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