Coal: The Rock That Burns (1976)

Then, great oceans flooded the land, covering the peat with a thick layer of sand and mud. Finally, the great weight of the sand and mud and water squeezed the soft peat into rock. A rock that burns, called coal. Coal deposits are found throughout the world. But, the majority of the known deposits are in the northern hemisphere in North America and in the continents of Europe and Asia. Half of the known coal resources have been found in North America, primarily in the United States. In the East, there are several small deposits of a very hard type of coal, called anthracite. Squeezed under very great pressures, [music] anthracite coal contains very little moisture and only a small amount of impurities. This means that anthracite coal produces less smoke and pollution when [music] it is burned. Most of our nation's coal, however, is bituminous coal. This is much softer and less pure, but it does produce more heat than anthracite coal and it is usually found closer to the surface of the ground. The rest of our coal reserve is either subbituminous coal or lignite coal. These coals are extremely soft and at present are not mined extensively. The most important of our coal reserves is the bituminous coal because it is our most abundant, because it produces more heat, and because it can be removed from the ground in so many different ways. At one time, the only tools that men had to cut the coal from the earth were the pick and the shovel. Cut free, the large blocks of coal had to be lifted by hand into wooden carts or wagons, which were then pulled out of the mine by mules or by the men. Mining was hard and dirty work. Today's miner also works hard, but he is aided by machines to help him meet the world's growing needs for coal. Instead of 2 or 300 lb, these men average nearly 19 tons of coal per man per day. This is the shovel of today. The continuous miner, biting into the hard wall of coal and ripping it free. Leaving behind it a continuous stream [music] of coal, speeding to the surface by conveyor belt. Another machine used by today's coal miner is this giant cutting machine. Running continuously, much like a huge chainsaw, the cutting machine slices deep into the coal to provide a space for [music] shattered coal once it has been blasted free from the vein. At one time, dynamite was used to blast the coal free. But, the explosives were extremely dangerous, often igniting the gases and dust in the mines and killing many men. Instead of dynamite, the miners now use compressed air cartridges. The cartridges are shoved to the back of the hole and then charged with highly compressed air. When all of the men are safely under cover, they trigger the cartridges, which expand and rupture the coal into bits and pieces safely. These are just some of the specialized machines and modern safety techniques which are at work in today's coal mines. Cutting, picking up, and moving the coal out of the deep mines. Not all coal, however, is found in deep mines. Some beds of coal can be mined by boring into the base of a hillside without going underground. Like a giant drill bit, this auger, 32 in in diameter, penetrates as deep as 200 ft into the vein. And as it bores deeper, it pulls the coal out to where it can be loaded into trucks. In many areas of the country, even drilling is unnecessary. Here, the coal lies so close to the surface that the miners need [music] only to remove the overburden. That is, the earth from above the coal bed. This is called strip mining. Giant shovels like this one first strip off the rock and soil that cover the bed of coal. Moving up to 325 tons of earth with each bite, these monsters can gobble up several miles of land each year. Behind the earth movers, other [music] machinery then breaks up the exposed coal bed. Loading the coal into trucks capable of carrying many tons each trip. Nearly half of our nation's coal is obtained by strip mining. What happens to this land when the mining is completed? Sometimes, particularly in older mining areas, nothing has been done. Poor and inconsiderate mining practices [music] have left the land torn and useless. This destruction, however, is not necessary. >> [music] >> In most strip mining states, regulations require that the land be reclaimed. It is usually graded, [music] then reseeded to cover the scars of mining. In other areas, most mining companies have now assumed this responsibility themselves to either replant the land or to convert the mines to public recreational areas for boating and fishing. This reclaimed land indicates changing attitudes, recognizing a finer balance between industry and a respect for the ecology. The [music] transportation of coal is an industry in itself, for often the coal must be moved several thousands of miles from the mine. This coal, for example, may be on the way to Italy or Japan or any number of countries of the world. Within the country, coal may be transported nearly the full length of the Mississippi and Ohio rivers, across the Great Lakes, or by way of other major waterways of the United States. Each of these barges can hold as much as 1,000 tons of coal, and sometimes a single tow of such barges can move as much as 30,000 tons down river. But, nearly 70% of the nation's coal is moved by rail. [music] At the destination, the coal is often dumped directly onto conveyor belts to save time and handling. This, too, is coal on the move. The coal has been pulverized and mixed with water to form a slurry, a kind of coal soup. The soupy mixture is then fed into [music] large pumps, which push the slurry to where it is needed. Transported by pipeline, the slurry is burned like any other coal, and surprisingly, this mixture does not have to be dried out before it is used. Here is still another example of coal energy on the move. Coal energy converted to electricity. Several electric companies have built their power plants at the mouths of coal mines, eliminating the expense of transporting the coal over great distances. The coal moves directly from the mine to the furnaces. A little more than half of our nation's electric energy is created through this process. The coal is burned, heating gigantic volumes of water, turning the water to steam. The pressure of the steam is then released into the generators, causing them to turn and generate electricity. air conditioners in schools and businesses. Electricity to run the tools of industry. And the electricity that allows us to see throughout the night. But, by day, we can also see that there are certain disadvantages in using coal to generate our electric needs. When coal is burned, some undesirable substances, [music] particularly sulfur dioxide, are released into the air we must breathe. This pollution can be brought under control, but we must realize that the pollution controls are very expensive and often difficult to install. Millions of dollars are currently being spent on research to find better, more economical means of removing the sulfur dioxide from the flue gases and ways to use it as a byproduct. Research has already produced several surprising byproducts of coal. First, for every ton of roasted coal, we can produce about 1,300 lb of coke. Coke is an essential ingredient in making steel and several other metals. The coke is the solid byproduct produced by roasting coal. Many other byproducts are taken from the gases rising up from the roasting coal. Some of the gases are condensed and distilled into a liquid called coal tar. Further distilled, coal tar can be refined [music] for use in detergents, antiseptics, dyes, roofing materials, [music] and a variety of other products for home and industry. Another liquid condensed from the gases of roasting coal is called light oil. The byproducts of light oil are used in varnish and linoleum, printer's ink, herbicides and motor fuels, plastics and nylon, and in making preservatives for food such as ice cream. Another byproduct of roasting coal is ammonia. You have probably used ammonia at home when you help wash the windows. And the farmer who grows the food you eat probably applies ammonia to some of his crops to speed their growth. Finally, there is still one other major byproduct of roasting coal, flammable gas. Actually, the gas that rises from roasting coal is flammable, but when burned, it is not hot enough to adequately cook your food or heat your home. However, several major coal and petroleum companies have been working together to increase the heat capacity of this abundant gas, so it will work in stoves and furnaces. And so coal has perhaps come the full circle, for it was once the hard rock coal that heated the homes of America. And now with the turn of a valve, coal may again become a major source of heat. This is coal, a solid, a liquid, a gas, >> [snorts] >> a source of electricity, a source [music] of heat, and a major industry. >> [music]