Development of a new high-performance belite cement

新型高性能贝利特水泥的研制

• 批准号: 14550799
• 负责人: FUKUDA Koichiro
• 金额: $ 2.56万
• 依托单位: Nagoya Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550799/
• 关键词: belite; crystallization differentiation; zonal structure; calcium aluminoferrite; tricalcium aluminate; cements; interstitial materials; 再融反応; 固溶形式; 高温X線回析; 顕微ラマン分光; 相転移

In the present research, we have obtained the following results(1) Crystallization mechanism of interstitial melts : we have found, for the first time, the occurrence of fractional crystallization in cement clinkers during cooling. This reaction, in principle, determines the chemical compositions of the crystals and melts. In the pseudobinary system Ca2SiO4(C2S)-Ca2AlFeO5, for example, C2S solid solution, Ca2A10.41Fe0.5905, and melt coexisted at temperatures between 1375 and 1635℃. At temperatures above 1375℃, the two phases of C2S(ss) and melt was stable. Accordingly, Ca2Al0.41FeO.5905 crystallize out of the melt, thus the chemical composition of the coexisting melt becomes poor in Fe2O3 component.(2) Zonal structure of calcium aluminoferrite, which records the information on the crystallization process : As the result of the fractional crystallization, the crystals of calcium aluminoferrite showed the zonal structure, the Al/(Al+Fe) values of which seadily increases from the cores toward the rims. Tricalcium aluminate solid solutions eventually crystallize out of the differentiated melt.(3) Cationic substitution of tricalcium aluminates : the chemical formula of the tricalcium aluminate doped with Na, K, Mg, Fe and Si has been developed to be (Na, K)2x(Ca, Mg)3-x-y[(Al, Fe)1-ySiy]206 (0≦x<0.158, 0≦y<0.136).(4) Effect of substituent ions on the stable phases of calcium aluminoferrite and belite : The crystal structure of calcium aluminoferrite was dependent on the Al/(Al+Fe) value (=x). with 0≦x<0.235, space group was Pcmn, while, it was Ibm2 with 0.235≦x<0.7. The starting temperature of the α' -to-βtransformation steadily decreased from 680℃ to below the ambient temperature with increasing concentration of foreign oxides.

在本研究中，我们获得了以下结果：(1)间隙熔体的结晶机理：我们首次发现水泥熟料在冷却过程中会出现分式结晶。原则上，这个反应决定了晶体和熔体的化学成分。在Ca2SiO4(C2S)-Ca2AlFeO5赝二元体系中，C2S固溶体Ca2A10.41Fe0.5905与熔体在1375 ~ 1635℃之间共存。在1375℃以上，C2S（ss）和熔体两相稳定。因此,Ca2Al0.41FeO。5905结晶出熔体，使共存熔体的化学成分在Fe2O3组分中变差。(2)铁铝酸钙的地带性结构，记录了结晶过程的信息：由于分步结晶，铁铝酸钙晶体呈现地带性结构，其Al/(Al+Fe)值从核心向边缘急剧增大。铝酸三钙固溶体最终从分化的熔体中结晶出来。(3)铝酸三钙阳离子取代：经Na、K、Mg、Fe、Si掺杂后的铝酸三钙化学式为（Na， K）2x(Ca, Mg)3-x-y[(Al, Fe)1-ySiy]206（0≦x<0.158, 0≦y<0.136）。(4)取代离子对钙铝铁氧体和白石稳定相的影响：钙铝铁氧体的晶体结构依赖于Al/(Al+Fe)值（=x）。当0≦x<0.235时，空间群为Pcmn；当0.235≦x<0.7时，空间群为Ibm2。随着外源氧化物浓度的增加，α′→β相变的起始温度从680℃逐渐降低到低于环境温度。

项目成果

K.Fukuda, H.Matsubara: "Anisotropic Thermal Expansion of Yttrium Silicate"J.Master.Res.. 18. 1715-1722 (2003)

K.Fukuda、H.Matsubara：“硅酸钇的各向异性热膨胀”J.Master.Res.. 18. 1715-1722 (2003)

Koichiro Fukuda: "Determination of the Pcmn/Ibm2 Phase Boundary at High Temeperatures in the System Ca_2Fe_2O_5-Ca_2Al_2O_5"Journal of the American Ceramic Society. 85・5. 1300-1302 (2002)

福田晃一郎：“Ca_2Fe_2O_5-Ca_2Al_2O_5 体系中高温下 Pcmn/Ibm2 相界的测定”美国陶瓷学会杂志 85・5（2002 年）。

K.Fukuda et al.: "Fractional Crystallization of Liquid Coexisting with α-Ca2SiO4 Solid Solution in CaO-Si-2-Al2O3-Fe2O3 Pseudoquaternary System"J.Am.Ceram.Soc.. 86. 2154-2161 (2003)

K. Fukuda 等：“CaO-Si-2-Al2O3-Fe2O3 伪四元体系中与 α-Ca2SiO4 固溶体共存的液体的分级结晶” J.Am.Ceram.Soc.. 86. 2154-2161 (2003)

Koichiro FUKUDA: "Thermal Expansion of δ-Yttrium Disilicate"Journal of the American Ceramic Society. 87. 89-92 (2004)

Koichiro FUKUDA：“δ-二硅酸钇的热膨胀”美国陶瓷学会杂志 87. 89-92 (2004)。

Koichiro FUKUDA: "Chemical Zoning of Calcium Aluminoferrite Formed during Melt Crystalliation in CaO-SiO2-Al2O3-Fe2O3 Pseudoquaternary System"Cement and Concrete Research. (In press). (2004)

Koichiro FUKUDA：“CaO-SiO2-Al2O3-Fe2O3 准四元体系中熔融结晶过程中形成的铁铝酸钙的化学分区”水泥和混凝土研究。