Alum, whose main component is potassium aluminum sulfate dodecahydrate, has antibacterial and astringent properties and is used in Traditional Chinese Medicine. Traditional Chinese Medicine believes that alum has the effects of detoxification and insecticide, dampness-relieving and antipruritic, hemostatic and antidiarrheal, and heat-clearing and expectorant. Recent studies have confirmed that alum also has antibacterial and anti-trichomoniasis properties. Some traditional Chinese medicine practitioners use alum to treat conditions such as hyperlipidemia, duodenal ulcers, and hemoptysis caused by tuberculosis. Alum is also used in the preparation of aluminum salts, baking powder, paint, tanning agents, clarifiers, mordants, papermaking, and waterproofing agents. When consumed as a food additive, alum is rarely excreted and remains permanently deposited in the body. The aluminum in alum is not a required trace element for the human body, and excessive intake can impair the body's absorption of iron, calcium, and other nutrients, leading to anemia and osteoporosis.

Alum's main uses include:
A rosin sizing agent in papermaking, a sedimentation aid for turbid water purification, a film hardener for photographic paper, a foam rubber foaming aid, and a dye mordant. It is also used as a sedimentation aid for turbid water purification. In the papermaking industry, it's used as a rosin sizing agent. In the photographic industry, it's used as a film hardener for fixer solutions and photographic paper. In the dyeing and printing industry, it's used as a mordant and a resist for anti-discharge processes. It's also used as a foam rubber foaming aid and a food additive. It's also used as a water purifier, a papermaking sizing agent, a dye mordant, a dye retarder, a pharmaceutical preservative, an astringent, and a topical hemostatic. It's also used as a film hardener for fixer solutions during photo processing.