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. ■

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? ■

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. ■

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.

Regards

KS Dilip

Chennai ■