The surface of the crucible 10 is covered by {TAIL ~ a housing} 18 into which {HEAD ~ a reducing gas} is introduced at an inlet 19 so as to flow generally contrary to the flow of metal in the crucible 10 which will thus be exposed to the reducing action of the gas 
into is introduced
The surface of the crucible 10 is covered by { TAIL ~ a housing } 18 into which { HEAD ~ a reducing gas } is introduced at an inlet 19 so as to flow generally contrary to the flow of metal in the crucible 10 which will thus be exposed to the reducing action of the gas
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH REL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH