Process and {HEAD ~ apparatus} for accurately controlling {TAIL ~ the rate} of introduction and the content of alumina in an igneous electrolysis tank in the production of aluminium 
for accurately controlling
Process and { HEAD ~ apparatus } for accurately controlling { TAIL ~ the rate } of introduction and the content of alumina in an igneous electrolysis tank in the production of aluminium
OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH