巻号一覧
前身誌
1992 巻, 237 号
選択された号の論文の8件中1～8を表示しています
- |<
- <
- 1
- >
- >|
-
高橋 聡, 関 正伸, 瀬戸山 克己1992 年 1992 巻 237 号 p. 72-78
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーIn the previous investigation on CaSO4-SrSO4-H2O system, the authors made clear the formation of new products SrSO4·1/2H2O and (Cax, Sri-x) SO4·-1/2H2O-the solid solution between CaSO4·1/2H2O and SrSO4·1/2H2O and their behavior in water 8). In the present paper, the change of phase of these new products on heating has been studied. The results obtained were as follows;
Hexagonal SrSO4 ·1/2H2O was dehydrated on heating to hexagonal anhydrous SrSO4, which was unstable and rehydrated rapidly to hemihydrate by moisture in air. On further heating, hexagonal anhydrous SrSO4 changed to orthorhombic and then cubic SrSO4, both of which are already known phase. The process of this change of phase on heating was understood to be entirely similar to that for β-CaSO4 ·1/2H2O
Hexagonal solid solution hemihydrate (Cax, Sr1-x) SO4·1/2 H2O changed likewise on heating to hexagonal anhydrous solid solution, followed by phase separation on further heating into II-CaSO4 and orthorhombic anhydrous SrSO4, both of which were considered respectively to be limited solid solution each other.
The correlation between these polymorphism for CaSO4-SrSO4-H2O system are shown by flowsheet.抄録全体を表示PDF形式でダウンロード (858K) -
副田 孝一, 檜田 俊晴, 林 浩志, 上林 真幸1992 年 1992 巻 237 号 p. 79-84
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーIn previous report, authors mentioned that blown out shot occured using only quick lime, and approximately 100kg f/cm2 of expansive stress was obtained when adding retarding agent to hard burned quick lime.
In this report, the influence of additives such as cement minerals and super plasticizer on the expansive stress of quick lime was examined. The results are as follows.
1) When adding anhydrite to quick lime, the hydration is slightly delayed and 100kg f/cm2 of expansive stress is obtained.
2) When adding calcium aluminate to quick lime, the hydration is not delayed at all and it is impossible to charge it into the pipe.
3) Alite possesses large delaying effect on CaO hydration among additives, and expansive stress of quick lime added it reaches 160kg f/cm2. The reason of this is assumed that the expansion of CaO works effectively on side wall as expansive stress because of self-hardening property of alite.
4) When adding super plasticizer to CaO-Alite, expansive stress increases enormously to more than 300kg f/cm2.抄録全体を表示PDF形式でダウンロード (1012K) -
金 尚奎, 鶴見 敬章, 大門 正機1992 年 1992 巻 237 号 p. 85-91
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーThe mechanism of carbonation in the synthesized Ettringite (3CaO ·Al2O3 ·3CaSO4 ·32H2O) was studied by means of a reaction device, which is capable of the real-time measurements of the amount of carbon dioxide gas absorbed and the weight change of specimen under the fixed carbon dioxide gas concentration, relative humidity and temperature. As a result, it was found that the carbonation rates of Ettringite and the amount of water released by carbonation changed with relative humidility. From the change of weight, the amount of carbon dioxide gas absorbed and the characterization of reaction products, the formulae of carbonation in Ettringite could be derived on the condition of 60% and 80% R.H. In 80% R.H., Ettringite decomposed into gypsum, calcium carbonate and alumina gel by carbonation, but in 60% R.H., bassanite was formed in place of gypsum. And, the amount of water in the alumina gel was found to increase with decreasing R.H. For all conditions in R.H., the amount of water released from Ettringite was less than that estimated from the theoretical formula assuming a stoichiometric reaction. It was concluded that the carbonation of Ettringite was influenced not only by the character of Ettringite itself, but by reaction products and their pore structures around Ettringite crystals.抄録全体を表示PDF形式でダウンロード (1367K) -
相沢 守, 板谷 清司, 宮本 ユタカ, 岸岡 昭, 木下 真喜雄1992 年 1992 巻 237 号 p. 92-100
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーCalcium metaphosphate (Ca (PO3) 2 ; Ca/P=0.50) and calcium diphosphate (Ca2 P2 O7 ; Ca/ P=1.00) powders have been prepared by spray-pyrolysis technique, i.e. a technique for spraypyrolysing the mixed solutions of Ca (NO3) 2 and (NH4) 2HPO4 at 600°C. The concentrations of starting solutions of Ca (NO3) 2/ (NH4) 2HPO4 in mol·dm-3/ mol·dm-3 were 0.50/ 1.00, 1.00/2.00, 1.50/3.00 and 2.00/4.00 (Ca/P ratio=0.50), while for Ca/P=1.00 they were 0.50/0.50, 1.00/1.00, 2.00/2.00 and 3.00/3.00. The spray-pyrolyses of the solutions with Ca/P ratios of 0.50 formed δ-Ca (PO3) 2 and a small amount of γ- Ca2P2O7, while those of the solutions with Ca/ P ratios of 1.00 formed γ- Ca2P2O7; the best crystalline phases were formed by spray-pyrolysing the 1.50 mol·dm-3 Ca (NO3) 2/ 3.00 mol·dm-3 (NH4) 2 HPO4 solutions (Ca/ P= 0.50) and the 1.00 mol·dm-3 Ca (NO3) 2/ 1.00mol·dm-3 (NH4) 2 HPO4 solutions (Ca/ P= 1.00). X. ray fluorescence results showed that the former powder had a Ca/P ratio of 0.54, while the latter powder had a Ca/P ratio of 0.99; the chemical composition of the powder shifted slightly from the stoichiometry when the Ca/P ratio of the starting solution was 0.50. All of the powders prepared by the present technique were composed of spherical and hollow agglomerates (diameter : -5μm) containing minute crystallites with sizes below 0.1μm.抄録全体を表示PDF形式でダウンロード (1344K) -
中村 章寛, 関 宏次, 鈴木 喬1992 年 1992 巻 237 号 p. 101-107
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーIn order to manufacture a high purity and heat-stable quartz glass, a new preparation method for raw materials has been proposed. The method described consists of preperation of cristobalite powder by dispersing fumed silica in water, freezing, drying and sintering at 950°C for 6 hours. The sintering is facilitated by addition of 0.18wt % Na+ ions. The process results in the formation of densified and crystallized cristobalite powder which yields a high purity (Na;0.04, A1; 0.44, Fe<0.01, C1<0.2ppm) and heat-resistant quartz glass.抄録全体を表示PDF形式でダウンロード (921K) -
門間 英毅1992 年 1992 巻 237 号 p. 108-114
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーPDF形式でダウンロード (686K) -
鯉渕 清, 山口 博之1992 年 1992 巻 237 号 p. 115-122
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーPDF形式でダウンロード (979K) -
杉本 賢司1992 年 1992 巻 237 号 p. 123-129
発行日: 1992/03/01
公開日: 2011/03/07
ジャーナル フリーPDF形式でダウンロード (3394K)
- |<
- <
- 1
- >
- >|