Volume 4 Issue 4
Authors: Makoto Takahashi; Tomonori Nagaya; Takaya Suzuki; Yuki Yogo; Tatsunosuke Omi; Masahiro Tahashi; Sadao Ohkido; Yukio Inoue; Satosi Yamaguchi
Abstract: Calcium carbonate (CaCO3) is one of the main components of mineral scale. Removing this CaCO3 scale is very important in many fields of the industry, such as the boiler, the air conditioner, the oil well drilling and so on. In this paper, CaCO3 was dissolved under various decompression conditions (1.0, 0.50, and 0.20 atm) and studied the relationship between the decomposition efficiency and acid concentration under various decompressions. It was found out that when the proton concentration was near the stoichiometric ratio for the dissolution reaction (CaCO3 + 2H+ ------ > Ca2+ + H2O + CO2(gas)), decomposition efficiency increased significantly with decreasing pressure. This phenomenon was explained by the Le Chatelier’s Law, stirring effect due to the ascent of CO2 bubbles, and the cavitation effect of CO2 bubbles.
Keywords: Calcium Carbonate; Mineral Scale; Dissolution Reaction; Decompression Effect