How is limescale formed? The principle of the formation of scale

This is calcium bicarbonate and magnesium bicarbonate in trick-or-treating, they work chemically with soap and turn into white precipitates of calcium stearate and magnesium stearate. It is also bad to boil water with this kind of water, because when the temperature is high, the calcium bicarbonate and magnesium bicarbonate in the water will decompose accordingly, forming calcium carbonate and magnesium carbonate precipitates and forming scale. If there is scale in the boiling kettle, it is not easy to transfer heat, and it will waste a lot of firepower.

This kind of water containing calcium bicarbonate and other impurities is called hard water, and in nature, spring water, well water, and seawater are generally hard water containing more or less calcium and magnesium salts, while rainwater is soft water. Hard water is so harmful that people try to "soften" hard water and turn it into soft water that does not contain these impurities. The most common way is to boil the water to precipitate the calcium bicarbonate and magnesium bicarbonate.

In factories, adding the right amount of soda (sodium carbonate) to water can also remove these impurities. Because sodium carbonate can react with calcium salts and magnesium salts in hard water to form calcium carbonate precipitates. In addition, some factories use sodium aluminosilicate as a softener, which can be used repeatedly after treatment and is very cheap.

In recent years, people have adopted a new method to soften hard water: hard water is passed through ion exchange resin to remove calcium ions and become soft water.

Hard water is formed by uneven heating when it is heated unevenly to form calcium carbonate and other water-insoluble precipitates, which are poured into boiling water bottles and accumulated over time.

It is the result of precipitation of bacteria and microorganisms in the water.

Magnesium carbonate and calcium carbonate precipitate.

First, the formation principle of scale:

Water contains calcium, magnesium ions, carbonate, bicarbonate, sulfate, etc. When the water reaches a certain temperature, the calcium and magnesium ions in it combine with the acid to form calcium carbonate, magnesium carbonate, calcium sulfate, etc.

Second, the removal method of scale:

1. Baking soda removes scale. When boiling water in an aluminum kettle with limescale, put 1 teaspoon of baking soda and boil for a few minutes to remove the limescale.

2. Vinegar to remove scale. If the kettle has scale, you can put a few spoonfuls of vinegar into the water and boil for an hour or two to remove the scale. If the main ingredient in the scale is calcium sulfate, the soda ash solution can be poured into the kettle and boiled to remove the scale.

3. The scale cleaner sold in supermarkets and tea shops is hydroxymalonic acid, which is safe and non-toxic and environmentally friendly. This limescale cleaner is easy to use and effective, with the right dosage and detailed instructions, making it suitable for home use.

3. Precautions:

1. To remove scale from water appliances, food-grade descaling agent should be used, because industrial-grade descaler contains impurities, even toxic, and is harmful to the human body if drunk;

2. Water appliances are descaled with strong acid, which is corrosive and harmful to household appliances and human body.

1. Scale, commonly known as "water rust", refers to the crystalline body formed by the continuous attachment and accumulation of impurities in natural water on the inner surface of the boiler boiler, which is generally white or yellowish-white, and the main components are calcium carbonate, magnesium carbonate, calcium sulfate, magnesium sulfate, calcium chloride, magnesium chloride, etc.

2. Scale is due to a thick layer of impurities that will grow on the inner wall of some containers that are often in direct contact with water, and the composition of scale is generally more complex, which is composed of many compounds, which are divided into calcium and magnesium scale, silica scale, phosphate scale, iron scale and copper scale according to their main chemical components.

3. The reason for the formation of general scale is: after the container has been boiled many times, the calcium sulfate slightly soluble in water contained in the water is precipitated due to the evaporation of water, and the original dissolved calcium bicarbonate and magnesium bicarbonate are decomposed in the boiling water.

Water contains a lot of calcium ions, magnesium ions. Under the condition of heating, insoluble magnesium hydroxide, calcium carbonate, etc. are deposited at the bottom of the pot to form scale.

Because the water contains alkali, it will form scale if you use a container for boiling water for a long time.

And the urinal will turn yellow for a long time.

Scale is mainly formed by the precipitation of salts such as calcium and magnesium contained in boiler feed water after being heated and sticking to the metal surface. The thermal conductivity of scale is very small, about 2 5% of ordinary steel, and the scale is formed on the heating surface of the boiler, which will greatly deteriorate the heat transfer effect and affect the efficiency of the boiler; It is easy to burn out the metal material due to local overheating.

The main harm to the human body is that if people accidentally drink limescale fragments, they will enter the stomach and react with hydrochloric acid, which will release calcium and magnesium ions and carbon dioxide. Calcium and magnesium ions are necessary for the formation of stones; Carbon dioxide can make people bloated and uncomfortable; Patients with gastric ulcers may also be at risk of gastric perforation.

The water is constantly heated and evaporated and concentrated, resulting in an increase in the concentration of calcium and magnesium salts in the water, and when their concentrations are exceeded, they precipitate out of the water to form a precipitate.

At high temperatures, the carbonate in the water will combine with calcium and magnesium ions to generate insoluble calcium carbonate, magnesium carbonate, etc., and calcium carbonate, magnesium carbonate and other substances are precipitated from the water and adhered to the container, which becomes scale.

Scale, also known as "water rust" and "water alkali", is a white lump or powder substance that is gradually formed by the mineral contained in hard water after boiling in the container.

The main components of scale are calcium carbonate, magnesium hydroxide, magnesium carbonate, calcium sulfate, magnesium sulfate, calcium chloride, magnesium chloride, etc., and the thermal conductivity is very poor.

The scale is formed on the heating surface of the boiler, which will greatly deteriorate the heat transfer effect, and it is easy to burn out the metal materials due to local overheating, and even burst pipe accidents.