What Is Industrial-Grade Polyaluminum Chloride?
Industrial-grade polyaluminum chloride (PAC) is an inorganic polymer flocculant with the general formula [Al₂(OH)ₛCl₆₋ₛ]ₜ. Compared to conventional aluminum salts, PAC offers faster flocculation, lower dosage requirements, a wider operating pH range, and superior effluent quality. It is one of the most widely used coagulants in the global water treatment industry.
Five Key Application Areas
1. Municipal & Industrial Water Treatment
As a core coagulant, PAC neutralizes suspended particles and colloids through charge neutralization and adsorption bridging. The hydrolysis process rapidly forms dense flocs that settle quickly, producing low-turbidity effluent. In municipal water plants, switching from traditional aluminum sulfate to PAC can reduce chemical consumption by 20–30% while generating less sludge.
2. Industrial Wastewater Treatment
PAC is highly effective for color, COD, and suspended solids removal across multiple industries:
- Textile & Dyeing Wastewater: Decolorization rates exceed 80%, with significant COD and BOD reduction
- Paper Mill Effluent: Effectively removes lignin, fine fibers, and filler particles
- Oily Wastewater: Excellent demulsification performance for petrochemical and machining industries
3. Paper Manufacturing
Beyond wastewater treatment, PAC serves as an internal sizing agent and retention/filtration aid in papermaking. It improves water resistance and paper strength, reduces linting and dusting, and lowers white-water consistency — ultimately reducing production costs per ton of paper.
4. Petrochemical Industry
In oilfield operations, PAC is used to condition drilling and completion fluids by adjusting viscosity and stability. For produced water reinjection, PAC removes suspended solids and emulsified oil, preventing formation plugging and pipeline scaling.
5. Mining & Metallurgy
For tailings wastewater containing heavy metal ions and fine ore particles, PAC promotes solid-liquid separation through adsorption and sweep flocculation. It accelerates tailings settling, increases water reuse rates, and supports the recovery of valuable metals.
How to Choose the Right PAC Product
Key specifications to evaluate:
- Basicity: Typically 40–90%. Higher basicity improves coagulation but reduces product stability
- Al₂O₃ Content: Industrial grade generally 26–30%
- Water-Insoluble Matter: Lower is better — affects effluent clarity and equipment scaling
- Heavy Metal Content: Must be strictly controlled for drinking water applications
Always conduct jar tests to determine the optimal dosage and pH conditions before full-scale application, balancing treatment performance with cost-efficiency.
This article is for informational purposes. Consult a professional water treatment engineer for specific product selection and application guidance.