JOURNAL OF THE CHINESE CERAMIC SOCIETY TOTAL CONTENTS Vo1.30,No.1～6,2002

SubjectCeramicAuthor [No.](Page)Effect of Annealing Temperature and Doping on Characteristics of Pseudocapacitors Utilizing Nickel Oxide Electrode ………………………………………………………LiangKui,ChenAi,Wu Mengqiang,^kLi,Zhou WangSiC Whisker Synthesized by Sol—Gel and Carbothermal Reduction Reaction …………………………………………………讹n Long,Liu Yuanfeng,Lu Zhian,Li眈撕,Tang ShaoqiuInvestigation on the Mechanism of Self-Propagating High—Temperature Synthesis Ni——Zn …     

JOURNAL OF THE CHINESE CERAMIC SOCIETY TOTAL CONTENTS Vol.2 9,No .1～ 6 ,2 0 0 1

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BENEFITS OF A COÖRDINATED PROGRAM OF CERAMIC INVESTIGATIONS BY FEDERAL,STATE, AND UNIVERSITY AGENCIES1

The rapid development of ceramic technology is necessary to the well-being of our industry. A comprehensive plan should be laid out and the required machinery, responsible to the manufacturers, set up to accomplish this.     

USE OF BROMATE IN VOLUMETRIC ANALYSIS: IX,DETERMINATION OF ARSENIC AND ANTIMONY BY THE GYÖRY METHOD*

The determination of arsenic and of antimony by the oxidation of the hydrochloric acid solutions of their tervalent forms using standard bromate as oxidant by the Györy method has long been a preferred procedure. This method involves the use of strongly acid, hot solutions and nonreversible internal dye-stuff indicators. Difficulties result from the instability of the indicators under the required conditions. The published improvements as applied to the Györy method are discussed and evaluated. The new study of the old procedure shows that the use of a hot solution is not required. The experimental proof of this conclusion is given, and the use of the “electron beam sectrometer” and a modified “dead stop” equivalence-point determination has been applied to establish the concordance between the potentiometric and visual indicator applications. The performance of the various applicable internal indicators has been described and those preferred are specified.     

THE OXIDATION OF CERAMIC WARES DURING FIRING.1 IV.—THE ABSORPTION OF SULPHUR GASES BY FERRIC OXIDE IN CLAY

The nature and amount of absorption of sulphur gases by an almost pure clay to which seven per cent of ferric oxide had been added is studied at various temperatures. Ferrous salts and sulphites were found as traces or not at all. The amount of ferric sulphate increased with increasing temperature on a smooth curve to a maximum at about 450 °C, then decreased sharply to almost nothing at 630 °C. At its maximum, nearly half of the iron present was in this form. Most of the remaining iron was in an insoluble form called “ferrous sulpho-silicate.” On the basis of this work, recommendations are made in regard to kiln fuels.     

THE OXIDATION OF CERAMIC WARES DURING FIRING.—II. THE DECOMPOSITION OF VAFUOUS COMPOUNDS OF IRON WITH SULPHUR UNDER SIMULATED KILN CONDITIONS1

The progress of sulphur evolution is traced from a series of clay bars containing known amounts of various iron-sulphur compounds, both with and without the addition of carbon, when heated in imitation of a kiln schedule in atmospheres varying from pure oxygen to those commonly encountered in kiln practice, including neutral and reducing atmospheres. The varying degree of incompleteness of sulphur evolution is noted. The residual sulphur is found to be practically insoluble in water or aqua regia, but is rendered soluble by hydrofluoric acid. As a plausible explanation there is advanced the theory of the formation of “ferrous sulpho-silicate.”     

THE OXIDATION OF CERAMIC WARES DURING FIRING.—I. SOME REACTIONS OF A WELL KNOWN FIRE CLAY1

After a review of the literature, a chemical laboratory study is made of the gases evolved on heating a lower Kittanning fire clay at various rates to various temperatures in a current of pure oxygen. The rates of evolution of CO₂, SO₂, and SO₃ are determined under varying conditions. Determinations of the remaining sulphur in the clay after heating are made. Possibilities as to the chemical mechanism of sulphur evolution are suggested. Plans for continuation of the work are outlined.     

