hard vs soft coal

Scottscoaled wrote:I don't think that is the case. A perfect ton of coal would be a square block. As soon as it is broken in half it takes up more room. That keeps going. As the pieces get smaller, they weigh less, have more surface area, and take up more volume. I know a ton of nut in a pickup bed takes up considerably less space than a ton of rice.

Hmmm.. I think this topic has been debated before with split opinions
I have an Uncle thats burning rice. I'll see if I can compare buckets..
It would depend on settling too.. When I haul 55 gallon barrels of nut size, by the time I get home the level in each barrel is a couple inches lower than when I left the dealer. Lotsa variables again hahahaha... I'm sure its pretty close..

http://wiki.answers.com/Q/What_is_the_density_of_coal

- Coal, Anthracite, solid 1.506 gr/ml
- Coal, Anthracite, broken 1.105 gr/ml

- Coal, Bituminous, solid 1.346 gr/ml
- Coal, Bituminous, broken 0.833 gr/ml

Cool, so yeah, I guess bit is a little lighter than ant.. Good find McGiever

Lightning wrote:- Coal, Anthracite, solid 1.506 gr/ml
- Coal, Anthracite, broken 1.105 gr/ml

- Coal, Bituminous, solid 1.346 gr/ml
- Coal, Bituminous, broken 0.833 gr/ml

Cool, so yeah, I guess bit is a little lighter than ant.. Good find McGiever

A little???? Almost 33%. I wish I had a little more coal out in the barn right about now. Just kidding. That has to be an European thing because the people I listen to measure in oz/lbs.

When I fill 5 gallon buckets with Bituminous Coal they weigh 34# and the same bucket filled

with Anthracite Coal they weigh 37#.This is done with nut size coal.So the Anthracite is about

10% heavier,therefore it occupies about 10% less space than Bituminous Coal,then if ~40 cu. ft.

is one ton of Anthracite a ton of Bituminous would occupy ~44 cu.ft.

The smaller the size would increase the space needed to store coal.It is not a great amount of

difference anyway in the small quantities we are dealing in.

BigBarney

The smaller the size of coal the less air space between the peices of coal. So if a solid block of coal weighs a ton and is 40 cubic feet, a ton of coal dust will also occupy 40 cubic feet. Because there is little to no room for air in either ton of coal.

That's my line of thought too Carl

You can lead them to water but you can't make them drink.
A solid block of coal. Takes up so much space. crack it in half, and it all ready takes up more space. Take the two halfs of the original block, crack them in half. They too take up more space. All this is if they fit back together perfectly. Once they become misaligned, they take up more space. That drama keeps going. As much as you would think they "pack together", they really have all ready taken up more space, and have more surfaces that are misaligned. Basic physics. One extreme to another. From more to less. This case it's more dense to less dense.

You have to remember that a solid block of coal has (zero) 0% air so it is always

heavier as "scottscoaled " has said. You cannot beat 0%.


BigBarney

You are indeed correct my friend.

In the earth moving world what you describe is called "Bucket Swell". That is, when you drive a bucket loader into say a gravel bank, and then back out, because the gravel in the bucket has been loosened and not as compacted as it was in the ground, it swells.

The best way to buy any earthern product is by tonnage, but at least here in Maine, rock, gravel, sand, etc is still sold by the yard, which is an inexact science, but change is hard in that industry.

Road builders get run into "Bucket Swell" a lot when they are making cuts and fills for new roads. When they calculate a cut through a hillside,they must automatically make a 15% increase in the amount of fill moved because of bucket swell. It can make the difference between profit and loss, which was posted in RG LeTourneau's book when he failed to do this and paid dearly when he built the road to the Hoover Dam (Boulder Dam then).

Scottscoaled wrote:You can lead them to water but you can't make them drink.
A solid block of coal. Takes up so much space. crack it in half, and it all ready takes up more space. Take the two halfs of the original block, crack them in half. They too take up more space. All this is if they fit back together perfectly. Once they become misaligned, they take up more space. That drama keeps going. As much as you would think they "pack together", they really have all ready taken up more space, and have more surfaces that are misaligned. Basic physics. One extreme to another. From more to less. This case it's more dense to less dense.

Paulie wrote:Studying for my engineers license, and was surprised to learn that soft coal actually had a higher btu value than hard? Who knew?

Depends, anthracite can go as high as 28 million AFAIK. Perhaps even higher. Same thing with soft coal.

To the best of my knowledge the BTU value of anthracite doens't dip below the low 20 million BTU area while soft coal for example from the Powder River Basin is around 18 or 19.

I can assure everyone that the smaller the coal size the more space it takes. This is 5 ton of buck:



If that was barley it would barely fit on the truck, it would be stacked up another 4 or 5 inches. If it were nut you would barely see the top of it. If it were stove coal you wouldn't see anything becsue it would be a few inches below the sides. If you were using volume to compare barley or even rice vs stove coal it would appear you were missing about 1 ton with the stove if you were using the barley as your baseline. It's that much of a difference.

carlherrnstein wrote:The smaller the size of coal the less air space between the peices of coal. So if a solid block of coal weighs a ton and is 40 cubic feet, a ton of coal dust will also occupy 40 cubic feet. Because there is little to no room for air in either ton of coal.

Carl you have trillions of pieces of coal with micro air pockets. Matter of fact this is why fine coal is preferable to sand for water filtration because it doesn't clog as easily. The smaller the coal gets the more surface area of the coal to produce those air pockets. If you vibrated it down you might be able to get the same volume as the larger pieces, if I was going on long road trip I would lose a lot of volume. It's like where the coal go? It's just like flour, there is huge difference in volume of sifted and unsifted flour.

I had not thought of how the peices of coal could be fluffed up.