Evaluation of the scaling and corrosion in Tai'an geothermal water, China

Tai'an city, located in Shandong Province, China, is rich in geothermal resources, characterized by shallow burial, high water temperature, and abundant water supply, making them high value for exploitation. However, corrosion and scaling are main challenges that hinder the widespread application and effective utilization of geothermal energy. This study focuses on the typical geothermal fields in Tai'an, employing qualitative evaluations of the geochemical saturation index with temperature, combined with the corrosion coefficient, Ryznar index, boiler scale, and hard scale assessment, to predict corrosion and scaling trends in the geothermal water of the study area. The results show that the hydrochemical types of geothermal water in the study area are predominantly Na-Ca-SO4 and Ca-Na-SO4-HCO3, with the water being weakly alkaline. Simulations of saturation index changes with temperature reveal that calcium carbonate scaling is dominant scaling type in the area, with no evidence of calcium sulfate scaling. In the Daiyue Qiaogou geothermal field, the water exhibited corrosive bubble water properties, moderate calcium carbonate scaling, and abundant boiler scaling. Feicheng Anjiazhuang geothermal field showed non-corrosive bubble water, moderate calcium carbonate scaling, and significant boiler scaling. The Daidao'an geothermal field presented corrosive semi-bubble water, moderate calcium carbonate scaling, and abundant boiler scaling. The findings provide a foundation for the efficient exploitation of geothermal resources in the region. Implementing anti-corrosion and scale prevention measures can significantly enhance the utilization of geothermal energy.