Caustic Soda

August 25, 2019
7 minutes

Caustic Soda is a chemical substance which is used as corrosive base in a range of industries. In the manufacturing process of textiles, paper, soaps, cleaning products, this chemical substance plays a vital role; which is why every country is willing to import this product.

Caustic Soda is manufactured by the electrolysis of a sodium chloride solution. In the room temperature, it is solid, waxy, and odorless. Driven from sodium and hydroxide ions, the chemical formula for caustic soda is NaOH. However, commercially available form of this product  is usually sodium hydroxide monohydrate, or NaOH·H2O.

Caustic Soda Flakes

What are Other Names for Caustic Soda?

Caustic Soda is a term mostly used by traders. As the substance has a corrosive and caustic feature, traders call it caustic soda. Another synonym for caustic soda, is sodium hydroxide which has been derived from its chemical properties as a sodium hydrate.

This product is also known as lye and soda because of its strong alkali nature. As an alkali or base, caustic soda is soluble in water and cause other chemicals burn.

Sodium Hydroxide: used mostly by chemists, because of its sodium ions,

Caustic Soda: used mostly among traders, because of its corrosive and caustic feature,

Lye and Soda: because of its strong alkali.

What are Various Forms of Caustic Soda?

Caustic soda can be found in many forms and types such as liquid, flakes, granular, cubes and blocks depends on the usage. However, the liquid and flake forms are far efficient than other types. 

Liquid caustic soda which is mainly produced in China, is suitable for pulp and paper industry, water and sewerage treatments and as additive in food industry.

Suggestion: You can read about Caustic Soda applications in Food Industry

Producers and suppliers provide the market with liquid caustic soda as 50% and 73% solutions in water.

Being environmentally friendly is the advantage of this form due to its moderate impact on environment. In water, sodium hydroxide is dissolved to sodium and hydroxide ion and become neutralized. 

It is worth to mention that liquid form is much more energy-efficient. These pros are remarkable for eliminating energy waste and reducing final costs.

Another popular form of this product is Flake, which absorbs water faster than Granular and cube. This feature results in less heat release and thus lowers the risk of explosion.

In comparison to granular, cubes, and blocks, these two forms have more competitive prices, respecting higher production rates.

If you require to know the latest caustic soda price in both flakes and liquid type, check the Caustic Soda Price page.

Caustic Soda Pearls

Caustic Soda Flakes

Caustic Soda Loading by Infinity Galaxy Team
Technical Data Sheet (TDS) Caustic Soda Liquid
PropertyISIRI Compliant RangeInfinity Galaxy Product Range
Standard Reference

Purity of Sodium Hydroxide (%W)Min 48
Min 48
ISIRI 364
Carbonate as Na2CO3 (%W)Max 0.5
Max 0.3
ISIRI 364

Chloride as NaCl (%W)Max 0.03
Max 0.015
ISIRI 364

Sulfate as Na2SO4 (%W)Max 0.007
Max 0.004
ISIRI 364

Silicate as SiO2 (%W)
Max 0.01
Max 0.005
ISIRI 364

Fe (mg/kg)
Max 10
Max 7
ISIRI 364
Insoluble in Water (%W)Max 0.05
0.00
ISIRI 364

Aluminum as Al2O3 (mg/Kg)Max 10
Max 10
ISIRI 364

Heavy Metals as Pb (mg/Kg)Max 10
Max 10
ISIRI 364

Hg (mg/Kg)
Max 0.1
Max 0.1
ISIRI 364

Arsenic as As2O3 (mg/Kg)Max 1
Max 1
ISIRI 364

Appearance

Colorless, Clear, Free of Sediment & Suspended particles
OK
ISIRI 364

What are Caustic Soda Properties?

Caustic soda has usually a solid form. But be careful not to put it in a wet place, because the substance can absorb water very easily. If you dissolve caustic soda in water, it bubbles, splash and produce a reasonable amount of heat. That’s why it is recommended to keep caustic soda away from wet surfaces and humidity.

