Lithium zirconate, an alkali metal oxide, and {HEAD ~ an alkali earth metal oxide} is used as {TAIL ~ an absorbing/separating agent} 
is used as
Lithium zirconate , an alkali metal oxide , and { HEAD ~ an alkali earth metal oxide } is used as { TAIL ~ an absorbing / separating agent }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL