Introduction
Poly Aluminium Chloride (PAC) is manufactured through two primary drying methods: spray drying and roller (drum) drying. The production process directly impacts product quality, solubility, and performance. Understanding the differences is essential for buyers evaluating PAC suppliers.
Spray Dried PAC
Process: Liquid PAC is atomized into fine droplets and dried instantly in a hot air chamber (200-300C). The rapid drying preserves the polymer structure and produces uniform, hollow microspheres.
Advantages:
- Basicity 40-85% — wide range available, including high-basicity grades
- Excellent solubility — dissolves rapidly in cold water without mixing issues
- Low water insolubles — typically <0.5%, meeting drinking water standards
- Uniform particle size — consistent dissolution and dosing
- Higher Al2O3 content — 28-31% for premium grades
- Better coagulation performance — larger, faster-forming flocs
- Lower dosage requirement — due to preserved polymer activity
Roller Dried PAC
Process: Liquid PAC is applied to heated rotating drums (150-180C). The material dries as a thin film and is scraped off as flakes or irregular particles.
Characteristics:
- Basicity 10-30% — lower range, primarily low-basicity grades
- Slower dissolution — flakes require more mixing time
- Higher water insolubles — typically 1-3%, may need filtration
- Irregular particle shape — inconsistent dissolution rate
- Lower Al2O3 content — typically 26-28%
- Lower unit cost — simpler production process
Quick Comparison Table
| Parameter | Spray Dried PAC | Roller Dried PAC |
|---|---|---|
| Basicity range | 40-85% | 10-30% |
| Al2O3 content | 28-31% | 26-28% |
| Water insolubles | <0.5% | 1-3% |
| Bulk density | 0.65-0.75 g/cm3 | 0.85-1.10 g/cm3 |
| Dissolution speed | Fast (powder) | Slower (flakes) |
| Dosage vs alum | 50-70% less | 30-50% less |
| Application | Drinking water, high-end industrial | General wastewater |
| Unit price | Higher | Lower |
Which Should You Choose?
Choose Spray Dried PAC 30% for: drinking water plants, textile wastewater, POME treatment, desalination pretreatment, paper mills, and any application where consistent quality and low insolubles matter. This is the industry standard for professional water treatment.
Choose Roller Dried PAC for: budget-sensitive general wastewater treatment where some insolubles are acceptable and wide pH performance is not critical.
Hydrochemix PAC Products
Hydrochemix Chemicals produces spray dried PAC 30% with Al2O3 content of 28-31% and water insolubles below 0.5%. We provide Certificate of Analysis (COA) with every shipment and offer free product samples for quality verification.
Visit hydrochemix.com or contact jingshuicc@gmail.com for specifications and pricing.