I am huangduo from Dalian xiyinhe Co. ltd. in China,which produces metal silica and silica fume ,the production of them is 2000 tons and 600 tons respectively per month. Our fume recovery installments are introduced from the Norway,which are the most advanced in the world as far. So you will be assured that the quality of our silica fume is steady: the content of sio2 is not less than 92% and the average sio2 is not less than 94%.We also remain good relations with other metal silica companys of northeast in China.