Magnesium sulfate anhydrousItem | Indicators |
MgSO4.7H2O % ≥ | 99.5 |
Fe % ≤ | 0.003 |
Cl % ≤ | 0.014 |
Pb % ≤ | 0.001 |
PH | neutral |
As % ≤ | 0.0004 |
Loss on calcination% | 48.0-52 |
Effect of magnesium sulfate
1, Role of magnesium sulfate in industrial applications:
1. In the leather industry, magnesium sulfate is used as a filling reinforcing agent to enhance heat resistance.
2. In printing and dyeing applications, magnesium sulfate can be used as fabric dyeing agent, weighting agent and mordant to ensure uniform dyeing with pH value between 6 and 7.
3. In the application of fireproof materials, magnesium sulfate is used as a flame retardant for plastics such as acrylic resin.
4. In the field of papermaking, magnesium sulfate is used as a synthetic assistant for ABS and PVC resins.
5. In organic chemical industry, magnesium sulfate can be used as desiccant and dehydrating agent, used in printing and dyeing thin cotton and silk, as weighting agent for cotton silk and filler for kapok products.
6. In electroplating industry, magnesium sulfate is used as conductive salt, which can improve the conductivity of plating solution and make the coating white and soft; Magnesium sulfate is used as aluminum smelting additive to color the surface of aluminum.
7. In terms of environmental protection, magnesium sulfate is used for industrial sewage treatment, which plays a role in coagulation and sedimentation of waste water to make it meet the sewage discharge standard.
8. In the chemical industry, magnesium sulfate is used to manufacture magnesium stearate, magnesium hydrogen phosphate, magnesium oxide and other magnesium salts, potassium sulfate, sodium sulfate, etc
9. In the microbial industry, magnesium sulfate is used as a culture medium component, a natural additive for brewing, magnesium to supplement brewing water and a nutrient source during fermentation;
10. In light industry, magnesium sulfate is used to produce fresh yeast, monosodium glutamate, beverage, mineral water, health salt, sea crystal, bath Kang and stabilizer of calcium hydrogen phosphate in beer and toothpaste;
11. In the cement industry, magnesium sulfate can be used as a coagulant aid for cement.
Role of magnesium sulfate in agricultural application:
1. In the field of fertilizer, magnesium sulfate can be directly used as base fertilizer, topdressing and foliar fertilizer.
2. Magnesium sulfate is a dual nutrient high-quality fertilizer, which can not only increase the yield of crops, but also improve the taste of fruits and loosen the soil.
3. Magnesium in magnesium sulfate is an important component of chlorophyll and pigment and a metal element in chlorophyll molecule. It can promote photosynthesis, promote the formation of carbohydrates, proteins and fats, promote the metabolism in crops, improve the disease resistance of crops and prevent the invasion of bacteria, so as to improve the quality of fruits, vegetables and other crops.
4. Magnesium sulfate has the advantage of higher solubility than other fertilizers. It is usually used for potted plants or magnesium deficient crops, such as tomatoes, potatoes, roses, etc., which plays an important role in improving productivity and agricultural output.
Role of magnesium sulfate in animal husbandry:
The grass applying magnesium sulfate fertilizer can provide sufficient magnesium content (an appropriate amount of magnesium sulfate can also be added to feed and drinking water), can meet the needs of cow sebum growth, and can greatly improve the quality and quantity of cow milk.
The role of magnesium sulfate in daily life
1. Adding an appropriate amount of magnesium sulfate to the foot bath and shower can remove beriberi, reduce muscle hardness, quickly eliminate fatigue, and make rough skin soft and smooth.
2. Adding an appropriate amount of magnesium sulfate to the shampoo will help reduce the oily nature of the hair and make the hair soft.
3. Magnesium sulfate can be used to make artificial snow for TV crew shooting.
Role of magnesium sulfate in food application
In food additives, magnesium sulfate is used as nutritional supplement, curing agent, flavor enhancer, processing aid and nutritional enhancer. It can adjust the hardness of water and improve the fermentation ability.
Preparation method
Method 1
It is obtained by adding sulfuric acid to natural magnesium carbonate (magnesite) and recrystallizing after removing carbon dioxide. It is obtained by dissolving kieserite (MgSO4 · H2O) in hot water and recrystallizing, which is prepared from seawater.
Method 2 (seawater drying salt bittern method)
Bittern is obtained by drying salt in seawater. After evaporation by brine mixing method, high-temperature salt is produced. Its composition is MgSO4 > 30%, NaCI < 35%, MgCl2 is about 7% and KCl is about 0.5%. Bittern can be dissolved in 200g / L MgCl2 solution at 48 ºC, less NaCl is dissolved, and more MgSO4 is dissolved. After separation, the leaching solution is cooled to 10 ºC to precipitate coarse MgSO4 · 7H2O, and the finished product is obtained by secondary recrystallization.
Method 3 (sulfuric acid method)
In the neutralization tank, the siderite is slowly added to water and mother liquor, and then neutralized with sulfuric acid until the color changes from soil color to red. The pH is controlled to be 5 and the relative density is 1.37 ~ 1.38 (39 ~ 40 ° B é). Filter the Neutralization Solution at 80 ºC, then adjust the pH value to 4 with sulfuric acid, add an appropriate amount of crystal seed, and cool to 30 ºC for crystallization. After separation, the finished product is dried at 50 ~ 55 ºC, and the mother liquor is returned to the neutralization tank. Magnesium sulfate heptahydrate can also be prepared by neutralization reaction between low concentration sulfuric acid and bitter soil with magnesium oxide content of 65%, filtration, precipitation, concentration, crystallization, centrifugal separation and drying.
