Coal fines Agglomeration

[kudzi]

I am a junior Chemical engineer who has been tasked to find a scheme of reclaiming coal fines which have been and are currently been generated in our plant. The sieve analysis of the coal fines is given below.

Screen Analysis %

+2000µm 18.2
+1000µm 11.5
+850µm 2
+500µm 12
-500µm 56.3

Moisture 1.50%


I have tried pelletisation using burnt lime as a binder but the pellets produced where not strong enough for as they crumbled during conveyance to the smelter.

The agglomerates formed are supposed to be reusable and must be tough enough to withstand both abrasive and compressive forces of up to 1 bar, and must have a mean diameter of 20mm.

I would be grateful for your inputs

 

[YouthfulEngineer]

you have a lot of < 500 microns sized particles. would additional moisture not be a good binder? more agglomeration rather than pelletisation. Just a thought. It may affect your combustion with the higher water content. Is there any other liquid binder you could use on site? diesel/light oils?

 

[cheme6540]

Have you considered briquetting? The economics would not be as favorable as pelletizing but the pellets/briquettes would be stronger depending on the binder used. If the coal is hydrophilic water would not be a good binder, but I have seen that a little molasses solution (which is sold as an additive for animal feedstocks) can be effective and would not have a detrimental effect on heating value.

 

[kudzi]

thanks youthfull engineer but water addition is not an option as the moisture content has to be at the absolute minimum. I had actually taken up Cheme6540 approach and had already contacted some briquetting machine manufacturers for quotes.

all the sam thanks a lot guys