microsilica,silica fume,ferroalloy ,SIO2:93-97%,CL-:0.02%max;burning loss :1-2%;min surface area:18000m2/kg USD195/MT FOB China Erdos microsilica,silica fume, Code:SHERDOSSF0901 ,SIO2:93-97%,CL-:0.02%max;burning loss :1-2%;min surface area:18000m2/kg USD195/MT FOB China Payment:L/C at sight or T/T before shipmentferroalloy,Erdos microsilica/silica fume