Soda Ash And Anhydrous Sodium Sulfate – Efficient Additives In The Papermaking Industry
Soda Ash Dense
Soda ash is a key chemical in the papermaking and pulp making process, especially suitable for alkaline cooking techniques. It is a core additive for the separation and purification of wood fibers.
Soda Ash Light
Soda ash is a key chemical in the papermaking and pulp making process, especially suitable for alkaline cooking techniques. It is a core additive for the separation and purification of wood fibers.
Application differences between heavy and light soda ash
SPECIFIC APPLICATIONS
Pulp making process
The core additive for “delignification”
MECHANISM
Lignin reacts with soda ash to produce soluble lignin sodium salts, which detach from fibers and separate them from each other
MECHANISM
Mainstream bleaching agents need to be effective in alkaline environments with pH 9-11: too low pH can cause bleaching agents to decompose too quickly, resulting in insufficient whiteness; If the pH is too high, the fibers will oxidize and the paper will become brittle. Soda ash slowly releases OH ⁻ by ionizing CO ∝⁻, accurately stabilizing the pH of the system, ensuring bleaching efficiency and inhibiting pulp yellowing.
Whitening process
providing protection for bleaching agents
Whitening process
providing protection for bleaching agents
MECHANISM
The sizing agent is more easily emulsified and dispersed under alkaline conditions, and combines with the hydroxyl groups on the fiber surface to form a water-resistant film; At the same time, soda ash neutralizes organic acids in pulp (such as residual acetic acid from cooking) to avoid acidic environments damaging the fiber structure.
Anhydrous Sodium Sulfate
As an auxiliary electrolyte for sulfate cooking, it enhances pulp efficiency and optimizes pulp properties.
Application Stage
Synergistic effect of sulfate cooking method
Principle: Sodium sulfide can break the ether bonds in lignin, accelerating its dissolution, while anhydrous sodium sulfate serves as a “sulfur source reserve” to maintain stable sulfide concentration in the cooking solution and ensure continuous and efficient reaction.
Pulp washing and concentration
Anhydrous sodium sulfate can adjust the ionic strength of the washing solution, promote the separation of fibers and waste liquid, improve washing efficiency, and reduce the subsequent wastewater treatment load.
APPLICATION EFFECT
The pulp yield is increased by 3-5% (reducing fiber loss), and the cooking time is shortened by 10-15% (reducing energy consumption), especially suitable for pulp production of industrial paper such as high-strength corrugated paper and kraft paper.
PRODUCT ADVANTAGES
High purity (≥ 99%) anhydrous sodium sulfate with minimal impurities can prevent the introduction of iron and calcium ions, which can cause discoloration of pulp or scaling of equipment, and is suitable for the production needs of high-end paper products (such as writing paper).
