Bulletin, Ausgabe 17

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University of Illinois, 1912
 

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Seite 63 - Sand. 7 days (1 day in moist air, 6 days in water)... 200 Ibs.
Seite 20 - Clay may be defined as a complex derivative rock, generally of a soft and earthy nature, in which a mass of mineral debris of variable composition and amount is bonded and held together by a matrix of kaolin, or allied hydrous silicates of alumina. The distinguishing characteristics of clays as a class are, first, plasticity when ground and mixed with sufficient amount of water; and second, the property of hardening by heat to form strong and durable silicates. This definition is not exact, for there...
Seite 21 - ... the one obtained by means of the Le Chatelier formula. Owing to the fact that a great amount of data is now available concerning the composition of Portland cements, this method of calculation is justifiable and practical; any changes involving a decrease or an increase in the amount of lime must be made empirically in any case. Once having established the best proportion of a mixture, the daily mixture can be calculated from the raw materials available by the following simple calculation: Let...
Seite 121 - ... Analysis of Waters from Various Parts of the State. Classification of waters according to physical and chemical properties, by Edward J. Bartow; Geological Classification of Waters of Illinois, by JA Udden; Boiler Waters by SW Parr; Medicinal Springs of Illinois, by Dr. George Thomas Palmer. Postage 7 cents. Bulletin 11. The Physical Features of the Des Plaines Valley, by James Walter Goldthwait. Geography and History of the Des Plaines Valley; Structure of Bed Rock. Deposition of Paleozoic Sediments....
Seite 35 - O.OGO per cent. A cement with 2.8 per cent free lime showed an expansion of 0.220 per cent in the same period. The effect of magnesia like that of lime depends less upon its total amount than upon the form in which it exists. Combined magnesia like combined lime has no injurious effect in Portland cement. Magnesia combined with silica and alumina forms a hydraulic cement which is safe but a,s compared with Portland cement is too weak to be of any commercial value. Free magnesia has no appreciable...
Seite 35 - ... between pebbles and the charge takes place anywhere except at the point where the pebbles strike the surface on falling from the highest point. The pebbles climbing up the side of the mill drop away from it as soon as the vertical component of the forces acting upon It is equal to the centrifugal force. "The grinding effect depends on the vertical distance of the drop, the velocity of the drum, and weight and number of the pebbles.
Seite 35 - The last named investigators1 probably offer the soundest view upon this subject, which is quoted as follows : "The effect of magnesia, like that of lime, depends less upon its total amount than upon the form in .which it exists. Combined magnesia, like silica lime, has no injurious effect in Portland cement. Magnesia combined with silica and alumina forms a hydraulic cement which is safe but, as compared with Portland cement, is too weak to be of any commercial value. Free magnesia has no appreciable...
Seite 22 - Not constant in volume (does not stand boiling test.) Store longer. Decrease lime content or increase content of ferric oxide, or increase silica content in clay base; grind raw mixture finer; reduce sulphur content. Tendency to dust. Increase lime content; quench clinlter in water or cool rapidly in air; add ferric oxide to raw mix.
Seite 29 - ... will be unnecessary. 3. Fire Clays. — This is a somewhat indefinite term, standing in general for clays which do not melt at high temperatures. A great deal of confusion prevails in regard to the conception of high temperatures among practical men. Though no definite limit has ever been put down, it may be said that no clay can be called a fire clay or refractory clay unless it stands a temperature approximately 3000° F. or 1650° C, expressed in the scale of fusible cones adopted by Seger...
Seite 30 - This mill (see figure 40) consists essentially of a revolving ring and three rolls pressing against its inner face. The rolls are convex and the ring is concave and tracks on the rolls. Springs support the rolls yieldingly and the rolls support the ring so that the four crushing parts are free to move. The material falls from the inlets on to the inner face of the ring.

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