Caustic soda is also a corrosive substance. It reacts vigorously with some metals such as aluminum, magnesium, zinc, and tin. This kind of reaction may be hazardous and lead to explosion, mainly because a huge amount of hydrogen is generated. This means caustic soda cannot be handled without having safety rules in mind.

Must read: Tips on MSDS that you should follow to maintain safety when using caustic soda.

Specifications of Infinity Galaxy Caustic Soda Flakes 99.5% Purity
∞ Test Name UnitImportance DegreeAccepting LimitTest Result
Test Method
Purity of Sodium Hydroxide (NaOH)% WImportant
Min 98

99.16

IRISI-364 clause1-7/IRISI 6135

Carbonate as Na₂Co₃% WImportantMax 10.43
IRISI-364 clause2-7/IRISI 6135


Chloride as NaCl
% WImportant
Max 0.06
0.0085
IRISI-364 clause3-7/IRISI 2535

Sulfate as Na₂So₄
% WImportant
Max 0.01

0.0047


IRISI-364 clause4-7/IRISI 2539

Silicate as SiO2
% WImportant
Max 0.02
0.0019
IRISI-364 clause5-7/IRISI 2531

Fe
mg/kg
ImportantMax 30
12.5
IRISI-364 clause6-7/IRISI 2537

Insoluble in water% W
ImportantMax 0.1
0
IRISI-364 clause7-7/IRISI 7904

Aluminum as Al₂O₃mg/kg
ImportantMax 20
<20
IRISI-364 clause8-7/IRISI 7903

Heavy metals as Pbmg/kg
ImportantMax 20
<20
IRISI-364 clause9-7/IRISI 7905

What Caustic Soda Reacts with?

Sodium hydroxide has chemical properties, reactivity, and incompatibilities that must be considered during its handling and storage.

This product reacts promptly to some metals like magnesium, zinc, aluminum, bronze, copper, chromium, brass and any other alloys which contain these metals. There are vital principals to avoid contacting caustic soda with zinc coated (Galvanized) materials, halogenated organics, organic nitro compounds and specially acids. In contact with metals, caustic soda corrodes the surface and produce a reasonable amount of hydrogen, which can behave like an explosive gas.

Dilution of sodium  hydroxide in water can be hazardous too. Generally, caustic soda reacts with water and produces strong heat. If you pour the water on caustic soda it may spatter, so be careful.

This product’s reactivity is also expandable to live texture such as animals’ skin and other organs of body. Reacting caustic soda with some sugars like maltos, galactose and fructose can produce carbon monoxide. This feature can be highly dangerous in case you ship caustic soda in a cargo containing food and beverage.

What is the difference between sodium hydroxide and potassium hydroxide?

Both sodium hydroxide and potassium hydroxide (KOH) are used as catalyst in a wide range of industries. However, these two chemical compounds have differences.

Sodium hydroxide is stronger than potassium hydroxide in terms of reactivity. However, KOH is more soluble in water, ethanol and methanol.

Due to its wider range of applications, potassium hydroxide is cheaper than caustic soda. In the manufacturing of fertilizers, soaps and chemical batteries, it is potassium hydroxide that plays a vital role, not caustic soda.

What is the difference between caustic soda and Soda Ash?

Despite their Alkali feature, Sodium Hydroxide and Sodium Bicarbonat are not the same. Sodium Bicarbonate is also known as Soda ash by Na2CO3 Formula. Being less hazardous than sodium hydroxide, this chemical substance is used for reducing the acidity in cooking, baking, and even medicine.

It is also a raw material in glass manufacturing. Because of its alkali nature, it has a vital role in shaping the glass items. It also supports the energy efficiency by reducing the temperature of furnace which is a must to melt the silica (the main raw material of glass). Soda ash is also useful in mixing other raw materials in the production of glass. It prevents the mixture from being segregated and solidified.

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Ahmad Reza Yousefi

August 25, 2019
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