Economic geology: with special reference to the United States

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Macmillan, 1910 - Technology & Engineering - 589 pages

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Page 531 - For each 0.02 per cent, or fraction thereof, in excess of 0.20 per cent phosphorus there shall be a deduction of 2 cents per unit of manganese per ton. Ores containing less than 40 per cent manganese or more than 12 per cent silica or 0.225 per cent phosphorus are subject to acceptance or refusal at the buyer's option. Settlements are based on analysis of sample dried at 212 F., the percentage of moisture in the sample as taken being deducted from the weight.
Page 553 - ... subjected. This left them in the right physical condition to be readily jointed and fissured by the contraction of the diabase. After the deposition of the cobalt-nickel arsenides, which seem to be among the first minerals deposited, the veins appear to have been slightly disturbed, giving rise to cracks and openings in which the silver and later minerals were deposited. Veins which escaped this later, slight disturbance contain little or no silver.
Page 18 - Dry storage has no advantage over storage in the open except with high sulphur coals, where the disintegrating effect of sulphur in the process of oxidation facilitates the escape of hydrocarbons or the oxidation of the same.
Page 221 - This addition is not as an adulterant, as was the case a few years ago, for it is now appreciated that the addition of barytes makes a white pigment more permanent, less likely to be attacked by acids, and freer from discoloration than when white lead is used alone.
Page 62 - It is, of course, necessary that the oil-bearing stratum shall be capped by a practically impervious one. If the rocks are dry, then the chief points of accumulation of the oil will be at or near the bottom of the syncline, or lowest portion of the porous bed. If the rocks are partially saturated with water, then the oil accumulates at the upper level of saturation.
Page 37 - ... DISCOVERY. Though La Salle in his hypothecated descent from the headwaters of the Allegheny to the Falls of the Ohio in 1669-703 would have passed by the eastern Kentucky coal field, he left no record indicating that he found coal during these explorations. To Father Hennepin,4 a French Jesuit Missionary, who in 1679 recorded the site of a "cole mine...
Page 294 - The pressure, although primarily due to variations In level In the different parts of the artesian system, may be transmitted in so many ways and is subject to so many modifying factors that the postulation of a specific cause is impracticable.
Page 523 - Some of the Leadville ores are used in the manufacture of spiegeleisen. All the other localities produce these ores for fluxing only. Manganiferous zinc residuum is obtained from zinc volatilizing and oxidizing furnaces using New Jersey zinc ores. The residuum consists largely of iron and manganese oxide, the zinc having been removed by volatilizing and collected as zinc oxide.
Page 143 - Portland cement is the product obtained by burning a finely ground artificial mixture consisting essentially of lime, silica, alumina, and some iron oxide, these substances being present in certain definite proportions. Portland cement was first made by Joseph Apsdin, of Leeds, England, who desired to make an artificial cement that would replace natural hydraulic cements. It received its name because it hardened under water to a mass resembling the Portland stone of England. The following combinations...

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