Journal of the Society of Inorganic Materials, Japan
Online ISSN : 2185-4378
ISSN-L : 1345-3769
13 巻 , 320 号
選択された号の論文の9件中1~9を表示しています
  • 林 剛
    2006 年 13 巻 320 号 p. 5-15
    発行日: 2006/01/01
    公開日: 2011/08/16
    ジャーナル フリー
  • 今井 勉, 神原 信志, 守富 寛
    2006 年 13 巻 320 号 p. 16-23
    発行日: 2006/01/01
    公開日: 2011/03/07
    ジャーナル フリー
    Aim of this paper is to develop an evaluation index of desulfurization reactivity for quicklime calcined limestone that produced from eight different mining in Japan. The quicklime is calcined at 1173 K under air atmosphere, and the desulfurization reactivity is investigated by a fixed bed quartz reactor.
    The desulfurization experiments are performed for 120 min at 1173 K under SO2/N2 atmosphere. Variation of CaO conversion during reaction obtained for eight different quicklime. Effects of physical and chemical characteristics of limestone or quicklime on CaO conversion are examined. Geological time, thermal conductivity, calcination temperature, crystal grain size, surface area and pore volume are analyzed for an investigation of the evaluation index.
    The quicklime having macro-pore over 1, um shows good desulfurization reactivity. Therefore, CaO conversion, X120, is closely connected with total macro-pore volume for over 1 μm, Pv1.0. Its cor relation coefficient, R2, is 0.945. The desulfurization reactivity for various limestone is able to estimate accurately by the evaluation index, Pv1.0.
  • 棚橋 尚貴, 安藤 新悟, 井上 洋一, 小島 義弘, 松田 仁樹
    2006 年 13 巻 320 号 p. 24-31
    発行日: 2006/01/01
    公開日: 2011/03/07
    ジャーナル フリー
    For effective HCl gas removal from waste incineration, the effect of H2O and CO2 on HCl sorption with CaO and Na2CO3 was studied. Experiments of HCl sorption were conducted in a gas flow-type tubular reactor packed with CaO and Na2CO3 fine particles under 5 μm in the diameter, at the temperatures 473-1073 K. The mixed gas of HCl (1000 ppm), H2O (10 vol%) or CO2 (10 vol%) and N2 (balance), was introduced into the reactor at a flow rate of 3.00×10-4m3·min-1.
    As the results, a maximum conversion value of 0.69 for HCI sorption by CaO was obtained at 873 K in N2 atmosphere. With the presence of H2O and CO2, the conversions decreased to 0.49 and 0.40, respectively. It was found that H2O was influential on HCl sorption in whole reaction period, while the influence of CO2 appeared after the conversion attained 0.18 A maximum conversion value of 0.76 for HCl sorption by Na2CO3 was obtained at 673 K in N2 atmosphere. With the presence of H2O, the conversion decreased to 0.64. The influence of H2O 0n HCl sorption by Na2CO3 was smaller than that by CaO. Moreover, HCl sorption by Na2CO3 was not appreciably affected by CO2.
  • 胡秀 らん, 柳澤 和道, 恩田 歩武, 梶芳 浩二
    2006 年 13 巻 320 号 p. 32-39
    発行日: 2006/01/01
    公開日: 2011/08/16
    ジャーナル フリー
    室温混合法と高温混合法の二つの水熱プロセスがケイ酸カルシウム水和物の生成におよぼす影響を, Ca/Si比が2.0のβケイ酸二カルシウム (β-C2S), ライムと微細石英あるいは非晶質シリカの混合物を原料として, 250℃の条件で調べた.水熱プロセスや原料の違いにより, 9種類のケイ酸カルシウム水和物が生成した.高温混合法では全ての原料から, 室温混合法ではβ-C2Sから, γ-C2S水和物が初期相として生成した.室温混合法では, ライムとシリカの混合物からは低結晶性のC-S-Hゲルが初期相として生成した.室温混合法では1日間の反応により, γ-C2S水和物はC8S5 (Ca/Si=1.6) とreinhardbraunsite (Ca/Si=2.5) へと変化した.一方, 高温混合法ではC8S5を経由してjaffeite (Ca/Si=3.0) とkilchoanite (Ca/Si=1.5) が生成することを初めて見出した.室温混合法によるライムとシリカとの反応ではhillebrandite (Ca/Si=2.0) が生成したが, 高温混合法では不均化反応が進行して, カルシウムあるいはシリカに富む化合物が生成した.
