what is Caustic Soda Liquid?

Caustic soda liquid, also known as sodium hydroxide, is a strong alkali that is highly soluble in water. Sodium hydroxide is colorless unlike the previous types of caustic soda which were white.
Caustic soda is a mineral compound with the formula of NaOH, which can be solid (penetrating or granular) or solutions with different concentrations.
Sodium hydroxide in the vicinity of air easily absorbs moisture and its surface becomes wet and gradually dissolves.

Liquid Sodium Hydroxide is soluble in water and in equal proportions as Ethanol, Methanol, and Glycerin. The freezing point of this material is 4.4 and the boiling point is 145 °C.

History

Caustic soda liquid’s history is a surprising adventure. Ancient people used lye, a crude version, for soap and textiles. Centuries later, science unlocked its secrets. The 19th century’s Chaptal method led to industrial-scale production, fueling the rise of modern industry. Today, this versatile liquid remains important in everything from cleaning to food processing.

properties of caustic soda liquid

Caustic soda liquid, also known as sodium hydroxide (NaOH) solution, exhibits distinct physical and chemical properties that make it a valuable yet hazardous industrial material. Here’s a breakdown of its key characteristics:

Physical Properties

• Color: Clear or colorless
• Odor: Odorless
• Viscosity: Slightly viscous, increases with concentration. Higher concentration solutions feel more syrupy.
• Density: Denser than water. The specific value depends on concentration. A 20% solution at 20°C will have a density around 1.2 g/cm³, while a 50% solution might be closer to 1.5 g/cm³.
• pH: Strongly alkaline due to hydroxide (OH-) ions. A dilute solution (less than 4% concentration) might have a pH of 12, but concentrated solutions approach 14, the maximum for a basic solution.
• Melting Point: Not applicable for the liquid, but solid caustic soda melts at 318°C (604°F).
• Boiling Point: Varies with concentration. Water boils at 100°C, but concentrated caustic soda solutions boil at higher temperatures due to the presence of the solute elevating the boiling point.

Chemical Properties

• Highly Soluble in Water: Dissolves readily in water, releasing significant heat in an exothermic reaction. Proper handling is crucial to avoid burns from the heat.
• Soluble in Some Polar Solvents: Can dissolve to some extent in polar solvents like ethanol and methanol, which share a similar charge distribution with water.
• Insoluble in Non-Polar Solvents: Doesn’t dissolve in non-polar solvents like ether, which have a different electrical charge distribution than water and caustic soda.
• Strong Base (Alkali): Exhibits strong alkaline properties due to hydroxide ions. It reacts with acids to neutralize them.
• Exothermic Reaction with Acids: Reacts with acids in an exothermic reaction, generating heat.
• Corrosive to Metals: Reacts vigorously and damages certain metals, including aluminum, magnesium, zinc, and tin, by dissolving them.
• Decomposes Proteins and Lipids: Due to its strong alkaline nature, it can break down proteins and fats (lipids) even at room temperature. This is why it can be harmful to human tissue.

VARIOUS GRADES OF caustic soda liquid

caustic soda liquid (sodium hydroxide solution) is available in various grades tailored for specific industrial applications. The primary differentiating factor between these grades lies in the production method employed and the resulting level of impurities. Here’s a closer look at the two most prevalent commercial categories:

• Membrane Grade Caustic Soda: This grade represents the pinnacle of purity within caustic soda liquids. It is manufactured through a membrane cell process. During this process, a selective membrane meticulously separates chlorine gas from the sodium hydroxide solution. This meticulous separation yields a product with exceptionally low levels of sodium chloride (salt) contamination (typically less than 50 ppm) and other impurities. Due to its superior purity, membrane grade caustic soda is the preferred choice for applications where even minute traces of contaminants can significantly impact the final product. These applications include:
• Rayon production
• Aluminum manufacturing
• Pharmaceutical industry
• Food processing 

Diaphragm Grade Caustic Soda: Compared to membrane grade, diaphragm grade caustic soda represents a less pure form. It is produced using the diaphragm cell process. Here, a diaphragm separates the chlorine gas from the sodium hydroxide solution; however, some level of salt contamination (typically ranging from 1% to 6% sodium chloride) remains in the final product. Despite the presence of these impurities, diaphragm grade caustic soda proves suitable for applications where high purity is not an absolute necessity. These applications include:

• Pulp and paper production
• Soaps and detergents manufacturing
• Textile processing
• Water treatment
• Drain cleaning 

Additional Considerations:

• Food Grade Caustic Soda: This highly specialized grade adheres to stringent food safety regulations, ensuring minimal residual amounts when used in specific food processing applications.
• Rayon Grade Caustic Soda: A specific sub-type of membrane grade caustic soda optimized for rayon production processes.

