What Is The Role Of Sodium Sulfate In The Pulp And Paper Industry?

Sodium sulfate, also known as Glauber's salt, plays an important role in the pulp and paper industry as a key ingredient in the Kraft process. In this process, wood chips are treated with a solution of sodium hydroxide and sodium sulfide to break down the lignin and separate the cellulose fibers.

Sodium sulfate is added to the solution to increase the solubility of the lignin in water and prevent it from re-attaching to the cellulose fibers during the washing process. It also helps to balance the chemical reactions that occur during the pulping process and maintain a consistent pH level.

Additionally, sodium sulfate can be used as a filler in papermaking to improve the strength and opacity of the paper. It can also be added to the paper coating to improve its resistance to water and moisture.