{HEAD ~ A process} for the manufacture of highly dispersed silicon dioxide with improved thickening action by treatment of pyrogenically produced silicic acid comprising {TAIL ~ the following steps}: 
comprising
{ HEAD ~ A process } for the manufacture of highly dispersed silicon dioxide with improved thickening action by treatment of pyrogenically produced silicic acid comprising { TAIL ~ the following steps } :
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH