Evening star. [volume] (Washington, D.C.) 1854-1972, 1900-06-16
THE MANUFACTURE OF SALT
CONSPICUOUS NATURAL RESOURCE
OF THE STATE OF MICHIGAN.
How the Product Is Obtained and the
Process by Which 1t In
Refined.
From the Scientific American.

From the Scientific American.
Conspicuous among the natural resources
of the state of Michigan are the forests
which cover considerable extent Of its
surface and the large deposits Of salt which
underie a great portion of its area In the
vicinity of Manistee, where the salt
blocks which form the subject of the pres
ent article are located. this deposit consists
of a stratum of rock salt, which Is from
twenty-five to thirty feet in thickness, and
lies some 1900 feet below the surface. Salt
blocks are usually built in connection with
sawmill plants, with view to making
of the refuse as fuel; and for this reason
the city Of Manistee has of late years be-
come such a large producer of salt that
about half of all this commodity manufac-
tured in the state is made at that point.
Driving the Well.
AS soon as the site Of a well has been Sc
and derrick. usually about eighty feet
high. is erected. and the work of driving
commences. The first operation is to sink
section Of 10-inch pipe, by means of a
sand pump. to a depth of about 400 feet
from which point the we'll is continued by
inserting an S-inch pipe within the 1O-nch
pipe and driving it down to the rock forma-
rock up through the 1O-inch pipe to the
surface of the ground. From the rock for
nation down the rock Is drilled without
any pipe casing, except through such por-
tons as are liable to cave. Salt well No.
D OF the Buckley & Douglas Company's
plant at Manistee, which is described in
the present article, is fairly typical of the
wells In this vicinity. The 1U-inch pipe
reaches to a depth of 400 feet the S-inch
pipe to depth of GIG feet, where the rock
formation Is encountered. The bed of rock
salt. which is 30 feet in thickness, reaches
to depth of 1885 feet, making total
depth of 2,O15 feet. The yield pumped from
this well amounts to from 1000 to 400
barrels of brine in twenty-four hours. The
same engine, shaft and walking beam used
in putting down the wells of this company
were formerly utilized to do the pumping,
which was accomplished by sucker rods
tending down the casing to the pump cyl
fnder in the well pipe. OF late years the
air-lift system has been adopted with such
good results that 100 per cent more brine
Is now forced from well by air than
could be raised by the old method. AS the
brine is pumped from the well it Is deliver
ed to the storage cisterns. from which it
falls by gravity to the settlers. and from
the settlers to the grainers. In the settlers
1t Is heated to temperature of about 110'
F. Upon being allowed to cool the gyp-
sum, which, il 1t were not removed, would
form coating on the steam pipes in the
grainers. is precipitated. and as soon as
precipitation Is completed the brine is
drawn to long box running across the
head ends of the grainers. and from the
box 1t Is fed to the grainers as required.
The latter are long. shallow tanks. near the
bottom of which, and extending through
out their full length, is a series of steam
pipes The brine being admitted to the
grainers. the steam Is turned on. the liquor
soon acquires high temperature and
rapid evaporation takes place. To assist
the precipitation Of the grains of salt the
surface of the brine is agtated at frequent
intervals by means of series of paddles.
IL; ot, 4
of the graner. The salt accumulates at
the bottom. until in the course Of twenty
four hours there will be layer from to
inches deep. The salt is lifted from the
grainer by means of ong-handled. perfor-
ated Shovels. and is deposited on the run
way. AS soon as 1t is thoroughly drained
1t Is shoveled into cars run out over the
storage bin and dumped.
The vacuum-Pan Process.
Part of the salt manufactured in this
plant is made by the vacuum pan process.
for which purpose two pans are in use. One
Of the pans is run during the day and the
other during the night. each pan making
in a 12-hour run from 600 to 100 barrels of
salt. the combined production being from
1900 to 400 barrels day.
In the manufacture of salt 1t is q recog-
nized necessity that large quantity must
be kept in storage and for this purpose the
salt is dumped into vast store rooms which
measure from 200 to 300 feet in length, and
the same in width: the amount in store
frequently aggregated 100000 barrels. AS
these rooms are from 16 to % feet deep the
salt becomes tightly packed, and has to be
worked loose by packers with picks,
Shovels, grub hoes, etc, who proceed to
quarry. break up and pack the salt into
barrels. With the coarser grades of salt
made in the grainers this is not a difficult
matter, but the finer grained, vacuum-pan
salt becomes compact and very hard, and
the packer soon finds himself confronted
by a wall Of salt 20 feet in height and as
white. If not hard, as marble. To I'M
dermine and bring down this mass of salt
Is dangerous operation, and involves long
delays; and to overcome these difficulties
the companies have used compassionate
driven spiral auger, which Is 10 inches in
diameter and provided with double-spoon
point. The auger Is mounted on a truck
and the back end Of the shaft Is attached
to a 3-horsepower Boyer rotary air-drill
machine. A row of holes is driven into the
salt wall at a height of 10 inches from the
floor for distance of 8 feet into the mass.
the holes being drilled as closely together
as possible. After an interval of one to
three hours fall of salt takes place, a
mass equal to 400 or 800 barrels of salt be-
ing brought down in each section. The
saving of labor by the use of the compress
ed-air drill is shown by the fact that suffi-
Gent salt can be undermined and caved in
this manner in one-half day to keep the
packers at work for two or three days fol-
lowing.