Reaction chemical equation: MgO + H2SO4 + 6H2O → MgSO4 · 7H2O
physical property
Appearance and properties: it belongs to orthorhombic crystal system, which is tetragonal granular or rhombic crystal, colorless and transparent, and the aggregate is white, rose or green glass luster. The shape is fibrous, acicular, granular or powder. Odorless and bitter.
Solubility: easily soluble in water, slightly soluble in ethanol and glycerol.
chemical property
Stability: it is stable in humid air below 48.1 ºC and easily weathered in warm dry air. When it is higher than 48.1 ºC, it loses one crystal water and becomes magnesium sulfate hexahydrate. At 67.5 ºC, it dissolves in its own crystal water and precipitates magnesium sulfate monohydrate. At 70 ~ 80 ºC, it loses four crystal water, five crystal water at 100 ºC and six crystal water at 150 ºC, At 200 ºC, all crystal water is lost and becomes powdered anhydrous magnesium sulfate. The dehydrated product is placed in humid air to absorb water again. Hydrated crystals with 1, 2, 3, 4, 5, 6 and 12 water can be crystallized in saturated magnesium sulfate solution. Magnesium sulfate dodecahydrate can be precipitated in saturated aqueous solution at - 3.9 ~ 1.8 ºC, magnesium sulfate heptahydrate can be precipitated in saturated aqueous solution at - 1.8 ~ 48.18 ºC, magnesium sulfate hexahydrate can be precipitated in saturated aqueous solution at 48.1 ~ 67.5 ºC, and magnesium sulfate monohydrate can be precipitated when it is higher than 67.5 ºC, Magnesium sulfate hexahydrate melts at 87 ~ 92 ºC and generates magnesium sulfate pentahydrate or tetrahydrate. Magnesium sulfate tetrahydrate is transformed into magnesium sulfate trihydrate at 106 ºC, magnesium sulfate trihydrate is transformed into magnesium sulfate dihydrate at 122 ~ 124 ºC, and magnesium sulfate dihydrate is transformed into stable magnesium sulfate monohydrate at 161 ~ 169 ºC.
Toxicity: toxic
PH value: 7, neutral
Main purpose
food
As a food fortifier. It can be used in dairy products according to Chinese regulations, and the dosage is 3 ~ 7g / kg; The dosage in drinking liquid and milk beverage is 1.4 ~ 2.8g/kg; The maximum dosage in mineral beverage is 0.05g/kg.
Industry
It is mostly used in combination with calcium salt for mother wine water. Adding 4.4g/100l water can improve the hardness by 1 degree. If it is used for many purposes, it will produce bitterness and hydrogen sulfide odor.
It is used for tanning, explosives, papermaking, porcelain, fertilizer, oral laxative in medicine and mineral water additives.
Agriculture
Magnesium sulfate is used as a fertilizer in agriculture because magnesium is one of the main components of chlorophyll. It is usually used for potted plants or magnesium deficient crops, such as tomatoes, potatoes, roses, etc. Magnesium sulfate has the advantage of higher solubility than other fertilizers. Magnesium sulfate is also used as bath salt.
matters needing attention
Hazard overview
Health hazard: irritating to eyes and skin. Basically non-toxic.
Environmental hazard: it is harmful to the environment and can pollute the atmosphere.
Fire and explosion hazard: This product is non combustible and irritating.
Others: this substance is harmful to the environment, and special attention should be paid to the pollution of the atmosphere.
Risk terminology
Safety terminology: S24 / 25
Hazard identification: R36 / 37 / 38
Storage and transportation characteristics
Precautions for transportation: the package shall be complete and the loading shall be stable. During transportation, ensure that the container does not leak, collapse, fall or damage. Mixed loading and transportation with acids and edible chemicals are strictly prohibited. During transportation, it shall be protected from sun exposure, rain and high temperature. The vehicle shall be thoroughly cleaned after transportation.
Handling and storage
Precautions for operation: close operation and strengthen ventilation. Operators must receive special training and strictly abide by the operating procedures. It is recommended that operators wear self-priming filter dust masks, chemical safety glasses, anti poison penetration work clothes and rubber gloves. Avoid dust generation. Avoid contact with acids. Handle with care to prevent package damage. Equipped with leakage emergency treatment equipment. Emptied containers may leave harmful substances. When the dust concentration in the air exceeds the standard, you must wear a self-priming filter dust mask. In case of emergency rescue or evacuation, wear gas mask.
Storage precautions: store in a cool and ventilated warehouse. Keep away from fire and heat source. It shall be stored separately from acids and avoid mixed storage. The storage area shall be provided with suitable materials to contain leakage.
First aid measures
Skin contact: take off contaminated clothes and rinse with flowing water.
Eye contact: lift the eyelids and rinse with flowing water or normal saline. See a doctor.
Inhalation: leave the site to a place with fresh air. If breathing is difficult, give oxygen. See a doctor.
Ingestion: drink enough warm water, induce vomiting and seek medical attention.
Emergency Management
Isolate the leakage contaminated area and restrict access. It is recommended that emergency treatment personnel wear dust masks (full face masks) and gas suits. Avoid dust, sweep it carefully, put it in a bag and transfer it to a safe place. If there is a large amount of leakage, cover it with plastic cloth and canvas. Collect, recycle or transport to waste treatment site for disposal. In case of leakage, dispose with safe burial method after neutralization.