摘要:

AbstractCordy glass consisting of a mixture of fibers or laminations of various glasses of slightly differing compositions is separated in the form of powder by differences of density. These differences in general run parallel with differences of thermal expansion which produce the polariscopic appearance of cordiness. The separated fractions can be analyzed chemically, and therefore, perhaps, for the first time an estimate can be made of the chemical errors involved in the cords of the old polariscopic gradings, A, B, C. The most important features of the technique are (1) the elimination of moisture from the glass and the suspending liquid and (2) the use of a special centrifuge with accurate control of temperature.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1941.tb14818.x

出版商:Blackwell Publishing Ltd    

年代:1941

数据来源: WILEY

摘要:

AbstractUsing the disappearance of batch as a criterion of melting, a comparison of the rate of melting of twenty‐six soda‐lime‐silica glass compositions has been made. With the composition, Na10 14%, CaO 12%. and SiOt (+R20.) 74%, as abase glass, theeffect of substituting small amounts of B.O., BaO, SOI, etc., on the rate of melting was studied. Theraw materials used were soda ash, calcite limestone. silica sand, dehydrated borax, barytes, salt cake, Chilean saltpeter, ammonium sulfate, fluorspar, and common

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1941.tb14819.x

出版商:Blackwell Publishing Ltd    

年代:1941

数据来源: WILEY

摘要:

AbstractThe effect of various electrolytes on the acid resistance, “set,” and defects of acid‐resisting enamels was studied. The defects encountered were scumming, pitting, and shorelining. It was found that (1) insufficient set caused scumming which was aggravated by aging the enamel; this defect may be eliminated by increasing the set of the enamel; (2) one of the enamels studied had a marked tendency to shoreline whenever a sulfate or an electrolyte containing the sulfate radical was used; and (3) the pitting tendency of one enamel was traced to the high soluble salt content of the mill liquor; this defect was eliminated by spraying the enamel at a high gravity or by applying the acid‐resisting enamel in a heavier coating. Some of this work has been continued in regular plant practice, and a discussion of this phase of the work is i

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1941.tb14820.x

出版商:Blackwell Publishing Ltd    

年代:1941

数据来源: WILEY

摘要:

AbstractThe action of a considerable number of pure oxides, fluorides, chlorides, borates, phosphates, carbonates, and other compounds and of certain mixtures, as well as the effect of several minerals in promoting or accelerating the inversion of quartz to cristobalite and tridymite at temperatures between 1000 and 1500°C. has been studied. Alkali oxides are found to be superior to all other substances, and they are effective in amounts of less than 0.1%. Acid oxides, such as BIOs or Plot., seem to have little or no value as catalysts for this inversion. Possible mechanisms for the inversion process are presented, and some applications of controlled inversion in the heat treatment of ceramic bodies are mentioned. A few data are also given on the temperature of the “low‐high’ change in cristo

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1941.tb14821.x

出版商:Blackwell Publishing Ltd    

年代:1941

数据来源: WILEY

摘要:

AbstractA method of preparing clean clay suspensions is described. Organic matter is removed by hydrogen peroxide and sodium hydroxide digestion, followed by an electro‐dialysis treatment to remove other inorganic salts and to prepare a clay‐water suspension. After NaOH is added, viscosity and titration values are given for (a) a regular water‐washed Florida clay, (b) the same clay after electrodialysis, and (c) the same clay after a thorough cleaning according to the method described. If the sample contains lignite, a clean clay exhibits rheopexy at certain concentrations of

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1941.tb14822.x

出版商:Blackwell Publishing Ltd    

年代:1941

数据来源: WILEY

摘要:

AbstractThermal‐expansion and moisture‐expansion determinations were made on four kaolins of the Georgia, Florida, North Carolina, and English types alone and on typical semivitreous, hotel china, and electrical porcelain bodies embodying each of these kaolins after being fired at cones 6, 9, and 11. The Georgia and Florida kaolins and bodies showed surprisingly similar expansion characteristics. The general order of decreasing thermal expansion and increasing moisture expansion of the kaolins at all three firing treatments was Georgia, Florida, North Carolina, and English china. The semivitreous bodies at cones 6 and 9 showed the same order of expansion as the kaolins alone, but at cone 11 the thermal expansion of the English china clay body was the highest and the North Carolina kaolin body next in order. Moisture expansion of the bodies at cone 11 was found to be a function of the absorption, regardless of the kaolin used with no expansion obtaining at zero absorption. Mixtures of clay, flint, and feldspar, given an autoclave treatment after being fired to cones 6 and 9, showed that feldspar additions increased moisture expansion. When these mixtures were dehydrated at different temperatures, the data obtained were insufficient to confirm any theory on the nature of moisture expansion in a porous ceramic b

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1941.tb14823.x

出版商:Blackwell Publishing Ltd    

年代:1941

数据来源: WILEY