History
Menthol
Crystals are manufactured by extraction of menthol
from menthol oil.
In
the process the oil is gradually cooled from +15
to -40 deg C and takes the shape of block. It is
then cut and centrifuged. The frozen menthol remains
inside the jacket and unfrozen oil is collected
at the bottom of centrifugal machine. The dementholised
oil is stored.
Frozen
material is remelted in a tank. The concentration
of melted is checked and crude mentha oil and/or
menthol powder is added for menthol crystallization
at room temperature.
This
oil is heated to 50 deg C. After filtration it is
poured in tanks for crystallization in small tanks.
Now the mother liquor is slowly cooled from the
bottom of the container and heated at the top of
the container simultaneously crystallize menthol
in 18 to 20 days.
After
crystallization, the material is taken out on steel
trays so that un-frozen oil trickles by gravity.
Crystal blocks are cut into pieces and centrifuged.
This process removes oil from the crystals and makes
them dry.
The
crystals are subjected to natural drying for 48
hours, sieved and packed. The small crystals are
recycled in plant. The final product thus obtained
is bold sized menthol crystals. These crystals are
available in the following three grades and conform
to IP/BP/USP
standards.
