Anhydrous aluminum sulfate is often used as an additive in the papermaking industry. Why choose anhydrous aluminum sulfate instead of aluminum sulfate:
Application advantages of iron-free aluminum sulfate in papermaking:
1. Cheap calcium carbonate filler can be added, which not only reduces production costs and improves the whiteness and folding resistance of the paper, but also overcomes the inevitable shortcomings of synthetic sizing materials (such as AKD, etc.) (such as slippage, difficulty in controlling the sizing degree, etc.);
2. The retention and filtering aid functions of the slurry are significantly improved;
3. The appearance is white, and the iron content is extremely low, which can meet the needs of paper manufacturing;
4. Except for the breaking length, all other paper performance indicators have been improved to varying degrees;
5. It is a pre-hydrolyzate of aluminum chloride. The degree of hydrolysis is relatively low, and the decrease in pulp pH is smaller than that of aluminum sulfate;
6. Industrial aluminum sulfate is only suitable for acidic sizing, while iron-free aluminum sulfate can be used for sizing in acidic and neutral environments. The corrosion of the system is significantly reduced, and the treatment of white water is easier;
7. Polyaluminum chloride can maintain high electropositivity in the neutral or even alkaline range, unlike aluminum sulfate, which quickly forms Al(OH)3 precipitation, and due to the pre-hydrolysis of polyaluminum chloride, it will not reduce the pH value of the system very low.