Application of Enhanced Gravity Separators for Fine Particle Processing: An Overview

Recent Trends in Mineral Processing Based on Density and Particle Size – A review

“…The enhanced density-based separation is a separation process, which employs centrifugation to recover the fine/ultrafine valuable minerals from the gangue minerals, based on the density differences. The centrifugal force produces a force larger than the gravitational force [22]. Some of the major enhanced gravity separation technologies are shown in…”

“…Furthermore, the dense particles usually remain in the bottom grooves, and the medium-dense particles settle at the top grooves as a result of the greater radial velocity of fluidized water in the top grooves than that in the bottom grooves [23]. In the Falcon separator, the bed stratification on the bowl wall takes place as a result of the variance in settling velocity against fluidization water flowing through holes in the bowl grooves [22].…”

“…The extremely high centrifugal energy of up to 300 g's, which can also reach 600 g's in some recent types, makes Falcon concentrator a unique technology that can separate particles at a separation density lower than that of the other enhanced density-based separation technologies. Falcon concentrator has the capability to upgrade particles of sizes finer than 25 µm (dense particles) and 75 µm (lower density particles) [22].…”

“…The UF type is designed with a smooth bowl with a reduced diameter at the overflow outlet without using countercurrent water pressure that may flush ultrafine dense particles to the wrong stream. The UF type is capable of treating particles finer than 3 µm with an enhanced gravitational force reaching 600 g's [22], while SB and C series can provide up to 300 g's [29,30]. Both SB and UF types should be turned off prior to saturation to avoid the loss of dense particles [25].…”

“…Knelson concentrator is more favorable in mineral industries attributable to its low cost, small environmental influence, and its capability of upgrading a wide feed size from 850 µm to 20 µm by optimizing the enhanced gravitational force and the pressure of fluidized water [32]. In most applications, the common optimum enhanced gravitational energy of the Knelson concentrator is in the range of 60 and 100 g's, reaching to 180 g's [22]. Knelson concentrator was primarily a semi-batch system for gold concentration [22].…”