Bituminous coal

“ That is, they were all bituminous; but during the violent contortions and upheavals of the earth’s crust at the time of the Appalachian revolution at the close of the Carboniferous age, the bituminous coals involved in that disturbance were changed by heat, pressure, [13] and motion, and the consequent expulsion of volatile matter, from bituminous to anthracite.
Cannel coal is a variety of bituminous coal, burning with great freedom, the flame of which affords considerable light. ”

“ It burns with a rather long and smoky flame, and is also much used for steaming purposes. Many bituminous coals have the property of coking or caking (see Coke) when heated to redness. Most of the Carboniferous and many of the Mesozoic coals of the United States are bituminous.
Semi-Bituminous Coal resembles bituminous coal in appearance, but is intermediate between it and anthracite. It contains from 70 to 84 per cent. of fixed carbon, and is considered of superior value for steaming purposes. This variety is obtained from Pennsylvania, Maryland, and West Virginia. ”

“ The tests made with reference to the manufacture and combustion of briquetted coal have demonstrated conclusively that by this means many low-grade bituminous coals and lignites may have their commercial value increased to an extent which more than covers the increased cost of making; and these tests have also shown that bituminous coals of the higher grades may be burned in locomotives with greatly increased efficiency and capacity and with less smoke than the same coal not briquetted. ”

“ Bituminous coal, of which there are several varieties, is the best suited for the production of coal gas. The Newcastle coal is principally used in the manufacture of London gas. Scotch parrot coal produces a superior gas, but the coke produced is of inferior quality. Boghead coal is also used for gas making—in fact, every kind of coal, except anthracite, may be used for this purpose. The bituminous shale produces a very good gas, and it is used partly to supply the place of cannel or parrot coal. ”

“ Bituminous coal is our most abundant fuel, occurring the world over in seams from less than an inch in thickness to some over fifteen feet thick. The United States is peculiarly fortunate in the abundant and easily accessible deposits of this type of coal, in Pennsylvania, West Virginia, Ohio, Kentucky, Tennessee, Indiana, Illinois, Michigan, Iowa, Missouri, Kansas, Nebraska, Texas, Utah, and Colorado.
The volatile constituents, hydrogen and oxygen compounds, of bituminous coal may be driven off by heating the coal in closed ovens, and the residual mass is known as coke, almost pure carbon. ”

“ The lower rocks hold both anthracite and bituminous coal in the Queen Charlotte Islands, but elsewhere contain bituminous coal only. The upper have so far been found to yield bituminous coal only. The fuels of the tertiary rocks are, generally speaking, lignites, but include also various fuels intermediate between these and true coals, which in a few places become true bituminous coals."
It is thought to be more than likely that the Comox District may prove far more productive than the Nanaimo region. ”

“ Semi-bituminous coal, which stands midway between hard and soft coal, is also an article of importance, being especially well adapted for blacksmiths use, and also for ocean-going steamers. Geologically, the anthracite, semi-bituminous, and bituminous coals nearly all belong to the same formation, the Carboniferous par excellence. All the coal of the Appalachian region and Central Valley is of this geological age, excepting the small field near Richmond, Va., and two in North Carolina, the Deep River and Dan River fields, which are of Mesozoic age. ”

“ Our fields of bituminous coal are yet too distant from dense population, and too far removed from easy communication, to be looked to at present, but unless modes be invented by which the anthracite coal can be used without mixture in the [Pg 379] blast furnace, these will become the ultimate seats of the manufacturing industry of the United States. ”

“ According to Bischoff, the inflammable gases which are always escaping from mineral coal, and are so often the cause of fatal accidents in mines, always contain carbonic acid, carburetted hydrogen, nitrogen, and olefiant gas. The disengagement of all these gradually transforms ordinary or bituminous coal into anthracite, to which the various names of splint coal, glance coal, culm, and many others, have been given. ”

“ Of the two general varieties—bituminous or soft, and anthracite or hard—it is safe to say that bituminous coal is the more economical, assuming that the grade employed is the best, this economy lying both in the original cost and the fact that the bulk of it goes to serve its purpose, there being comparatively little waste in the way of ashes; while the anthracite produces many ashes and clinkers, requires much more care and attention on the part of the stoker or fireman, and costs, as a general rule, about thirty per cent. ”

“ Moisture in coal may be more detrimental than ash in reducing the temperature of a furnace, as it is non-combustible, absorbs heat both in being evaporated and superheated to the temperature of the furnace gases. In some instances, however, a certain amount of moisture in a bituminous coal produces a mechanical action that assists in the combustion and makes it possible to develop higher capacities than with dry coal. ”

“ In America it is the ordinary fuel, and this is the case in all other countries where it is obtainable at the price of bituminous coal. Our perversity in this respect shows out the more strikingly when we go a little further into the subject by comparing the two classes of coal in reference to our methods of using them, and when we consider the fact that our South Wales anthracite is far superior to the American.
Our open fires only do their small fraction of useful work by radiation. Their convection is all up the chimney. ”

“ Bituminous coal, though still hard, breaks more easily and more irregularly, often dividing into large cubic pieces in the plane of stratification and by cleavage. It is generally quite black, still with some lustre, contains less carbon with a larger proportion of inflammable substances than anthracite, and therefore takes fire more easily and rapidly, and burns with a bright yellow flame, developing less heat. ”

“ Several of the poorest grades of bituminous coals have shown remarkable efficiency in the gas producer, and lignites and peat have been used with great facility, thus opening the way to the introduction of cheap power into large districts that have thus far been commercially unimportant owing to lack of industrial opportunities. Experiments with “bone,” a refuse product in bituminous-coal mining, have given excellent results, showing an efficiency in the producer equal to that reached by good steam coal under boilers. ”

