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COAL AND ITS PRODUCTS AND METHODS OF MINING Different Theories Advanced as to Origin of Coal—Some of the Properties Which It Contains—Carbon the Principal Element—How It Is Handled 1 - BY DICK WELLS 4 Coal and Its prodticts comprise 4 4 the most Important features of 4 4 the Industrial life of Birmlng- 4 4 ham. In nearly every one ot' the • 4 great manufacturing plants of 4 i the district coal has some bear- 4 4 lng, either direct or Indirect, 4 4 on the finished product. Despite 4 4 the Important part which this 4 4 gift of nature takes In the pro- 4 4 ress and development of this sec- 4 4 tlon, there are comparatively 4 4 few persons not directly engaged 4 * In Industrial pursuits who know 4 i nnthlng at all concerning Its or- 4 4 Igtn, the process of mining and 4 4 Its products. 4 l-: No suitable definition for the word coal exists. To say that anything dug out of the ground that will burn is coal, Is too loose to b^e considered a val uable definition; then again to give a definition based on the chemical analy sis is not accurate on account of the varied forms of coal, none of the prop erties being identically the same. Generally speaking, coal Is believed to represent the remains of plant life which has long since been buried and lias eventually taken this form. It is found in seams or beds, separated by • strata of shale or grit and limestone. Since all forms of plant life depend upon the energy received from the sun which fixes the carbon or carbon monoxide in a stable form, coal may be defined as burled sunshine. This in dicates the great heat and energy given off by the coal fire. Many theories have been advanced as to the origin of coal, some being that the beds are dried up petroleum lakes; others that they are sea weed long since buried, but none of these can be reasonably accepted. The most logical theory so far advanced is that when the woody fiber of leaves and stems of plants fall on the ground they soon oxidize or decay and the oxygen, hydrogen, carbon and nitrogen present pass Into the soil or air as gases, the oxygen and hydrogen chiefly as water, the carbon as carbon dioxide, and the nitrogen as ammonia. This process goes on until finally only the ash is left, which is composed of silica, aluminum and iron oxide. It is for this reason that the residue of thousands of years may be represented by only a few inches of vegetable mould or humus. A dump climate and a land where the W'ater runs off very slowly favor the formation of swamps, though in a cli mate as damp as that of Ireland the moss will climb the hillside and bring the water up for great distance by capillary action, thus making the peat bogs climb the hills also. The loss of water and of carbon, nitrogen, oxygen and hydrogen causes a great loss of bulk. The presence of the overlying strata which warps and changes the locks makes the mass even smaller. From this it can be easily seen that a coal seam one foot thick may have been 60 feet of peat in the ancient swamp, and the assumption may bo made that the average coal seam is not one-fifth the thickness of the original peat bed. Carbon Is the Basis Since the chief heat producing- ele ment In coal Is the carbon, a classi fication In wide use Is one based on the value of coal as fuel; that Is, on the percentage of carbon present In the coal and also the condition of Its carbon. Part of the carbon In the coal Is fixed and cannot be driven oft by heat . Ing In a retort and part Is combined with the hydrogen as volatile hydro carbon compounds which are easily driven off. The percentage of fixed car bons is greatest In anthracites. The percentage of volatile hydrocarbon to the fixed carbon In a coal Is called Its fuel ratio. On this basis the coals are usually classed as lignite, bituminous, seml-bltuminous, anthracite and seml antharclte. Cannel coal in which the percentage of volatile hydrocarbons ts very high, Is believed to be of dif ferent origin from other coals. Lignite, or brown coal, is brown to black In color though the powder is always brown. It often shows its vege table origin, boring stems and other plants, which look to be In an unde composed state. The luster is change able for the type, the specific gravity being 5 to 1.5, some kinds even float ing on water. Lignites burn easily with a very dirty smoky flame, crumbles eas ily and generally contain a high per centage of water and slack or even mud on long exposure. Different Kinds of Coal Bituminous or soft coal is black: the powder is black, and the luster is resin ous or dull. Its specific gravity is 