The concentrator at WMC's Leinster Nickel Operation has operated with flash flotation in the grinding circuit since the early 1990s. There has always been a positive correlation between flash flotation Ni recovery and overall Ni recovery - however this relationship could be explained by differences in the ore, rather than by the action of the Flash flotation cell in reducing overgrinding of Ni.
In July 2003, refurbishment within the plant made it necessary to operate the concentrator for a period with the flash flotation cells off. The resulting data set provided evidence that flash flotation in the grinding circuit changes the size distribution of Ni to reduce the amount of slow-floating fine (-7 m) Ni produced. Ni recoveries in the finer size fractions were similar with flash flotation on or off - but because less fine Ni is produced when the flash flotation cells are operated, overall Ni recovery improved.