First, the basic information: 
anhydrous sodium sulfate, anhydrous sodium sulfate is white fine particles crystal or powder, hygroscopic, soluble in water, aqueous solution is neutral. Soluble in glycerin, not soluble in alcohol. The anhydrous substance with high purity and fine particle size is called anhydrous sodium sulfate. 
Third, the preparation method 
Sodium sulfate method one (Bandian method) 
using the natural temperature changes in different seasons to evaporate the water in the raw material liquid, crystallized the Glauber's salt. In the summer, salt water containing sodium chloride, sodium sulfate, magnesium sulfate, magnesium chloride and the like is poured into the beach, and evaporated by the sun, and the palmite is precipitated in winter. This method is the main method for extracting thenardite from natural resources. The process is simple, the energy consumption is low, but the working conditions are poor, and impurities such as mud and sand are easily mixed into the product. 
Sodium sulfate method 2 (mechanical freezing method) 
uses a mechanical device to evaporate the raw material liquid and freeze it to -5 to -10 ° C to precipitate Glauber's salt. Compared with the beach method, this method is not affected by seasonal and natural conditions. The product quality is good, but the energy consumption is high. 
Sodium sulfate method 3 (salt lake comprehensive utilization method) is 
mainly used for sulfate-carbonate type salt water containing various components. The crude Glauber's salt is separated while extracting various useful components. For example, processing salt lake water containing sodium carbonate, sodium sulfate, sodium chloride, boride and potassium, bromine and lithium, carbonizing the salt lake brine first, converting sodium carbonate into sodium hydrogencarbonate crystallizing; cooling the mother liquor to 5 to 15 ° C, The borax is crystallized; the secondary mother liquid after separating the borax is frozen to 0 to 5 ° C to precipitate Glauber's salt. [2]  
Other methods of sodium sulfate 
can be obtained by reacting sulfuric acid with sodium hydroxide. H2SO4 + 2NaOH → Na2SO4 + 2H2O. It can also be obtained by extraction from natural products. 
It can also be prepared by reacting sodium hydrogencarbonate with sulfuric acid: 2NaHCO3+H2SO4→Na2SO4+2H2O+2CO2↑. 
Sodium sulfate can be prepared in the laboratory using sodium chloride solids and concentrated sulfuric acid under heating. 2NaCl+H2SO4→2HCl↑+Na2SO4 
or reacted with sodium hydroxide and copper sulfate: 2NaOH+CuSO4=====Na2SO4+Cu(OH)2↓
In the family, sodium carbonate or sodium hydrogencarbonate can be reacted with copper sulfate: 
2CuSO4+2Na2CO3+H2O=Cu2(OH)2CO3 ↓+ 2Na2SO4 +CO2↑ 
4NaHCO3+2CuSO4=Cu2(OH)2CO3↓+2Na2SO4+3CO2↑+ H2O 
can be used in the beach method, mechanical freezing method, and salt lake comprehensive method. The beach method and mechanical freezing method are suitable for processing seawater-type brine with Na, Mg, Cl, SO42- as main components and various other mirabilite mines. Since the solubility of sodium sulfate is rapidly reduced at low temperatures, the crude mirabilite can be separated from the brine according to the phase equilibrium relationship of the water-salt system. 
4. Classification of anhydrous sodium sulfate 
First-grade products (content more than 99.2%): mainly used in printing and dyeing, glass manufacturing, various fillers, synthetic detergents, vinylon and so on. 
Content: 94%. Particle size 60 
content 99%, particle size 80-120 
five, product packaging 
50 kg woven bag packaging 
Six, the company's sales of by-product anhydrous sodium sulfate  
a content of about 94%, with white agglomerates, but easy to break, no chloride ions It is more suitable for cement grinding aid (Shouguang delivery). It 
is white or blue and does not agglomerate. It is packaged separately and does not distinguish colors when shipped. 
7. Uses 
1. The chemical industry is used to manufacture sodium sulfide sodium silicate water glass and other chemical products. 
2. The cooking agent used in the paper industry for the manufacture of kraft pulp. 
3, the glass industry to replace soda ash as a cosolvent. 
4. The textile industry is used to blend vinylon spinning coagulants. 
5, used in non-ferrous metallurgy, leather and other aspects.
6, used to make sodium sulfide, pulp, glass, water glass, enamel, also used as a laxative and antidote to strontium salt poisoning. It is a by-product of the production of hydrochloric acid from salt and sulfuric acid. Chemically used in the manufacture of sodium sulfide, sodium silicate, etc. The laboratory is used to wash away the strontium salt. Industrially used as a raw material for the preparation of NaOH and H?SO?, also used in paper, glass, printing and dyeing, synthetic fiber, leather and so on. Sodium sulfate is the most commonly used post-treatment desiccant in organic synthesis laboratories. [4]  
7. Mainly used as a filler for synthetic detergents. A cooking agent used in the paper industry to make kraft pulp. The glass industry is used to replace soda ash. The chemical industry is used as a raw material for the manufacture of sodium sulfide, sodium silicate and other chemical products. The textile industry is used to blend vinylon spinning coagulation baths. The pharmaceutical industry is used as a laxative. Also used in non-ferrous metallurgy, leather and other aspects. 
8. The hydration product calcium sulphoaluminate is formed faster, thereby accelerating the hydration and hardening speed of the cement. The dosage of sodium sulfate is generally 0.5% to 2% of the mass of cement, which can increase the early strength of concrete by 50% to 100%. The strength of 28 days is sometimes increased, sometimes decreased, and the increase is about 10%. With the variety and curing conditions of cement. It varies with its amount. It is also used as a filler for synthetic detergents, and is also used in the paper industry, the glass industry, the chemical industry, the textile industry, and the pharmaceutical industry. 
9. Used as an analytical reagent, such as a dehydrating agent, a digestive catalyst for nitrogen determination, and an interference inhibitor in atomic absorption spectrometry. Also used in the pharmaceutical industry.