The Maxwell underground coal mine development in New South Wales, Australia is being undertaken by Maxwell Ventures, a wholly owned subsidiary of Malabar Coal.
The historical coal production within exploration licence EL 5460 that hosts the mine commenced in the late 1940s and continued until the 1970s. The EL 5460 and the Maxwell Infrastructure facilities were formally acquired by Malabar in February 2018.
The Independent Planning Commission (IPC) of New South Wales, Australia approved the project development in December 2020.
The Maxwell underground coal mine development is estimated to require a capital investment of approximately £285.4m ($509m).
The project is expected to produce up to 4.8 million tonnes (Mt) of coal annually over an estimated mine life of 26 years.
Project location and geology
The Maxwell underground coal mine sits within the EL5460 mining and exploration license, approximately 16km south-southwest of Muswellbrook, in the Upper Hunter Valley of New South Wales, Australia.
The Maxwell coal mine comprises the Wittingham Coal Measures in the northern Permo-Triassic Sydney Basin of the southern Sydney-Gunnedah-Bowen Basin.
The underground mine is hosted on the gently dipping western Muswellbrook Anticline with mining operations targeting the Whynot, Woodlands Hill, Arrowfield and Bowfield Seams which form the upper and middle units of the Wittingham Coal Measures.
Mineralisation and reserves
The mining targets are hosted within the Jerrys Plains Subgroup that are overlain by a sequence of sandstone, siltstone and laminate units within the Wittingham Coal Measures.
The Maxwell Underground Coal Mine is estimated to contain approximately 670 million tonnes (Mt) of measured and indicated resource including 100Mt as inferred coal resource.
The Maxwell underground mine will utilise the bord and pillar, as well as the underground longwall extraction methods. The run-of-the-mine (ROM) coal production capacity of the mine is expected to be 5.7 million tonnes per annum (Mtpa).
The Whynot coal seam will be mined using the underground bord and pillar technique, while the longwall extraction method will be used for the Woodlands Hill, Arrowfield and Bowfield coal seams. The mine entry area (MEA) for the underground operations will be developed to the north of the mining license tenement.
The ROM coal will be transported by road to the processing facility in the early stages of the mining operation until the completion of a covered, overland conveyor system from the mine to the Maxwell infrastructure area.
Coal handling and processing
The Maxwell infrastructure area located to the north of the mine includes an existing coal handling and preparation plant (CHPP), train load-out facilities, and other support infrastructure, including water management facilities and workshops.
The ROM coal will undergo secondary and tertiary crushing at the CHPP and would either be beneficiated through the processing plant or bypassed directly to the product coal stockpile.
The coal processing plant comprises of a bypass and the coarse coal circuit, medium coal and fine coal circuits.
The medium and fine coal circuits house dewatering, filtering and thickening facilities for producing the final coking coal product.
The existing Antiene Rail Spur and the Main Northern Railway will be used to supply coal to local markets or to the Port of Newcastle for export.
Access to the project site will be via an existing access road from Thomas Mitchell Drive. The access road will be extended up to the mine access area.
The power supply requirement for the underground mine will be met through existing overhead power lines to the Maxwell infrastructure area. A new 66kV power supply line is envisaged to link the mine access area (MEA). Electricity distribution at the mine site will be done using a combination of overhead and underground power lines.