A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . to the market of other seams, olijects of national importance. The differences between the specific gravities of coal and its impurities, allow of theirbeing separated by the action of water when sufficiently crushed. The water processhitherto most commonly adopted is that known as jigging, which consists in forcing thewater alternately up and down through the mass of coal. The downward current of waterin jigging is prejudicial, and entails a large sacrifice of
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . to the market of other seams, olijects of national importance. The differences between the specific gravities of coal and its impurities, allow of theirbeing separated by the action of water when sufficiently crushed. The water processhitherto most commonly adopted is that known as jigging, which consists in forcing thewater alternately up and down through the mass of coal. The downward current of waterin jigging is prejudicial, and entails a large sacrifice of the finer particles of the bestcoal; whilst the upward current, from its rapidity and irregularity, is costly both in timeand power, besides failing to effect the more perfect separation which is obtained by a slow,continuously ascending or pulsating current, regulated to the proportion of shale in thecoal, and to the size of the particles to be acted upon. MackwortKs patent coal purifier.—In the late Mr. Herbert Mackworths purifier, , the water ascends with a velocity of an inch or two in a second. It is sufficient to. DatictR rra/\p~~- keep the particles in constant agitation, and the area of the separator can be reduced to asmall fraction of its former size. The coal is supplied into the machine in a uniformstream, and as it is purified is raised out of the water on to a perforated plate, and delivered WASHING COAL. 1073 by the coal-sweep into a long perforated shoot, down which it descends into the tram orwagon placed to receive it. The purified coal is thus obtained for coking and otlicr pur-poses in a comparatively drier state. Tlie shale, which has during the so[)aratiou accunm-lated in the shale-box, will discharge itself into anotlier tram without stopping the machine,if the shale valves are fiist closed by the valve lever belore throwing open the shale pump, or agitator, is capable of throwing from 50 to 200 gallons of water per minute,according to t
Size: 1764px × 1417px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864
