In this study, an investigation of the optimum conditions to extract boric acid from ulexite mineral was examined for the first time to explore the boric acid extraction yield by employing a new extraction process, ultrasound-assisted extraction (UAE) by the help of reduced graphene oxide (rGO). Moreover, the influence of rGO has been investigated on the extraction of boric acid from ulexite mineral. Besides, the amount of extraction of boric acid from ulexite depends on reaction conditions. For this reason, the impacts of various solvent/solid ratio, pH, extraction time, and extraction temperature on the yield were investigated by the conductometric method. Experiments with rGO were carried out using one-factor-at-a-time methodology. Several experimental situations (with or without rGO) were used in order to compare the boric acid yield. It was explored that the amount of the boric acid extraction was increased importantly in the presence of rGO. Also, thermo-gravimetric assay (TG-DTA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses were utilized for the characterization of materials. Under optimum conditions, the yield was calculated as about 93-94% by the help of rGO, which is a greater value than the yields reported in the literature. (C 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.