An investigation on the production of sodium metaborate dihydrate from ulexite by using trona and lime

In this study, it was investigated the optimum conditions (extraction temperature and extraction period) for the production of sodium metaborate dihydrate (NaBO2.2H2O) by the reaction of ulexite (NaCaB5O9·8H2O) with trona (NaHCO3-Na2CO3·2H2O) and lime (CaO). The optimum extraction conditions were determined as 50 °C and higher temperature; 6 h and longer extraction time. The characterizations of the product (sodium metaborate dihydrate crystals) were performed by thermogravimetric (TG-DTG) and X-ray diffraction (XRD) analyses. In addition, the percent purity of the product was found to be 96% by using a conductometric method.