Name of Mine Hiragaofuku Mine Mining Area Registered Number Mining Rights No. 784 of Yamaguchi Prefecture Mining Area Location Kamiaza Ryugenchi, Ofuku-cho, Mine-shi, Yamaguchi Prefecture Ores Silica stone, Gold, Silver, Copper Mining Area Size 13,589 ares Entitled Mining Company Japan General Inc. Address 14-22, Konya-machi, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture Date of Registration September 8, 1952 1. Location and Access The mine exists at the north side of Ofuku station of JR Mine line along Route 316. The mining office is located approximately 2 Km from Ofuku station and mining area is at approximately 300 m from the mining office taking an exclusive road for the mine to east. The location is very easy to access. 2. Operations ≪History≫ Silica stone had been shipped to users as a raw material for refractory brick from 1953 to 1955. After 1956, we had stopped mining of silica stone due to decrease of demand. Afterward, mining operations have been resumed earnestly since 1960 on the backdrop of new demand for ferro-alloy application. Currently, we supply silica stone to various users for production of steel, silicon carbide and building materials. ≪Recent Condition≫ There was a ridgeline from south to north with the summit at the altitude of 348 m in the middle of 13,600 ares mining area. Digging was started from at the middle of the mining area. Now, we are digging north slope and south slope, where is approximately 270 m down area from the summit of ridgeline, by bench-cut method. Top soil is as thin as 2 to 3 m and there is a hard silica rock layer under the topsoil. Silica rocks are exposed at various points. 3. Reserve Definite Ore Reserve Estimated Ore Reserve : : Approx. 3.6 million metric tons. Approx. 25 million metric tons. 4. Ore Sorting After raw ores are thrown into bin from dump trucks, screened small size ores are removed. Afterward, raw ores are crushed in the first and second crushers. The crushed ores are washed with fresh water in a drum washer and stocked in material tanks after size sorting. 5. Chemical Composition (Standard Grade) >>Silica stone SiO2 Al2O3 Fe2O3 MgO CaO lg-loss 97.50 0.80 0.36 0.05 0.03 0.65 >>Silica sand (Maximum size 5 mm) SiO2 Al2O3 Fe2O3 MgO CaO lg-loss 96.83 1.14 0.40 0.07 0.07 0.67 >>Loose sand SiO2 Al2O3 Fe2O3 MgO CaO lg-loss 94.80 2.70 1.30 0.20 0.60 1.10 6. Application Ferro-alloy, Silicon carbide, Building materials, Sub-raw materials for steel production, Cement, Civil engineering and construction (Road and floor etc.), others