Disadvantages Of Gravity Concentration

Gravity concentration is the most famous and the oldest method in mineral processing industry, it uses the differences of densities between minerals to manage a separation and Although, it cannot be understood perfectly after very long years (Burt, 1984-pp.80). The separation of minerals by gravity depends on their relative movement in response to gravity and some other forces, which is generally related with the resistance to motion offered by a viscous fluid (Burt, 1999).

The gravity concentration has some huge advantages such as low capital, operating costs and high efficiency (dependent on the feed size), and also there is no need to any chemicals and excessive heating requirements it is usually defined to be environmentally friendly (Turner, 1991; Luttrell et al., 1995; Burt, 1999; Laplante and Spiller, 2002; Falconer, 2003; Oruc et al., 2010; El-Midany and Ibrahim, 2011).

Gravity concentration has lower efficiency at below 100 µm particle sizes. It is very disadvantages at these sizes for separation without imparting an extra force on the particles, which led to the

In the case of using wide particle size distributions in separation process, the performance of separation is badly affected because of the loss of small, heavy particles which are acting like light, coarse particles during the separation process. All gravity concentration devices function more efficiently on prepared feeds, that is with particles of comparatively narrow size range (Burt, 1984). Sometimes, the separation processes take advantage of the large density difference between minerals, but often there are not large differences between minerals which would like to be separated. In these cases, the narrow particle size distributions should be considered to supply best efficiency of separation