Geochemical characteristics of silica scales precipitated from the geothermal fluid at the Onuma geothermal power plant in Japan

The scale precipitation is a major issue at geothermal power plants as it reduces the production rate of energy. precipitates different physical and chemical conditions in each plant result from fluid–rock interaction for specific plant. Thus, important to understand characteristics process fluid. information on transportation metals its hydrothermal fluid general will be useful formation ore deposit. In this study, we have examined silica scaling Onuma Akita Prefecture, Japan. consists mainly amorphous trace amounts smectite, kaolinite, euhedral pyrite. Chemical composition indicates that Fe content shows positive correlation with Pb, Cu, REE. These elements probably incorporate into pyrite scale. texture suggests possible crystalize prior growth silica. Silica gradually changes well toward reinjection well. Concentrations SiO2, Fe2O3, MgO, MnO significantly decrease well, those Al2O3, LOI, alkali earth (Na2O, K2O, CaO) increase Most including REE also furthermore HREE decreases more extensively than LREE though (Be, Rb, Sr, Cs, Ba) change element concentration scales can utilized pipes