Highactivity metakaolin concrete additive
WEBgrinding: crushing the coal Jianshi material into fine powder smaller than 800 meshes by using a vertical mill system; ... Superfine grinding and drying: the coal gangue powder with the grain diameter of about 24 mu m is obtained. (5) Depolymerization and roasting: because the coal gangue is small in size of 24 mu m and is obvious in ...