Manufacture of Sodium Salicylate,As

Manufacture of Sodium Salicylate,
As sodium salicylate is demanded as much if
not more than the acid and as its manufacture
requires special apparatus and technigue, it is
thought best to include it here.
Sodium salicylate is made from the wet acid
from the centrifugal machine. It is first
necessary to determine its moisture content. This
is done by drying about 10 gm, in vacuum at 80",
Centrifuged acid contains as a rule about 4%
moisture, 165# of dry acid equivalent is placed
in the enameled dehydrating pan (Pig. 14) which
rests in a shallow tank of water kept at 60*D.
5 gal. distilled water are added and the mixture
stirred. 100# of the highest quality sodium
bicarbonate are now added and well stirred,
carbon dioxide being evolved, When the evolution
of gas ceases the pan is closed and connected to
vacuum and the temperature raised to 60". not
more. The beat, vacuum and stirring are
continued until the salt is absolutely dry, which
takes about six hours. This forms the granulated
salt which may be removed and immediately bottled,
An excess of acid is used because the salt
if alkaline in reaction turns brown as it also
does if left in contact with air or dried above
60*. Sodium salicylate crystallized from alcohol
is also demanded. To the dry salicylate in the
pan is added 50 gal. 96% ethyl alcohol and heated
to 75° with stirring until dissolved