Difference between caustic soda and soda ash

In the chemical industry, caustic soda and soda ash seem to be similar, but in fact they are very different in nature. Accurately distinguishing their differences is essential for the control of the production process and the assurance of product quality.

There are significant differences in the chemical names of caustic soda and soda ash. Caustic soda, the chemical name is sodium hydroxide (NaOH), is a strong corrosive substance, commonly used in industrial production and living water. The chemical name of soda ash is sodium carbonate (Na2CO3), a colorless crystal, commonly used in the food industry and glass manufacturing. This name difference directly reflects their chemical nature and use difference.

There are significant differences in the physical properties of caustic soda and soda ash. Caustic soda is white or colorless crystal, soluble in water, melting point of 78.5 ℃, boiling point of 136 ℃, density of 2.17g/cm³. Soda ash is a white crystal with a melting point of 82 ℃, a boiling point of 1335 ℃ and a density of 1.36g/cm³. Caustic soda has a higher melting point, a slightly higher boiling point than soda ash, and a higher density, and these differences in physical properties are particularly important in industrial applications.

Again, the main components of caustic soda and soda ash are different. The main component of caustic soda is NaOH, which contains a certain amount of water and some soluble impurities, such as CaCO3, SiO2 and so on. The main component of soda ash is Na2CO3, which also contains a small amount of impurities. Soda ash has higher purity and lower impurity content, so it pays more attention to quality control when using it.

In industrial applications, the application scenarios of caustic soda and soda ash are also very different. Caustic soda is mainly used to neutralize acidic solutions, such as acid-base neutralization reactions in industrial production, and is also an important raw material for the fertilizer industry. Soda ash is mainly used to prepare alkaline solutions, such as glass manufacturing and food processing, and its use requires very low impurity content to ensure the safety and stability of the final product.

There are also significant differences in the quality testing standards and storage methods of caustic soda and soda ash. Caustic soda should comply with GB 2751-1992 "Caustic Soda" and GB 227-2008 "Metal Oxide Exposure Limit Contact Toxicological Data" standards, storage should pay attention to moisture-proof, dust-proof. Soda ash should comply with GB 2751-11 "glass soda ash" standard, storage should be moisture-proof, dust-proof, and avoid contact with acidic substances.

There are significant differences between caustic soda and soda ash in terms of chemical name, physical properties, main components, industrial applications, quality testing and storage methods. When chemical companies use these two substances, they need to strictly distinguish their differences to ensure production quality and safety.