Trace elements in coal, ventilation

[Glenn]

Excerpt from

 

This may get a little long so stay with me. Look at all the references as they supply additional information.

 

Trace Elements

Coal is made up primarily of "organic" elements (carbon, hydrogen, oxygen and nitrogen) and "inorganic" elements (primarily silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, and sulfur). Organic elements comprise the combustible body of the coal, whereas the inorganic elements are present in coal in minerals that largely form the ash when the coal is burned. Inorganic elements (e.g. silicon and aluminum) are present in most West Virginia coals in the range of several percent or more in ash forming minerals, but other "inorganic" elements, such as sulfur, present in lesser amounts, may detrimentally impact the use of West Virginia coals.

Trace elements are defined as elements present in coal in amounts of less than 1 percent by weight. Generally, trace elements are present in coal in amounts much lower 1 percent, and are reported in parts-per-million (ppm) by weight in the coal. A trace element concentration of 1 ppm = 0.0001% by weight, or expressed in another way, a 1 ppm concentration of a trace element equals one pound in one million pounds (500 tons) of coal. Most trace elements in West Virginia coals are present at levels of 10 to 100 ppm, or less.

Highly toxic elements (e.g. arsenic, mercury, lead, and selenium) are present in West Virginia coals, though generally in very low concentrations. How hazardous elements present in very low amounts adversely impact the environment is a matter of scale. For example, a coal fired power plant with no pollution controls in place theoretically would produce 10 tons of lead for each million tons of coal burned containing 10 ppm lead. However, modern pollution control measures provide controls against the release of large amounts of hazardous trace elements to the environment.

A table of statistical correlations of trace elements with ash yield, in decreasing order of significance, includes Chromium (Cr), Thorium (Th), Scandium (Sc), Cesium (Cs), Rubidium (Rb), Lithium (Li), Vanadium (V), Hafnium (Hf), Cerium (Ce), Lanthanum (La), Zirconium (Zr), Tantalum (Ta), Niobium (Nb), Dysprosium (Dy), Holmium (Ho), Lead (Pb), Samarium (Sm), Europium (Eu), Gallium (Ga) and Tellurium (Te). These elements likely occur within mineral matter in coal. Most of these elements probably occur in silicate minerals, especially clay minerals, which make up 60-70% of the mineral matter in coals.

 

Trace Elements in West Virginia Coals (your coal may be different)

Antimony (Sb) Erbium (Er) Manganese (Mn) Tantalum (Ta) Arsenic (As) Europium (Eu) Mercury (Hg) Tellurium (Te) Barium (Ba) Fluorine (F) Molybdenum (Mo) Terbium (Tb) Beryllium (Be) Gadolinium (Gd) Neodymium (Nd) Thallium (Tl) Bismuth (Bi) Gallium (Ga) Nickel (Ni) Thorium (Th) Boron (B) Germanium (Ge) Niobium (Nb) Thulium ™ Bromine (Br) Gold (Au) Praseodymium (Pr) Tin (Sn) Cadmium (Cd) Hafnium (Hf) Rhenium (Re) Tungsten (W) Cerium (Ce) Holmium (Ho) Rubidium (Rb) Uranium (U) Cesium (Cs) Indium (In) Samarium (Sm) Vanadium (V) Chlorine (Cl) Iridium (Ir) Scandium (Sc) Ytterbium (Yb) Chromium (Cr) Lanthanum (La) Selenium (Se) Yttrium (Y) Cobalt (Co) Lead (Pb) Silver (Ag) Zinc (Zn) Copper (Cu) Lithium (Li) Strontium (Sr) Zirconium (Zr)
 

Repeated material: A trace element concentration of 1 ppm = 0.0001% by weight, or expressed in another way, a 1 ppm concentration of a trace element equals one pound in one million pounds (500 tons) of coal. Most trace elements in West Virginia coals are present at levels of 10 to 100 ppm, or less.

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The best way to reduce exposure to the trace elements is to reduce the smoke and or dust. This includes a chimney, room air filtration, dust elimination, and good housekeeping.

