use during the ECI phase. The gate documentation produced by Chemech was initially used to select the preferred ECI contractor, before becoming the minimum design standard for Northern Star during the FEED phase. Three review stage gates were designed as Hold Points in the design process ensuring alignment between Northern Star and the contractor would be achieved while minimising the risk of rework.
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Gate 1 – Basis of Design Alignment. The objective of this stage was to reach alignment early in the design on key areas such as the process design criteria and the plant layout.
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Gate 2 – Operability and Maintainability. This stage was critical for Northern Star to confirm that their operability, maintainability and safety expectations were being met prior to detailed design commencing.
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Gate 3 – Automation, Instrumentation and Control. High throughput and relatively low grades would require a very high level of automation and control in meeting the project outcomes. This gate specified Northern Star’s expectations and provided some assurance that they would be met.
Formal client reviews during the design process are typical, but what was unique about this process is that Chemech set out numerous detailed criteria for each plant area based on operational learnings, benchmarking, and large plant design experience. A number of design and operating issues typically associated with each major equipment item was provided for the contractor to formally assess based on specific assessment factors agreed with Northern Star. The contractor was then required to identify the risks and opportunities with each issue and recommend specific solutions for agreement with Northern Star. The agreed outcomes would then form the basis of the detailed design.
The Final Outcome
Northern Star’s adoption of Chemech’s stage-gate review process allowed for the early identification of important design requirements which are often overlooked. This ensured that process risks and opportunities as well as process plant operability and maintainability were identified and incorporated into the design right from the start. It also significantly improved the alignment of design outcome expectations between the owner and the engineer and is a great example of the benefits of a strong owner’s team with early involvement in engineering design.