At present, the main method of extracting salt from seawater is to use seawater to dry salt. What is the material separation method it uses?

At present, the main method of extracting salt from seawater is to use seawater to dry salt, and the material separation method is evaporation and crystallization.

1. The principle of salt drying in seawater

Salt drying in seawater is a method to obtain salt by using the solar radiation energy in nature and gradually condensing and crystallizing the salt in seawater through evaporation and crystallization. This is because seawater contains a lot of soluble salts. Through artificial drainage and seawater exposure, the water in it slowly evaporates and finally forms salt crystals.

2. The process of drying salt in seawater

Firstly, impurities and suspended solids in seawater are removed by filtration and pretreatment, and relatively pure seawater is obtained. Then, put the seawater in a shallow salt pool or shallow pool and let it go and be exposed to the sun. With the irradiation of sunlight and the evaporation of water, the dissolved salts in seawater gradually concentrate and begin to crystallize after reaching the saturated concentration. Finally, the crystallized salt can be collected and artificially extracted to obtain the salt.

3. Advantages and limitations of salt drying in seawater

Seawater salt drying is simple, low cost, and does not need complicated equipment and energy consumption. It can also make full use of solar energy resources and has little impact on the environment. However, the disadvantage of salt drying in seawater is that the production cycle is long, and a batch of salt takes months or even years, and the output is limited. In addition, this method has certain requirements for weather conditions, such as sufficient sunshine and no rainfall.

4. The regional distribution of seawater sun-dried salt?

Sea salt drying is a widely used sea salt production method, and its regional distribution is mainly concentrated in coastal areas and islands with suitable climatic conditions. These areas usually have sufficient sunshine resources and marine resources to facilitate the production of seawater salt.

5. Other methods of extracting salt?

Besides drying salt in seawater, there are other methods to extract salt, such as vacuum evaporation, ion exchange, reverse osmosis membrane and so on. Vacuum evaporation method is to use vacuum equipment to heat and evaporate seawater, and then condense and crystallize to obtain salt; Ion exchange method separates sodium ions and chloride ions in seawater through ion exchange resin, thus obtaining salt; The principle of reverse osmosis membrane is to separate salt from seawater by using special semi-permeable membrane.

Summary:

At present, the main method of extracting salt from seawater is to dry the salt in seawater, and gradually concentrate and crystallize the salt in seawater through evaporation and crystallization to obtain salt. The drying process of salt in seawater includes filtration pretreatment, sun exposure and crystallization extraction. Although seawater salt drying has the advantages of simplicity and low cost, it has a long production cycle and limited output, which has certain requirements for weather conditions.