Mining Studies

Emmie Bluff Mechanical Cutting

Commodities

Cobalt Copper Zinc

Client

Coda Minerals

Location

Emmie Bluff, South Australia

Work Conducted

Concept Study

EMMIE BLUFF: CONCEPT STUDY

Coda Minerals engaged Mining Plus (MP) to assess the feasibility of using mechanical cutting as an alternative to traditional drill-and-blast mining at Emmie Bluff. Located 400m below the surface, Emmie Bluff hosts copper, cobalt, silver, and zinc across two mineralized zones. MP partnered with Komatsu to evaluate continuous mining machines, which could enable efficient mining of the orebody's narrow, flat mineralized zones, thereby potentially enhancing productivity and reducing costs.

CHALLENGES

The Emmie Bluff orebody posed unique challenges, including narrow orebody heights (2.0–6.0m) and the need to maintain a high production rate to achieve 6 Mtpa. Traditional drill-and-blast methods were considered less optimal for this geometry, prompting a need for more precise mining. Additionally, the project required a balance of development costs, production rates, and achievable cut-off grades to ensure commercial viability. The selection of suitable machinery and access designs to support efficient ore extraction and ventilation development presented further complexities.

SOLUTIONS

MP collaborated with Komatsu to identify continuous mining machines ideal for Emmie Bluff’s requirements. The Komatsu 12HM27 was chosen for development, and the 12HM36 for production, each capable of operating efficiently within the orebody’s height constraints. A “super panel” layout was introduced to increase productivity, with a single spiral decline to access the orebody. Stope shapes were developed using a 1.0% CuEq cut-off grade, maximising ore extraction with minimal waste. A SWOT analysis and cash flow modelling were conducted to ensure economic viability, resulting in an average mining cost per tonne of $41.48, compared to $53.73 with traditional methods.

OUTCOMES

The mechanical cutting approach at Emmie Bluff offers several advantages: lower operating costs, higher productivity, and enhanced geotechnical precision. The optimized plan will allow extraction of approximately 2.5 million more tonnes of ore than the traditional method. The mechanical cutting strategy achieved a cumulative pre-tax cash flow of AUD2,015M, with an anticipated 1.5-year reduction in mine life. Recommendations include further drilling to refine the geotechnical model and validate production rates, supporting the progression to a pre-feasibility study with a targeted processing throughput of 2.7Mtpa.