Magnesium sulfate heptahydrate:The magical crystalline compound
Magnesium sulfate heptahydrate, with the chemical formula:MgSO_4·7H2O, is a common inorganic compound. It is a white crystalline powder or granule with unique physical and chemical properties, widely present in nature and often used in multiple fields.
Purification method: By taking advantage of the combined precipitation effect of freshly precipitated Mg(OH)2, impurities such as Ni,Co,Fe,Zn, and Cu can be removed from MgSO4. Add NaOH solution to a solution containing 2g of MgSO4·7H2O in a polyethylene cup to form Mg(OH)2 precipitate, which is then washed clean. Add this precipitate to a boiling solution containing 200-240g of MgSO4·7H2O(analytical grade), stir the mixture vigorously for 30 minutes, and let it stand overnight. The transparent liquid is sucked out by siphoning. Then a highly pure MgSO4 solution can be obtained. From then on, purer MgSO4·7H2O crystals can be crystallized from the solution. It is obtained by adding sulfuric acid to natural magnesium carbonate (magnesite), removing carbon dioxide and then recrystallizing. It is obtained by dissolving Kieserite (MgSO4·7H2O) in hot water and recrystallizing. 5. Dissolve 20kg of industrial magnesium sulfate (the lower the chlorine content, the better) in 30kg of distilled water by heating, then add a slightly excessive amount of silver sulfate solution (determined by the chlorine content of the raw material), stir, test the chlorine content in the solution until it is qualified, filter, and add an appropriate amount of magnesium carbonate to the clear magnesium sulfate solution while stirring to make the solution slightly alkaline. To remove the 2+ ions in the form of , pass hydrogen sulfide for 15 minutes, let stand for 24 hours, then filter. Slowly add 0.25-0.5mol/l , sulfuric acid solution to the filtrate and continuously take samples for analysis: Add 4 drops of bromomusk blue indicator to 10ml of 犾 sample, stop adding acid when the solution turns blue. Evaporate and concentrate the solution (about 110℃), cool and crystallize it, centrifuge and spin dry it, and dry it at 50-60℃ (not exceeding this temperature) to obtain the reagent magnesium sulfate. 6. In a small white porcelain jar, stir 1kg of high-purity magnesium oxide into a paste with 1000 mL of conductive water, and slowly add 30% high-purity sulfuric acid to the magnesium oxide to carry out the reaction
When less foam is produced, stop adding acid, leave a small amount of magnesium oxide, let it stand for 15 minutes, and then filter. The filtrate is fed into a glass-lined pot, evaporated and concentrated until a film is formed. It is then indirectly cooled and crystallized with cold water and centrifuged and dried. Wash twice with cold conductive water, crystallize in a white porcelain plate and dry at low temperature in an oven to obtain spectral pure magnesium sulfate heptahydrate. If the quality indicators are not met, recrystallization can be carried out again. To prepare anhydrous magnesium sulfate, magnesium sulfate heptahydrate can be carefully heated to 238℃, and then anhydrous magnesium sulfate can be obtained.
It is used for printing and dyeing fine and thin cotton fabrics and silk, serving as a weighting agent for cotton and silk and a filler for wood cotton products. It is also used in the manufacture of porcelain, pigments and fireproof materials. It is used as a laxative in medicine. Magnesium is used as a component of culture medium in the microbial industry, as an additive in brewing, to supplement the magnesium in brewing water, and as a nutrient source during fermentation. It is used as a filler in the leather industry to enhance heat resistance. It is used as magnesium fertilizer in agriculture. It is used in the light industry for the production of fresh yeast, monosodium glutamate and as a stabilizer for calcium hydrogen phosphate in toothpaste production. A setting aid for cement. It is also used in the pulp industry, rayon and textile industries, etc. Nutritional supplement Curing agent Flavor enhancer Processing AIDS. Brewing additives, supplementing magnesium in brewing water, serve as a nutrient source during fermentation to enhance fermentation capacity. Improve the flavor of synthetic sake (dosage: 0.002%). Adjust the hardness of the water. It is used for the production of "Burton" type beer in Europe. 2. It is often used in combination with calcium salts in the water for yeast. Adding it at 4.4g/ 100g of water can increase the hardness by 1 degree. Excessive use will produce a bitter taste and a hydrogen sulfide odor. As a food fortifier. In China, it is stipulated that it can be used in dairy products, with a usage amount of 3 to 7 grams per kilogram. The usage amount in liquid drinks and milk beverages is 1.4-2.8g/kg. The maximum usage amount in mineral beverages is 0.05g/kg. 3. It is used for supplementing the trace element magnesium in feed additives. Magnesium is a cofactor for many enzyme systems in animals and is also a component of bones. It is used as a nutritional supplement, a curing agent, a flavor enhancer and a processing aid. Brewing additives, supplementing magnesium in brewing water; As a nutrient source during fermentation to enhance the fermentation capacity. Improve the flavor of synthetic sake (dosage: 0.002%). Adjust the hardness of the water. It is used for the production of "Burton" type beer in Europe. It is often used in combination with calcium salts in the water for yeast. Adding 4.4g per 100L of water can increase the hardness by 1 degree. Excessive use will produce a bitter taste and a hydrogen sulfide odor. It can also be used as a feed additive. 5. It is used as an analytical reagent, such as a precipitating agent for sulfates. It is also used in the pharmaceutical, printing and dyeing, papermaking, ceramic and leather industries. 6. This product is used as a tannery filler. It is used as a weighting agent for thin cotton fabrics in the printing and dyeing industry. Papermaking sizing agents, etc.