 

Application and uses of Sodium Hydroxide

• Pulp and Paper Production: Caustic soda plays a crucial role in the paper-making process. It helps in separating lignin, a natural polymer that binds cellulose fibers together in wood, during wood pulping. This separation frees the cellulose fibers, which are the main component of paper. Caustic soda is also used for bleaching paper pulp, giving it a brighter and cleaner appearance.
• Soaps and Detergents: Caustic soda is a key ingredient in soap manufacturing. It reacts with fats and oils through a process called saponification to form soap. By breaking down the greasy molecules into water-soluble components, soap helps lift dirt and grime from surfaces. Caustic soda is also present in many modern detergents, where it serves similar purposes by aiding in the breakdown of dirt and grease.
• Rayon Production: Caustic soda is involved in the viscose process, a key step in the production of rayon, a type of synthetic fiber commonly used in clothing textiles. In this process, wood pulp is treated with caustic soda to dissolve it and then transformed into a viscose solution. This solution is then extruded through spinnerets to form rayon fibers.
• Aluminum Manufacturing: Caustic soda is utilized in the Bayer process, the dominant method for extracting aluminum from its natural ore, bauxite. The process involves dissolving aluminum hydroxide, the main component of bauxite ore, in a concentrated caustic soda solution. This leaves behind impurities and allows the aluminum hydroxide to be separated and further processed into pure aluminum metal.
• Textile Industry: Caustic soda has several applications in textile processing. It is used in mercerization, a treatment that strengthens cotton fibers and gives them a lustrous appearance. Mercerized cotton is often used in high-quality fabrics for clothing and home goods. Caustic soda is also used for scouring textiles, which removes impurities like natural oils and waxes that can hinder dyeing and finishing processes. Additionally, it can be used for bleaching textiles to achieve a desired level of whiteness.
• Water Treatment: Caustic soda is a valuable tool in water treatment processes. It helps adjust water pH levels by neutralizing acidic water. This is important because acidic water can be corrosive to pipes and infrastructure. Caustic soda can also be used to remove impurities like carbonates and phosphates from water during the softening process.
• Drain Cleaning: Some drain cleaners utilize caustic soda to break down clogs caused by grease and fats. However, due to its hazardous nature, extreme caution is advised when using such products. Caustic soda can react with organic matter in drains to generate heat and potentially flammable hydrogen gas. If not handled properly, it can cause severe skin and eye burns.
• Food Processing: Small, carefully regulated amounts of caustic soda are used in some specific food processing applications. For instance, it may be used in peeling fruits and vegetables or treating pretzels to give them a shiny appearance. Food safety regulations strictly govern these uses to ensure that any residual caustic soda levels are well below safety thresholds for human consumption.
• Biodiesel Production: Caustic soda plays a role in the transesterification process, which converts vegetable oils into biodiesel fuel. In this process, caustic soda acts as a catalyst, reacting with the triglycerides in vegetable oil to produce fatty acid methyl esters (FAME), the main component of biodiesel.
• Pharmaceutical Industry: Caustic soda is used in the production of some medications. It can act as a neutralizing agent during various stages of drug synthesis or be used in the purification process of certain pharmaceuticals. The specific applications in this industry are highly regulated to ensure the safety and purity of medications.

SAFETY

Caustic soda liquid is hazardous! Here’s the safety gist:

• Wear chemical-resistant gloves, goggles, and protective clothing.
• Work in ventilated areas.
• Slowly add caustic soda to water while stirring, never the other way around.
• Store it properly in a cool, dry place.

If contact occurs:

• Flush with water for 15 minutes and seek medical attention immediately.
• DO NOT induce vomiting if swallowed. Call poison control or seek medical attention immediately.

PACKING

We often use Plastic drums and iso tanks, However, according to the customer inquiry it is capable of packing in IBC and drums. IBC capacity will be 1000-1200 kg. Drum capacity is 200-220 kg of Caustic Soda Liquid.

• Iso tank
• Plastic Drum
• IBc