摘要:

AbstractThe rate at which North Carolina kyanite of various grain sizes decomposes into mullite and glass in the range 1350° to 1600 °C. is given. Kyanite from other sources is also discusse

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14270.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractThis investigation was undertaken to ascertain whether or not certain properties of kaolinite are definite functions of particle size. The studies were carried out on carefully fractionated, single‐base kaolinite. The following properties of these fractions were measured: (a) base‐exchange capacity, (b) permeability, (c) heat of wetting, (d) thermal conduct, and (e) drying shrinkage. Base‐exchange capacity, heat of wetting, and drying shrinkage are not simple functions of the measured particle size of kaolinite because of the unpredictable physical characteristics and habits of the crystalline aggregates. The first three properties named are each linear functions of the other. These properties are independent of the physical groupings of the kaolinite crystals and therefore cannot be predicted from measured particle size except in the case of the finest fractions. Permeability is dependent both on apparent surface and true surface. Thermal‐analysis curves may be useful as a rough guide to clay pro

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14271.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractThe addition of aluminum metal powder to fire‐clay‐grog mixtures greatly increased the strength of the fired brick as a result of an aluminothermic reaction between the metal and the silica in the clay and grog. Because the reaction takes place at 930°C. and causes the temperature to rise rapidly, it is necessary to heat these refractories only to 930°C. to produce hard, well‐fired brick. Such products have a high load‐carrying capacity at furnace temperatures and also a fair spalling r

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14272.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractThe effect of heat treatments on the chemical, physical, and mineralogical properties of topaz is described. The samples were obtained from a deposit of potential commercial importance. Brick made from calcined and uncalcined topaz were tested according to standard A.S.T.M. test methods, and the results are presented.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14273.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractThe electrical conductivity of some glasses in the soda‐lime‐silica system was measured at 400 °C. with an apparatus which is described. The specific resistance at this temperature ranged from 0.06 to 5.0 × 105ohms per cc. Measurements were made on other glasses containing equivalent amounts of various oxides incorporated in a parent soda‐lime‐silica glass. It was found that an increase in resistance was produced by additions of MnO, ZnO, B2O3, Fe2O3, BaO, PbO, TiO2, and K2O, the resistances increasing in this order. A decreased resistance was produced by Na2O, CaO, and Al2O3. Previously published data on the power factors of these glasses are

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14274.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractThe effect of the substitution of A12O3for the oxides of sodium, silicon, calcium, and magnesium in the ratio in which they occur in dolomite on the liquidus temperatures and phase relations for glasses lying within the composition range, Na2O 12 to 16%, CaO‐MgO 0 to 20%, SiO263 to 78%, and A12O30 to 10%, has been determined. The results on 116 individual determinations are given. Devitrite is the primary phase in very few glasses. Several glasses were found which cannot be devitrified. A comparison of devitrification temperatures of calcite and dolomite‐lime glasses is m

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14275.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY

摘要:

AbstractSix samples of clay from Dutch Guiana were analyzed chemically and thermally to determine the silica, the alumina, and the clay minerals present. The thermal method gives excellent quantitative results with a precision of 3 or 4% on clays of this type. Thermal curves are also shown for a few other hydrated iron minerals as data on these were not previously available.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1940.tb14276.x

出版商:Blackwell Publishing Ltd    

年代:1940

数据来源: WILEY