Abstarct: The comminution is a costly process in the mining operation. Blasting is the most cost effective stage in the comminution process. The blasting using fragmentation and preconditioning affect the comminution and decrese its costs. Blast-induced preconditioning using the creation and extension of cracks and microcracks” can increase grindability. In the pervious researches, preconditioning has studied using small scale blasting. In this research, first, preconditioning induced by bench blasting has been studied in small scale bench blasting tests on originally virgin material. Specimens of magnetic mortar, with an approximate scale of 1:100 relative to normal bench blasts, were blasted, weighing about 80 kg each. To evaluate the preconditioning induced by bench blasting, the the blast fragments from the tests for for the first row (virgin mortar) and the third row (preconditioned by the shooting of rows 1 and 2) were collected and subjected to so called Optimized Comminution Sequence (OCS) testing. The OCS test in this research included two steps crushing and two steps milling in closed circuit design to guarantee a small size reduction ratio. The results obtained showed a reduction of about 11% and 15% for batch 2013 and batch 2014 respectively in specific energy consumption due to the blast preconditioning of the third row burden relative to the virgin burden of the first row. Also, this method is suitable method to quantify the preconditioning. In the next step, geomechanical and breaking properties of the oxide ores have been studied using small and full sclale blasting tests. The results showed that the percentage of magnetite has a direct relationship with uniaxial compressive strength, tensile strength and P and S wave’s velocities has an inverse relationship with Poisson's ratio and porosity. In addition, increasing the percentage of magnetite increase the mean fragment size and decrese energy consumption in comminution process.