Deposition of CaCO3 in Porous Materials by Flashing Geothermal Fluid

Abstract

Deposition of CaCo3 from natural geothermal fluid was studied by using porous substrates made from several granular materials. These experiments aimed to explore connection between the process of steam flash from superheated CO2 charged water and the consequent changes in the carbonate chemical equilibria. Fresh hot geothermal liquid flowed into the porous substrate where it flashed to steam and deposited calcite and aragonite. Interpretation of test experiments requires tracking the several factors which affect carbonate equilibria, especially CaCO3 deposition, as the steam flash progresses. Those factors are viewed as components of a complex process through which the geothermal fluid passes. This point of view introduces aspects of sequence and time, providing a realistic extension from other models that are constrained to concepts of chemical equilibrium.