It is not often that one sees something new in the world of centrifugal gravity concentration, it is mostly just the same old copies of redundant models. APT’s new GK-X centrifugal concentrator brings a number of refreshingly new developments, all designed to overcome a problem from the past and move things forward.

The GK-X is targeted at the middle ground and is rated for 20tph solids feed in a slurry that can range from 30 to 60% solids. Application is either alluvial, hard rock or tailings and the feed is optimal at -2mm, although -3mm is acceptable and will allow more nugget like gold recovery in alluvial applications.

The first major departure of the GK-X from the conventional units is that the GK-X is a fluidized concentrator but does not incorporate a water jacket. The fluidization water is fed to the fluidizing nozzles via an exo-skeleton of fluidization pipes which gets the water straight to where it is needed. Without the water jacket, the rotating weight is kept to a minimum saving energy from swinging all that water. Line velocities are also kept high, avoiding the problematic settling out of any silt that may be in the fluidization water. Each fluidizing water line (after feeding it’s group of fluidization nozzles) terminates in a silt exit nozzle that ejects the silt directly with no chance of settling out under the g-force and slower velocity in a water jacket.

The next major revolutionary change is that each of the exit nozzles sprays it’s fluidizing water via a stainless steel jet that metres the flow to exactly the volume required at the recommended line pressure. The main feed routing is big bore right through to the jet, so there is nowhere for solids to get stuck, contributing to another major advantage over the past systems. The need to restrict or set the line flow to try to achieve a set pressure is thus negated, the jets do that for you. Line turbulence is therefore eliminated and so is the tendency for small particles to block the jets as they are forced through.

Cleaning the fluidization system is the third major departure from the old days of needing to remove the cone. Cleaning is as simple as back-flushing each of the eight lines, one at a time, by removing the silt exit nozzle for that line and attaching the pressure back-flush hose. The back-flushed material is ejected through a dedicated port so you can see when the line is clear and move to the next one. Should a jet be blocked it is as simple as removing it with a screw driver and replacing it, which also solves the problem of enlarged jets over time that plagued the previous generation.

Because of the accurate water metering to each part of the cone with even distribution, it has proved possible in practice to reduce water requirement. The standard 2mm jets use 6 cubic metres of water per hour at 2 bar line pressure. For fine gold applications and where finer feeds allow less water we recommend changing out to the optional 1.5mm jets, a quick and easy operation that does not require the cone to be removed. The GK-X cone can therefore be ‘tuned’ to the application you have and easily adjusted for future changes in application.

All GK-X wetted surfaces are either poly or stainless steel for corrosion free life. The standard rotating water union is brass but can be changed out for a stainless steel unit upon special request. All slurry contact surfaces are lined and replacement liners are incorporated in high wear zones. The inlet and exit pipes are standard sized poly, not only making for easier sourcing of replacements upon wear, but also fitting standard poly fittings available universally.

The GK-X launder shape is somewhat revolutionary too, and easily recognizable by it’s inverted bowl shape. This is entirely by design, so that the tailings slurry, now expanded by fluidization water and at a lower velocity, has more room to flow away. This has resulted in a squatter design for the launder, making for easier installations.

The GK-X comes in a standard manual flushing option as well as an automated flushing option. An operation platform is also available that incorporates a slurry header tank with bypass valve to enable flushing of concentrates as well as two concentrate tote boxes to hold a shift’s worth of concentrates. A dedicated water pump is also supplied with the platform package to ensure correct pressure to the fluidisation jets.

Contact us here or email us on info@aptprocessing.com for further information.