that is mono(ethylene
glycol) monobutyl C4E1, di(ethylene glycol) monoethyl
C2E2, di(ethylene glycol) monobutyl C4E2, di(ethylene
glycol) monohexyl C6E2, tri(ethylene glycol) monobutyl
C4E3 can be used for separation of carbonaceous copper
shale from quartz by flotation.