熱水条件(150℃)におけるカルサイトのマグネサイト化反応の条件とマグネサイトと熱水溶液間の希土類元素分配挙動

• 中野 悠

  名古屋大学大学院環境学研究科地球環境科学専攻

• 川邊 岩夫

  名古屋大学大学院環境学研究科地球環境科学専攻

書誌事項

タイトル別名

• Experimental magnesitization of calcite at 150℃ and partitioning behavior of REE between magnesite and hydrothermal solution
• ネッスイ ジョウケン 150ドC ニ オケル カルサイト ノ マグネサイトカ ハンノウ ノ ジョウケン ト マグネサイト ト ネツ スイヨウエキ カン ノ キドルイ ゲンソ ブンパイ キョドウ

抄録

Reagent grade calcite was reacted with MgCl₂ solutions doped with REE (Mg concentration of 0.089M-1.8M and REE concentration of about 0.3 ppm each) at 150℃ for 10 or 20 days. Solid products were identified by X-ray diffraction. Solid and liquid phases were analyzed for Mg, Ca and REE. The solid phases reacted with MgCl₂ solutions (0.89M and 1.8M of Mg²⁺) were almost magnesite (about 95%). The molar ratios of Mg/(Mg + Ca) in solutions of the run products were consistent with the extrapolation of the reported experimental equations in the high temperature range from 275℃ to 420℃ to lower temperatures. The values of pH at room temperature of the final solutions are ranging from 5-7, and they show a decreasing trend with increasing Mg concentration. This is probably caused by the precipitation reaction of brucite, which is more likely to occur at 150℃ than at 25℃. The REE partition coefficients between solid and liquid phases defined by K_d(REE)={X_REE/(X_Mg+X_Ca)}_solid/{[REE]/([Mg]+[Ca])}_liquid have been determined experimentally. The series variation of logK_d (REE) in the run in which the solid phases were almost magnesite, shows a decreasing trend in LREE and a convex tetrad effect.

収録刊行物

• 地球化学

  地球化学 40 (3), 239-244, 2006

  一般社団法人日本地球化学会

キーワード

• magnesite
• rare earth element
• tetrad effect

詳細情報

• CRID: 1390282680718364928
• NII論文ID: 110008680129
• NII書誌ID: AN00141280
• DOI: 10.14934/chikyukagaku.40.239
• ISSN: 21885923
• ISSN: 03864073
• NDL書誌ID: 8077448
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8077448
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • NDL
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可