On January 15, 2025, Great Boulder Resources (ASX: GBR) announced a significant milestone in the development of its Side Well Gold Project located in Western Australia. The company confirmed that IMO’s metallurgical testwork results have demonstrated the Mulga Bill deposit’s suitability for conventional gravity recovery and cyanide leaching processing methods. These methods, widely utilised gold mills of the region such as those owned by Westgold Resources, are critical to advancing the project’s development and improving its economic viability.
The metallurgical testwork was managed by Justin McGinnity, a metallurgist from IMO (Independent Metallurgical Operations), who oversaw the comprehensive testing program conducted at the metallurgical laboratory Metallurgy Pty Ltd in Welshpool, Western Australia. The results from this testing program are crucial in demonstrating the potential for high gold recoveries from the Mulga Bill deposit, an important step in de-risking the project.
Key Findings from the Metallurgical Testwork
The results from the metallurgical testwork have exceeded expectations, revealing a range of positive outcomes that strengthen the Side Well gold project’s potential:
1. Gold Recoveries Up to 98.7%
The testwork achieved outstanding gold recoveries of up to 98.7%, which includes a significant contribution from gravity recovery. This high recovery rate suggests that the Mulga Bill deposit is highly amenable to traditional processing methods, improving the project’s overall feasibility. The use of gravity recovery methods in conjunction with cyanide leaching is expected to optimize processing efficiency and maximise gold yields.
2. Moderate Cyanide Consumption
Another critical outcome of the testwork was the determination of moderate cyanide consumption during the cyanide leaching process. This is a positive result, as high cyanide consumption can increase operational costs and impact environmental management strategies. The low cyanide consumption rates associated with the Mulga Bill deposit further enhance the project’s economic outlook by reducing processing costs.
3. Copper Content Does Not Impact Gold Recovery
The testwork also evaluated the impact of copper content in the Mulga Bill deposit on gold recoveries and cyanide consumption. The results confirmed that the copper levels within the deposit will not unduly affect the gold recovery process or the required cyanide consumption. This finding is significant because high copper concentrations can complicate the leaching process and increase operational costs. With minimal impact from copper, the project is expected to maintain efficient processing and lower cost structures.
Next Steps: Optimising the Metallurgical Flowsheet
Following the positive results from the initial metallurgical testwork, Great Boulder plans to conduct additional testwork to optimise the metallurgical flowsheet for the Side Well Gold Project. This further testing aims to refine the processing methods and ensure the highest possible recovery rates, efficiency, and cost-effectiveness throughout the project’s life cycle.
Independent Metallurgical operations is focused on enhancing the flowsheet by examining different processing parameters, reagent types, and recovery methods. Optimising these factors will be crucial for ensuring that the project is economically viable and able to meet its full production potential.
Strategic Importance of the Side Well Project
The Side Well Gold Project is located in the heart of the prolific Western Australian goldfields, an area renowned for its rich history of gold mining and high-quality deposits. Great Boulder’s Side Well project, particularly the Mulga Bill deposit, has demonstrated considerable potential as a high-grade, low-cost gold asset. The positive metallurgical results are a critical component in advancing the project toward feasibility studies and eventual development.
With conventional processing methods showing strong recovery potential and low associated costs, the Side Well Gold Project is positioned to become a key asset in Great Boulder’s portfolio. The company’s focus on de-risking the project through technical advancements and testing ensures that the project remains on track to deliver value for stakeholders.
Conclusion: Advancing Towards Development
The announcement from Great Boulder Resources marks a key moment in the advancement of the Side Well Gold Project. IMO’s successful metallurgical testwork has not only demonstrated the Great Boulder’s project’s strong gold recovery potential but also confirmed that conventional processing methods can be effectively utilised to optimise the extraction process. With additional testwork planned to refine and optimise the metallurgical flowsheet, the project is well on its way to achieving key milestones that will pave the way for future development.
Great Boulder’s focus on utilising proven processing methods, combined with its ongoing commitment to refining the technical aspects of the project, enhances the outlook for the Side Well Gold Project. As the company continues to progress toward feasibility and eventual production, it remains focused on delivering strong returns for its shareholders and advancing its gold portfolio.
About Independent Metallurgical Operations (IMO)
Independent Metallurgical Operations (IMO) is a leading metallurgical consulting firm that provides expert services to the mining industry. With extensive experience in metallurgical testing, flowsheet development, and process optimization, IMO is a trusted partner for mining companies seeking to advance their projects and enhance operational efficiency. IMO played a crucial role in supporting Great Boulder with the metallurgical testwork for the Side Well Gold Project and continues to provide valuable insights to improve the project’s development.