Nowadays gravity methods of separation are used to treat a variety of materials , ranging from minerals with high specific gravity like galena , a heavy metal sulphide to low density materials like coal . Particle sizes being processed vary from 50mm in most cases to microns in some cases.
The relative simplicity of gravity processes and most important of all the fact that these processes produce comparatively little or no environmental pollution makes gravity concentration my choice of technology . I believe there will come a time when even flotation is replaced by some of these novelty gravity processing methods that are coming on stream as I write this blog.
The principle of gravity separation is one of the most simple and straightforward technologies that process industry has produced. The only requirement is that there be a marked density difference that exists between the materials to be separated . That is all and nothing much . The concentration criterion which we will discuss in more detail later should be above 2.5 and for now we should just take note of the fact that efficiency of separation decreases as the value of this quotient decrease.
Gravity separators come in different forms . The following are worth looking at :
- jigs
- spirals
- shaking tables
- centrifugal concentrators – knelson and Falcon concentrators
- dense medium separators – dense medium cyclone
This concludes the quick summary on gravity concentration . We will look at how each equipment finds its space in the mineral industry. So make sure that you follow my posts.
