Polyaluminum chloride

Polyaluminum chloride (CAS 1327-41-9), commonly known as PAC or ACH, is an inorganic coagulant used across water treatment and industrial processing. It neutralizes suspended particles and colloidal matter, enabling their removal through sedimentation or filtration.

In municipal and industrial water treatment, PAC destabilizes turbidity and organic load across a wide pH range, reducing downstream chemical demand compared to alum. This efficiency makes it a preferred choice for large-scale purification systems.

Pulp and paper manufacturers apply it as a retention and drainage aid, improving filler and fiber retention on the wire while controlling pitch deposits. This process enhances the overall quality and structural integrity of the final paper product.

Textile and leather processors use PAC in effluent treatment to precipitate dyes, suspended solids, and COD before discharge. This application is critical for meeting environmental regulations and ensuring safe wastewater management practices.

In paper sizing, it acts as a precipitant for rosin-based sizing agents, anchoring them to fiber surfaces to improve water resistance. This chemical interaction is essential for producing durable paper goods used in various commercial sectors.

Polyaluminum chloride is supplied as a liquid solution and as a dry powder or granule form, with liquid grades being the dominant commercial format. Standard basicity levels and Al2O3 content vary significantly by specific application.

Water treatment grades typically conform to drinking water standards such as those found in the FCC or USP. Technical and industrial grades are available for non-potable applications in paper, textile, and effluent treatment.