Utilising CAT® HW300 at the Kangaroo Coal Mine to maximise coal production

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The Kangaroo Coal Mine is an open cut truck and shovel operation located within the Gunnedah Basin in New South Wales. The aim of this study was to investigate the financial feasibility of highwall mining using CAT® HW300 at the Kangaroo Coal Mine. To achieve this, costs were estimated, highwall mining pillar and extraction panel dimensions were designed, reserves were created, scheduled and financially evaluated.Highwall Mining Index was used as a preliminary indication of whether further planning and financial feasibility should be completed. It was indicated that the Kangaroo Coal Mine had good potential for highwall mining and in-depth planning and financial feasibility should be conducted.Panels were designed for each individual seam based on seam thickness and corresponding cutter-head module; pillar dimensions were designed using tributary theory where a safety factor of 1.3 was applied.Several constraints were considered such as equipment constraints limiting maximum seam dip and penetration recovery. Geological constraints includes geological faults and geological uncertainty due to lack of exploration drilling. Multi-seam constraints include only mining one seam when the interburden thickness is less than 5m and aligned pillars between seams with less than 10m interburden thickness.Reserves were created based on panel dimensions, pillar dimensions and constraints on highwall mining. It was found the total highwall mining reserve was 3.9 Mt, which was 24.8% of the total resource along the final highwall. Significant amount of resource were lost in coal pillars (4.3Mt) and geological faulting (3.3Mt). A schedule was completed, and found the equipment will only be fully utilised two out of its thirteen years of operation.Financial technical modelling was conducted based on assumed financial parameters. It was found the total NPV for the project was -16.8Mt. Even though, the operating margin was positive, the capital of the project was never fully recovered. It was calculated the NPV cutoff sales price was $AUD93/t of coal.Recommendations include evaluating selling products such as low rank metallurgical coal, and low ash thermal coal and to further evaluate methods to improve equipment utilisation.