Agnew gold mine - Mining
Current mining consists of the Waroonga and New Holland underground complexes, with the bulk of production presently sourced from the high-grade FBH lode and Cinderella. Drill platforms have now been established for the Waroonga North lodes, with initial production aiming for 2018. New Holland is in the process of identifying and extracting remnant lodes in the New Holland and Genesis ore bodies to supplement the production front established in the Cinderella and Sheba lodes.
Mining methods
Access to the Waroonga underground mine is via a decline with the portal located in the previously mined Waroonga open pit. In 2017, the Waroonga mine produced from the Kim South, Main, and FBH lodes. All primary infrastructures, including escape ways and ventilation shafts, are located in the hanging wall sandstone. The primary mining method at Waroonga is long-hole sub-level stoping with paste fill.
Access to the New Holland underground mine is via twin declines with portals located in the Genesis and New Holland open pits. In 2017, the New Holland underground mine produced from the Cinderella, Sheba and New Holland areas. The selection of the stoping method is dependent upon the geometry of the ore structure. The primary mining method employed at New Holland is retreat up-hole long-hole mining.
Mine planning and scheduling
The current mining areas situated at Waroonga include high-grade ore from Kim South and FBH, supplemented with run-of-mine grade ore from Main North and South. At New Holland, mining of the Cinderella and Sheba areas has been the main focus. Remnant mining from New Holland has also contributed to the overall production. Additional mining fronts in incrementally costed areas of New Holland are contributing run-of-mine material assisting in leveraging mill throughput and equipment efficiencies.
The stope design takes practical stope layouts and geometry into consideration, as well as planning for mining losses in pillars or other parts of the resource excluded for technical reasons. Dilution material is included in the stope design. Ore losses can occur when material cannot be practically extracted from the stopes, and are accounted for as part of the planning process.
LoM plans have been generated for these areas with the necessary development, advance rates and sustaining capital to support the planned production schedules and profiled grade and tonnage.