Rock Island daily Argus. (Rock Island, Ill.) 1886-1893, 1888-09-29
HOW SODA IS MADE.

HUW SUDA IL MADE.
NEARLY ALL OUR SUPPLY OBTAINED |
INDIRECTLY FROM SALT.
A Description of the Methods Employed
at the Furnace-Abating a Nuisance.
Profit in a Waste Product-washing
Soda-The Common Bicarbonate.
Strange as it may seem, abont all of our
washing and baking soda is obtained indi-
rectly from our common table salt Not
withstanding the fact that large quantities
of these compounds occur in many parts of
the earth, it has been found more profitable
and more desirable TO manufacture them,
even Though the process is long and com
plicated one, rather than to merely mine and
purify the materials Among the more i'm
portant localities where they are found native
may be mentioned the soda lakes of Egypt
and Central Africa, the borders of the Cas-
plan and Black seas, in California, Mexico
and many parts of South America. The
crude soda coming from the different places
goes under various names as 1ro Ma, Natron,
Urao, &c.
Another source of supply is the ashes of
sea weeds and of plants growing on the coast.
The sea weeds are collected by the inhabi-
tants dried, burned and the ashes treated
with water, lixiviated, as is technically
termed. The water is then boiled dow or
concentrated, when the soda crystallizes out
Though the yield of soda from given guam
tlty of sea weed is very small, it being said
| that it takes twenty-four tons of dried weeds
| to make 50 to 100 pounds of soda, still there
| are great many people engaged in the bus-
| ness; at one time over 10000 people in
| the Orkney islands alone followed it
for a livelihood. OF course, there are
a few other substances obtained at the same
time which somewhat increase the income,
but the soda is the main one. The soda from
this source also has several names, among
the more common of which are Barilla, Sal
sola Soda and Varec.
| In specially constructed furnace well
warmed oil of vitriol or sulphuric acid is
added in certain proportions TO heated COM
mon salt, A violent action takes place and
immense quantities of an exceedingly suffo-
eating gas are given off When the reaction
has ceased the mixture is shoveled or raked
into another part of the furnace, where it
is heated to much higher temperature
More of the same gas is now given off and the
substance formed on the mixing of the acid
and salt, chemically known as bisulphate of
soda, is converted into the normal sulphst,
of soda, or as it is commonly called, Glau
ber's salts This is the ''salt cake of the fac
tory hands. For long time the gas giver
off was a source of great trouble It is very
soluble in water forming rnuriatic acid and
1t is from this source that we obtain the aciG
found in commerce. Now. at first the ga.
was allowed to escape directly into the atmoS
phere from the factory chimneys and uniting
with the watery vapor fell as a rain Of muri-
attic acid, killing all vegetation within a long
distance, and even the fish in the neighboring
streams. Thus many fertile parts of the
country were converted into barren wastes.
This continued until law was passed com.
pelling the manufacturers to abate the nui-
ssnce, which WAS accomplished by passing
the gas through ''scrubbers.n These are high
towers filed with coke, over which water is
kept constantly trickling The water alb.
serbs the gas and thus the difficulty is over.
come. The resulting liquid (cruds muriatic
acid is largely used in making bleaching
powder, and is really about the onlysourct
of profit now TO the soda manufacturers. We
have here very good illustration of the
fact that substance which is regarded as @
waste product and thrown away often turn,
out to be more valuable than the main sub
stances ought to be obtained when its com
position has been determined and use fonnt
for it. How well do we sec this same fact
demonstrated in the case of the manufactur,
OF common Illuminating gas. few yesr.
ago men were paid for carting away vast
material which today produces several time.
the amount of profit that all the coke ant
gas together pay.
But TO go on with our process; the ''sal
cake" is mixed with chalk or marble an,
coal, the mixture is put into what is known
as reverberatory furnace and fused Th.
sulphate of soda IS converted into the car
Donate of soda, and the chalk into the oxysul
phide of calcium. The mixture of these tw,
substances which has n dark color due to tn
presenceof some undecomposed coal, is calle,
''black ash" while the process itself is tech
nically known as "baNing" The .'blacl
ASH is then dissolved in water and allowe,
to stand so that some of the impurities an,
the coal can settle This solution after care
| lui uetdhtdtioii 10 eva poIdUeb 10 uiy utsS an
the resulting solid heated to redness. Sod
ash or crude carbonate of soda is the result
and it is from this substance that our wash
ing and baking sodas are directly made.
To obtain washing soda the soda ash is di.
. solved In hot water unttl the water wiz nc
dissolve any more and the solution allowe
60 stand until all the solid impurities hav
settled to the bottom. The clear liquid
then carefully drawn off into very shallo,
iron pans so that large surface may be g,
posed to the air and the evaporation of waite
go on more rapidly. The refined carbonat
of soda gradually crystaiiizes, but formin
. large masses These masses Of crystals ar
now collected, and after the adhering liqui
has been drained from them they are packe
in barrels and sent into commerce as wasl
ing soda. In this condition they contai
over 60 per cent. of water, hence when OF
buys ten pounds of washing soda he pays IL
six pounds of water and but four pounds
soda
To make baking soda they dissolve the sod
ash in hot water and let it stand and settl
as In making washing soda, but it is furth'
purified by flltering it through layers
black sand and bone black. The soda is the
crystallized out and drained After draiI
ing 1t is ground into a coarse powder al
- formed into cakes having holes runnir
through them. These cakes are placed {
. perforated shelves in specially constructt
air tight rooms, which have capacity
about ten tons Of soda. After the room b
been filed the door is closed and locked al
. carboDic acid gas, formed by burning cos
re is forced in by means of blower. The sot
Of remains in THIS atmosphere for from ttr
re weeks to month, at the end of which tin
60 it has absorbed enough of the gas to chan
i' it from the carbonate to the bicarbonate
soda, which latter is our baking soda. II
- room is now opened and the cakes taken OF
"a Each cake is broken into halves and the FIRE
az surfaces examined by an expert, who jndg
by their appearance to what grade the piec
belong. The sorting over, the cakes are p
into a machine resembling a coffee mi
NJ, where they are ground to coarse powdt
This powder Is conveyed to other mil
which grind it very fine. 1t is then pack
- in boxes and casks and sent into the nark'
I-Anti-Adulteratio Journal.
A Remarkable Similarity.
"How fond Charley Roberts is Of