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Applicable Equipment


Award-winning, portable processing plant for high recoveries by gravity separation.


Flexible plant components for versatile, cost-effective flowsheets.


Innovative design that pre-concentrates high-value material.

Applicable Minerals


Free gold is unbound to other materials and is easy to liberate.


Gold associated with sulphides requires a modified flowsheet.


Free silver and silver complexes behave unpredictably and contain impurities.

Applicable Minerals


A combination of different metals in a single compound.


Such as tin/tantalum, diamond, garnet and other gemstone-containing material.

Gangue Rejection

Gekko’s dedication to designing energy-efficient flowsheets includes exploiting the importance of gangue rejection.

Gangue rejection is the process of separating and disposing the poorest, low-quality, low-value material in an ore feed prior to further downstream processing. Simply put, the focus is on the waste to reject, rather than the mineral to recover.

Economic benefits are gained when the gangue volume is replaced with useful material of a higher grade. The energy expended by the subsequent operations is used more efficiently to process more valuable material. It does not waste energy on gangue.

Removing gangue results in a higher-grade material for processing, reducing energy consumption.


By providing a higher-grade material for processing, the returns from the energy expended during recovery are higher.

Gravity separation to remove gangue saves equipment from wearing out due to processing low value material.

Greater returns are achieved due to lower capital costs, reduced life of mine costs, reduced infrastructure investment and low environmental costs.

Using gravity to reject gangue from high-value material is an environmentally safe, low energy process.

Innovative, modular gravity separation devices reject gangue to produce a higher-grade material for intensive downstream processing.

Gekko's expert technical services provide advice for energy efficient flowsheet design and ongoing circuit optimisation.

How It Works

Gangue rejection aims to improve low-grade material by removing non-valuable gangue and replacing with material of higher quality.

Exploiting the difference in crushability of the mineral versus the surrounding waste uses screening, ore-sorting, magnetic separation, gravity separation and jigs. Gangue rejection harnesses the same physical separation processes as pre-concentration, however the purpose is different.

Rejecting gangue substantially upgrades the mass going forward for intensive processing. This has economic benefits because it lengthens equipment life, cuts power costs, saves water, reduces chemicals and improves valuable mineral recoveries.

Depending on the features of a particular ore body, a gangue rejection flowsheet may use several devices to prepare material with the best liberation properties.

The Gekko Difference

A range of particle types can be derived from an ore body. Knowing which size and other ore characteristics to exploit, as well as how to reject the gangue, requires specialist laboratory testwork. When Gekko’s technical services team establishes the ore-specific information, a gangue rejection flowsheet that promotes maximum liberation of mineral will be designed.

Gekko’s core technologies, such as the InLine Pressure Jig, or the comminution strength of the Python processing plant, are well suited to gangue rejection flowsheets. The modular design and construction of plant components provide speed-to-operation for fast financial returns.

Gekko’s expertise in gangue rejection flowsheet design delivers major gains to mining operations, through environmental and economic improvements. Speak to Gekko today to find out how gangue rejection will enhance operational efficiencies.

Is The Python Right For Me Python Amenability Test Work

Technical Papers (3 of 52)

More Technical Papers
technical paper
Technical Paper 047 - Is The Python Right For Me Python Amenability Test Work

AusIMM Gravity Gold Conference, Ballarat, Australia. T. Hughes, K. Donaldson, and B. Murphy. | 03 September 2010

technical paper
Technical Paper 029 - Use Of The InLine Pressure Jig In Diamond Applications

Gravity, Perth, Australia. D.H. Davidson, P.M. Grady and R.A. Heins. | 02 March 2006

technical paper
Technical Paper 015 - Successful Applications Of The InLine Pressure Jig

SAIMM Gravity Conference, Mount Amanzi, Hartebeespoot. Russell Heins, Robin Spargo and Andrew McCallum. | 29 January 2003

From the left: Eric Vesel, General Manager and Sandy Gray, Technical Director Gekko Systems

Case Studies (3 of 14)

More Case Studies
case study
Case Study - BHP Billiton Temco

BHP Billiton's Tasmanian Electro Metallurgical Company Pty Ltd (TEMCO) is Australia's only producer of manganese ferroalloy. | 01 July 2008

case study
Case Study - Beaconsfield

Beaconsfield Gold Mine in Tasmania operates a gravity recovery circuit ahead of a flotation plant in order to maximise the gold recovery in the total plant. | 01 January 2003

case study
Case Study - Penjom Gold Mine

Gekko Systems installed six InLine Pressure Jigs (IPJ500) to recover both free and sulphide associated gold from grinding circuit. | 13 June 1998

Gangue Rejection Circuit Increases Python Throughput x 5

Articles (3 of 88)

More Articles
Gangue Rejection Circuit Increases Python Throughput x 5

The Python 500 modular processing plant was originally developed to process ore in an underground environment. | 01 September 2012

IPJ Gangue Rejection and Pre-concentration Plant Results Match CGR Lab Work

Full scale installations of the InLine Pressure Jig (IPJ) continuous gravity recovery circuits at Pirquitas (Silver Standard Resources) and Kloof (Gold Fields) provide further evidence of the strong.. | 01 July 2011

Positive Recovery Results from Python at Kloof

Gekko Systems was contracted by Gold Fields in June 2010 to design, build, install and commission a Python 500 modular plant for its Kloof GROWTH project in South Africa. | 01 July 2011

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