CaO・2Fe_2O_3 の安定条件下での 2 成分系カルシウムフェライトの生成機構

概要

論文の詳細を見る
Calcium ferrite is very important for improving the properties of strength and reducibility of sinter. But the formation mechanism of binary calcium ferrite under the stable condition of CaO・2Fe_2O_3 was not studied sufficiently. Therefore, as fundamental study of calcium ferrite formation, the mechanism of calcium ferrite formation in solid state reactions between CaO and Fe_2O_3 at 1190℃ in air was investigated by using the diffusion-couple method. The results are summarized as follows. (1) The reaction between CaO and Fe_2O_3 starts at the CaO/Fe_2O_3 interface to form CaO・Fe_2O_3. After a short initial period, three kinds of calcium ferrites, 2CaO・Fe_2O_3 (C_2F), CaO・Fe_2O_3 (CF), and CaO・2Fe_2O_3 (CF_2) grow in that order from CaO layer toward Fe_2O_3 layer. (2) The formation rates of C_2F, CF and CF_2 are controlled by the diffusion of Ca^<2+> and Fe^<3+> in each layer. (3) The C_2F forms at the interfaces of CaO/C_2F and C_2F/CF, but the formation rate at the CaO/C_2F interface is larger than that at the C_2F/CF interface. The CF forms at the CF/CF_2 interface, and grows toward CF_2 phase except for the beginning of the reaction. The CF_2 forms at the CF_2/Fe_2O_3 interface, and grows toward Fe_2O_3 phase. The thickness of each layer of calcium ferrites increaces with the progress of reaction time.
社団法人日本鉄鋼協会の論文
1995-01-01