Isaac Plains Complex

Project Details

Overview

Commenced production in 2006 as a truck shovel operation.

Dragline operations commenced in 2011/2012.

Placed on care and maintenance late 2014.

Stanmore acquired Isaac Plains in November 2015.

Mining operations commenced in January 2016.

Layout

Well laid out site with mine infrastructure located along western side of lease.

Short spur connection to Goonyella Brach Railway.

Ease of access for potential Isaac Plains East extension via haul road.

Close to camp accommodation facilities.

Geology

The Leichardt seam (LHD) of the Rangal Coal Measures averages 3.5m thickness across the deposit.

Depth of cover in the present open-cut operation starts at about 60m, the LHD seam dips east at around five degrees and tracks east into the 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.

Approximately 1000 exploration holes were drilled within the Isaac Plains Mining Lease, of which over 100 core boreholes have been completed.

Over 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.

Infrastructure Position

Approximately 1.1Mtpa of rail and port capacity.  Further expansion capacity available in current market environment.

Total transport infrastructure costs under A$15/tonne at steady-state production.

Significant capacity within Isaac Plains CHPP and train load out up to 3Mtpa of product.

Coal Resources/Reserves

Xenith Consulting Pty Ltd updated the Resource and Reserve estimate for Stanmore in 2017 within the Mining Lease area and the Isaac Plains East area.  Total resources now total 79 million tonnes with 55.2Mt compliant as measured and indicated resources under the JORC (2012) code.

Current Reserves support over 12 years of open cut mining at planned mining rate of 1.2Mtpa of product coal.  Total reserves as at August 2017 were 16.4Mt (ROM).  These represent mineable reserves by open cut methods. 

Coal Quality

Mid-volatile, weak coking coal known as semi-soft coking coal, with a secondary thermal coal.  Coke oven yield is substantially higher than the Newcastle SSCC coals, due to lower volatile matter levels.  The coal also displays low impurity levels of sulphur and alkalis.  The thermal product has a high calorific value, low sulphur and nitrogen content and excellent handling characteristics and is easy to grind.

 

Product Split (%) Isaac Plains - Coking Isaac Plains - Thermal Isaac Plains East1 - Coking
Inherent moisture (%) 2.5 3.1 2.2
Ash (%) 9.5 16.0 9.5
Volatile Matter 25.5 23.6 24.9
Fixed carbon (%) 62.5 57.3 63.4
Total Sulphur (%) 0.36 0.37 0.4
Phosphorus (%) 0.10 0.16 0.059
Crucible swell number 4 - 4
Hardgrove grindability index - 65 -
Calorific value (kcal/kg) - 6,730 -

1The indicative results from Isaac Plains East deliver a SSCC product slightly higher in rank, with lower VM content and phosphorous than the present IPM product. This should further broaden market opportunities for semi-soft coking coal from the Isaac Plains Complex.

Environment

The Isaac Plains Project operates under an Environmental Authority (EA); which was first granted in 2006 by the Queensland Government for mining activities to be undertaken within ML70342. The EA sets out the environmental monitoring requirements and regulatory limits which must be met or bettered in order to continue to mine coal whilst protecting the environment.

Isaac Plains Coal Mine monitors the following environmental activities:

  • Water (potable, mine affected water, natural creek flows, water releases, groundwater, receiving environment)

  • Dust (personal, depositional and real-time air monitoring)

  • Noise and vibration (real-time monitoring at three locations to the west and south of the mine site)

  • Rehabilitation (re-contoured and re-vegetated land form)

  • Coal rejects (waste from the mining process)

  • Dam integrity/stability; and

  • Waste (general, recyclable and regulated)

The processes and systems in place for achieving compliance are expanded upon in the following sections.

 

WATER MANAGEMENT

The site water management system is comprised of sediment dams (for sediment laden water runoff from spoil dumps), release dams (for releasing good quality water to the environment), a raw water dam (for storing the allocated raw water supply) and a drainage system which allows for clean water run-off collected by the catchment to be diverted away from the active mining area.

Maintaining an appropriate water balance is a key challenge faced by all mines sites – to ensure the site has enough water storage capacity for wet season or flash flood events but at the same time does not run out of water for activities such as coal processing and dust suppression. At Isaac Plains, a site water balance model has been developed by specialist water engineers. This model is calibrated on a regular basis to ensure the water inputs and outputs are accurate.

