Location: Bowen Basin
Nearest Port: Gladstone
Rail Line: Blackwater
Mines in Region: Blackwater, Minyango, Cook, Curragh, Jellinbah, Yarrabee
Coal Type: Metallurgical Coal & PCI Coal
Mining Method: Underground
Study: Concept Study completed April 2013
The Belview Project is a large scale, metallurgical coal project located in the heart of Queensland’s Bowen Basin. The Company has established a 330 Mt JORC Inferred Resource. Coal quality analysis completed to date confirms a high overall washed yield with the ability to produce a Hard Coking Coal primary product and a secondary low volatile Pulverised Coal Injection product. Both products exhibit low ash, low volatile matter and low sulphur. The Company has submitted a Mining Lease Application and is targeting first coal in 2018.
1. GEOLOGY, RESOURCES AND EXPLORATION TARGETS
The Rangal Coal Measures occur within the Belview Project from 385m in depth and dip gently to the east at 3-5 degrees. Within the Rangal Coal Measures, the Castor and Pollux seams coalesce into the Gemini seam, which exists in the south and west of the project area and is approximately 6m thick. In the east of EPC1114 and within EPC1186, the Gemini seam splits into the Castor seam and Pollux seam which are on average 1.9m and 3.0m thick respectively.
AVERAGE THICKNESS (m)
AVERAGE THICKNESS (m)
Figure 1: Belview Project Existing Drill-hole Locations
A geological model for the project has been developed taking into account 28 holes within the project area (refer to Figure 1) and a further 20 drill holes outside the EPC 1186 and EPC 1114 tenement areas that have been incorporated into the model to aid in controlling seam structure.
The geological model indicates that the north-west area of EPC 1186 has the shallowest overburden and consequently initial underground mine development has focussed on this area, as demonstrated in Figure 2.
Figure 2: Aries Seam Depth of Cover
2. COAL QUALITY
Coal quality testing was carried out using samples of coal collected from cores taken from representative locations within the target seams and washed to produce a 7.5% ash (adb) HCC product and a 9.0% ash (adb) PCI product.
The sample taken from these cores was reduced to a 50 mm top-size and split into four size fractions of -50 + 8 mm, -8 + 1.4 mm, -1.4 + 0.25 mm and –0.25mm. The -0.25 mm fraction underwent modified tree flotation analysis (froth flotation) while all other size fractions underwent separate heavy medium float/sink analysis. The clean coal composites selected from each float/sink process except the coarse size (-50 mm + 8 mm) were then combined in proportion by weight with the froth flotation product composite to simulate production of a primary coking product. The clean coal composite from the coarse fraction was used to produce the secondary PCI product.
Analysis of the clean coal composites from washing tests presented the following indicative coal quality parameters:
|Parameter1||Primary HCC Product||Secondary PCI Product|
|Crucible Swell Number (CSN)||6 - 7||1|
|Vitrinite Reflectance (RoMax)||%||1.50||1.48|
1 Air dried basis unless otherwise noted
It is anticipated that with further refinement to the simulated washing process, including reducing the top size to promote liberation and concentration of coking properties, a reduction in ash and an improvement of the coking coal and PCI quality is likely. This is currently seen in the operating practice of nearby Rangal coal washing operations. Larger samples from larger diameter bore cores are planned during the next exploration program to refine washplant modelling, refine coal quality outcomes and to provide samples for coke tests.
2.1 Primary HCC Product
Quality results indicate that the HCC product will be a low volatile, low ash, low sulphur coking coal from the Rangal coal measures that is similar in quality to other nearby Rangal coking coals of similar rank that are well established and accepted in the international coking coal market, such as Curragh. Such coals are noted for their consistent quality, low coke oven wall pressure, high mechanical coke strengths and excellent coke yields. Consequently, it is anticipated that the Belview HCC product can be sold in established markets including Japan, South Korea, Taiwan, China, India, Europe and South America.
2.2 Secondary Pulverised Coal Injection Product
Quality results indicate that the potential PCI product will be a low sulphur, low volatile, high calorific value PCI which are well established and accepted in the market and similar in quality to that produced by neighbouring mines. The low volatile matter content, combined with the high calorific value of the Belview product are its key features and indicate that it will exhibit a high coke replacement ratio. All other coal characteristics fall within the expected range for low volatile PCI coals. Other Bowen Basin PCI brands that fit into the low-vol category include Moorvale, Curragh and Lake Vermont.
3. PROPOSED MINING METHOD
Mining of the Rangal Coal Measures is regionally well established and the performance of operating mines in the region provides a level of confidence to support the Belview mining concept. Operating coal mines targeting the Rangal Coal Measures in the region include:
- the BMA owned South Blackwater operations;
- Wesfarmer’s Curragh and Curragh North operations;
- Caledon’s underground Cook Colliery;
- Yancoal’s Yarrabee operation;
- Jellinbah Mine; and
- Idemitsu’s Ensham open-cut and underground mines.
The mining method assumed for this study is longwall mining. The practical and economic limit of mining at Belview is likely to be driven by geotechnical conditions and, economic analysis in the study has been limited to coal at depths down to 800m. Initial access depths for coal in the north west of the Project area are well within achievable ranges by Australian standards.
Figure 3: Australian Longwall Mining Depths
All mining seams modelled in the Concept Study are greater than 1.8m thickness and mining is therefore considered amenable to conventional underground mining. Modelled interburden between the Belview target seams are generally greater than 10 metres in thickness and thus considered likely to be amenable to multi seam mining. The viability of multi-seam mining will ultimately require detailed geotechnical investigation, particularly where the interburden thins between the Castor and Pollux seams adjacent to the Gemini split line which is located on the border of EPC 1186 and EPC 1114.
In the southern project area within EPC 1114, the Gemini seam is modelled to be up to six metres thick. The maximum cut height for a conventional longwall is generally in the order of 4.5 to 5.0m, although configurations of greater than 6.5m have been installed overseas. The more common practice for thick seam mining is the method known as Longwall Top Coal Caving. The method has been employed in both Australia and overseas. Thick seam mining has been assumed in this study.
The initial longwall mining concept targeting seams at a depth less than 800 metres is based on the following key features:
- Panels orientated to be favourable with respect to:
- expected principle insitu stress direction
- consistent depth
- (Likely) gradual variation in coal quality and gas content
- Access point at the western extent of the initial mains at approximately 400m depth
- Two drifts for coal clearance and men and materials access plus one initial ventilation shaft
Figure 4: Australian Longwall Productivity (4 year average) vs Depth of Cover
A maximum panel length of 4.0km in the concept layout has been assumed. This length takes into consideration that Belview would be deep and likely have significant ventilation requirements to assist with methane gas management. The concept layout features a set of main headings orientated approximately along the existing road and rail network in the north of Belview. Coal in the central and southern regions of Belview (as identified in figure 5) cannot be accessed from longwall panels connected to this set of main headings. For this reason, Xenith has proposed a Belview concept of a Northern, a Central and a Southern mine.
Figure 5: Concept Belview Mine Layout and Mining Zones
In the case of the Central and Southern sections, an independent surface access and an overland conveyer to the northern region infrastructure would be required to allow infrastructure sharing benefits. An alternative option would be to drive a second set of main headings from the initial west – east mains to form an underground connection.