Appalachian Blacksmiths Association

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Organized in 1978, the Appalachian Blacksmiths Association is an affiliate of ABANA. We represent blacksmiths, bladesmiths, and farriers in West Virginia and its surrounding states of Pennsylvania, Ohio, Maryland, Virginia, and Kentucky. 

We publish a quarterly newsletter which keeps our membership up to date on events. The newsletter also features many metalworking tips.  

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Appalachian Blacksmiths Association

© 2002-3

Nothing herein may be reproduced unless permission of the submitter and/or the Appalachian Blacksmiths Association is given.

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Coal is a fossil fuel and is classified into four types--anthracite, bituminous, sub-bituminous, and lignite.  Coal is found in seams (veins/coal beds) which vary from a few inches to 100' or more in thickness.  Depending on the amount of ground cover or overburden, the coal can be mined by the surface method (complete removal of overburden) or the deep (underground) method.  In some circumstances, the auger method was used; the perimeter of a hilltop was surface mined and the interior coal was bored using an auger, a large horizontal drilling machine.  The deep mine method originated with miners using picks and shovels to dig the coal (room and pillar method) and then loading it into small carts.  At one time, horses and mules pulled the carts from the miner (who worked at the face of the mine) to the adit (the entry portal of the mine.)  If a surface adit could not be made due to the depth of the mine, then a large elevator or a skip bucket brought the coal to the surface.

The individual coal miner in the deep mine was replaced by machines in the mid-20th century.  The continuous mining machine uses a rotary cutting drum to dig the coal from the face and convey it to a tram car (a motorized cart.)  Another machine using a large cutter bar (similar to a chain saw) makes horizontal cuts at the top and bottom of the coal seam.  

Mining methods are always changing as machinery and technology improve.  Today, huge draglines and power shovels remove entire hilltops to uncover coal seams.  Gigantic bucket excavators standing several stories high mine thick seams in some coal fields.  And underground, the longwall mining machine needs just three miners to cut a 500' wide swath through the coal seam.  With this system, there is no need to even prop up the mine roof--it is allowed to cave in behind the machinery.  Such advances in productivity are the reason why more tonnage of coal is mined in the USA today with fewer than 10% of the coal miners employed in 1940-50. 

Since coal was first mined in earnest some 150 years ago, the industry has been plagued with problems.  Thousands of miners have died in accidents, roof falls, and methane gas explosions.  With the advent of the continuous mining machine, many believe that the coal dust it generated is what is primarily responsible for black lung disease.  And there continue to be environmental concerns for the air, the surface and sub-surface waters, and the landscape.  But, coal has been and will continue to be indispensable for electric power generation and steel manufacturing for the foreseeable future.  Concerns about acid-mine water drainage, the greenhouse effect, or the disappearing horizon, will continue to occupy our environmental debates.

Coal's formation is always taught as the successive decomposing of organic material (vegetation) under extreme pressure.  In certain geologic ages, there were huge lakes and swamps where mountains now stand.  The Appalachian Mountains are a perfect example.  During the Pennsylvanian period of the Paleozoic Era, many millions of years ago, plants and trees grew in a great shallow sea and then fell and began to slowly decompose.  Then, over millions of years, sediment covered this "stew" and the weight of thousands of feet of sediment began compressing it into a carbonized layer known to us as coal.  The Pittsburgh coal is from this geologic age.  The mountains, on the other hand, did not rise until millions of years after the coal formed.

There may be more to the formation of coal than this simplistic "composting" theory.  Some scientists¹ have proposed that bacteria played a very important role in the development of all fossil fuels, whether coal, oil, or natural gas.  This is not so far-fetched as it sounds because we now use bacteria to "digest" crude oil from a tanker spill and render it into non-toxic waste.  Another type of bacteria could just as easily turn organic matter into oil or coal.  At least one prominent scientist, Thomas Gold, has proposed that these creative bacteria, or bacteria-like life, form a whole universe of hydrocarbon life deep within the Earth's mantle.  In the future, our knowledge of geology may change radically as we explore the depths of the planet.

As you will read, there are many different grades of coal, all with varying properties.  The main properties of coal that we rate are heat value, moisture, ash, sulfur content, and volatiles.  We mine different grades of coal for different reasons.  The coal from the Powder River Basin (Wyoming) was essentially worthless until air pollution emissions from power plants became a concern.  Then, the market for PRB coal surged as it is very low in sulfur.  Even when you factor in that you have to burn two tons of sub-bituminous PRB coal to equal the heat of a ton of bituminous coal, it is still cost-effective in reducing SO² emissions.  The Pittsburgh coal is valued for many reasons; a relatively high heat value, volatiles for chemical and tar making, and desirable coking qualities.  Other coals are valued as being "steam coals"; they provided a good flame characteristic and have less ash.  Steam coals fired industrial boilers, home furnace boilers, and train engines for over a century.  Whereas electric power plants preferred to burn one type of steam coal, they now blend different coals to reduce emissions. 

There are also ways to clean up or improve the various grades of coal.  The Kittanning coal is low in sulfur, but unlike the PRB coal that is found in 50'-100' thick seams near the surface, the Kittanning is found in 3 seams, each a few feet thick.  It is costlier to mine and also has the disadvantage of relatively high ash from slate in its binder seams. (Binder slate is "almost, but not quite" coal.)  But after the coal is "prepped", it has the characteristics of a metallurgical grade coal (high heat with low impurities).  At the preparation plant, the coal is sized using screens and crushers.  It is then fed in to a large concrete tank filled with water.  By controlling the specific gravity of the water with chemicals, the "clean coal" can be separated from the slate and binder.    

