The Application of Magnesium Chloride Flakes in the Paper Industry，As an eco-friendly magnesium salt auxiliary agent, magnesium chloride flakes (hexahydrate magnesium chloride) are widely adopted in the paper industry for manufacturing wood pulp, waste paper pulp, flame-retardant paper, food packaging paper and other paper products.

I. Functions of Magnesium Chloride Flakes Throughout the Entire Papermaking Process

1. Boost Efficiency in Pulp Bleaching

Sodium hydroxide is extensively used as an alkaline regulator in traditional papermaking bleaching processes. It easily triggers excessive degradation of carbohydrates in pulp, lowering pulp yield and generating large volumes of problematic anionic trash that disrupt stable operation of paper machines.

When magnesium chloride flakes are added during bleaching, they slowly release weakly alkaline magnesium hydroxide. This enables gentle pH adjustment for bleaching, while reducing iron and manganese ion concentrations in pulp to below 10 mg/L, fundamentally eliminating yellowing of paper pulp caused by excessive iron ions.

Actual production data shows that production lines supplemented with white magnesium chloride flakes for bleaching can cut consumption of bleaching chemicals by over 15% while achieving the same brightness standard. Pulp yield rises noticeably, and the long-term brightness stability of finished paper is greatly improved, extending the shelf life of paper products significantly.

2. Targeted Performance Optimization of Finished Paper

When dissolved, magnesium chloride flake solution disperses evenly among pulp fibers in the papermaking stage. On one hand, it acts as a viscosity regulator to strengthen bonding force between fibers, greatly boosting the toughness and burst resistance of finished paper. On the other hand, its inherent non-flammable property endows paper with basic flame retardancy, meeting production requirements for fireproof packaging paper and special industrial paper.

For color paper production requiring dyes, magnesium chloride flakes also serve as stabilizers and humectants for pigment particles. They allow dyes to distribute uniformly within fibers, enhancing color vividness and preventing fading or color bleeding after long-term storage. This characteristic makes them widely used in cultural and creative paper as well as high-end packaging paper manufacturing.

3. Low-Cost Solution for Papermaking Wastewater Treatment

Sewage treatment remains a major cost burden for papermaking enterprises, yet white magnesium chloride flakes deliver highly cost-effective auxiliary water treatment performance. In biochemical treatment processes, they act as nutrients for microorganisms to activate activated sludge flora in sewage tanks, drastically improving decomposition efficiency of organic matter and helping factories steadily lower COD discharge levels.

Meanwhile, magnesium chloride flakes adsorb residual fine fibers and decolorizing impurities in wastewater via flocculation and sedimentation, reducing pressure on subsequent sludge treatment. Compared with dedicated water treatment chemicals, white magnesium chloride flakes can slash enterprises’ auxiliary agent costs for sewage treatment by around 30%.

4. Pulp Bleaching Stabilizer to Eliminate Paper Yellowing (Specially for Chlorine-Free Bleaching)

Oxygen bleaching and hydrogen peroxide bleaching are mainstream eco-friendly processes in modern papermaking, and magnesium chloride flakes function as core stabilizing auxiliaries — this is also the most critical application scenario for white magnesium chloride flakes:

Hydrolysis produces weakly alkaline magnesium hydroxide to stabilize hydrogen peroxide activity, avoiding ineffective decomposition of bleaching agents and cutting chemical consumption;

Chelates heavy metal ions such as iron and manganese in pulp, preventing paper yellowing and brightness attenuation induced by catalytic oxidation of metal ions;

Replaces traditional sodium silicate stabilizers without silicate scale clogging wire screens, filters and pipelines, greatly reducing equipment cleaning frequency;

Improves long-lasting pulp brightness, suitable for manufacturing high-brightness paper including copy paper, coated base paper and premium writing paper.

Special paper for EU export and food-contact packaging paper impose strict restrictions on heavy metal content. Only refined white magnesium chloride flakes produced by professional magnesium chloride manufacturers can meet the EU REACH certification standards for heavy metal indicators.

II. Why Papermaking Enterprises Prefer White Magnesium Chloride Flakes Over Ordinary Magnesium Chloride Flakes

Higher Purity and Stable Indicators

White magnesium chloride flakes maintain a stable magnesium chloride content of 46%–47%, with tightly controlled sulfate, sodium chloride and iron ion levels. Ordinary grey magnesium chloride flakes contain excessive impurities, and over-standard iron ions directly cause paper yellowing and bleaching failure.

Clear Aqueous Solution Without Precipitates

Manufactured via refined purification processes, white magnesium chloride flakes dissolve completely without suspended solids, avoiding blockages in paper machine pipelines and forming wires and suiting automated continuous feeding production lines.

Compatible with High-End Paper and Export Orders

Food packaging paper and EU export special paper enforce strict limits on heavy metals and harmful impurities. White magnesium chloride flakes supplied by qualified magnesium chloride manufacturers come with complete clearance documents including CMA test reports, REACH certificates and SDS safety data sheets.

Lower Losses During Storage and Transportation

Uniform crystal structure with moisture-proof laminated packaging resists caking even in rainy seasons, maintaining stable quality during ocean shipping and long-term storage.

III. Conclusion

Magnesium chloride flakes serve multiple functions including fiber protection, brightness enhancement, paper strengthening and flocculation throughout pulp making, bleaching, papermaking and wastewater treatment procedures. Ordinary grey magnesium chloride flakes are only fit for low-grade corrugated paper production, while white magnesium chloride flakes stand as standard auxiliary agents for high-end cultural paper, packaging paper and export special paper thanks to their low impurity and high purity advantages.

The above introduction from Yuze Chemical, a professional magnesium chloride manufacturer, elaborates on the applications of white magnesium chloride flakes in papermaking and the reasons for choosing white-grade products. With 13 years of experience in magnesium chloride production, Yuze Chemical can recommend magnesium chloride products matching your demands in terms of quality and price. Follow us to stay tuned for more updates on magnesium chloride products (anhydrous magnesium chloride and hexahydrate magnesium chloride).