In this study, the benefication of low-grade Espey -10 mm. colemanite stocks of more than 30,000 tons, which have been waiting for longer years, can not be evaluated in any way in Emet Boron Works in order to get salable product. Chemical, physical, mineralogical and thermal characterization of low-grade colemanite stock, in the sizes of 10 mm, are located in Espey region primarily conducted. Grades of 10 mm size of Espey used in this study is 28.87% B203. In the microwave experiments, a concentrate of 50.82% B203 was obtained with the efficiency of 88.13%. Evaluating colemanite concentrate by microwave technology may have great importance in solving environmental problem.