{HEAD ~ A compartment} is provided within the kiln for selectively introducing a reducing agent into {TAIL ~ the chamber} 
{ HEAD ~ A compartment } is provided within the kiln for selectively introducing a reducing agent into { TAIL ~ the chamber }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL