Mining & Sustainability: Researchers exploring new water-based method for testing met-coal samples

A new method of testing exploration coal samples could not only be less harmful to the environment, it could also result in a more accurate assessment of how economically viable coal projects are.

The Canadian Carbonization Research Association (CCRA) and Geoscience BC will this month launch a research project to assess the effectiveness of a water-based cleaning process for washing exploration samples of B.C. metallurgical coal used in the steel-production process to determine coal and coke quality – key considerations in evaluating the economic feasibility of coal deposits.

“The ability to accurately evaluate coal quality and the coking characteristics of metallurgical coal during the exploration stage is essential to determining the economic viability of a coal deposit”: Melanie Mackay, president of the Western Canadian Coal Society

The research project will compare the water-based Roben Jig coal washing process to the traditional method of analyzing small-scale exploration samples of metallurgical coal, known as the float-and-sink method. This process uses various solvent-based chemicals such as white spirit, methylene bromide, and perchloroethylene (PCE) to remove impurities, namely ash, and produce a clean coal sample suitable for analysis. PCE, a chemical that was commonly-used in the dry cleaning industry, is also a known carcinogen posing potential health risks for laboratory workers.

Coal washing using the Roben Jig process involves loading the coal sample into a specially designed cylinder with water. A motor moves the cylinder up and down in a “jigging” motion which sorts the coal particles by density, with the heaviest particles sinking to the bottom and the lightest particles moving to the top.

“This research will help us identify the best method of determining coal quality before a mine is built,” said Melanie Mackay, president of the Western Canadian Coal Society and technical member of the CCRA. “The ability to accurately evaluate coal quality and the coking characteristics of metallurgical coal during the exploration stage is essential to determining the economic viability of a coal deposit.”

“The potential of finding a faster, safer more reliable method of determining coal quality is a real boon for the coal industry,” added Bruce Madu, vice president, minerals and mining at Geoscience BC. “Ultimately, the more accurate information a prospector or company has about the quality of coal beneath the ground, the higher the value they could get for their property or the end product.”

If the Roben Jig process provides equivalent or superior results to traditional coal washing methods, it could potentially benefit B.C. and the global coal industry by eliminating the need to use harmful chemicals for treating/cleaning coal prior to coal and coke quality analysis.

Final study results of the effectiveness of the Roben Jig process compared to coal washing using the traditional float-and-sink method will be available in the fall 2017 on Geoscience BC’s website at www.geosciencebc.com.