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Light
soda ash is a white, odourless, uniform product,
free from dirt and other foreign matter.
Physical
and chemical properties
Soda ash has a tendency to absorb moisture from
the atmosphere. The moist soda ash then starts
absorbing atmospheric carbon dioxide. This phenomenon
of absorption of moisture and carbon dioxide by
soda ash is known as weathering. After weathering,
soda ash is likely to contain appreciable moisture
and sodium bicarbonate, but the total alkali content
of the bag does not change. Soda ash has a tendency
to cake when it comes in contact with moisture
and, consequently, becomes lumpy.
Chemical
formula: Na2CO3
O
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Structural formula: Na -- O -- C -- O --
NA
Common
names: Sodium carbonate, calcined soda, disodium
carbonate
CAS
registry number: 497-19-8
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Characteristics
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IS
251 : 1998 specifications
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TCL-assured
specifications
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Units
|
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Molecular
weight
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106
|
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Bulk
density
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500
– 750
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550
– 720
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Kg/m3
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Volatile
matter content
(at the time of packing)
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2
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0.80
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%,
max
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Total
alkalinity (as Na2CO3)
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98.5
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99.0
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%,
min
|
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Sulphates
(as Na2SO4)
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0.08
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0.03
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%,
max
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Chlorides
(as NaCl)
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1.0
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0.80
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%,
max
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Iron
(as Fe2O3)
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By
colorimetric method
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0.0029
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%,
max
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By
spectrophotometric method
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0.007
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0.002
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Matter
insoluble in water
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0.15
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0.03
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%,
max
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Manufacturing
process
Common salt and limestone are the raw materials
that are processed and converted into light soda
ash and calcium chloride.
In the Solvay process, soda ash is manufactured
by dissolving salt in seawater. This is followed
by purification. The purified brine is ammoniated
and carbonated to get crude bicarbonate slurry,
which is filtered and calcined to get light soda
ash. This light soda ash is packed directly in
the auto silo. Tata Chemicals has tailored its
manufacturing process to meet the individual needs
of its customers.
Applications
Light soda ash is one of the most important basic
industrial chemicals. Light soda ash is used to
regulate pH in many chemical process streams.
The superior buffering capacity of soda ash versus
caustic soda offers advantages in adjusting plant
wastewater pH ranges.
Soda
ash is used as the sodium source for sodium sulfite/bisulfite
pulping liquors used in the sulfite, CMP, and
CTMP processes, and in NSSC pulping.
It
is also possible to replace a portion of the caustic
soda in many pulp bleaching applications such
as caustic extraction or hydrogen peroxide bleaching
of mechanical or chemical pulps. However, the
higher pH requirements of these applications may
necessitate the continued use of some caustic
soda.
In
addition, it is the most widely used fixed alkali
for the manufacture of other alkali products,
sodium salts, glass, soap, sodium silicates, detergent,
bicarbonates, bichromates, cellulose and rayon,
iron and steel, aluminium, cleaning compounds,
textiles and dyestuffs, drugs and many other materials.
It is also used as an alkali for household purposes
and as washing powder by laundries.
Packaging:
Available in 50-kg HDPE / PP bags and 750-kg PP
jumbo bags with lamination / liner.
Storage:
Soda ash should be stored under cover in a cool,
dry place and the bags should not be stacked more
than 15 bags high.
For
more information about this product or to place
orders, please contact:
ZN Langrana at:
znlangrana@tatachemicals.com
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