The bellows blow fiercely,

the lead is consumed by the fire;

in vain the refining goes on,

for the wicked are not removed.

(from the New Standard Revised Version [NRSV])

Nota bene:

“The melting point of lead—at 327.5 °C (621.5 °F)—is very low compared to most metals. Its boiling point of 1749 °C (3180 °F) is the lowest among the carbon group elements.”
From Lead – Wikipedia

Does that seem low to you?