Rich Weinstein, engineering manager at the Falkirk Mine, said the company was currently developing an economic model of the process to determine whether or not to purchase a commercial unit, an undertaking he estimates will be completed by the third quarter of the year.
Previously, “air jigging” was only used in the eastern US to clean bituminous coal. The technology was first put to the test last year on over 1000 tons of lignite from the Freedom and Falkirk mines of North Dakota, a process involving the separation of the coal from heavier non-coal matter. Weinstein identified air jigging as an “evolutionary improvement to technology” compared with the air table the coal industry previously used.
Weinstein was pleased with the results of the project, a joint undertaking by the University of Kentucky, the US Department of Energy and several energy organizations.
“The tests showed the quality of lignite could be significantly improved,” he said. “The cleaning process increased the heat content of the coal and reduced ash. The process also reduced the environmental impacts normally associated with coal combustion, such as particulate matter, sulfur dioxide and mercury.”