Originally Posted by s.chattopadhyay

Dear members,

Do you have any idea how to handle coal (Indonesian) with inherent moisture of 17% and arb moisture of 40-45%. Does this type of coal chokes chutes or cause belt slippage or difficulties during unloading from wagons.

Chattopadhay

Dear Chatterjee,I think you have a valid point.Our so called intelligent importers are Importing coal from Indonesia with High Moisture contents and paying 30-40% of the freight to carry water only which does not have any commercial value.Now, they are thinking to put dryers before loading of coal.The position is getting bad day by day by increasing in freight prices.

Please provide us some more details with existing arrangement.You will have to modify your unloading pit and extraction arrangement a little bit.

Regards, Anil

www.libranengineering.com ■

Originally Posted by anil seth

.....Our so called intelligent importers are Importing coal from Indonesia with High Moisture contents and paying 30-40% of the freight to carry water only which does not have any commercial value.....www.libranengineering.com

Don't bite the hand that feeds you.

If it wasn't for the clowns in commerce there would be no need for much of our remedial activity. ■

Namaskar S. Chattophaddyay

you have not provided sufficient detail about your problem and that of course is

the muddy rugby pitch.

Asking is fine but you have not examined what informationis available in coal preparation methodology.

No trying to steal Louis or Anils excellent points;

Unfortunately for me anyway there is a tremendous amount

information missing from your inquiry to us.

Including;

What type of fuel coal ? is it highly volatile low btu steam coal or a higher grade metallurigical grade coal?

How friable of a coal is it?, the easier it breaks the more water it wil attract.

How much coal dust is delivered with the product?

Is the coal stored on the quay for weeks at a time in the open?

Who is the bulk carrier from Indonesia to the subcontinent?

Is the bulk carrier employing conventional deep water bulk carriers or ocean going barges?

If ocean going barges are useed are they uncovered or susceptable to wash over when fully laden?

Have you checked for sodium chloride content to determine if the moiture is from salt water?

Is lightering employed to allow transhipment for shallow draft vesses or barges

when the cargo arrives?

What of the weather conditions when the cargo arrives, is it raining?

It honestly sounds as if you are simply not doing any coal preparation at all using

the coal from Indonesia with nothing other than transport to the stock pile if the

system has one.

If the coal in question is highly volatile thats much of the problem as you will

require a coal washing and preparation plant prior to stock piling or end use

which appears to be what your operation entails.

A coal preparation plant will solve most if not all your issues at the end use point

where drying the coal prior to ocean shipment will not.

A coal preparation plant will-

a. crush the coal to a uniform size

b. screen the oversize coal for recrushing

c. wash the coal to free it it of any dirt and oil

d. the coal will be pumped through hydrocylones and screens

floatation thickeners and use desilting cones to remove any excess moisture

and clay or oil sludges.

e. the coal prep plant will properly treat the used wash water to be reused

if desired and have an oil recovery system using settling ponds and oil

skimmers using stripping tapes which attract the oil to the tape and then strip

it from the tape to be disposed of and or burned as a fuel adjunct.



The coal is typically centrifuged as well to remove additonal moisture at the

coal preparation plant.



As you seem to want the problem solved you should examine the problem fully as it seems to be your operating methodology which is at issue here.

Help us, to help you, to help us to help you.

lzaharis ■

The way to handle wet coal is to measure the wall friction and shear strength and design hoppers and chutes accordingly. I suggest that contact be made with TUNRA at Nexcasle University in Australia, who have substantial experience in coal testing, because of their experience in this area and the flow properties of coal can have a large degree of variation. ■