The ability of sorbent injection technology to reduce the potential fo
r trace metal emissions from coal combustion was researched. Pilot sca
le tests of high-temperature furnace sorbent injection were accompanie
d by stack sampling for coal-based, metallic air toxics. Tested sorben
ts included hydrated lime, limestone, kaolinite, and bauxite injected
at 1000, 1150, and 1300 degrees C, and through the burner at several f
eed rates. Continuous gas monitoring and solids sampling by particle s
ize determined changes in metal concentrations from baseline measureme
nts. The impact of sorbent injection on trace metal emissions is a fun
ction of metal type, sorbent type, and injection mode. Reductions in s
ubmicrometer concentrations of antimony, arsenic, mercury, and seleniu
m were observed when hydrated lime and limestone were injected. The to
tal amount of captured arsenic, cadmium, and lead increased when using
, variously, hydrated lime, limestone, and kaolinite.