Report, Band 8Johns Hopkins Press, 1909 CONTENTS.--Vol. I (1897)--Vol. II (1898)--Vol. III (1899)--Vol. IV (1902)--Vol. V (1905)--Vol. VI (1906)--Vol. VII (1908)--Vol. VIII (1909)--Vol. IX (1911)--Vol. X (1918)--Vol. XI (1922)--Vol. XII (1928)--Vol. XIII (1937)--Vol. XIV (1941) |
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Allegany County alumina amount analyses argillaceous average Baltimore and Ohio Baltimore County Big Vein Brick burning calcareous cars cement plant cement rock cent chemical City Engr clays clinker coal bed Cockeysville color composition cost Cumberland and Pennsylvania deposits E. G. Zies east employed Engineer feet formation Frederick County Frederick Valley Frostburg furnace Garrett County Georges Creek Hagerstown Valley Helderberg hydrated lime hydraulic Ignition impurities Iron oxide J. J. Porter kilns lime and cement Lime CaO limestone located M. R. Schmidt magnesia Magnesia MgO manufacture of Portland marble marl MARYLAND GEOLOGICAL SURVEY mile mill minerals Mining Company Montello natural cement occur operation output Pennsylvania Railroad Piedmont Portland cement Potomac pounds quarry raw materials Ridge road sample sandstone seam shale side silica Silica SiO2 slag slates stone T. M. Price thickness tipple tons Total tracks Tyson Union Bridge upper ventilation volcanics Washington County Western Maryland Railroad western Piedmont
Beliebte Passagen
Seite 144 - In examining sand in order to ascertain its value for glass making, inspection with a magnifying glass is the best preliminary test. The following points should be observed : The sand should be nearly white in color; it should be of medium fineness (passing a 20 to 50 mesh horizontal sieve) ; the grains should be uniform in size, even, and angular, or, less preferably, they may be rounded. A simple chemical test may be employed by heating the sand in a dilute acid. Effervescence indicates the presence...
Seite 149 - ... ago of much more extensive deposits in other sections of the country, in Michigan, Minnesota, and Alabama, as well as in Cuba, coupled with the incidental extension and cheapening of transportation resulted in driving out the old charcoal furnaces and thus left no place for the lean ores of Maryland. Within the last few years, however, there has been a revival of interest in the abandoned iron-ore deposits of the eastern seaboard states and already their importance as sources of ore supply has...
Seite 315 - X, p. 181. gas-slack coal contains about 10 per cent, of ash in practice. This ash is composed of about 40 per cent, silica and about 20 per cent, each of iron oxide and alumina. If, therefore, 90 pounds of coal are required to burn a barrel of cement, about 16 pounds (equivalent to 1.5 pounds of ash) are required per 100 pounds of raw material burned. Assuming half the ash to enter the raw material, the silica in the latter is increased by £x 1.5x0.40 = 0.30 per cent., and the iron and alumina...
Seite 100 - Vein," but the gradual exhaustion of this wonderful seam has led to the exploitation with most satisfactory results of many of the " Small Veins " both above and below the chief seam. There are many companies to-day mining the smaller seams either exclusively or in conjunction with the large seam. There is unquestionably a great future for these smaller seams in Maryland, especially in the Upper Potomac basin in southern Garrett County, where they reach their greatest thickness. The total amount...
Seite 148 - One of the most important factors in the development of the iron industry was the organization in 1722 of the Principio Company, which in that year commenced the erection of a furnace in Cecil county near the mouth of Principio creek. This company was composed of English gentlemen of wealth who were familiar with iron , manufacture in the old country. At an early date in the history of this enterprise, probably 1725, Augustine and Lawrence Washington, the father and half-brother of the future President...
Seite 154 - Diatomaceous earth, known in the trade under the name of ''silica," "infusorial earth," or "tripoli," is composed of the minute shells or tests of microscopic plants known as diatoms. It was first reported from the vicinity of Richmond, Virginia, and for that reason received the name of "Richmond earth," under which term it is sometimes referred to in the literature.
Seite 251 - The hydrator consists of a number of cylinders, one over the other, which are provided with paddles revolving around a central shaft. The lime is fed into the upper cylinder in a continuous stream and here water is sprayed upon it, the amount being regulated by valves. The moist lime is worked by the paddles and passes from the upper cylinder to the lower ones.
Seite 313 - In mill practice, however, it is seldom that as high a ratio as this can be carried. Just what the ratio should be depends upon conditions of manufacture and the nature of the materials. When the alumina is low this ratio is often carried as low as 1.9 without obtaining quick setting cement.
Seite 276 - ... also said to give, in replacing and lowering the amount of alumina, the cement the property of resisting the magnesium sulphate (Mg S04) of sea-water. Cement made from materials containing alumina and no iron is perfectly white. It requires a higher temperature to burn, but when properly clinkered possesses all the setting and hardening properties of Portland cement. White Portland cements are now made at York, Pa., * RK Meade. 7th Congress of App. Chem.; see Chem. Eng., X, 187. Canaan, Mass.,...
Seite 297 - SURVEY 303 etc., and distances from the leading markets. From these facts the investigator, be he a geologist, mining engineer, or even an untrained prospector acting for himself, or another, may decide in what particular district it would probably be best to locate and where detailed work may be pursued with the best chances of finding sufficient material of a composition suitable for the purpose. One can hardly expect, however, to find in geological reports the detailed information as to the quantity...