FUNDAMENTAL STUDY,AND EQUIPMENT FOR SINTERING AND TESTING OF CERMET BODIES,I–III*

Cermet bodies, † composed of metals and oxides, are being developed for high-temperature service. Part I covers the theoretical aspects of experiments of a fundamental chemistry nature which accompanied the laboratory development of test specimens. Compacts of metal powders (Xi, Fe, Co, Cr, and Cr-B) were fired at 2880° to 3500°F. on pure Al₂O₃ tile in various controlled atmospheres. The results indicate that a controlled layer of oxide on the surfaces of the metal-powder grains is essential for good bonding. Special furnaces, described in Part II, were necessary for the fundamental study and for sintering cermet specimens. Equipment for determining instantaneous modulus of rupture and tensile rupture, and longtime stress-rupture in bending at temperatures up to 2400°F., is described in Part III.     

CLAY SEWER PIPE MANUFACTURE.—IV. THE INFLUENCE OF DIFFERENT SALT GLAZING TEMPERATURES UPON THE COLOR AND GLOSS OF GLAZES OBTAINED ON CLAYS WITH VARYING SILICA,ALUMINA, AND IRON OXIDE CONTENTS1

Object .—A study was made of the effects of different salt glazing temperatures upon the color and brightness of salt glazes produced upon clays with varying silica, alumina, and iron oxide contents. Results .—In tests conducted in commercial kilns operating under normal conditions, it was found that increasing the salt glazing temperatures has a tendency to produce duller and darker glazes on clays containing iron oxide. The brightness of the glazes produced may be approximately represented by the following formula: -1.00×₁+ 0.376×₂ - (1.885 + 0.385(1.01253)^(T-1110))×₃= 100G ×₁, ×₂ and ×₃ represent the percentages of silica, alumina and iron oxide, respectively. T is the salt glazing temperature in °C. When G was greater than 0, the glazes were bright; when between -0.1337 and 0 they were semi matt; and when less than -0.1337 they were matt. The color obtained may be approximately represented by the following formula: 10.3x₁ - 2.65x₂+ (14.6 + 54.1 (1.0066)^(T-1110))x₃= 100°C When C was between 0 and 2, white to tan glazes were produced; when between 2 and 3.5, light brown glazes were obtained; when between 3.5 and 4.75, brown glazes were produced; when between 4.75 and 8.2, mahogany colors were obtained; and when above 8.2, dark brown to black glazes were produced. Clays containing a high iron oxide content should be salt glazed at low temperatures while clays containing a low iron oxide content should be glazed at high temperatures to produce the best glazes. Decreasing the iron oxide and alumina contents will improve the brightness of the salt glazes. High alumina clays will produce darker colors than high silica clays with the same percentage of iron oxide.     

DENSITIES AND DERIVED THERMODYNAMIC PROPERTIES OF THE BINARY SYSTEMS OF BENZENE WITH BUTYL METHACRYLATE,ALLYL METHACRYLATE,METHACRYLIC ACID,AND VINYL ACETATE AT 298.15 K

Densities of the binary systems of benzene with butyl methacrylate, allyl methacrylate, methacrylic acid, and vinyl acetate have been measured as a function of the composition, at 298.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess molar volumes are positive for the four binaries studied.     

INFLUENCE OF VARIABLE AMOUNTS OF NEW YORK TALC,FLINT, AND CALCINED CLAY ON SERVICEABILITY OF GLAZÉD COOKING-WARE BODIES*

The effect of composition on the ability of glazed dishes to withstand thermal-shock treatments ordinarily received in cooking was studied. Bodies which gave best results contained approximately 10% of New York talc and also a small amount of calcined clay substituted for potters' flint. Bodies which had sufficiently high thermal expansion to throw the glaze into moderate or strong compression gave the best results. A terra sigillata finish applied to talc-free bodies was found to withstand autoclave treatment without crazing, and ware so made stood up very well in service tests.     

PREPARATION AND ADSORPTION PROPERTIES OF THE POLYSTYRENE RESIN HAVING DIETHYLENETRIAMINE-N,N′- BIS(METHYLENEPHOSPHONATE) GROUP

Styrene-divinylbenzene copolymer beads containing diethylenetriamine-N,N′-bis(methylenephosphonate) group have been synthesized. The adsorption properties, of the present resin for some trivalent and bivalent metal ions have been examined. The selectivity sequence of the present resin at pH lower than 2.0 is as follows: Ga(III)> A1(III)> Sm(III)>Cu(II)>Co(II)>Zn(II)>Ca(II). The present resin reveals remarkable selectivity for the trivalent metal ions. The selective concentration of In(III) Ga(III) and Sm(III) from an acidic aqueous solution has been demonstrated by using a column of the present resin.