Every seam of coal differs from every other seam because they were made at intervals that were millions of years apart.  Even within any particular seam, the quality will vary.  And the thickness of a coal seam is not always consistent; many a mine has failed because the coal "pinched out."  Over time, with the thrust of the Earth's plates, fault lines develop in coal seams, allowing for intrusions of mud and sediment--another hurdle for miners.  And in rare cases, two seams of coal have merged together as the prehistoric sediment layers separating them either never formed or eroded away.  

If you pile up coal and light it on fire, the result is a smoky, cold fire.  However, if you put the coal inside of a metal stove and control the air draft, then the coal will burn much hotter.  Early iron furnaces used this drafting technique (Bernoulli's principle) to create enough heat to smelt the iron ore.  To get the maximum heat from a coal fire, an air blast is required.  The blacksmith's forge uses some type of air blower to generate an air blast. In colonial and pre-Civil War times, the bellows pumped air into the firepot of the forge.  At large ironworks, the bellows was operated by a waterwheel.  The hand-cranked, rotary fan replaced the bellows in the later 1800's.  Today, most blacksmiths use an electric powered fan blower with an adjustable air damper to blow air into the firepot.  The result is still the same--a fire hotter than 2,000^o F is achieved with an air blast.

To produce its maximum heat, coal must be converted to coke.  Coke is nearly-pure carbon.  The coke-making process is classified as the recovery method or the non-recovery method.  To start with, coal is placed in an oven and burned with very little air (pyrolysis  or destructive distillation).  The coal tar, smoke, gases, and volatiles that are released can be "recovered" or left to the four winds (non-recovery).  After the coal has been cooked in this oven, it is removed and quenched with water to stop the oxidation process.  The major use for coke is for fuel in iron and steel furnaces.  Coke is very porous and lightweight, much like a sponge.

In the recovery method process, the smoky emissions from the coke ovens are distilled and condensed.  Aspirin, believe it or not, is made from this process.  The Bayer Company (Germany) began making fabric dyes from coal tar and later discovered that they could make aspirin from the same process.  Aspirin is the tradename that Bayer registered for acetylsalicylic acid, the actual miracle chemical that cures our aches and pains.

Thousands of products and chemicals are made from the compounds found in a lump of coal.  Manufactured gas, made from coal, was the fuel that lighted London's street lamps until the 1950's.  Road tar is one of these products (asphalt is a similar material made from crude oil).  Railroad ties are treated with creosote, a coal product, to prevent rot; creosote also has insecticidal and fungicidal properties.  Chemical disinfectants are made from coal.  The list goes on and on.  Even if we quit using coke altogether, we would still find ourselves dependent on the chemical compounds that we now make from coal.  Chemicals made from coal have been around longer than the chemicals made from petroleum.

The blacksmith uses coke to generate a hot fire in his forge.  In this case, however, the raw coal is converted to coke in the firepot.  Raw coal is piled over the fire pot and set afire.  The blower is turned on.  And within 10 minutes, coke is burning in the bottom of the firepot.  The blacksmith rakes raw coal (also called green coal) to the fire as it burns down.  The biggest problem a blacksmith has is keeping the fire from burning too fast.  Frequent water sprinkling on the green coal pile will control the inferno.

Blacksmiths are choosy about the coal they burn.  Since they have to make coke in this one-step process, the better the coal, the easier the job.  Blacksmiths like coals that are high in heat values and low in impurities.  In West Virginia, the Sewell coal is about ideal.  The coke it produces has a good shoulder (it will support itself at high temperatures in the fire pot).  It also produces very few clinkers.  Clinkers are coagulated metals, usually pyrites, that melt from the coal.  Just as iron melts and bleeds from the iron ore in a blast furnace, the small amounts of metals in a lump of coal do the same in a blacksmith's forge.  

In comparison to Sewell coal, Pittsburgh coal has two undesirable qualities.  It tends to run in the firepot at high heat and also produces clinkers.  While the coal is okay for general forging, you will have to remove clinkers from the firepot every few hours whereas a Sewell fire will only have to be cleaned once a day.  If you are doing a lot of welding heats in the forge, coals that run and produce clinkers will drive you batty.  But for general forging, anthracite and most bituminous coals will perform adequately.  

The best blacksmith coals are bituminous.  Coals that have been through a prep plant will serve you even better as they will have fewer impurities and be uniformly sized.  The cost differential between prepped Sewell coal and raw Pittsburgh coal is about $40.00 per ton (FOB Mine).  But it is worth the cost to avoid the aggravation.  You can also blend coals to save money and still get optimal results.

Coal smoke is heavier than wood smoke.  A wood fireplace uses a standard 8" flue.  A coal flue should be sized at 10" round pipe or 8" x 13" masonry.  A side-draft hood is the best way to draft coal smoke from the forge.  No other system works as well and you are kidding yourself by using any other type of smoke collector.  Click on thumbnail for schematic drawing of a side-draft hood.

Check your suppliers for available coals.  Pittsburgh, Kittanning, and Sewell were mentioned in this article because of their availability and the author's personal use.  There are comparable coals in other areas where these are not available.  Quality coals are also bagged and shipped on one-way pallets to most anywhere.

  For the Appalachian Blacksmiths Association, by Dave Allen, Editor

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