#Coal mining
9 messages in this thread
I've got a question about coal mining, and I thought I'd ask here for lack of
anywhere better. <g>
My impression is that these days, most US-produced anthracite coal (aka "hard"
coal) is mined in the Western states, and most of the coal mined in the East is
bituminous or "soft" coal. Am I correct in this? If not, what's the actual
distribution of anthracite coal mines vs. bituminous coal mines?
Thx in advance for any replies I get.
Jon W.
Jon:
Re: "Hard" vs. "soft" coals. I think that it is just the opposite of what
you stated – anthracite is (or was) much more common in the Eastern states
(i.e., Appalachia), because those coal measures were mostly in older rocks that
had suffered some degree of metamorphism. Out West, most of the productive
coal measures (I believe) are Mesozoic in age and by & large have not been
subjected to prolonged heat & pressure like good ol' West Virginia anthracites.
You might try posting your inquiry in the Earth Forum's "Energy" section. On
occasion, a New Mexico coal geologist lurks around there.
Cheers,
Scott M.
Scott,
>> Re: "Hard" vs. "soft" coals. I think that it is just the opposite of what
you stated – anthracite is (or was) much more common in the Eastern states
(i.e., Appalachia), because those coal measures were mostly in older rocks that
had suffered some degree of metamorphism. <<
I agree that sounds logical. But as best I can tell from the very general
references I have (MS Bookshelf and a 1992 CD-ROM encyclopedia), the
coal-mining Eastern states like Pennsylvania, Kentucky, and West Virginia
produce mainly bituminous coal.
It also seems that coal of any grade can be found in any age rock. There's
bituminous coal in the rocks of southeastern Ohio, which I believe are of
Pennsylvanian or early Permian age. Kentucky is almost exclusively
Carboniferous and older rocks, but it produces some lignite. And you can find
high grade anthracite in Cretaceous and even Tertiary rocks.
Jon W.
Jon,
It may be even more complicated than east = hard, west = soft. In
Pennsylvania, the anthracite was mined in the east in the Scranton,
Wilkes-Barre, area of the Pocono Mountains. This coal, as you know, had a high
silica content. These mines are now kaput.
In Western Pa., in the area around Pittsuburg, there are still operating
mines in bituminous coal seems. I don't recall the silica contents of the east
and west Pa. deposits, but they are quite different. They did undergo rather
different degrees of metamorphism.
Nathan
Nathan,
In fact, one of those old Pennsy anthracite coal mines has been turned into a
tourist attraction, complete with an operating mine-tunnel train. My family
went there on a vacation once, many years ago. Can't remember the name of the
place, though.
Jon W.
Further to the replies you've already received — there is quit a bit of
production these days from Alaska, I believe. I dont know much about it.
Regards, Dick gibson
Hello,
From what I understand most of the anthracite came from Pennsylvania, though
there are a few small deposits in the Rockies. There is not much anthracite
left, and very little mined today. What is mined is typically used in
metallurgical applications. The western coals are typically lower rank, and
thus softer coals, alot of lignites and sub-bituminous coal is mined out west.
The eastern coals are typically bituminous coals, therefore they are harder.
Some of these harder coals, particularly the low and medium volatile bituminous
coals are now being used in metallurgical applications as well.
I hope this helps.
Steve Brooks
Steve,
It does help. Thanks.
One more question: Of the different ranks of coal mined in different parts of
the country, which are high in sulfur content and which are low in sulfur? I
thought that rank was basically a measurement of the purity, so the lower the
rank, the higher the content of impurities like sulfur.
Jon W.
Jon,
Coal rank is more a function of coal age, more than purity. The ranking system
is based on carbon content for the higher ranked coals, and BTU for the lower
ranked coals. The older coals have had more time to undergo coalification, thus
has had more of the water squeezed out. The lower rank coals in the west are
known for their low sulfur content. Generally western coals have less sulfur,
while eastern are typically higher. For all practicle purposes the Illinois
coal basin coal have the highest sulfur content. These coals include Illinois,
Indiana, and Western Kentucky. There are alot of low sulfur eastern coal
reserves as well, but as they are typically more expensive to mine, thus
western coals are prefered cost wise.
Lower ranked coals normally contain more moisture, and less BTU's than higher
ranked coals. As the moisture is locked into the structure, it cannot be
romoved, so when transported you are shipping less coal than if you had a
higher ranked coal. Ash, the unwanted parts of coal varies from coal to coal.
Higher ranked coal can be just as high in ash as lower ranked coals. Ash can be
cleaned out of a coal to a limited extent. Often this cleaning will take out
some of the sulfur. This activity is called coal preparation, and is an
important activity in some coal mining operations.
Steve Brooks