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You will find answers to some of the most commonly asked questions of the Knelson batch-type concentrator. If you find your question is not answered, use the batch concentrator information request form.

  1. What does the Knelson batch-type concentrator do?
    • Answer: The Knelson semi-continuous (batch) concentrator is a specially designed fluidized centrifuge that separates heavy material, such as gold and platinum, from lighter background material such as quartz. The material must be ground to an appropriate size, mixed with water, and then fed into the machine. The Knelson Concentrator is generally applied to materials in which the heavy component to be recovered is a very small fraction of the total material. For most primary applications the grade of the heavy material will be less than 500 grams/tonne (0.05% by weight).
    • View the online movie of how the Knelson batch-type concentrator works.


  2. What can the Knelson technology recover?
    • Answer: The Knelson Concentrator will separate any heavy material from any light material so long as there is sufficient difference in the densities of the individual particles in question. The Knelson Concentrator can treat particle sizes from below 10 microns up to a maximum of 6mm and is most commonly used for recovery in Gold and Platinum. Other recovery uses include Mercury, Palladium, Tantalum, Copper, Silver and Diamond Indicator Minerals.
    • Learn more on the Knelson batch-type concentrator.


  3. What is the maximum tonnage of a Knelson concentrator?
    • Answer: We have a full range of equipment for varying tonnage requirements from the laboratory sized KC MD3 rated at 40 kg/hr up to the Knelson XD70 concentrator rated at 650 tonnes/hr. Downloadable specification sheets are available for the Extended Duty (XD), Centre Discharge (CD) and Laboratory / Testwork (MD) models that include tonnage requirements for each model.


  4. How much does it cost?


  5. What G-force does the Knelson concentrators operate?
    • Answer: The Knelson Concentrator can operate up to 200 g's.


  6. Can the Knelson concentrator be automated?
    • Answer: Yes. The Knelson Concentrator is available in both manual and automatic. There are three different levels of individual machine automation as well as a number of options for multi-unit control and for incorporation into an existing control system. Ask your Knelson representative for complete details. Learn more about the Knelson automation options.


  7. What are the different models and sizes of the Knelson concentrator?
    • Answer: The Knelson Concentrator is available in the Manual Discharge (MD), Center Discharge (CD), Extended Duty (XD) series. The MD line is available in capacities up to 40 tonnes/hour while the CD and XD lines are available in sizes up to 650 tonnes/hour. Visit the batch-type concentrator product page to learn more on each series available models.


  8. Who is the originator of the fluid-bed centrifuge?
    • Answer: Byron Knelson has been widely recognized throughout the mining industry as the modern-day originator of the fluid-bed centrifugal separator, which bears his name.
    • Official acknowledgment of this status came in 1999 during the 100th Anniversary Celebrations of the Canadian Institute of Mining and Metallurgy (CIM) when Byron Knelson was presented with two prestigious awards. The first was the CIM Centennial Achievement Award given in recognition to those making significant contribution to the Canadian Mining Industry and the second was the CanMet Technology Award in further recognition of his outstanding contribution to technology advancement in the field of mineral processing.


  9. How many years has Knelson Concentrators been in business?
    • Answer: Knelson Concentrators has been in business since 1978. Year 2003 was Knelsons 25th anniversary.


  10. How many Knelson Concentrators are in the marketplace today?
    • Answer: There are thousands of Knelson units that have been shipped into over 70 countries. View some of Knelsons customers comments.


  11. What criteria should I evaluate for selecting a centrifugal gravity concentrator?
    • Answer: There are a number of key individual factors which must be considered when evaluating a gravity concentrator. Among the most important are:
    • However the most important and relevant parameter to evaluate is success. To show the superiority of a unit in all these critical areas is to show successful implementation in plant-scale operations. Knelson Concentrators is the only manufacturer of this type of equipment with an extensive and verifiable client list to prove the value and commitment to their clients. It is strongly recommended that any prospective buyer of a centrifugal gravity concentrator to obtain extensive client contact information lists and verify all aspects of theory, design, quality, operation, support and price.


  12. Why choose a Knelson Concentrator?
    • Answer: In a recent survey of over 100 Knelson Concentrator installations, 100% of respondents said they would recommend a Knelson Concentrator to other potential customers who are interested in installing a free gold gravity circuit.
    • Knelson is the world leader in gravity separation with over 2000 units shipped to over 70 countries.
    • All equipment is environmentally friendly.
    • Constant and dedicated commitment to R&D continues to add value to customers operations.
    • Quick payback - often less than 30 days.
    • Global support.

