Role of water film in water-rock reaction under unsaturated condition

2015 Fiscal Year Final Research Report

• Project/Area Number: 25400513
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Osaka University
• Principal Investigator: Yokoyama Tadashi 大阪大学, 理学(系)研究科(研究院), 助教 (60403101)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 水膜 / 溶解 / 砂岩 / 水飽和率

Outline of Final Research Achievements

To study how water film wetting the surface of pores mediates the reaction and transport in a rock, water was passed through Berea sandstone under both the cases of water-saturated condition and unsaturated condition, and the amounts of elements dissolved from the rock were compared. Dissolution rate was predicted to be independent of water saturation if sufficient dissolution occurred via water film, but the result obtained was that the dissolution rate of Si under the unsaturated condition was 50% of that under the saturated condition. By comparing the cases of Berea sandstone and the other sandstone for which no difference of dissolution rate was observed between saturated condition and unsaturated condition, it is inferred that the efficiency of dissolution in water film depends heavily on the roughness of the pore surface.

Free Research Field

岩石-水相互作用