1.25 to 1.4. It has less water than lignite and is much harder. For that reason it can stand shipment much better than the soft lignite. Bituminous coals are subdivided according to their properties or uses into coking, free burning, smokeless, gas coal and so forth. Cok ing coals partly fuse or melt together. If they are low in ash and sulphur they are used as forging coals, and for making coke and gas. Cannel coal is black or brownish and has a dull lus ter; it does not soil the hand, and does not show traces of vegetable origin. It burns with an easy flame, is easily ignited and is often used in the grate I and for household purposes. But its greatest use is enriching gas made from other coals. It is mined in the United States at Cannelburgf, Ind., and | in the Jellico district of Kentucky. Anthracite is also a black coal with j a black powder which does not soil the I lingers. The specific gravity is 1.3 to! 1.75. It is hard to kindle but it is very valuable nevertheless owing to the high percentage of fixed carbon it contains. It burns with hardly any smoke and with one of the most in tense heats mado by any of the classes of coal. It was formerly much used In the country for the smelting of iron but its chief use now is for household purposes and in the grates. The less water, ash and sulphur a coal contains the better the coal and good coal should not contain over 6 to 7 per cent of ash und 7 per cent of sulphur. Location ol' Coal Fields North America, Asia and Burope con tain tho great coal fields of the world. In southern Africa, in Australia and in New Zealand are deposits of import ance. Only small and disconnected areas are known in South America, and the only mines worked on a large scale are in Chili. As to Asia, the coal fields of China are vast and of great import ance, but they are practically undevel oped. Coal is abundant In Borneo and Burma and the output Is increasing, sspecially from Bengal. The United States, Great Britain and Germany together produce about 80 per cent of the total amount of coal mined in tlie world. The mining consists in getting out as little dust as possible. The princi pal gases found In a mine aro carbon dioxide, heavier than air, suffocating but not inflammable, called choke damp by the miners; carbonmonoxlde. pois onous and Inflammable which Is the dreaded white damp of the mines; C. H. 4, which is known as marsh gas, this gas being light, non-polsonous but inflammable, Its chief constituent being firedamp; also but less Important, sulph uretted hydrogen, which is poisonous and Inflammable but easily detected by its odor. Of all these gases the marsh gas often given off in large quantities Is the cause of the worst mine disas ters. A mixture of marsh gas and atr explodes violently when they come to gether in the proper quantities and if brought into contact with a flame. Coal dust In the air makes a very much smaller proportion of marsh gas. Safety Device Used To be able to work In the mines when these explosive gases are present HOW TO MAKE A CUP r piece s' 'DflDer* 7lncbo t Square. j i1 I rblong'tWllrn* r C. / Fol<J rn~<*9 i+h«*DOint r ?n mg line A.C Fold) ' point. E^ovcr0 [In3«r+ A A iw \\ ' „ " y doablr (fold g^C Fold iRXbocW. r OD«n I along ifhc line tr-j-F. end thara'a your 5oniToro i DKI/SKl/NG CUP - Illinois recently passed a law forbidding all public drinking cups and the Chicago board of health ha^ issued instructions on how to make a 1 good drinking cup out of onlinary White paper. v m. r \ ENTRANCE TO LARGE MINING PROPERTY (and there is no way to get them out) a safety lamp Is used by the miners which keeps the flame from contact with the gases. The first one of these lamps was made by Sir Humphrey Davy in 1815. This lamp consists of a flame inside of a wire gauze which makes it safe so long as the wire gauze does not get to the combustion point of the gas. Many other lamps have been Invent ed since then, some of the latest type.' being the wolf lamp. This lamp indi cates the presence of dangerous gases by tite lengthening of the flame. Car bon dioxide and carbon monoxide are known as ‘g'ob.M These gases are what is known as the afterdamp, caused by an explosion of dust or firedamp, and are often the cause of the great loss of life after an explosion; the victim not knowing the danger until he has succumbed to the gas. From this it can be seen that to operate sucessfully the mine must be well ventilated. This ventilation is sometimes obtained by a furnace at the top of the mine which affords a strong up current sufficient to keep the mine well ventilated. Others are fitted with fans