Coal has been mined in Collie for over 120 years having a variety of uses from steam locomotives and ships in early days to power generation and metallurgical uses in the past 60 years. Primary present uses are power generation, mineral processing applying direct reduction with coal as the reducing agent, cement manufacture and as a pure heat source. Over the next few years, Premier’s coal is expected to form the basis of new processes such as gasification, char production and other carbon product manufacture.
Premier coal is a sub bituminous steaming coal suitable for:
• Steam raising (power generation);
• Cement making;
• Direct reduction; and
• Heating.
Historically, Collie coal has been mainly utilised for steam raising, as it burns well on grates, and hence early consumption was dominated by locomotives and steam ships.
In the early 1950’s, Collie coal was commercially used for production of town gas, using a carburetted water gas plant in Fremantle, WA.
Collie coal is fairly easy to grind and is now usually used in a pulverised form for power generation. Other favourable characteristics include a high volatile content (enabling stable flame and burner conditions) and low ash.
The State’s generation section, Verve Energy, purchase about 80% of the coal mined at Collie for use in their power stations at Muja, Collie and Kwinana. Worsley Alumina Pty Ltd uses about 13% of the annual production for on-site power generation. Collie coal has had several industrial uses over time.
Western Mining Corporation used nut coal (25-50mm) for air preheaters and pulverised coal as a reducing agent in the smelting process.
SCM Chemicals (Crystal) used Collie coal to raise steam for heating requirements during processing.
Iluka used Collie coal for drying concentrates. Iluka now use Collie coal to fire kilns as part of a process to produce synthetic rutile from beach sands ilmenite.
The Tiwest Joint Venture based on the Cooljarloo mine near Cataby, also produces synthetic rutile using Collie coal as a reductant while roasting ilmenite in a 90m long rotary kiln.
Collie coal is also used by various brick and cement manufacturers for firing kilns and by nurseries for a hot house heating source. Cockburn Cement produces cement by firing a slurry of limestone and bauxite flux using Collie coal or gas to heat the kiln.
The technical and economic viability of manufacturing higher grade products from Collie coal such as char, briquettes or form coke, have been assessed on numerous occasions, commencing with the establishment of an experimental briquetting factory in Bunbury during 1902.
Although metallurgical applications for briquettes exist (and have been proven very successful), eg. steel foundries, limited markets have opened.
Collie coal has seen minor domestic usage but is finding an application as a soil additive for farm land – providing trace elements and organic content.
Export of raw coal has been minimal to date.
The high moisture content of Collie coal is improved by char manufacture, enhancing general utilisation and export opportunities.
Total coal production from Collie is currently in the order of 6.5 million tonnes, with over 80% used for power generation and steam raising (Verve Energy and Worsley). The remaining coal is consumed in synthetic rutile production by Iluka Resources (Capel and Narngulu) and Tiwest (Chandala) and cement production (Cockburn Cement). Small quantities of coal are also used as a heat source by industry and nurseries.