Single Stage Crushing

Posted in: , on 24. Dec. 2010 - 06:07

Single Stage Crushing from -400 mm to -25 mm

Dear experts,

Please suggest me a single stage crusher for the following application.

Input : -400mm (sieve analysis not available)

Required output : -25mm (98%)

TPH : 1800 TPH rated , 2000 TPH Design

Material : Imported Coal

Moisture content : 35%

Fines : new fines generated due to crushing shall not exceed 15%

Single Stage Crushing From -400mm To -25mm

Posted on 24. Dec. 2010 - 01:03

Dear Experts,

Can u please suggest a single stage crusher for the following application

Material : Imported coal


Fines in Input : 40%

Input Size : -400mm ( Sieve analysis not available from client)

Out size required : -25mm (98%)

Output fines : Newly generated fines < 15%

Re: Single Stage Crushing

Posted on 24. Dec. 2010 - 01:40

Threads merged into one as there is no need to post twice on the same topic. It only confuses others that would like to help you.

You are asking for a 16:1 turndown ratio which is very large in the crushing world and would be very inefficient. You may want to consider a two stage crushing system.

Rule of thumb is 6:1 turndown for highest efficiency.

Gary Blenkhorn
President - Bulk Handlng Technology Inc.
Linkedin Profile:

Offering Conveyor Design Services, Conveyor Transfer Design Services and SolidWorks Design Services for equipment layouts.

Single Stage Crusher

Posted on 25. Dec. 2010 - 11:51

Your rejection of fines exceeding 15% is not defined. GIven the top size of the product is 25 mm, can you provide the cutoff size defined as fines?

As Gary says, 6:1 is typical for reduction ratios of common comminution stages. However, there may be machines that can do your specification. Are the fines cutoff on a typical Rosin-Ramler curve? DO you scalp the -25 mm product before crushing?

Lawrence Nordell Conveyor Dynamics, Inc. website, email & phone contacts: phone: USA 360-671-2200 fax: USA 360-671-8450

Re: Single Stage Crushing

Posted on 27. Dec. 2010 - 06:43

Dear Nordell,

Thanks for your reply

1. Yes, we have a vibrating grizzly screen before the crusher to eleminate (-)25mm.

however, the crusher has been sized considering 100% feed (blanked grizzly).

2. (-)1mm is considered as fines.

We have received a crusher offer and we are still enquiring about the amount of fines generated.

Please advise if there are any reference installation similar to the above application.



Coal Etc.

Posted on 28. Dec. 2010 - 12:18

The only way to really eliminate fines as an issue is

to install a compactor pelletizer to make use of them.

So is it safe for me to assume that you are not using a

pulverised coal boiler system?

Ideally you simply want a high tonnage per hour "Coal Sizer"

with twin sizer rolls to break the coal and then dealing with

a vibrating grizzly is no longer an issue as it can be eliminated.

The fines can be compacted or extruded with a binder such as oil

to aid in the extrusion process. to the size you would require for

coal feed stock.

There are more than a handfull of coal crusher sizer builders that

maintain a world wide presence on all continents except Antartica

and Greenland.

Single Stage Crusher

Posted on 31. Dec. 2010 - 04:06

Dear lzaharis,

The system has a pulverised coal boiler only, but the restrisction for fines is to avoid the dust nuisance in the stock yard and in the conveying system (Present after crushing). Client is more concerned about this because input coal itself has fines of about 40% and also the plant falls with in the city limit.



What Is The Feed Size?

Posted on 31. Dec. 2010 - 05:48

Dear Sir,

You have stated that the material is imported coal and indicated the top size as (-) 400mm. Imported coal is received with a top size of (-) 50mm (90%) and 10% between 50 and 75mm.

The data if correct then it is both indigenous coal as well as imported coal.

Please clarify.


KS Dilip


What Is The Feed Size?

Posted on 31. Dec. 2010 - 10:44

Yes you are correct. But this is as per the input received from client.