When purchasing polyaluminum chloride, sometimes there will be some granular impurities, which are only some caking of polyaluminum chloride, and will not affect the use effect of polyaluminum chloride.

A kind of production process of polyaluminum chloride is drum drying type. The polyaluminum chloride produced by this process contains more particles, so how do these impurities come from? When polyaluminum chloride is dried by roller, some of them will be pushed unevenly. In this state, these small particles will appear when polyaluminum chloride is dried, which is just not good-looking. In actual use, it will dissolve after adding water, and the effect will not be affected, The only effect is that polyaluminum chloride may dissolve more slowly than powder polyaluminum chloride.

The water-insoluble matter of polyaluminum chloride refers to the existence in the water solution after dissolution. For example, some polyaluminum chloride will find that the water solution is turbid after dissolution, which is caused by the water-insoluble matter. This is different from the granular material in polyaluminum chloride products. The more water-insoluble polyaluminum chloride is, the more turbid the aqueous solution will be. Similarly, the less water-insoluble polyaluminum chloride is, the more transparent the aqueous solution will be. This is also one of the methods to determine the content of water-insoluble polyaluminum chloride. The water-insoluble matter of polyaluminum chloride will gradually block the pipeline in the process of use, so the water-insoluble matter of polyaluminum chloride has strict indicators.

At present, the way to reduce the water-insoluble content of polyaluminum chloride is through plate and frame pressure filtration. At this time, the particulate matter in polyaluminum chloride products is much less, and the content of water-insoluble matter will be greatly reduced.