“ If the more marked characters which indicate the several species of mineral coal are easily recognized at first sight, and if everybody knows the bituminous coal from the anthracite or the cannel, it is not the less certain that, considering the matter in itself and in its compounds, coal is an indivisible whole. Not only have all the kinds of coal the same constituent chemical elements, merely varying in proportion in a slight degree, but all the varieties of coal, of bituminous especially, are found in some localities in the same vein. ”

“ Chemists tell us that coal is chiefly constructed of carbon, compounded with oxygen, hydrogen, and nitrogen. There are many varieties, but all may be classified under two general headings—bituminous and anthracite. Bituminous coal contains a large amount of a tarry substance, a kind of mineral pitch or bitumen, which burns with a brilliant flame and a black sooty smoke, exceedingly rich in carbon. Anthracite coal is hard and stone-like in its texture, burning with scarcely any flame and no smoke. It produces a fire of intense heat when it is once ignited. ”

“ Coal, chiefly bituminous, occurs in large quantities in Nova Scotia, British Columbia and in various parts of the north-west (lignite) , though most of the anthracite is imported from the United States, as is the greater part of the bituminous coal used in Ontario. Under the stimulus of federal bounties, the production of pig iron and of steel, chiefly from imported ore, is rapidly increasing. Bounties on certain minerals and metals are also given by some of the provinces. The goldfields of the Yukon, though still valuable, show a lessening production. ”

“ From its position in the earth, and its relations to bituminous coal, as well as from its composition, we are justified in regarding it as a coal that was originally bituminous, but which has been altered by heat, acting under great pressure. ”

“ It is true also that the dust of bituminous coals is much more liable to be explosive than the dust of anthracite. No well authenticated instances of coal dust explosions have been reported from the anthracite regions, while in mining soft coals they have undoubtedly occurred. ”

“ Used for hauling coal from the mines
“Semi-anthracite” also ranks as a hard coal, though it is less hard than anthracite. Very little is mined in this country, and it is generally sold as anthracite.
“Semi-bituminous” coal is a softer coal, which, when properly burned, gives off but little smoke. The best semi-bituminous coal ranks highest among the coals in heating value. It is the most valuable fuel for manufacturing purposes; also for steamships, as it requires less bunker space per unit of heat than any other coal. ”

“ Anthracite contains from 90 to 94 per cent of pure carbon, bituminous coal from 70 to 85, and much of this being combined with hydrogen burns away as flame. On a rough average we may say that the fixed or solid carbon capable of burning with a smokeless flameless glow, amounts to 65 per cent in ordinary British bituminous coal, against an average of 92 per cent in British anthracite. The advantages of anthracite as a fuel for open radiating grates are nearly in the proportion of these figures. ”

“ They differ even as fuels; they differ fundamentally in other particulars. Anthracite coal has no substantial use beyond a fuel; bituminous coal has other uses. Products of utility are obtained from it. ”

“ New processes were invented by which valuable gas and coal tar are taken out of bituminous coal, leaving, as a residue, coke that is equal in quality to that made from the Connellsville coal. Fortunes have been made out of the separation of the elements of the once despised soft coal. For the coke and each of its by-products, coal tar and coal gas, are commercial necessities of life. [Pg 173]
The impurities absorbed by the melting iron ore include carbon, phosphorus, and silicon. Carbon is the chief cause of the brittleness of cast iron. ”

“ In the United States the anthracite industry is well organized, and its railroad connections make it notably efficient and powerful. Bituminous coal, on the other hand, is so widely distributed on both public and private lands that no private organization has attempted to control the industry. Such control has always been opposed by Congress and the general public.
Except during the war, neither Great Britain nor the United States has attempted any control over commercial mining and the sale of coal. ”

“ As far as the gas-making properties of the first three are concerned, the relative proportions of carbon and volatile products are much the same. Everybody knows a piece of cannel coal when it is seen, how it appears almost to have been once in a molten condition, and how it breaks with a conchoidal fracture, as opposed to the cleavage of bituminous coal into thin layers; and, most apparent and most noticeable of all, how it does not soil the hands after the manner of ordinary coal. ”

“ The difficulties in burning bituminous coals with economy and with little or no smoke increases as the content of fixed carbon in the coal decreases. It is their volatile content which causes the difficulties and it is essential that the furnaces be designed to properly handle this portion of the coal. The fixed carbon will take care of itself, provided the volatile matter is properly burned. ”

“ Many grates and stoves have been devised for burning anthracite for domestic heating, and some of them are successful and economical; but, in view of the national prejudice in favour of a bright and open fire, it is not likely that anthracite will ever replace bituminous coal to any great extent in the British Isles, where the great coal-fields undoubtedly are the natural sources of fuel. ”

“ Its structure shows it to consist of the remains of the stems and leaves of plants, reduced to little more than their carbon. Again, some of the coal is made up of the crushed and flattened bark, or outer coat, of the stems of plants, the inner wood of which has completely decayed away. But what I may term the "saccular matter" of the coal, which, either in its primary or in its degraded form, constitutes by far the greater part of all the bituminous coals I have examined, is certainly not mineral charcoal; nor is its structure that of any stem or leaf. ”

“ Aside from the fact that anthracite is not met with solely in the lower coal measures, but is found in the middle and upper ones, and that bituminous coal itself is met with quite abundantly in the secondary formations, and even in tertiary ones, it seems to result from recent observations that if vegetable matter, when once converted into lignites, coal, etc., be preserved against the action of air and mineral waters by sufficient thick and impermeable strata of earth, preserves the chemical composition that it possessed before burial. ”