This model allows us to run scenarios of extended dry or wet periods. The data generated is then used to improve water management processes and systems on site.

 

REHABILITATION

At Isaac Plains, we undertake rehabilitation on a progressive basis with consultation between the environmental, technical services and production teams. All rehabilitation is carried out with future land use in mind. Our aim is to return the site to grazing pasture, with areas of native tree, shrub and grass species.

The rehabilitation objective for Isaac Plains is to create a safe, stable and sustainable landform using cost-effective spoil placement methods.

Profiling of the out-of-pit spoil dumps is completed to a slope of no greater than 15% (in compliance with the Environmental Authority). All surfaces are topsoiled, contour-ripped and sown with the nominated native flora species using both tractor and aerial seed sowing methods.

Rehabilitation of the first mined-out areas commenced in 2007, after only one year of production. The biodiversity and floral variation observed within the rehabilitation monitor areas have been measured by third-party environmental consultants as ‘good to very good’ in all plots to date.

Through the transition to new ownership we continue to invest in resources to undertake new, and improve existing rehabilitation at the site. Approximately 82ha of rehabilitation is planned to be completed in the first year of ownership.

 

WASTE MANAGEMENT

The waste management hierarchy employed at Isaac Plains begins with waste avoidance as the number one objective; followed by waste re-use, waste recycling, energy recovery from waste, with waste disposal as a last resort. Regulated waste, batteries, waste oil, recyclables including cardboard, paper, glass and aluminium have designated receptacles that allow these waste products to be recycled.

Monthly reports generated by our waste service provider allow the environmental team to track volumes of waste and identify areas for improving the site waste management system.

 

REAL-TIME MONITORING

Real-time monitoring of environmental parameters allows us to respond quickly and effectively to potential environmental nuisances caused by our operations before they reach the allocated EA trigger levels. Alerts are linked to a range of site shutdown procedures and notification is sent to site representatives to implement appropriate abatement measures.

The real-time monitoring equipment located on and around site includes eight ‘Dusttrak’ units and one BAM 1020 for air quality monitoring, three automatic ‘ISCO’ water monitoring stations, one automatic weather monitoring station and two vibration and overpressure monitors for blast monitoring.

Please click here to access a live map of our dust monitor locations.

dust monitor locations.

 

Dust Charts

Dust Charts from 10 - 17 March 2018

 

 

 

 

 

 

 

Dust Charts

Dust Charts

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Dust Charts

Dust Charts

Isaac Plains East

This project has been substantially advanced in preparation for development and operations as an extension of the existing Isaac Plains mine.

Marketable reserves of 8.99Mt at the current product coal mining rate of 1.2Mtpa provide for an economic mine life of approximately seven years.

Seven year average prime strip ratio (bcm/ROM tonnes) of 11:2, with the first three years at sub 8.8:1.

Bankable Feasibility Study (BFS) activities indicate a saleable product coal mix ~99% coking coal is estimated at an average life of mine yield of 81%.

Capital infrastructure requirements for the development have been extensively assessed and refined through the BFS design phase, leveraging heavily off the existing operational facilities resulting in minimal risk, low cost capital works program.

Environmental approvals for the proposed Isaac Plains East Mining Lease area are well advanced, with the forecast grant of the Mining Lease in Q2 of FY18 with mining to start shortly after.

 

GEOLOGY

The Burton Range Thrust Fault is responsible for repeating (bringing back to near surface) the LHD seam. This is the same seam that is presently open-cut mined in Isaac Plains.

The LHD seam averages 2.8m 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 16.9m.

Over 400 holes have been drilled.

Over 30km of 2D seismic has been completed.

Exploration

ISAAC PLAINS UNDERGROUND MINING PROJECT

Continued assessment of a potential underground extension in the eastern portion of Isaac Plains Mining Lease.

The area contains more than 21Mt of JORC Compliant Measured and Indicated Resources. Approximately 8-10Mt ROM (Economically Recoverable Resource) may be extracted.

Able to run parallel with open cut operations with minimal capital expenditure by accessing the exiting highwall and will fill surplus wash plant and rail load out capacity.

Initial production of 0.4 Mtpa of ROM coal, ramping up to produce 1-1.4Mtpa.

It will be operated and managed separately from Stanmore's open-cut mine, sharing elements of the existing surface operations site infrastructure, including coal preparation plant, rail transport and some coal handling.