Calcium sulfate has the characteristics of high whiteness, low hardness, high temperature resistance, chemical resistance, strong affinity with polymers, non-toxic and so on. It can bring obvious strength advantages when used in papermaking and filling. However, calcium sulfate in aqueous solution or in humid air, hydration reactions will occur, resulting in changes in crystal structure and properties, thus losing its original characteristics. If it is directly used as a filler in papermaking, its retention rate is extremely low, and the calcium and sulfate ions dissolved in the water seriously affect the recycling of white water in the system, causing production operational problems.

 

Calcium sulfate is an ideal filler for papermaking, which will help to improve the optical and strength properties of paper. By appropriately modifying the surface of calcium sulfate, the retention rate in the wet end can be significantly improved, and it also shows the strength advantage over calcium carbonate filling.
 

 

The paper industry's future market positioning for calcium sulfate is mainly focused on its functional characteristics after filling. In addition to providing excellent strength characteristics for paper filling, it is also necessary to consider whether it can simultaneously give positive impact to optical and surface properties of the paper. In addition, the cost factor of processing industrial by-product gypsum into paper and filling calcium sulfate is also an aspect that needs to be considered.

 

Calcium sulfate processing mill

 

Kefid's industrial mill products have been tested by the market and enjoy a high reputation among users. Its mill products include: raymond mill, high-pressure suspended roller mill, high-pressure micro-mill, three ring medium-speed micronized powder mill, overpressure trapezoidal mill, vertical mill, European-style coarse mill, etc. The scope of application of products covers almost all fields of current industrial milling, especially in the processing field of raw materials such as limestone, calcite, marble, and calcium sulfate. After the calcium sulfate is processed by the mill, the output is randomly selected between 325-3250 mesh. After a special process, calcium sulfate is used for papermaking and filling. It is possible that the unique fibrous properties of calcium sulfate are incomparable with existing papermaking fillers (such as calcium carbonate).