The chimney should works well, that is draft well or suck the smoke out of the work area. 8 inch diameter is considered the minimum, with 10 inch and 12 inch being better. Area of a 8 inch diameter circle is A = 50.26 square inches, a 10 inch diameter circle is A = 78.53 square inches and a 12 inch diameter circle is A = 113.09 square inches. The chimney does not have to be round, as square, rectangular, and other shapes will work. 

It is suggested that the top of the chimney be 3-4 feet taller than the peak of the roof and 10 feet away from and 3-4 feet taller than any near structure. Also consider anything that will interfere with air flow or create eddy currents in the air such as other buildings, trees, etc. The idea is to move air so the top of the chimney is important. You may or may not want a cap on the top of the chimney to keep rain etc out of the chimney. A round pyramid or Chinaaman's cap, or other cap sill work only if the area between the top of the chimney and the bottom of the cap is sufficient to allow the full volume of smoke to escape. If I recall correctly this height is 1-1/2 to 2 times the diameter of the chimney. There are what is referred to as high velocity chimney caps which is a pipe larger than the chimney and around the last feet of the original chimney with a space between the two. Rain is suppose to hit the outside pipe and then not get into the original chimney.

You will need to start a draft in any chimney by first burning a couple of sheets of newspaper to warm or preheat the chimney and induce the original draft, or get things going. You may wish to do this a second time just before lighting the fire in the forge. Good fire maintenance will eliminate a lot of the smoke. Start by poking a hole in the top of the fire to create a volcano of sorts and allow the smoke and fire to exit through the hole and burn the smoke, creating heat and more draft.

 

Room air filtration, dust elimination

This is as simple as putting an air filter over the intake side of a box or window fan. It will circulate the room air filtering out particles, dust, etc. You do not need a lot of air as it will run continuously.

 

Good housekeeping

Try not to create dust, debris, etc. That way it will not get spread out and settle all over everything in the shop. Once in the shop any air movement will cause it to become airborne again. A good broom or shop vac will collect a lot of the dust and debris. This may need to be followed by a wet mop. If it worth the effort to keep the shop environment aseptic, that is your call.

Just taking the dust and debris generating processes outside will eliminate a lot of problems. Just remember that outside the door puts all the dust and debris at the entrance of the door to be tracked into the shop. Move it to the side or away from the building and use a fan to blow the dust and debris away. (usually into the neighbor's yard LOL)

 

A properly fitting respirator with an industrial quality particulate filter may be a consideration. Be aware that this restricts air flow into the lungs and may cause some issues by wearing the  respirator.

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All this is related to smoke and the inside of the shop.

The geology of Cyprus is part of the regional geology of Europe. Cyprus lies on the southern border of the Eurasian Plate and on the southern margin of the Anatolian Plate. The southern margin of the Anatolian Plate is in collision with the African Plate, which has created the uplift of the Cyprus arc and Cyprus itself. Cyprus is commonly divided into four bedrock units, Keryneia Terrane, Troodos Ophiolite, and  Mamonia Terrane. (reference: wikipedia) All this plate movement may have left the ground surface covered with trace elements.

Another possibility is fall out from any volcano(s) in the area, or fall out carried by the atmosphere and winds from distant volcano(s).

Any garage or auto repair shop most likely will test positive for lead, due to the wheel weights used to balance tires. Road dust can test positive for asbestos that is sometimes used in brake pads and shoes. Then there is the sea breeze carrying the trace elements present in the ocean water. And do not forget rain washing the dust and debris out of the atmosphere. Choose your battles, go after the largest sources and eliminate or control those sources first.  

Other fuels to consider are induction heating, coke, charcoal and propane.

Ventilation is not as simple as you might expect. You MUST have make up or replacement air for any air that goes out the chimney. If you open an window and remove ALL the air in the room, you have not removed the contaminated air, you have diluted the contaminated air by mixing it with clean outside air. You now have a 50/50 mix of clean and contaminated air in the room. For instance, for every volume of air removed you brought in the same volume of clean air and mixed it with the room air. We will let the math majors crunch the numbers as to how much air you need to move to get acceptable number of clean air.

 

May I suggest reading the following references.