which draw the air out or force the air down in making an up-current. Various types of ven tilators are used but the majority in use at the largest and best mines are modifications of the Guibal type. Since the coal veins are only a few $feet thick and lie flat or dip at low angles in this country the mines can be opened much easier than in some of the other countries where the beds are more irregular. The coal is taken out as the mining proceeds, leaving air pass ages and roadways protected by posts or walls. How Coal Is Sorted Coal is broken from the face of the seam by the miner, who undercuts it with Ills pick and then puts in a blast | strong enough to bring down the coal. | Tn this country black powder usually is I used but In some of the other countries where there la danger of an explosion the miner uses explosives of less flame or even hydraulic wedges. In some mines, mainly those in Illinois, the coal Is blasted from the vein as oro Is mined but this Is not as good a method ss fine coal la not as valuable as lump coal. The coal when broken down Is rough ly sorted by the miner and his helper and then is loaded into cars which are hauled to the main shaft by mules. Here the cars are made up into trains and are thus sent along tracks to the bottom of the shaft, hence to be trans formed to the tracks on the surface. Occasionally coal is found so near to the surface*hat It may be had by the process known as stripping. Then coal is sometimes found in pockets along side a hill and this is known as pocket mining. In the shafts the chambers are dug out to the side 30 H>r 40 feet in length and the supports of timbers are put under the roofs and around the walls. After all the coal is taken out of these veins tho timbers are taken out and the chambers are allowed to collapse. The coal when brought to the sur face is screened out at many mines and is then sold as lump and slack; but :n others where there are many different grades sold the coal is broken and washed and a break is employed so as to get exactly tlie 'size of coal desired. Coal mining dates back to about tho end of the twelfth century. Coal as an Inflammable substance seems to have been known to the ancients and to tho Britons before the Romans in vaded their Isle. But it was not in use then because the forests were- so ex tensive as to afford a supply of fuel much more easy of access. The uses of coal were not very great until about the eighteenth century when | the steam engine was brought forward in 1705 and was applied to coal in New castle about 1715. Coke a Valued Product The most useful of tlie products of coal is the coke obtained when the coal is heated in an oven. It may be dellned as the cellular mass left after the expulsion of the volatile products of coal. In general the operation of coke making varies little from that of charcoal making, the only difference be ing that the carbon molecules are broken up more completely In the coke, requiring a higher heat, in coking the organic* compounds are destroyed and the decomposition form new products at the higher temperature. Gas begins to come off when the charge reaches the temperature of 100C, tho highest temperature of the charge being 14t)0 degree (\ The time required fur cok ing is from 18 to 72 hours, varrying with the coal and the typo of oven. The products beside coke are illumin ating gas, ammonia liquor, tar and asphaltum. There are various types of ovens used. Tlie oven most used for tho mak ing is from 18 to 72 hours, varying mice use is the beehive although it is predicted that in (lie near future tho byproduct oven will have completely taken its place. The advantage of the byproduct oven over the beehive is the utilisation of the byproducts of the coal besides coke. The coke as used in the blast fur nace is to reduce tlie ores by combin ing with the oxygen in theirs. The, objects of coking are to got a fuel rich in carbons by expelling vol atile constituents; to get a fuel giving no gas or smoke which would Interfere with the metalurgical operations; to get an inf usable fuel which will not swell or soften in heating in the fur nace, and to reduce tho sulphur present in coal in organic compounds combined with iron. High Grade Cahaba Domestic and Washed Steam Coal MARVEL COAL RED ASH Mined and Sold Exclusively by ON BOTH Louisville and Nashville and i Southern Railways Capacity, 1,500 TONS DAILY RODEN COAL COMPANY Marvel, Alabama Alabama Fuel and Iron Company 742-749 Brown-Marx Building Miners and Shippers of Acton=Margar et= Acmar - High Grade Steam and Domestic i ' • I GENERAL OFFICES BIRMINGHAM, ALABAMA. _ i.