Why is there wood in my coal?

We live in Ireland. When we are in Dublin, we burn smokeless fuel to prevent air pollution.* However, at the mother-in-law’s house beyond the Pale, the coal supplied is ordinary coal from Poland.

Occasionally I find a small piece of wood in the coal. When I was young, I believe most coal sold in ireland came from the UK. Even then, I remember sometimes seeing a small piece of wood in coal.

The wood is a tiny percentage of the volume, so no one is trying to cheat us by diluting coal with wood. As coal is sold by weight not volume, it would not make much sense to try that. In any event it is a very small volume, and seems like an impurity which finds its way into coal.

This wood is the only impurity that I see in the coal. Otherwise, it is pure chunks of carbon as mined from the ground - no bits of plastic or stones or pieces of miner.

Where does this wood come from? is it pulled in during the mining process? Surely they don’t use wooden props in mining today?

Or does it fall in somewhere in the transport process from the Polish mine to me?
*I remember the choking fogs of Dublin’s past, and I still offer thanks to Mary Harney for her courage in forcing through clean air in the face of vicious opposition from vested interests. A lady with guts, who got shafted by the vested interests in the Health Service. But that’s a different question.

I think you’re a little confused about the difference between coal and charcoal.


Can you post a picture? Some lower grade coals can have identifiable fragments of fossil wood in them, which are carbonized but still look an awful lot like regular old wood.

:confused: Why do you think this?

I don’t understand what you mean, either. In case there is some difficulty with the USA-ian dialect, I am talking about coal - the black lumps of carbon from ancient forests that we mine from the earth and burn.

Charcoal is a different thing. As charcoal is produced from wood, there would be an obvious explanation if an unburnt piece of wood survived in charcoal.
@ Greasy Jack -

No, this is just bits of wood, sitting in the coal, usually similar in size to the chunks of coal. It’s not part of the coal, but has become added to the coal at some point. It’s heavily stained with coal dust, so it has been with the coal for some time before it arrives to us.

I guess I’m wondering why wood is the only alien material which appears every now and then. Obviously they have a process to keep it clear of other material, but wood gets into it now and then.

I expect it’ll be because the coal has at some point been stockpiled in a yard that has been used for storing palletised or crated goods, or just piles of firewood or timber waste - and that some fragments got introduced that way.

That is to say: I expect the majority of the coal from which your supply was drawn is being mined for feeding power stations - and it may be that those power stations are also being fed waste timber from sawmills and paper mills - probably stacked separately in heaps, but not separately enough to prevent a measure of cross-contamination.

LOL! In voltaire’s defense, there would be many, many, Americans who *would *be confused at the difference. The vast majority of Americans have never seen a piece of coal.

I think the coal is probably dumped in a large pile at some point of the sorting process. (Chunks of different sizes are sold for different uses/prices.) In the course of bulldozing/scooping them up some yard waste crept in. Do the pieces look like mulch perhaps?

Michael of Lucan, my first WAG was the same as Greasy Jack’s: after all, coal is made from wood same as charcoal, the process happens to take much longer and involve no human intervention (except for the mining) but there can be bits of wood in coal which are as old as the rest of the coal. They’re leftovers of the big pile of wood which eventually became a big pile of coal.

I’ve seen bits of coal in which the structure of the original plant material was still discernible, but I think it would be pretty unlikely for a piece of it to still look and feel just like grubby, but ordinary wood after hundreds of millions of years.

No, it’s certainly not ancient material. It’s just small chunks of wood from the present.

Am I the only person who finds them in coal occasionally? Hmm. That worries me. Maybe there’s a film in this, “Eighth Sense”. I can already hear the key line, “I see dead trees. . .”

My parents burn coal as a supplementary fuel source through the winter months. As a youth, I spent many an hour feeding or shaking down that coal stove - enough that I’ll never have one in my house. We used pea-sized anthracite coal, if that makes any difference.

That being said, I’ve seen plenty of wood chunks in the coal. They were pieces of wood, not fossils or wood-shaped chunks, actual wood. I used to just send them down the hopper along with the rest of the coal. I recall there being sticks and what looked like broken pieces of cut lumber. None of the pieces were more than four or five inches long or an inch or two wide. They were, of course, covered in greasy coal dust, and stained pitch black.

We had our coal delivered from a coal company, all they did was move coal. You couldn’t get wood from them, so that would exclude contamination at the storage site. I had grown to believe that it was from one of two sources. For the cut lumber, I had thought parts from the timber shoring in a coal mine that were broken off as the coal came tumbling past. Sticks I attributed to stuff falling into the gondola cars of the train that delivered the coal to the coal distributor. Of course, I was about 10 or 12 years old when I came to that conclusion, so take it for what it’s worth.

This probably what you are seeing. They use alot of timber in underground mining and it is pretty common to find pieces in the coal. They not only use it for roof shoring as shown here:

But also for the rail beds.

Here is a site with pics taken from an actual working coal mine that has been turned into a museum. You can actually go underground and see what it was like to work in the mines. The pics show the extensive use of timber in the mine.


The OP didn’t confuse me. Of course, I’m from Pennsylvania, so I’m well acquainted with coal. My grandfather even had a coal furnace back in ancient days. He had a coal bin which the coal truck would fill via a chute from the street.

And I’m not admitting to anything, but Santa may have left the occasional lump of coal in my stocking on more than one Christmas Eve. :smiley:

If coal is sold by weight, there must by some mechanism for sorting relatively low density, light, burnable coal from heavy nonflammable rock. Maybe the sorting system can’t differentiate between the density of coal and wood.

I’m sure there are ways in which it is sorted, but as a quasi-nitpick: in my experience, coal is not especially lightweight. It feels like cold, heavy, dirty rock.

Is it just me, or does anyone else get excited when they see a coal question and then keep checking back every few minutes to see whether Una has answered yet?

my roomie is a farrier, i hear discussions about exactly which damned mine a particular lump of coal is from

How is that for obscure?!

Perhaps the railroad companies aren’t doing a good job of maintaining the right of ways and some low hanging branches are getting knocked into the coal cars.

A tarrier, perhaps?

Not part of daily conversation for most of us, but that’s what “number nine coal” in the song “Sixteen Tons” refers to – from here: “Geologists number regional coal seams for reference. There is a ‘Number 9’ seam in Kentucky, Pennsylvania, Virginia, and Ohio…” (the vein of coal), and here one of the mines.