Premier mines a sub bituminous, low ash (4-9%), low sulphur (0.3-0.9%), highly reactive coal suitable for power generation and metallurgical applications. Having been used in power generation for over 60 years, the coal is well proven. Low levels of trace elements such as selenium and mercury make it an attractive coal for utilities both in Australia and overseas.
Collie coal is commonly termed a thermal coal being highly suited to steam-raising boilers in power stations. This steam is then used to drive a turbine to generate electricity. It is also a highly reactive coal and is thus very good for metallurgical processes such as the reduction of ilmenite to rutile.
The coal has ideal properties for a sub bituminous coal with high volatile matter and a low fuel ratio of 1.6 (Fixed Carbon to Volatiles) on an air-dried basis. The Hardgrove Grindability Index of the coal is typical of sub bituminous coals and it has a low abrasion index of 25, demonstrated by low wear rates in milling trials.
Trace element analyses of Premier coal seams have shown excellent results (tabulated below on a dry basis). For many electric power utilities, selenium levels are of prime importance. The Premier coal values are lower than most other Australian coals and meet the specification limits of utility companies. The coal also has very low levels of boron and mercury.
| Boron ppm | Mecury ppm | Selenium ppm | Fluorine ppm | Arsenic ppm | Lead ppm | Cadmium ppm |
| 6.5 | 0.03 | 0.8 | 6.5 | 1.0 | 9.0 | 0.1 |
The coal handling plant produces mainly a coal that has a top size of 50mm with 3% of the coal larger than 45mm, 34% of the coal falling in the 22-45mm range and the remainder in the finer category. Less than 20% of the coal is less than 2.8mm. A sized product 18-75mm is achieved by further screening.