Experimental Study of Boron Recovery from Geothermal Water on Ion Exchange

Abstract

This paper presents studies regarding the process of boron recovery from geothermal waters using the method of ion exchange. The optimal conditions of this process were determined using fluids with a methaboric acid content in the range of 59 to 100 mg/l, and a good retention degree was achieved. Geothermal wells in northwestern Romania were selected after being found to have high borate contents during chemical analysis. First it was realized the retention of boric acid from waters on a resin Vionit AS-116 produced in Romania. It was noticed that waters that contain organic compounds like phenol reduce the retention process of boric acid. For these waters, a retention process of the phenols on a copolymeric resin CA-30 produced in Romania was applied, and a good resin performance was achieved;. After the phenol was removed, the retention of boric acid from water on Vionit AS-116 resin was performed under favorable conditions. The retained boric acid was then eluted from the resin with a diluted sulphuric acid solution. The ion exchange AS-106 was proven to have a high retention capacity. In the situation where the phenol content was high, a treatment was first applied to eliminate it from water, and then the procedure of boron recovery from water was continued under favorable conditions.