Product Details
Alum, primarily composed of potassium aluminum sulfate dodecahydrate, possesses antibacterial and astringent properties and is utilized in Traditional Chinese Medicine (TCM). TCM attributes multiple therapeutic effects to alum, including detoxification and insecticide, dampness-relieving and antipruritic, hemostatic and antidiarrheal, as well as heat-clearing and expectorant actions. Recent scientific studies have corroborated its antibacterial and anti-trichomoniasis properties. Some TCM practitioners employ alum to treat conditions such as hyperlipidemia, duodenal ulcers, and hemoptysis caused by tuberculosis. Industrially, alum is used in the production of aluminum salts, baking powder, paints, tanning agents, clarifiers, mordants, papermaking, and waterproofing agents. When consumed as a food additive, alum is minimally excreted and tends to accumulate permanently in the body. Aluminum, a component of alum, is not an essential trace element for humans. Excessive intake can interfere with the body's absorption of iron, calcium, and other nutrients, potentially leading to anemia and osteoporosis.
Chemical Properties
| English name | Aluminium potassium sulfate dodecahydrate |
| English synonyms | POTASSIUM ALUMINIUM SULFATE 12-WATER;POTASSIUM ALUMINIUM SULFATE DODECAHYDRATE:POTAS SIUM ALUM:POTASSIUM ALUMINUM SULFATE DODECAHYDRATE:POTASSIUM ALUM SULFATE, DODECAHY DRATE;POTASSIUM ALUM DODECAHYDRATE;POTASSIUM AMMONIUM SULFATE;aluminumpotassiumdisulf atedodecahydrate |
| CAS number | 7784-24-9 |
| Molecular formula | AIH8KO5S |
| Molecular weight | 186.2 |
| EINECS number | 616-521-7 |
| Melting point | 92°C (lit.) |
| Boiling point | 200°C |
| Density | 1.757 g/mL at 25°C (lit.) |
| Bulk density | 900 kg/m³ |
| Storage conditions | Store at +5°C to +30°C |
| Solubility | H2O: 0.5M, clear, colorless |
| Form | Solid |
| Specific gravity | 1.757 |
| Color | White |
| Odor | Odorless |
| pH | 3.0-3.5 (25°C, 50 mg/mL in H2O) |
| Water solubility | 140 g/L (20°C) |
| Merck | 14,360 |
| Stability | Stable. Incompatible with steel, aluminum, copper, zinc, alkalis, and strong oxidizers. |
| LogP | -1.031 (est.) |
Product Application
Alum's main uses include:
This substance serves as a rosin sizing agent in papermaking, a flocculant/sedimentation aid for purifying turbid water, a film hardener for photographic paper and fixer solutions, a foaming aid in foam rubber production, and a mordant in dyeing. It is also utilized as a resist agent in anti-discharge printing processes within the dyeing and printing industry. Furthermore, it finds application as a food additive, a water purifying agent, a dye retarder, a pharmaceutical preservative, an astringent, and a topical hemostatic agent.
