Centrifugal gold concentrator is a relatively new type of gravity concentration apparatus. The machines utilise the principles of a centrifuge to enhance the gravitational force experienced by feed particles to effect separation based on particle density. The key components of the unit are a cone shaped "concentrate" bowl, rotated at high speed by an electric motor and a pressurized water jacket encompassing the bowl. Feed material, typically from a ball mill discharge or cyclone underflow bleed, is fed as a slurry toward the centre of the bowl from above. The feed slurry contacts the base plate of the vessel and due to its rotation, is thrust outward. The outer extremities of the concentrate bowl house a series of ribs and between each pair of ribs is a groove. During operation the lighter material flows upward over the grooves and heavy mineral particles (usually of economic value) become trapped within them. Pressurized water is injected through a series of tangential water inlets along the perimeter of each groove to maintain a fluidized bed of particles in which heavy mineral particles can be efficiently concentrated.
Centrifugal gold concentrator was patented in China. It is an efficient equipment for recovering free gold in all particle size ranges, specially for recovery of fine gold which is lost during the operation of the gravitational concentrators(sluice boxes and jigs). It can be used not only for placer gold mining, but also for hard rock mining to recover the natural gold, replacing amalgamation, and recover gold from the old tailings.
Application shows that the recovery can be as high as 99%, and the concentrating ratio is up to 1,000 times. In recovering the natural gold in lode ore with size -0. 074mm, the gold is up to 98%, For 0.04mm in particle size, the gold recovery is 97%.
Main technical parameters of centrifugal concentrator
Model | STLB20 | STLB30 | STLB60 | STLB80 | STLB100 |
Capacity (t/h) | 0-0.6 | 2-3 | 8-12 | 40-45 | 60-80 |
Make up water (m3/h) | 2-3 | 3-5 | 7-10 | 30-36 | 50-60 |
Slurry water (m3/h) | 1.5-4 | 5-7 | 8-12 | 40-45 | 60-80 |
Feeding density (%) | 0-50 | 0-50 | 0-50 | 0-50 | 0-50 |
Feeding size (mm) | 0-3 | 0-3 | 0-5 | 0-5 | 0-6 |
Concentrate cleaning up cycle | Vein gold 1-3 hours, Alluvail gold 2-6 hours | ||||
Concentrate weight (Kg) | 2 | 3-5 | 10-20 | 40-50 | 70-80 |
Power (Kw) | 0.75 | 1.5 | 4 | 11 | 18.5 |
Weight (Kg) | 235 | 425 | 1150 | 2350 | 3760 |