Sodium sulfate is a salt formed by the ionization of sulfate radical with sodium, which belongs to inorganic compound. Its shape is colorless, transparent, large crystals or small granular crystals. It is mainly used in the manufacture of sodium silicate, glass, enamel, pulp, refrigerant mixtures, detergents, drying agents, dye diluents, analytical chemicals, pharmaceuticals and feedstuffs. Sodium sulfate is the most commonly used Post-disposal drying agent in organic synthesis laboratory. Since sodium sulfate is so widely used, what is its preparation method? Now Hengyi Chemicals will share it with you, let's take a look at it together.
1. Tantian Method
The crude mirabilite was crystallized by evaporating the water in the raw liquor with the change of temperature at different time in nature. Saline water containing sodium chloride, sodium sulfate, magnesium sulfate and magnesium chloride was irrigated into beach fields in summer, evaporated in the sun, and coarse mirabilite was precipitated in winter. This method is the main way to put forward mirabilite from natural resources. It has simple process, low energy consumption, but poor operating conditions and easy to mix with impurities such as mud and sand in products.
2. Mechanical refrigeration
The raw material liquid is heated and evaporated by mechanical equipment, and then frozen to - 5 ~10 ~C to precipitate mirabilite. Compared with the beach method, this method is not affected by time and natural conditions. The output and quality are good, but the energy consumption is high.
3. Comprehensive application of salt lakes
It is mainly used in sulfate-carbonate saltwater containing various components. The crude mirabilite was separated while extracting various useful components. For example, when processing salt lake water containing sodium carbonate, sodium sulfate, sodium chloride, boride and potassium, bromine and lithium, sodium carbonate can be converted into sodium bicarbonate to crystallize; the mother liquor can be cooled to 5-15 degrees C to crystallize borax; the secondary mother liquor after separation from borax can be frozen to 0-5 degrees C to precipitate mirabilite.
4. Other methods
可由硫酸和氢氧化钠反应制得。H2SO4+ 2NaOH→Na2SO4+ 2H2O。由天然产物萃取也可制得。
It can be prepared by the reaction of sulfuric acid and sodium hydroxide. H2SO4 + 2NaOH Na2SO4 + 2H2O. It can also be extracted from natural products.
It can also be prepared by reaction of sodium bicarbonate with sulfuric acid: 2NaHCO 3 + H2SO4 Na2SO4 + 2H 2 + 2CO 2.
Sodium sulfate can be prepared in laboratory by using sodium chloride solid and concentrated sulfuric acid under heating conditions. 2NaCl+H2SO4_2HCl_+Na2SO4
Or the reaction of sodium hydroxide with copper sulfate to prepare: 2NaOH+CuSO4=========Na2SO4+Cu(OH)2_
Sodium carbonate or sodium bicarbonate can be prepared by reacting with copper sulfate in the family.
2CuSO4+2Na2CO3+H2O=Cu2(OH)2CO3 ↓+ 2Na2SO4 +CO2↑
Beach field method, mechanical freezing method and salt lake comprehensive method can be used. Beach field method and mechanical freezing method are suitable for processing seawater brine with Na, Mg, Cl and SO42 - as main components and other mirabilite ores. Because the solubility of sodium sulfate decreases sharply at low temperature, coarse mirabilite can be separated from brine according to the phase equilibrium relationship of water-salt system.