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Removing Cobalt

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Removing Cobalt

Removing Cobalt (free & chelated)  From Saw

  Grinding Coolant

Removes 11.5 grams / Liter (1.6 oz. / gal.) 


We received one liter of coolant that the saw mill said was “used but clean”. First, we filtered it and got 2.4 grams of sludge. Then we added cobalt remover and filtered again. We got another 6.8 grams. Finally we used a fine filter (equivalent to our CP 2002 series filter units ) and got another 2.3 grams.  View some of are articles on Machine Coolant filtration to see the importance of filtering Machine Coolant and when it is necessary to Fine Filter.

The saw mill said the coolant was “Used but clean.” We filtered out 11.5 grams from 1 liter. 9.1 grams of that came from the use of cobalt remover.





This much sludge from this bottle

Magnetic due to Cobalt

Filter Cake

Background: Coolants typically dissolve the cobalt matrix out of tungsten carbide during saw sharpening. This situation can be greatly improved by coolant filtering. However coolant filtering also means that coolants will only be changed once or twice a year.


Laboratory tests show that there can be considerable coolant chelated (dissolved) in coolant after six months. This is also visible with clear coolants as the cobalt typically imparts a reddish tinge.


Test Procedure: We took 1 liter of coolant that had been filtered constantly at the grinder using a 25-micron bag followed by a ten-micron cartridge filter. We filtered this with a vacuum filtration setup using a filter paper in the 1 - 2 micron range and got a good coating of grit on the filter paper. We then added the cobalt inhibitor and filtered using a 30-micron filter. We got a huge amount of material out. The filter cake was about as thick as a penny. Finally we filtered the coolant with a filter in the 1 - 2 micron range and got a nice covering on the filter paper.


Test Results: The first filtering got out all the very fine grit. The cobalt inhibitor extracted the cobalt from the coolant and formed it into large, sticky clumps that could be readily filtered out. The results are very visible.



This product is intended for use with water based coolants. We believe that it may be effective with any coolant but we do not guarantee this. Many grades of carbide contain cobalt, which can leach out of the carbide matrix.


Cobalt Inhibitor / Remover will combine with any free cobalt in the coolant to form a powdery white solid. This white solid can then be filtered from the sump, effectively removing cobalt from the coolant. Cobalt is a heavy metal, and cobalt in high levels of metalworking mists can cause long-term respiratory problems.  See our article on Machine Coolant Health and Safety for possible health conditions that can result form cobalt exposure.


Directions For Use:

As a preventative measure, add 4 ounces of cobalt inhibitor for every 8 gallons of sump capacity. Maintain coolant flow throughout machine. Allow 30 minutes for powder to form, and filter accordingly. High levels of cobalt in the coolant will make the coolant appear reddish-brown. Repeat addition of cobalt inhibitor to coolant until color returns to normal or until addition of Cobalt Inhibitor / Remover no longer creates white powder.


Materials Compatibility
Safe for all metals and plastics.


Dilution Ratio
10:1 up to 30:1 - depending on application


Physical Properties
Appearance: Viscous amber liquid
Specific gravity (conc.): 1.09
Density (concentrate): 9.09 lbs./gallon
Total chlorine: 0.0%
VOC level: 0.0%
Flash Point: 2240 F
Boiling Point: 369 F
Mineral Oil Content: 0.0%