Bulletin, Issues 281-285

Front Cover
U.S. Government Printing Office, 1906 - Geology
 

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Page 64 - ... of the clayey materials. The burning takes place at a high temperature, approaching 3,000 F., and must, therefore, be carried on in kilns of special design and lining. During the burning, combination of the lime with silica, alumina, and iron oxide takes place. The product of the burning is a semi-fused mass called clinker, and consisting of silicates, aluminates, and ferrites of lime in certain definite proportions.
Page 64 - Portland cement mixture, when ready for burning, will consist of about 75 per cent of lime carbonate (CaCO3) and 20 per cent of silica (SiO2), alumina (AI2O3), and iron oxide (Fe2O3) together, the remaining 5 per cent including any magnesium carbonate, sulphur, and alkalies that may be present. The essential elements which enter into this mixture — lime, silica, alumina, and iron — are all abundantly and widely distributed in nature, occurring in different forms in many kinds of rocks. It can...
Page 115 - The oil and salt pockets of the Texas Coastal Plain are probably not indigenous to the strata in which they are found, but are the resultant products of columns of hot saline waters which have ascended, under hydrostatic pressure, at points along lines of structural weakness, through thousands of feet of shale, sand, and marine littoral sediments of the Coastal Plain section, through which oil and sand are disseminated in more or less minute quantities.
Page 65 - The more important of these factors are: 1. Chemical composition of the material. 2. Physical character of the material. 3. Amount of material available. 4. Location of the deposit with respect to transportation routes. 5. Location of the deposit with respect to fuel supplies.
Page 7 - ... to correct errors and make the line continuously good throughout. The latter or primary levels are determined with the Y level, precautions being taken against only the principal errors and the levels being run mostly in circuits of single lines. The allowable limit of error observed on the precise work already done by the Geological Survey in this State is represented in feet by 0.02 times the square root of D, and that for the primary...
Page 65 - ... mixture, varying from one extreme, where a natural rock of absolutely correct composition was used, to the other extreme, where two or more materials, in nearly equal amounts, are required. The almost infinite number of raw materials which are theoretically available are, however, reduced to a very few under existing commercial conditions. The necessity for making the mixture as cheaply as possible rules out of consideration a large number of materials which would be considered available if chemical...
Page 8 - ... number at the same time gives an approximate statement of the elevation. It is assumed that engineers and others finding these bench marks so stamped in the field will communicate with the director of the United States Geological Survey in order to obtain the accepted elevation to hundredths or thousandths of a foot.
Page 14 - British thermal unit (BTU) is the. amount of heat required to raise the temperature of 1 pound of water 1 F.
Page 66 - Location with respect to fuel supplies. — Every barrel (380 pounds) of Portland cement marketed implies that at least 200 to 300 pounds of coal have been used in the power plant and the kilns. In other words, each kiln in the plant will, with...
Page 66 - ... year. As the shale or clay may be assumed to contain considerable water, a cubic foot will probably contain not over 125 pounds of dry material, SO that each kiln will also require about 80,000 cubic feet of shale or clay. A cement plant is an expensive undertaking, and it would be folly to locate one with less than twenty years' supply of raw material in sight.

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