stone ball 1.9-11 cm 6-8cm 2.silicon content :99.8% 3.product surface mud and other impurities without A.Technological CharacteristicsDetermine the process characteristics of the silica, the value of industrial applications is: silica, hard texture, Mohs hardness of 6, excellent fire resistance and acid resistance, melting point 1730 ° C, the melt cooled into a quartz glass, crystal crystal, with ...