Gravity concentration

Achieve highest coarse and fine gold recovery with a Knelson gravity concentrator

Our gravity concentration equipment provides the most effective solution in the field of gravity separation for industry-best recovery of gold and other precious metals. Designed for versatile operation, it suits many applications and fits any circuit size.

Home/.../Precious metal recovery/Gravity concentration

Key benefits of Knelson Gravity Concentrators

  • Enhance gold recovery with fully fluidised cones

    Built on 40 years of innovation, our Knelson gravity concentrators are designed to capture the maximum amount of gold per cycle. They are the only enhanced gravity concentrator on the market with a fully fluidized bed, allowing for upgrading throughout the entire cone surface.

  • Reduce maintenance downtime

    We have improved the design of our Knelson gold concentrators to increase uptime and facilitate easier maintenance. Unit internals are rubber-lined to protect against abrasion, while stainless steel parts offer better value and longer service life. The latest design also features fewer parts and an automated lubrication system to further reduce maintenance needs.

  • Operational flexibility

    Unlike other gravity concentration equipment on the market, Knelson concentrators can operate at feed densities of up to 75% solids. This means they can be installed in multiple locations within the metal recovery process, making the system more versatile.

Models

Compare our gravity concentrators

QS70
QS48
Maximum feed capacity (Solids)
1000 tonne/hr
400 tonne/hr
Maximum total volumetric throughput
1360 m3/hr
545 m3/hr
Feed density (solids weight)
Up to 75%
Up to 75%
Feed top size - maximum
6.0 mm
6.0 mm
Feed top size - recommended
2.0 mm
2.0 mm
Matrix cone option (application specific)
G5, G6, G7
G5, G6, G7
Target recovery particle size
Coarse, coarse & fine, very Fine
Coarse, coarse & fine, very Fine
Motor size range
150-375 kW
45-75 kW

Want to talk? Reach out to our experts

Key equipment features

GX concentrating cone

Our patented GX concentrating cone lies at the heart of our latest-generation Knelson QS concentrators, an innovative step in metallurgical performance. Zone separator nozzles provide effective control and distribution of fluidisation water across the entire cone, facilitating the highest possible recovery of coarse and fine gold.

Tangential water distribution

The GX cone features tangential introduction of fluidized water into the concentrating rings, avoiding ratholing and dead spots. It also allows thorough flushing of the unit without the need for expensive and unnecessary variable frequency drives.  

Designed to eliminate vibration

We designed the Knelson gravity concentrator with a low centre of gravity and to be hung rather than supported from below, eliminating overall vibration. In contrast, similar products on the market can face problems with vibration if the feed is not properly diluted. 

Low number of parts

Knelson gravity concentrators are designed to reduce component parts, simplify construction, and reduce manufacturing time. These measures cut maintenance costs without impacting recovery rates or capacity 

Maintenance & Service of our gravity concentrators

Our Aftermarket Department offers reliable and timely supply of spares and wear parts, ensuring minimal downtime and optimal equipment performance. Our specialists are also readily available to provide ongoing operational support. Whether it’s technical advice, troubleshooting or circuit optimization, we work closely with mine site teams to ensure the longevity and efficiency of the equipment throughout its lifecycle.   

Additionally, we offer comprehensive support services, including circuit audits, preventive maintenance programs, training for mine operators and maintenance personnel, and detailed reporting on equipment performance. Our goal is to help maximise productivity, minimise downtime, and ensure the safe and efficient operation of our clients’ mining assets. 

Complete gravity circuit operations

Downstream processing of gravity-produced concentrate involves leaching. For a seamless gravity circuit operation, we recommend the Consep Acacia intensive cyanidation system. Featuring an up-flow fluidised reactor specifically designed for the leaching of Knelson concentrates, the Consep Acacia system creates the ideal solid-liquid interaction, maximising gold leaching reaction kinetics without the need for mechanical agitation, and typically achieving recoveries of more than 95%, often over 98%. Over 20 years, it has become the market leader in its field, maintaining an unblemished installation success rate with its reliability, simplicity and productivity.

Frequently asked questions

FAQs for Gravity Concentrators

Knelson concentrators use the centrifugal force and fully fluidized cones to enhance gravitational separation of free gold particles. 

Knelson concentrators are highly efficient at recovering free coarse and fine gold, achieving industry best recovery rates of up to 98%.

The Knelson Concentrator is highly configurable and available in a range of model sizes that will suit any hard rock or alluvial mining operation. With capacity range from laboratory scale up to 1000 tonnes of solids per hour, and feed densities up to 75% w/w solids. 

Knelson concentrators are installed in various applications, including closed-circuit grinding, open circuit applications, regrinding mills, flotation concentrates and tails. Other applications include precious metals recovery, such as silver and platinum group metals (PGMs). 

Want to talk? Reach out to our experts