Introduction of Knelson Centifugal concentrator
- A Knelson concentrator is a type of gravity concentration apparatus; it is predominantly used in the gold mining industry. The apparatus is used for the recovery of fine particles of free gold, which is, the gold that does not require gold cyanidation for recovery.
- The Knelson concentrator utilizes the principles of centrifuge to enhance the gravitational force experienced by feed particles, which aids in the separation process based on particle density. The key components of the unit include: a cone shaped “concentrate” bowl, which is rotated at high speed by an electric motor and a pressurized water jacket encompasses the bowl.
- Feed material, typically from a ball mill discharge or cyclone underflow bleed, is fed as a slurry toward the center 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 concentrated 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 the heavy mineral particles (usually of economic value) becomes 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.
- The Knelson concentrator typically operates as a batch process, with lighter gangue material being continuously discharged via overflow and a heavy mineral concentrate periodically removed by flushing the bowl with water.
Above content from: https://en.wikipedia.org/wiki/Knelson_concentrator
Application of Knelson Centrifugal concentrator
Knelson concentrator is an efficient centrifugal equipment for mineral dressing plant. It is suitable for the recovery of precious metals such as gold, silver and platinum groups from ore. Other solid materials has been successfully used for the selection of larger proportionate of minerals, too.
Working principle of Knelson centrifugal concentrator
Knelson concentrator is kind of gravity mineral processing equipment that is based on the centrifugal principle of strengthening. In gravitationally intensive gravitational fields, the gravitational differences of minerals with larger gravity and gravity are greatly amplified, which makes the separation between light and heavy minerals easier than natural gravity fields. Under the above conditions, heavy mineral particles can replace the light mineral particles in the selected bed to occupy the location and retained, light mineral particles are discharged as tailing, in order to achieve the proportion of mineral particles by sorting.
Installation of Knelson centrifugal concentrator
- Firstly, prepare a water pump for the centrifugal concentrator, flow rate no less than 50 cubic meters per hour, the water pump should be not too far from the water source, otherwise the water pressure is not enough for the the centrifugal concentrator.
- Secondly, water pump pipe outlet connects with the large water tank input, large water tank of 60mm outlet connects with small water tank. Water will be filtered first in the large tank, then sent to the smaller tank. Smaller thank will be connected with the rotary joint at the bottom of the centrifugal concentrator. The distributors above large tank is for spare use, also can reduce the pressure of water input. Check the following picture of connection.
Empty run test of Knelson centrifugal concentrator
Before running the machine, the operator should make sure the rotation direction is correct, all the lubrication places must add grease.
- Adjust the water pressure before centrifugal concentrator runs
- Turn the ball valve # 60 near to water pressure meter to maximum
- Adjust the water pressure by #60 butterfly ball valve from large water tank, adjust to 3 atmospheric pressure first, run the centrifugal concentrator for 3 hours and check if there is any gold in the tailing. Reduce the pressure little by little, and after testing then fix the pressure to a certain number.
- Adjust pressure before the centrifugal concentrator motor starts to run, water and sand materials are fed from top place, normally 40% materials and 60% water is a good ratio.
- Stop feeding first, then another 2 minutes stop water feeding, finally stop the centrifugal concentrator to collect gold.
Maintenance of Knelson centrifugal concentrator
- Check the equipment condition every day, clean up the machine interior in time before starts.
- The machine bearings should be lubricated with grease per shift.
- Clean the water tank from time to time