  13. Who are some commercial users of Knelson Concentrators?
    • Answer: To name a few....
      • Anglogold - Mali
      • Ashanti Goldfields - Ghana
      • Bimak AD - Bulgaria
      • BHP Tintaya - Peru
      • Barrick Gold - Canada
      • Barrick Gold - Tanzania
      • CVRD - Brazil
      • Harmony Gold Mines - Republic of South Africa
      • JCI - Republic of South Africa
      • Kinross Gold Corp. - Canada
      • Lonhro - Zimbabwe
      • Minera Alumbrera - Argentina
      • Newcrest Gold - Australia
      • Newmont - Canada
      • Norilsk Nickel - Russia
      • Penjom Gold - Malaysia
      • Placer Dome - Canada
      • WMC - Australia
    • See what these and other Knelson Concentrator customers have to say.


  14. How does the Knelson Concentrator compare to other available centrifugal units?
    • Answer: At last count there is somewhere between 10 and 15 companies offering centrifugal units in various parts of the world. This number may vary slightly as the companies come and go. Most of these units are based on the fundamental aspects of older Knelson technology while some go as far as to attempt to copy each piece as closely as possible without overstepping the bounds of Knelson Concentrator patents. Performance ranges from almost unusable to marginal. Nothing matches the performance of a genuine Knelson Concentrator.


  15. Has there ever been any independent side-by-side production scale tests comparing the Knelson to imitation units?
    • Answer: Yes. In the few installations where we have been put side by side in lengthy production comparisons the Knelson Concentrator will outperform any equally sized imitation unit by at least 25% and sometimes as much as 200% in the long term. The difference is attributable to both superior metallurgical and mechanical design. Some of the largest differences can be up to 60% attributable to the chronic reliability, quality and service problems of the imitation units. Comparisons have been noted in over a dozen instances where a total of five different types of imitation units fell far short of the standard that Knelson has set.
    • Some of these comparison tests can be found in technical papers and report.


  16. What is Knelson Concentrators role in the marketplace for technological advancements?
    • Answer: All technological advancements begin with extensive research and development. At Knelson Concentrators, research and development have always been a primary focus. Knelson currently has ongoing cooperative research projects with a number of different Universities and Research Centres around the world.
    • It's recognized Knelsons commitment to research will ensure the long term success of the company, the products and the people. That's why Knelson has allocated a significant portion of revenues back into R&D. In fact, Knelson spends more than 5 times the national average on new product development!


  17. What is the Knelson Concentrators average availability?
    • Answer: The most recent survey shows an average availability of over 97%.


  18. Why should I upgrade my current G4 cone to a G5 cone?
    • Answer: The G5 cone is the latest technological advancement in the Knelson Concentrate Cone. Its advantages over the G4 concentrate cone are…..
      • Reduced water usage up to 60%
      • Increased throughput
      • Improved metallurgical performance
      • Reduced concentrate volume
      • Reduced maintenance operating costs.
    • The most cost effective means of upgrading to the latest in concentrate cone technology is through the Knelson exchange/refurbishment program.


  19. Is pre-screening of feed to the Knelson Concentrator necessary?
      • Answer: The Knelson Concentrator can treat particle sizes up to 6mm (1/4 inch) in the larger units. Any material in excess of 6mm must be screened out. For many feeds it is recommended to screen at a much finer cut size although this increases the cost of screening. Contact Knelson through the "request for information form" to find out what is most cost effective in your application.
      • Learn more about Knelson feed preparation equipment.


   20.      What are the minimum air requirments for the Batch Knelson Concentrators?


Did you not find the answer to your question? Send your question to Knelson to have a representative contact you with your answer.

Share Your Knelson Experience
"We are extremely happy with the performance of the ACACIA (ConSep ACACIA Reactor). Not only have we seen improved efficiencies, this technology has enabled us to discard the use of mercury for amalgamation of gold in concentrates, thereby achieving a great advance in our strategy of eliminating environmental and security risks. This investment demonstrates our commitment to the business of gold mining in Zimbabwe, and we continue to believe that given the appropriate economic dispensation, gold mining will prove to be one of the industries that will lead an economic turnaround in this nation." - commenting on the payback of the first ConSep ACACIA Reactor in Africa. - Mike Marriott, Managing Director - Independence Gold Mining (Pvt) Ltd, How Mine, Zimbabwe ...more > >
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