In 1976, Byron Knelson designed the first Knelson Concentrator and revolutionised the gravity concentration industry. Ever since, continuous R&D ensures that Knelson Concentrators, now owned by FLSmidth, continues to pioneer and dominate the gravity concentration industry.
The initial batch concentrator was and still is the best on the market at recovering free, or gravity recoverable gold (GRG), as well as other precious heavy metals. The continuous variable discharge (CVD) model allows recovery of everything from fine free gold to high specific gravity minerals such as tantalum, cassiterite, chromite and mineral sands; or the pre-concentration of sulphide minerals and the scavenging of tailings streams.
FLSmidth Knelson Concentrators are the market leaders in gravity concentrators, and are more worth than their weight in gold. Using centrifugal force and water injection processes, FLSmidth Knelson Concentrators create enhanced gravitational forces of up to 200 g’s to recover free gold, fine gold and any other precious metals or minerals with high specific gravities. As pioneers of the gravity concentration industry, FLSmidth Knelsons have been replicated and competed with since their inception. However, due to their superior design, lifespan and continuous R&D they have forever led the industry in both innovation and market share.
The original Batch Knelson Concentrators run for pre-defined cycle periods, after which the concentrate is harvested by means of an automated Centre-Discharge system. They are perfectly suited for the secure recovery of gravity recoverable gold (GRG) and other heavy metals and minerals from both alluvial and hard-rock plants.
Batch Knelsons are available with a variety of concentrating cone designs and with centrifugal fields of up to 200g, to provide wide choices to suit different site and machine feed conditions. Furthermore, concentrating cones are disposable wear parts, greatly reducing operating and stock-holding costs.
Continuous Variable Discharge (CVD) FLSmidth Knelson Concentrators deliver a continuous stream of concentrate by discharging the concentrate whilst simultaneously processing fresh feed. This makes the CVD model more suitable for situations where higher concentrate mass yield is desirable, including the recovery of minerals with high specific gravity such as as tantalum, cassiterite, chromite and iron ore; the pre-concentration of coarse sulphide minerals and the scavenging of tailings streams. In addition to this, the FLSmidth Knelson CVD affords all the benefits of the Batch models and more – secure hands-off operation, full automation, and 5 variables that can be instantly changed to adjust mass yield, grade and recovery.
Having worked with FLSmidth Knelson Concentrators for decades, we are able to advise our clients on exactly which models they need to suit their ore type, technical and financial needs.
The GoldKacha is designed for the recovery of precious metals from alluvial sands, rubble beds and dump tailings. A rudimentary, unfluidised and low-g centrifugal Concentrator, the GoldKacha has been proven to recover both course and fine gold or precious metals.
The simplicity and robustness of the GoldKacha, as well as the fact that the concentrate is washed out by hand, make it a much cheaper option than alternative gravity concentrators, ideal for small mining operations or prospecting. As with many of of our mineral recovery products, the GoldKacha is designed for immediate installation on site or as part of a modular plant that requires little assembly time and effort.
ALLUVIAL GOLD PANS
The first recorded instances of placer mining are from ancient Rome, where gold and other precious metals were extracted from streams and mountainsides using sluices and panning.
Batch Knelson Concentrators
|Capacity (tph solids)||0.7||20||80/80||100/150/150||250/250||400/400||1000|
|Capacity (m3/hr slurry)||5.7||27||110/110||150/205/205||340/340||545/545||1360|
|Centrifugal field (g’s)||60||——————————————————-60-200——————————————————————–|
|Feed size (mm max)||4.7||———————————————————-6.0———————————————————————-|
|Feed size (mm recommended)||2||———————————————————-2.0———————————————————————-|
|Feed slurry density (% solids)||——————————————————————–0-75% solids by weight——————————————————–|
|Installed power (kW)||0.6||1.5||5.5||11||30||40||150|
|Installed mass (kg)||119||260||900/1045||1565/1725/1680||3980/3320||5680/5225||18460|
|Fluidising water (m3/hr)*||1.6-2.7||4-10||6-18||14-39||23-73||41-86||68-86|
|Concentrate mass (kg/purge)*||1.2-1.6||3-9||9-21||23-59||31-103||34-107||95-125|
|Recovery (%)||————————————————————-typically >90% of liberated metal————————————————–|
Continuous Variable Discharge (CVD) FLSmidth Knelson Concentrators
|Capacity (tph solids)||2||35||120||300|
|Capacity (m3/hr slurry)||4||75||250||635|
|Centrifugal field (g’s)||——————-30-90——————-|
|Feed size (mm max)*||——————-1.0——————-|
|Feed slurry density (% solids)||——————-0-75% solids by weight——————-|
|Installed power (kW)||1.5||11||30||75|
|Installed mass (kg)||230||2500||7000||18200|
|Fluidising water (m3/hr)*||1-2||3-9||11-23||9-27|
|Concentrate mass (%)||——————-0.5-50% of feed mass——————-|