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Anonymous asked in Science & MathematicsEarth Sciences & Geology · 9 years ago

Does coal burning produce mercury wastes?

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  • 9 years ago
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    Yes. According to the US EPA, coal contains about 0.1 ppm mercury. Almost all of that mercury gets released as mercury vapour into the atmosphere when the coal is burned, making coal-fired power plants by far the largest source of atmospheric mercury in the world.

    Another pollutant released by burning coal is uranium. In fact, a coal-fired power plant releases more radiation than a nuclear power plant.

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  • 9 years ago

    many metals are mobile under oxidizing conditions and immobile under reducing conditions. Coal-forming sediments, by their very nature, are highly reducing conditions (organic compounds are reducing compounds, are composed of carbon in a reduced state; this carbon will tend to react with any electron receptor (oxidized species) and in so doing reduce them and oxidize the carbon.

    As a result, many coals are enriched in base metals and sulfide (reduced sulfur). On burning, the metals and sulfur are released to the atmosphere or concentrated in the ash (depending on volatility; sulfur turns into sulfuric acid and creates acid conditions in the stack output). Hg has a low boiling point so is preferentially expelled in the flu gases, which causes Hg to be distributed into the surrounding area, to "contaminate" the soil and water downwind from the source of the emissions.

    Typically, the ash is not all that enriched in mercury, unless the ash or waste is collected from the flu gases (the volatilized mercury is recaptured in the baghouse (dust collectors) and flu gas scrubbers). The problem of mercury from coal is more of a discharge issue than a waste issue in most circumstances.

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  • 9 years ago

    Yes it does but despite what some people might say about burning coal and the supposed"huge amounts of mercury vapor" it produces,...that actually kinda pales when you look at the minig and electro plating industries and some water purification facilities...and too, "lightning strike" factors!!! yes I said "lightning strike factors"....that happens more in the upper northwest and midwest where mercury occurrs in nature in natural ores or in the soil. Mercury is normally a liquid at room temperature anyway and in particular ores it sits inside of rocks in tiny pockets until it's forced out by heat....when enough heat is applied, the mercury either falls to the bottom or it evaporates into the atmosphere. When lightning strikes an ore bearing sediment at upwards of 50,000 degrees, it's automatically evaporated in an explosive fashion, it gives off a bluish white smoke from the rock and after the strike there's a silverish blue sheen left on the rock where some mercury vapor clings to the rock surface with a dark blue spot in the center where the actual bolt of lightning hit......but that's only the facts if it were to hit an outcropping of mercury bearing oer called "cinnabar"....However, in a strike like that, there is an incredibly immense amount of mercury that gets sent into the air as a result and it's way more than a day's worth of caol burning at a power plant that uses coal. In the gold mining indiustry, Mercury is a natural biproduct in the ore and it gets smelted directly into the atmosphere because it's too costly to condense it out by means of a water condensing system. In smaller Gold claiming operations (mostly one man operations) Mercury is used to combine small gold pieces together and thereby lower the melting point of the gold pieces that were gathered (because not all gold is of the same quality) and then the gold can all be melted into one lump, the mercury is vaporized during this operation and the gold is left behind. In refining and alloying situations where two or more metals are being used to make one grade of metal such as "white gold" or "coin Silver" Mercury is used to help lower the melting points of all the metals and "gather" the metals into one type of alloy "Gathering" is a term used when a metalurgist or refiner decides upon a certain final recipe for a particular meatl he wants to end up with which he intends to use for whatever reason he needs such as "flatware" which might be "Sterling silver" which is about .945 on a scale of .000 to .999 fine silver. American coin silver is .900 pure, Mexican coin silver used to be about .850 pure to .900 pure. "Billon" which is another alloy using silver uses Silver, Tin, Copper, Mercury, and sometimes even Gold depending on who the metalugist was and what the purpose of the Billon was...In the end however, the mercury gets boiled away in the making of the final metal and it ends up in the air. Mercury is incredibly heavy however and it quickly falls back to earth as fast as possible due to it's wieght and if you ever see a coal plant that actually has coal that is heavy with mercury?...you'll notice that it rains more often down wind of the plant than it does anywhere else and in that area where it rains, the vegetation will be slightly less healthy...But the "downwind rain" or "down range rain" will always give away the high levels of mercury in the coal the plant burns...look for that clue...Also, in that down range are, the leaves on the tress will be much thinner and yellower looking than other areas....Usually in America, our weather moves from west to east so look to the west for greener foliage and to the east for poorer foliage.

    Source(s): If I told ya, You wouldn't believe me.
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