Stanmore acquired Isaac Plains in November 2015, after the operation was placed in care and maintenance in late 2014 by the previous owners. Stanmore recommenced mining at the Isaac Plains Mine in January 2016 and transitioned to the current operations at Isaac Plains East from July 2018 through to January 2019. All mining operations now occur at Isaac Plains East.
The Isaac Plains Complex incorporates:
- the operating Isaac Plains East mine
- Isaac Plains mine which ceased operation in 2018
- the Isaac Plains Underground development project
- operating assets including the dragline,coal handling plant, infrastructure facilities and train load out
- The Leichhardt seam (LHD) of the Rangal Coal Measures averages 3m thickness across the Isaac Plains deposits.
- Depth of cover in the present Isaac Plains East (IPE) open-cut operation starts at about 15m, with the LHD seam dipping east at around five degrees. The mining areas are being progressed down-dip to a proposed economic pit limit of approximately 120m depth.
- Operations will then extend to the Isaac Downs deposit which has similar geological characteristics and will include the mining of the underlying Vermont seam as well as the Leichhardt seam.
- The currently closed Isaac Plains deposit has been previous mined to a depth of approximately 80m and tracks east into Isaac Plains East tenement area to a depth of approximately 300 metres, before terminating at a regional fault structure referred to as the Burton Range Thrust Fault. This is the area that now forms the Isaac Plains Underground development project.
- Approximately 1,000 exploration holes were drilled within the Isaac Plains Mining Lease, of which over 100 core boreholes have been completed.
- More than 20km of 2D seismic lines have been completed within the Mining Lease area.
- A 3D seismic survey has been completed (September 2017) across the entirety of the Mining Lease, east of the open-cut pits, in the area being assessed for future underground potential.
- Currently 2.4Mtpa of rail and port capacity is secured under a long-term contract based on shipping coal through the Dalrymple Bay Coal Terminal (DBCT). Demand for further expansion capacity at DBCT is increasing in the current market environment and Stanmore Coal is actively securing further port capacity contracts as availability is defined.
- Total transport infrastructure are costs under A$15/tonne at steady-state production.
- Significant capacity within the existing Isaac Plains coal handling preparation plant (CHPP) and train load out facility up to 3Mtpa of product coal is available and further CHPP capacity upgrades are being considered.
Resources and Reserves
- Stanmore Coal published its annual statement of Coal Resources and Reserves for the Isaac Plains Complex on 21 August 2020.
- Total Coal Resources across all of Stanmore Coal's tenements total 1.7 billion tonnes. Total Coal Reserves formally declared and published total 167 million tonnes.
Isaac Plains East
Operations at Isaac Plains East (IPE) commenced overburden removal in July 2018, with the dragline relocating from the Isaac Plains mine in December 2018. Isaac Plains East leverages the existing Isaac Plains Complex coal processing and transport infrastructure, resulting in a minimal risk, low capital cost program.
The mine plan forecasts an average prime strip ratio (bcm/ROM tonnes) of 11:2. The IPE output is a saleable product coal mix of approximately 99% coking coal at an average life of mine yield of 81%
- The Burton Range Thrust Fault is responsible for repeating (bringing back to near surface) the LHD seam. This is the same seam that was open-cut mined in Isaac Plains.
- The LHD seam averages 3m thickness across the Isaac Plains East deposit. No seam splitting is known to occur.
- In the LHD seam sub-crop zone, the depth of weathering average is approximately 15m.
- Over 400 exploration holes have been drilled.
- Over 30km of 2D seismic has been completed as well as an extensive 3D seismic programme to support the underground mining plans.