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Seite 510 - Stove lining not separately classified prior to 1899. c Includes all products not otherwise classified, and those made by less than three producers, in order that the operations of individual establishments may not be disclosed. d Includes pottery for New Hampshire.
Seite 50 - ... 3. The color to which the clay burns. This may be judged approximately, for clays with several per cent. or more of ferric oxide will burn red, provided the iron is evenly and finely distributed in the clay, and there is no excess of lime. The above conditions will be affected by a reducing atmosphere in burning, or the presence of sulphur in the fire gases.2 4.
Seite 514 - REPORT ON THE CLAY DEPOSITS of Woodbridge, South Amboy and other places in New Jersey, together with their uses for firebrick, pottery, &c.
Seite 105 - ... of any sample that will pass through a sieve of 100 or 150 meshes to the inch, since in the preparation of clays for the market by the washing process they are not required to pass through a screen any finer than the one above mentioned.
Seite 49 - ... and lime (CaO), with the percentage of each given separately. The sum of these two percentages would, however, be equal to the amount of lime carbonate present. While the ultimate analysis, therefore, fails to indicate definitely what compounds .are present in the clay, still there are many facts to be gained from it. The ultimate analysis of a clay might be expressed as follows: Silica (SiO2) Alumina (A12O3) Ferric oxide .... (Fe2O3) Lime (CaO) Fluxing impurities Magnesia ....... (MgO) Alkalies..
Seite 100 - For practical purposes these cones are very successful, though their use has been somewhat unreasonably discouraged by some. They have been much used by foreign manufacturers of clay products and their use in the United States is increasing. The full series can be obtained from Messrs. Seger and Cramer, of Berlin, for $0.01 each (or about two and one-half cents apiece, including duty and expressage), or numbers .010 to 35 can be obtained for $0.01 each from Prof.
Seite 44 - Mica. — This is one of the few minerals in clay that can be easily detected with the naked eye, for it occurs commonly in the form of thin, .-scaly particles whose bright, shining surface renders them very conspicuous, even when small. Very' few clays are entirely free from mica, even in their washed condition, for, on account of the light scaly character of the mineral, it floats off with the clay particles. Some clays are highly micaceous, but such are rarely of much commercial value.
Seite 103 - While the temperature of fusion of each cone is given in the preceding table, it must not be understood that these cones are for measuring temperature, but rather for measuring pyrochemical effects. Thus if certain changes are produced in a clay at the...
Seite 91 - The cracking of some fine-grained clays in drying is due partly to the surface shrinking more rapidly than the interior, because the evaporation there is greatest. As the outer portion of the product cannot stretch, it must pull apart and crack. Fire shrinkage. — All clays shrink during some stage of the burning operation, even though they may expand slightly at certain temperatures. The fire shrinkage...
Seite 57 - All of the iron ores will in burning change to the form of oxide, provided the clay is not vitrified, and so affect the color of the burned material ; if vitrification occurs, the iron oxide enters into the formation of silicates of complex composition. The color and depth of shade produced by the iron will, however, depend on 1st, the amount of iron in the clay ; 2d, the temperature of burning ; 3d, condition of the iron oxide, and 4th, the condition of the kiln atmosphere.

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