凍結乾燥硫酸塩の熱分解によるスピネル（ＭｇＡｌ２Ｏ４）の生成過程

DOI Web Site Web Site オープンアクセス

書誌事項

タイトル別名
  • Formation Processes of Spinel (MgAl<sub>2</sub>O<sub>4</sub>) by a Thermal Decomposition of a Freeze-Dried Sulfate
  • トウケツ カンソウ リュウサンエン ノ ネツ ブンカイ ニヨル スピネル Mg

この論文をさがす

説明

The freeze-dried salt was prepared from the mixed solution of magnesium and aluminum sulfates in composition of spinel. The thermal decomposition processes of the resultant salt were studied with DTA, TG and X-ray powder diffraction methods, and the formation processes of spinel were discussed.<br>The results obtaind were as follows:<br>(1) The salt seemed to be composed of the mixture of two compounds of MgSO4⋅6H2O and Al2(SO4)3⋅17H2O, in which magnesium sulfate was amorphous and aluminum sulfate crystalline.<br>(2) On heating the freeze-dried salt, the crystalline Al2(SO4)3⋅17H2O decomposed to a crystalline anhydride which then decomposed to an amorphous alumina. In contrast, the amorphous MgSO4⋅6H2O decomposed to an amorphous anhydride. This anhydride was then crystallized, and finally decomposed to an amorphous magnesia.<br>(3) Once the amorphous magnesia was formed, some part of this reacted to form spinel immediately with non-crystalline alumina which had been already formed.<br>(4) The amorphous magnesia which did not react with this alumina then crystallized as the temperature raised. This crystalline magnesia did not completely react with alumina up to higher temperature.<br>Thus the spinel has been formed at two stages. The temperature of the first stage to give spinel was as low as 840°C in this study which was very low when compared with the case of the solid-solid reaction, for example, as of alumina and magnesia pellets.

収録刊行物

  • 窯業協會誌

    窯業協會誌 89 (1030), 287-291, 1981

    公益社団法人 日本セラミックス協会

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