Study of the behavior of iron ore particles in spiral concentratorsAbstract. Spiral concentrators are gravity separation devices widely used in the iron ore industry. .. as well as the mysterious Bagnold force are all in action to perform the particle classification in spirals (Burt ... (1978) investigated the effect of feed rate variations on a Humphrey spiral operation to concentrate an iron ore.humpry spiral classifier uses in iron ore,Gravity Spiral Concentrator Working Principle - 911 MetallurgistMar 26, 2016 . The Humphreys Spiral Concentrator, which was invented by I. B. Humphreys and first used in 1943 for concentrating chromite in Oregon beach sands, consists of five or six spiral turns of a modified semicircular launder which is about the size of a conventional automobile tire. Feed enters the top spiral and.