【化】 refined asphalt
make with extra care; refine
【化】 polishing; refining
【医】 purification; rectification; refine; refinement
【经】 refine; refining
bitumen; pitch
【化】 asphalt; bitumen; nigrite; pitch
【医】 asphalt; bitumen; Jew's pitch; mineral pitch; peucine; pitch; pix