Difference Between Aluminium Sulphate and Alum

We all know that alum can accelerate precipitation and make turbid water clear, and aluminium sulfate can also be used for water purification, so many of us often confuse the two, but in fact, the two are very different, let's take a look at the difference between the two with Xiaobian.

Aluminium sulphate is a white orthorhombic crystalline powder with a density of 1.69 g/mL at 25°C. In the paper industry, it is generally used as a precipitant for rosin gum, wax emulsion and other rubber materials, often used as a flocculant in water treatment, and can also be used as an internal retention agent in foam fire extinguishers, and is also used to manufacture alum, aluminium white, petroleum decolorization, deodorant, some raw materials, etc. Approximately 50% of the total production is used in papermaking, and a large part is used as flocculants in drinking water, industrial water and industrial wastewater treatment, which accounts for about 40% of the total production. When added to water, it can form gelatin, which can adsorb and precipitate other suspended solids, and is also used to control the colour and taste of water, and can also be used to control the pH value of water in papermaking.

Alum: Generally commonly known as alum, potassium alum, potassium alum, potassium alum, potassium alum, and aluminium sulfate in use, it is also similar to aluminium sulfate. Colourless cubic crystals, the appearance is generally octahedral, sometimes resembling hexagonal plates, belonging to the α-type alum double salt, with the lustre of glass. The density is 1.757g/cm3, and the melting point is 92.5 °C. 9 molecules of crystal water are lost at 92.5 °C, and 12 molecules of crystal water are lost at 200 °C, soluble in water and insoluble in ethanol. Alum has a sour taste, is cold, and poisonous. Therefore, it can also be used to have the effect of convergence and so on. Alum can also be used to prepare aluminium salts, baking powders, paints, tanning materials, etc. It is often used in our lives to purify water and make edible leavening agents, such as fried hemp balls and fried dough sticks.

After the above description, we learned that the two are completely different in terms of chemical properties, alum can be used for the clarification of clean water, and also has a certain role, and can also be used, while aluminium sulfate is a chemical product, mainly used in papermaking, water purification, used to adjust pH value and as a flocculant.