Sodium sulfate,CAS 7757-82-6

Sodium sulfate, also known by its chemical formula Na2SO4, is an inorganic compound that is commonly encountered in the form of a white crystalline solid or as a fine powder. This substance is renowned for its high solubility in water, meaning it can easily dissolve in liquid to form a clear solution. Additionally, sodium sulfate exhibits a neutral pH level, which indicates that it is neither acidic nor basic when dissolved in water. This neutrality makes it a useful compound in various industrial and laboratory applications.

Sodium sulfate Use and Manufacturing
Methods of Manufacturing
1. Vacuum evaporation method to dissolve the natural Glauber's salt after clarification, the clarification liquid for vacuum evaporation dehydration, thickening, centrifugal separation, drying, anhydrous sodium sulfate. The reaction equation is as follows: 2. Glauberite process Glauberite ore will be crushed, water ball mill, leaching, leaching Glauber's salt by filtering to remove impurities, the filtrate clarified, and then by evaporation, dehydration, centrifugal separation, drying obtained anhydrous sodium sulfate. The reaction equation is as follows: 3. Conversion of potassium chloride production by-product of high and low temperature salt as raw materials for anhydrous sodium sulfate. In a certain temperature and ingredients conditions, after three conversion, magnesium sulfate and sodium chloride into bauxite first, and then converted to anhydrous sodium magnesite, and finally into anhydrous sodium sulfate. The entire conversion process is continuous countercurrent operation. The slurry is mechanically driven and lifted, and the liquid flows backwards and overflows according to the potential difference. The phases are connected and influenced by each other. The first stage of conversion is controlled at Ph value of 3 to 4, and the temperature is 55-70 ℃. The second stage of transformation Ph4 ~ 5, the temperature of about 100 ℃; the third paragraph of the transformation conditions control Ph5 ~ 6, the temperature of about 55 ℃ under stirring in the next , Anhydrous sodium magnesium sulfate and sodium chloride aqueous solution generated by anhydrous sodium sulfate, by centrifugal separation, drying, anhydrous sodium sulfate obtained. The reaction equation is as follows: This method of high cost, low recovery, consumption of sulfuric acid, impurity removal is not easy, the resulting poor color products, but the equipment is simple. 4 rayon by-product artificial silk solidification waste by crystallization, dissolution, and, filtration, concentration, cooling, separation, drying process, the system was anhydrous sodium sulfate. The reaction equation is as follows. Sodium sulfate Na2SO4 · 10H2O hydrate into the porcelain dish, heated at about 100 ℃, until the formation of white loose powder so far. 5. Dissolved with hot distilled water industrial sodium sulfate, control solution density 1.1 ~ 1.2, a few hours after the filter sediment. The concentration of 1.26 sodium carbonate solution (sodium carbonate dissolved in pure water) to ph = 8 ~ 9, while adding the right amount of ammonium sulfide stirring (based on raw materials Fe2 +, Pb2 + plasma content to determine the amount of ammonium sulfide). Standing for a few hours, so that iron sulfide, lead sulfide precipitation complete. The supernatant was sucked out and filtered to be clear, and the iron and heavy metal were inspected. After heating, the solution was concentrated to dryness, centrifuged and then washed with a small amount of distilled water for 1 to 2 times. Adding the distilled water to the relative density of 1.10 to 1.15, adding the right amount of 0.5% silver sulfate solution, stirring for more than 4 hours, so that the silver chloride precipitation is complete.Filtering, evaporating and concentrating to crystallize film, cooling, crystallizing, centrifugal drying, washing with a small amount of distilled water, drying, namely chemical Na2SO410H2O finished product. Preparation of pure anhydrous sodium sulfate, in the process of recrystallization evaporation to no mother liquor water, centrifugal drying, with a small amount of distilled water rinse, the drying at 100 ℃. 6. The dry sodium carbonate (chemically pure) was added in small portions to 20% of the analytical sulfuric acid solution and the reaction proceeded until the carbon dioxide no longer escaped. The solution was weakly basic. The solution heated to boiling, filtration, evaporation and concentration to the crystallization occurs, cooling crystallization, centrifugal drying, which was Na2SO4 · 10H2O crystals. The above crystallization at about 100 ℃ heating, evaporation to water, can be obtained anhydrous sodium sulfate. 7. Full-solution evaporation dehydration raw materials for the natural frozen salt soil salt (containing N a 2S O 4 ≥ 35%). In the dissolved nitrocellulose tank has been added to crush the soil, dissolved with steam, when Baume degrees to achieve 3 0 ~ 3 2 ° B e, the temperature is 7 0 ℃, the pump into the sedimentation tank to clarify the insulation, clear liquid by the double-effect vacuum evaporator concentration. Concentrated with a crystal by centrifugal separation, air drying derived products. Finished water control is less than 0.2%. The mother liquor is returned to the evaporator for cyclic evaporation. 8. Hot-melt evaporation dehydration method Glauber's salt prepared by freezing method (including 10 crystal water) in the hot-melt tank to heat to 7 0 ℃ or so. Part of the sodium sulfate dissolved in its own crystal water to form a saturated solution. Part of the sodium sulfate into anhydrous salt precipitation. The centrifugal drying separation, anhydrous sodium sulfate crystals and saturated solution. The crystal is dried and finished. Saturated solution and then evaporated and then anhydrous Glauber's salt, the centrifugal dehydration, drying was finished. This is repeated.9. Hot-melt salting-out method The principle of salting-out method is the same as the ion effect, so that the solubility of sodium sulfate is reduced, more than the solubility of sodium sulfate is solid precipitation. To the molten saturated sodium sulfate by adding a certain amount of solid sodium chloride, the solution that is sodium sulfate precipitation, solid-liquid separation can be obtained solid anhydrous nitrate. Rinsing with saturated sodium sulfate, and then obtained by drying the finished product. Mother liquor can be evaporated crystallization, recovery N a C l, recycling.

Uses
It can be mainly used as the filler of synthetic detergent. Paper industry applies it for the cooking agent during the manufacture of sulfate pulp. Glass industry uses it as substitute of soda. Chemical industry applies it as the raw material for the manufacturing of sodium sulfide, sodium silicate and other chemical products. Textile industry applies it for the formulation of Vinylon spinning coagulation bath. The pharmaceutical industry applies it as laxatives. It can also be used in non-ferro