Laboratory Products

The Cyclosizer – Classic Version

MARC is now the manufacturer of the Cyclosizer (Originally known as the Warman Cyclosizer). 


M15 Cyclosizer

 M16 Cyclosizer





Use the »Calibration Tool« to check your Cyclosizer’s Performance!



The Background to the Cyclosizer

The Cyclosizer is a laboratory precision apparatus for the rapid and accurate determination of particle size distribution within the sub sieve range. Each machine is calibrated individually before it leaves the works and typically separates at around 40, 30, 20, 15 and 12 microns. The Cyclosizer was developed for the mining industry, and a feature of the Cyclosizer separation is that it returns the size fraction for assay or microscopic examination so that information on liberation sizes can be gathered. The operation of the Cyclosizer is robust so that although some operator skill is required, it is less sensitive than some other competing processes that do not produce size fractions for examination.

Particles are separated according to their Stokes equivalent diameter and in this sense differ from say mesh screen sizes, which rely on whether or not a grain will pass a square aperture. Thus when plotting the sizing results there is often a small inflection in the graph associated with the change in sizing principle. When a Cyclosizer sizing is plotted against sizings using other techniques, there is generally a small parallel shift for each technique that is a function of how the technique defines particle size.

Because the Cyclosizer uses the Stokes equivalent diameter, the fractions produced are specific gravity dependant. It is convention to express the sizings as quartz equivalents, but in reality, these sizings need to be corrected for variations in specific gravity. Corrections are calculated as part of the standard operating technique. Although a sizing may use an average specific gravity it is possible for discrete minerals to be classified separately. For instance in the first cyclone that separates at say 40 micron quartz equivalent this will also capture a 14 micron gold grain. Thus heavier minerals report to higher cyclones in the configuration.

Machine life depends on usage and the environment but it is not unusual for the working life to exceed 25 years.


C5 Overflow Settling Decanter

In certain tests it is commmon practice for the ore sample to be “pre-cycloned” or “deslimed” with a standalone single-cyclone C6 rig, and/or for the overflow of the Cyclosizer’s C5 (the last hydrocyclone) to be collected, decanted and filtered. This is for the extraction of the -C5 fraction of the sample for mass balancing and/or chemical analysis.

MARC can offer a settling & decanting system for use with the Cyclosizer to reduce the manual handling associated with the extraction of the ultra-fine component. This system also allows for water to be returned to the Cyclosizer feed tank if water consumption is a concern. 

Contact us for more information.



Cyclosizer Ordering/Purchasing Details

For all countries except Russia feel free to contact us directly via the Contact Us page or email us (click)


For all Russian market inquiries please contact our formal distributor for Russia:

   Dmitriy Zhiltsov – Eniseylab Ltd.



Any inquiry for a Cyclosizer should include advice of the single-phase power supply rating and the frequency required. The machines are supplied with either a 50 Hz or a 60Hz pump/motor assembly. The machines are supplied ex works in a crate measuring 1680mm long, 2000mm high and 590mm deep, and weighing nearly 400kg.

We also offer the Cyclosizer in a 316SS cabinet at a nominal upgrade cost. This is highly recommended as complete refurbishment after years of operation is definitely more viable if the cabinet is still corrosion free. 


There are 2 versions of the M16 Cyclosizer – Mild Steel & Stainless Steel Cabinet –  available in either 50 or 60Hz.


Cabinet Voltage (V) Frequency (Hz) Stock Code
Mild Steel     

(To be Discntd in 2020

220-240 50 120740 (default)
60 188950
316SS 220-240 50 189853
60 188949


Please address your enquiry to us via the Contact Us page or email us (click).

To reduce cost and turnaround, customers are advised that freight requirements would be better handled by the purchaser. Lead-time depends on demand but can be up to 12 weeks from order.


Current Stock Levels

Stock Code Description Qty Currently in Stock
120740 Mild Steel Cabinet 220-240V/50Hz 0
188950 Mild Steel Cabinet 220-240V/60Hz 0
189853  Stainless Steel Cabinet 220-240V/50Hz 0
188949  Stainless Steel Cabinet 220-240V/60Hz 0

For Cyclosizers not in stock a 12 to 16 week lead time applies. 


Spare  Parts

MARC maintains an extensive spare parts stock and most parts can be supplied ex stock on a quick turnaround. Consumables depend largely on the usage of the machines, but there is generally no call for spares for at least 10 years and then it is only for perishable items like gaskets etc.  

Some changes have occurred over the years to parts used, the most significant of which are the change from a two part glass cyclone assembly in the original Cyclosizers to a one part poly-carbonate cyclone assembly in the newer machines as well as a change in flow meters.

These changes have led to new model numbers being produced and after some 40 years of manufacture we are now up to model 16.

*Shipments to Central and Southern America: Due to abnormally rough handling by couriers in those regions all shipments will be packaged in a crate and increased packaging costs will apply (this does not include shipments consisting only of gaskets and calibration silica). 



We often get requests for refurbishments of old units and sales inquiries for second hand units so please feel free to send us your enquiry. Also if you have a unit that you want to get rid of then please contact us – we can possibly find you a buyer.


Product Development

At MARC we are continuously looking at ways to optimise our product range based on our client’s needs. The next development is a 6 cyclone Cyclosizer. While it is not intended to replace the well known and “classic” 5 cyclone Cyclosizer it will be an option that will be useful for those looking to reduce or eliminate the need for a separate pre-cycloning step.

Unlike copies of the Cyclosizer that have a 6th cyclone before the standard C1 that produces a larger particle size cut – we have added a C6 cyclone to produce a smaller particle size cut. This is because the original intent of the Cyclosizer was to provide the user with reproducible sub-sieve fractions. Our competitors produce an additional fraction – which at first glance seems to offer the potential buyer more –  but that fraction is in the sievable range and so please be careful when buying.  



Respirable Dust Measurement

The Cyclosizer’s C5 hydrocyclone and its underflow provide a low risk means of collecting larger samples of respirable size particles from a 30g soil, road or crushed ore sample without generating dusts in the test.  

At silica’s SG of 2.65 the Cyclosizer will generate a sub-sample of a mean particle size between 14 and 12 μm, the underflow will be smaller. Since the sample is run wet there is no exposure of the technician to dust particles (aside from sample weighing). The sub-sample can then be filtered (or settled and centrifuged), dried and analysed via XRD. 



Manuals, Tools, Etc. 


Quick Reference Table – Temperature Correction factor



Cyclosizer Run Sheet


Click Images Above to Open


  • For a manual for your Cyclosizer please contact MARC via the Contact Us page. 
  • For the online Calibration Calculator please Click Here.
  • For the online Correction Factor Calculators please Click Here.