Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1900-03-08
THE MAKING OF SALT.
ANCIENT AND MODERN SYSTEMS OF
REDUCING BRINE.


There are two general sources from
which salt is obtained, natural brines
and solid deposits. A number of theories
have been advanced to account for the
latter. The general impression among
scientific men is that rock salt has been
formed by evaporation from ancient seas,
which had become incloscd in some way
In Confirmation of this notion it is point
ed out that deposits are being made to-
day at the bottom of several well known
salt lakes. But doubts have been ex
pressed as to the applicability of the ex-
PLANTATION to such thick strata as those at
Stnssfurt, Germany, 1,S00 feet deep,
and at S.ercnberg, near Berlin, $500
feet thick. However this may be, the
substance is found, in greater or less
purity, in all parts of the world. The min
erals associated with it are those which
are apt to exist in the ocean. What is
commonly known as salt" is principally
chloride of sodium. But chlordes of
lime and magnesium, sulphatcs Of lime
and magnesium and even minute guam
titles of ioddes and bromides are usually
mingled with the chief constituent.
For long time Turks island in tbo
Voc. Irdios v,s n oonio,,. cor,,.ih,.,. g.,
this country's supply of rock salt. But
huinoei W niiheS are hoW oeins "orheu
IN the Chiteu states Inc most famous
at present are those at Livona, \. Y.
The salt is taken out in solid chunks,
ground, passed through sleeves of differ
ing mesh-to be graded according to
coarsencss-and put up in bags or bar
rels. There is a famous deposit in Lou
sana much nearer the surface of the
ground and more easily worked, which
will be an important producer some day.
There are many salt deposits in this
country which are made available not
by mining, but by the pumping of brine
from their vicinity. Through n large
part of Michigan, for instance, and from
the central part of New York state out
as far as Buffalo, there are beds varying
in thickness from 112 to 300 feet and ~
ing from 600 to 2.6OO feet below the sur
face. All through these two regions, as
well IA in northern Ohio. wells have been
sunk, and the brine is pumped up like
oil. Fresh water springs supply the wa
ter. no doubt, and this, flowing over and
through the solid salt, dissolves the lat
ter and puts it within mans reach. In
few places there are salt springs which
eject their mineral laden fluids without
coaxing.
There are FIVE principle methods of
treating brines in order to get the salt
from them. One of the oldest systems
is that so extensively employed at SYRIA
cuse The brine is poured into enormous.
shallow. wooden watts and exposed to the
sun and wind to dry. Whenever there is
rainstorm, covers are drawn over them
to exclude additional water. Precautions
are also taken against the admission Of
dirt. The product obtained in this way
is called solar salt" Owing to the slow
ness of the evaporative process the
grains thus formed are coarse.
To hasten matters artificial heat is Of
ten used. For instance, rows of kettles
are arranged so that coal fires may be
maintained under them. As the water
boils off the salt crystallizes in the bot
tom OF the receptacle BY regulating the
degree of heat applied and providing for
marked differences of temperature in two
sets of kettles, grains of different sizes
can be secured, the finer ones resulting
from the more rapid evaporation. This
method is an ancient one.
In Wyoming county, \. Y, artificial
heat is used in another way. Metal pans
about 12J feet long, % feet wide and
perhaps % feet deep. are warmed BY
furnaces directly under them. Coal is
used in the latter. The heat being ap.
piled directly, the system is known as
the direct heat" plan. 1t is further
chara cterstic of the process that il is
conducted with omen pans. An indirect
mode of bringing the heat TO bear on the
brine is to line the watts, which are small.
cr receptacles than those lust described.
with steam pipes, which run around the
inner edge of the same and transmit
their heat TO the fluid. The indirect heat
apparatus is called a "grainer."
Finally it has been found feasible to
save fuel and obtain a purer salt by in
closing the brine in n tight vessel from
which the air has been almost entirely
exhausted. This is called a "vacuum
nan" 1t is n well known fact that evap-
Grafton takes place at n lower tempera-
turc when the air pressure is reduced
than at ordinary treasures This is the
reason why water boils at A lower tom.
perature on a mountain ton than on n
plain. In the vaccum nan the work can
be done by heating the brine TO only 1lo
degrees. The nroduct of the vacuum nan
process is n hcoutiful article and com
mnnds n higher price than other salts.
The grains form in cubes instead of
fakes Tho salt obtained from the indi
rect be,t lstesm nine, svstem is also ~
n, oroouo,. o,,ol;tr