Aluminum sulfate (alum, CAS 10043-01-3) is a commodity chemical, but “commodity” does not mean “no quality differences” — the grade, the aluminum oxide content, the iron level and the COA all matter. This purchasing guide covers the specification sheet, the grades, packaging and the supplier checklist for aluminum sulfate.
1. Reading the Specification
| Parameter | Typical value | Why it matters |
|---|---|---|
| Al2O3 content | 15-17.5% (grade-dependent) | Active content |
| Iron (as Fe) | Low; iron-free grade for paper/dye | Color and application suitability |
| Insoluble matter | Low | Purity |
| pH (solution) | Acidic (approx. 3) | Handling |
| Appearance | White to light gray lumps/crystals | Visual QC |
2. What a Complete COA Should Contain
- Product name and CAS number (10043-01-3)
- Batch number and production date
- Al2O3 content (measured)
- Iron, insoluble matter, pH
- Test methods and quality manager signature
3. Grades and Forms
- Lump/ground: economical, standard for water treatment.
- Iron-free: for papermaking, dyeing and other color-sensitive uses.
- Solution (liquid alum): convenient for dosing, higher logistics cost.
4. Packaging, Storage and Handling
- Packaging: 25/50 kg bags, jumbo bags, or bulk.
- Storage: dry, sealed; alum absorbs moisture and is mildly corrosive when wet.
- Handling: avoid dust; solutions are acidic — gloves and goggles.
5. How to Verify Quality on Arrival
- Check packaging and labels against the COA batch number.
- Visual check: consistent color, no caking or foreign matter.
- Verify Al2O3 and iron against the COA.
- Run a jar test against your current batch.
- Keep a retained sample per batch.
6. Supplier Checklist
- Manufacturer vs trader — manufacturers control grade consistency.
- Consistent COA with measured Al2O3/iron on every batch.
- Multiple grades available (lump, iron-free, liquid).
- Stable supply and reasonable lead time.
- Price comparison on a per-kg basis at the same grade.
7. FAQ
What Al2O3 content should I buy?
15-17.5% is standard; the right level depends on your application and the supplier’s spec.
Why is iron content important?
Iron affects color — iron-free grades are required for paper, dyeing and other color-sensitive uses.
Is liquid or solid alum better?
Liquid is easier to dose but costs more to transport; solid is economical for bulk.
Can I get a trial sample?
Yes. PolyblueChem offers trial samples for validation before bulk orders.
8. References and Further Reading
- Standard specifications for aluminum sulfate (water-treatment grade)
- Manufacturer SDS and COA guidance
This article is published for industrial and technical reference by PolyblueChem. Specifications are typical; verify against the supplier’s COA.
PolyblueChem supplies aluminum sulfate (CAS 10043-01-3) in multiple grades with COA and MSDS. Contact us for samples and quotations.