  • 盛岡 実, 中村 圭介, 田中 智, 町長 治, 三五 弘之, 青山 芳夫
    2006 年 13 巻 320 号 p. 40-46
    発行日: 2006/01/01
    公開日: 2011/03/07
    ジャーナル フリー
    Calcium aluminoferrite immobilizes hexavalent chromium in a liquid phase following hydration, even under the coexistence of a large quantity of sulfate ions. However, the rate of immobilization is reduced by the coexistence of sulfate ions. In addition, the rate of hexavalent chromium immobilization is significantly affected by the composition of calcium aluminoferrite. Calcium aluminoferrite simultaneously immobilized sulfate ions together with hexavalent chromium in a liquid phase. MASH rapidly decreased chromium in a liquid phase. Compared with MASH, MFSH showed a slower rate of chromium immobilization. Calcium aluminate tended to speed up the removal of chromium in a liquid phase after the generation of monosulfate was recognized. From this fact, it is considered that the reason why the rate of chromium immobilization slows down under the coexistence of sulfate ions is due to the generation reaction of ettringite, which hardly immobilizes chromium, predominantly proceeds in the initial stage of hydration through the interaction between C3A and sulfate ions. On the other hand, in the case of calcium aluminoferrite, the timing of the formation of AFm and the timing when hexavalent chromium is in a liquid phase drastically decreased and were not always corresponding. Judging from the fact that the rate of chromium immobilization of MFSH is slower than that of MASH, AFm, which is generated from calcium aluminoferrite system compounds, is slower in the rate of chromium immobilization compared with MASH.
  • 望月 圭介, 手嶋 勝弥, 川南 修一, 米澤 卓三, 鈴木 孝臣, 大石 修治
    2006 年 13 巻 320 号 p. 47-50
    発行日: 2006/01/01
    公開日: 2011/08/16
    ジャーナル フリー
    Colorless and transparent corundum crystals were readily grown for the first time by a slow-cooling method of Li2Mo2O7 flux. They looked blackish at a glance because they had inclusions in their center. The crystals formed as plate bounded by well-developed {0001}, {0112} and {1014} faces. They were up to 5 mm in size. The crystal habit changed to thin hexagonal plate-like crystals as they grew large. Li2Mo2O7 flux was found to be a suitable flux for the growth of plate-like corundum crystals.
  • 三原 直人, 奥村 諭, 小島 義弘, 松田 仁樹
    2006 年 13 巻 320 号 p. 51-58
    発行日: 2006/01/01
    公開日: 2011/03/07
    ジャーナル フリー
    Effect of Fe2O3 on reductive decomposition of gypsum was investigated. The experiments were carried out by employing CaSO4 powder of the mean particle size of 80, um which was mixed with 150 mass% Fe2O3, under CO : 2%-CO2 : 30%-N2 : balance and CO : 10%-N2 : balance atmosphere at 1273 K, in a gas-flow type tubular reactor. Furthermore, SO2 absorption characteristic of CaO thus regenerated from CaSO4-Fe2O3 mixture by CO reductive gas was studied.
    It was found that the rate of reductive decomposition of CaSO4 was drastically enhanced by addition of Fe2O3. Moreover, the formation of CaS was inhibited by the addition of Fe2O3. Calcium ferrite such as 2CaO.Fe2O3 was detected in the reaction product after reductive decomposition of the mixture of CaSO4-Fe2O3. As the result of SO2 absorption experiment, it was found that CaO regenerated. from CaSO4-Fe2O3 by CO reductive gas had a lower SO2 absorption performance than CaO regenerated from CaSO4. due to a decrease in Dore volume.
  • 西川 治光, 小森 徳久, 川内 義一郎, 井奥 洪二
    2006 年 13 巻 320 号 p. 59-63
    発行日: 2006/01/01
    公開日: 2011/03/07
    ジャーナル フリー
    Photo-induced activity of hydroxyapatite synthesized from waste gypsum was investigated by photocatalytic decomposition of dimethyl sulfide (DMS). Hydroxyapatite samples were synthesized by the reaction of gypsum and diammonium hydrogen phosphate. The decomposition of DMS on the hydroxyapatite under UV (254 nm) irradiation was ca. 68% in the one path reaction method. The hydroxyapatite sample was very active based on photo-induced excitation under UV irradiation. It was assumed that the crystallinity of the apatite structure would influence the photocatalytic activity from the X-ray diffraction studies. The higher the pre-treatment temperature for the hydroxyapatite samples was, the lower the decomposition of DMS under UV irradiation became.
  • 山田 知行, 田中 久順, 下坂 建一
    2006 年 13 巻 320 号 p. 64-70
    発行日: 2006/01/01
    公開日: 2011/03/07
    ジャーナル フリー
feedback
Top