Knelson concentrator
Encyclopedia
A Knelson Concentrator is a type of gravity concentration apparatus, predominantly used in the gold mining
industry. It is used for the recovery of fine particles of free gold, meaning gold that does not require gold cyanidation
for recovery.
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. 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.
, like Geita
, Sunrise Dam
and the Serra Grande Gold Mine
as well as Barrick's
Bulyanhulu Gold Mine
.
Gold mining
Gold mining is the removal of gold from the ground. There are several techniques and processes by which gold may be extracted from the earth.-History:...
industry. It is used for the recovery of fine particles of free gold, meaning gold that does not require gold cyanidation
Gold cyanidation
Gold cyanidation is a metallurgical technique for extracting gold from low-grade ore by converting the gold to a water soluble coordination complex. It is the most commonly used process for gold extraction...
for recovery.
Operation
The machines utilise the principles of a centrifugeCentrifuge
A centrifuge is a piece of equipment, generally driven by an electric motor , that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis...
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. 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.
Mines
Knelson concentrators are used in a number of gold mines operated by AngloGold AshantiAngloGold Ashanti
AngloGold Ashanti Limited is a global gold mining company. It was formed in 2004 by the merger of AngloGold and the Ashanti Goldfields Corporation.AngloGold Ashanti Limited is now a global gold producer with 21 operations on four continents...
, like Geita
Geita Gold Mine
The Geita Gold Mine is an open pit gold mine located in the Geita District of the Mwanza Region of Tanzania. It is operated by AngloGold Ashanti....
, Sunrise Dam
Sunrise Dam Gold Mine
The Sunrise Dam Gold Mine is located 55 km south of Laverton, Western Australia. It is fully owned by AngloGold Ashanti. In 2007, it accounted for 11% of the company's production.The mine is currently the company's only Australian operation...
and the Serra Grande Gold Mine
Serra Grande Gold Mine
The Serra Grande Gold Mine is a gold mine located 5 km from Crixás, in the Goiás state of Brazil. It is jointly owned by AngloGold Ashanti and Kinross Gold Corporation, who are equal partners. The mine is operated by AngloGold Ashanti but revenue is spread evenly between the two companies.In...
as well as Barrick's
Barrick Gold
Barrick Gold Corporation is the largest pure gold mining company in the world, with its headquarters in Toronto, Ontario, Canada; and four regional business units located in Australia, Africa, North America and South America...
Bulyanhulu Gold Mine
Bulyanhulu Gold Mine
Bulyanhulu Gold Mine is an underground gold mine in the Shinyanga Region of Tanzania, located 55 kilometres south of Lake Victoria. It is operated by African Barrick Gold....
.