Grinding & Classification Circuits

Grinding & Classification Circuits 2017-04-04T06:57:16+00:00
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Dry Grinding Aid (6 replies and 3 comments)

Maya Rothman
2 years ago
Maya Rothman 2 years ago

Can anyone help me regarding the usage of a dry Grinding Aid & Dosing Pump for grinding of Ground Calcium Carbonate?
I am planning to use grinding aid and require assistance for choosing correct aid, pump and dosage.

Bob Mathias
2 years ago
Bob Mathias 2 years ago

For grinding aids to be used for calcium carbonate processing is from a supplier called Technochem. The grades which are used are the 252 (for for fine and standard finenesses) and TC 121 for superfine products. The dosage depends highly on the product fineness and the milling system type. Usually for products coarser than 20 microns, it's not necessary to use grinding aids.
For the pumps used, there are plenty of manufacturers and types. A general type is a diaphragm pump.

Tony Verdeschi
2 years ago

Can we use for dry grinding of iron ore, preparing pellet feed need -45 micron 85 % is there any help of using grinding aid in mill performance and throughput?

Victor Bergman
2 years ago
Victor Bergman 2 years ago

For dry grind you don't need any chemicals. Fan above grinding unit will do the work of size separation. Few such dry grinding equipments are, A. RAYMONDS MILL, B. METSO Make verti-stirred mill, with dry cyclones.

For these grinding there is no need for dosing pumps, only air is used as medium. Blower is used for blowing air.

In Rajasthan many do such processing. But they use CaO + Moisture to make powder and then do classification in cyclones. Grinding may be done or not depends on market requirement.

You can do grinding up to 2 micron.

Bob Mathias
2 years ago

I am sorry but I guess you have misjudged my query. I am looking for Grinding Aid & not air separators. Anyways thanks for your input.

David Kano
2 years ago
David Kano 2 years ago

On the grinding aid selection it is critical you understand the application of the final product first. If it is being used in the food processing industry or as a lubricant in electrical cables will determine the additive, and more importantly the properties of the additive.

For pumps I would recommend using either a rotor-stator pump if constant flow is needed (vsd pumps with feed control) or alternatively use a diaphragm pump. My reference is the diaphragm pump as they are very robust, and these pumps are generally neglected and have relatively poor housekeeping.

John Koenig
2 years ago
John Koenig 2 years ago

I'm in the field of calcium carbonate processing for 20 years. As I informed you earlier that for products higher than 20 microns insize, you don't need grinding aids. While for finer products, you definetely need it. It comes absulutely necessay when you process products below 8 microns. The dosage rate is really different from a plant to a plant as it depends on the raw material (limestone or marble/ metamorphic) also it depends on the grinding media size used in your mill. For example, a product of D50=2 microns, you may need to add 1.0 liter per ton.

John Koenig
2 years ago

The issue hear is about a liquid chemical to remove the electrostatic charge and the Van Der Waals forces which is resulting when grinding a product to the micron and sub micron range.
At fine grinding, there is a great tendency for particles to join back together forming agglomerates or branch particles in which the classifier efficiency drops down if no grinding aids chemicals are used to over come these forces. Usually grinding aids improve the fines recovery by 10-20%.

1 year ago
Arif 1 year ago


Did you finally try any grinding aid..
Please share your experience

1 year ago
David 1 year ago

Hi Arif, am not if Maya is around but here is a report you may find useful

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