Alum is shabby and has a strong astringent effect. Chinese medicine believes that alum has the functions of detoxifying and killing insects, eliminating dampness and relieving itching, stopping bleeding and diarrhea, clearing away heat and resolving phlegm, and resisting trichomonas vaginalis. Some Chinese medicine practitioners use alum to treat hyperlipidemia, duodenal ulcer, tuberculosis and hemoptysis.

Edible function

Alum can also be used to cook mung bean porridge, the main function is to make mung beans easier to cook, but it is not recommended because the dosage is difficult to control and may be poisoned. Edible alkali can be used instead.

Alum can also be used to prepare aluminum salts, paints, tanning materials, mordants, papermaking, waterproofing agents and so on.

Clean water: Alum is dissolved in water and ionized to generate Al3+, and Al3+ combines with OH generated by water and ionized to generate aluminum hydroxide. Aluminum hydroxide colloidal particles are positively charged and meet negatively charged sediment colloidal particles, and their charges are neutralized. The charged colloidal particles will soon get together, and the particles will get bigger and bigger, and finally sink to the bottom of the water. In this way, the water becomes clear and clean.

Extended data:

Potassium aluminum sulfate dodecahydrate, also known as alum, alum, potassium alum, potassium aluminum alum and potassium alum, is a double salt of potassium sulfate and aluminum sulfate containing crystal water. Colorless cubic crystals are usually octahedral in appearance, or form a cluster with cubes or rhombic dodecahedrons, and sometimes they are attached to the container wall with {11} faces, which look like hexagonal plates. They belong to α -alum double salt and have glass luster. The density is 1.757g/cm3, and the melting point is 92.5℃.

At 92.5℃, it loses 9 molecules of crystal water, and at 200℃, it loses 12 molecules of crystal water, which is soluble in water and insoluble in ethanol. Alum tastes sour, cold and toxic. Therefore, it has antibacterial and astringent effects and can be used as traditional Chinese medicine. Alum can also be used to prepare aluminum salt, baking powder, paint, tanning materials, clarifier, mordant, papermaking, waterproof agent and so on. , can also be used as food additives. In our life, it is often used to purify water and as an edible swelling agent, such as fried sesame balls and fried dough sticks.

References:

Potassium aluminum sulfate dodecahydrate _ Baidu encyclopedia