This is the fourth of an eight week short information program that is intended to keep people in the mineral processing sector up to date with the developments at Gekko Systems.

This week's topic:

Pre-Concentration in the Diamond Industry

Gekko’s InLine Pressure Jig (IPJ) is attracting a lot of attention from diamond metallurgists and is revolutionising pre-concentration in diamond applications. The IPJ is a compact continuous gravity recovery unit. It is designed to be employed ahead of DMS or X-ray sorting devices to prepare a low volume/diamond rich concentrate feed of low mass. Recent tests have shown up to 100% recovery of diamond tracers, reporting to concentrates of 10 to 30% of the total mass fed to the IPJ.

It is simple and modular in design and requires minimal infrastructure and logistical support, leading to savings in upfront capital costs. Furthermore, the plant can be easily expanded if throughput requirements change.

Operating costs per volume treated are reduced significantly (as little as USD 0.02) because power and water consumption is very low, maintenance is low and operating efficiency is high. Operating costs are further reduced due to the IPJ’s capacity to reject a high proportion of waste material, thereby effectively increasing the capacity of the DMS plant downstream (or reducing the size of the DMS plant required.)

The IPJ’s lower overall capital and operational costs combined with the high recovery and high unit throughput offer a greater return on investment.

Over 100 IPJs are installed on sites around the world and a high proportion is currently used in diamond recovery applications.


  • High recovery
  • Capacity of downstream plant increased due to the upfront removal of waste products
  • Capital costs lower than alternative technology
  • Low-cost throughput per ton treated
  • Pre-concentration means significant cost savings because of reduced downstream volumes treated
  • Further reduction in operating costs because no media usage required
  • Low power consumption
  • Low water consumption (10% of that of traditional jigs) increases applicability in water-sensitive areas
  • High availability due to low wear rate and low maintenance
  • Recovery maximised by capacity to vary mass pull
  • Simple and efficient operation
  • Plant can be expanded easily as needs change
  • High security because of fully enclosed operation

Jig Performance:

The best recovery and cost outcomes are achieved using a combination of the IPJ and DMS units.

The Partition (Ep) curve shown below outlines the performance of the two units.

  • The IPJ can be set to recover 100% of 3.2SG and higher particles to sinks. This is also true for DMS technology
  • DMS recovers a lower mass at a more accurate cut point; however the unit has significantly higher capital and operating costs
  • Whilst the IPJ does not cut as accurately, it will remove a higher proportion of gangue (waste) with minimal losses at a lower cost
  • The volume of material taken to concentrates (sinks) by the IPJ is shown in the area coloured in yellow and grey. The volume taken by the DMS is coloured in grey. Therefore the area coloured in yellow indicates the mass of material that will report to DMS tails from the IPJ concentrate. Importantly, the chart demonstrates that the IPJ does not cut into the DMS separation zone.

Pilot Plant:

Gekko’s pilot plant is used for testing, exploration and small-scale recovery. It utilises a small feed hopper with an 80mm grizzley. The 80mm feed is treated in a scrubber with a 22mm aperture trammel screen. The sub-22m material is treated through an IPJ1000 with the concentrate and tailings exiting onto a screen for tracer recovery.

Click through to more information on the InLine Pressure Jig or contact to be connected with your local sales person.