灰重石 : MnCl_2 : H_2O系における交代作用のメカニズムに関する実験的研究

概要

論文の詳細を見る
Experiments on metasomatism were carried out in the scheelite-aqueous MnCl2 solution system at 100, 125 and 150°C.As a result, the replacement texture of scheelite by huebnerite was confirmed in all experimental systems. Based on SEM observation of the section of the reacted samples, dissolution of scheelite and precipitation of huebnerite are considered to have occurred simultaneously. The replacement texture of scheelite by huebnerite progresses toward the inside of scheelite because there was no change in the form of the sample after the reaction. Since molar volume of huebnerite and scheelite are 41.88 and 47.05 cm3, respectively, large volume of void space is formed in the reaction layer. Activation energies of the dissolution reaction of scheelite were estimated to be 56.4 kJ/mol in 0.01 mol/l aqueous MnCl2 solution, 70.2 kJ/mol in 0.10 mol/l aqueous MnCl2 solution and 62.2 kJ/mol in 1.00 mol/l aqueous MnCl2 solution. SEM observation, observation in the polished section and estimated activation energies suggest that the dissolution reaction of scheelite is a rate-limiting factor.
日本鉱物科学会の論文
2002-03-30