ammonium sulfate brief introduction

Ammonium sulfate, abbreviated as ammonium sulfate, has the chemical formula (NH4) 2SO4, is a colorless orthorhombic crystal that is easily soluble in water. The aqueous solution is acidic.

ammonium sulfate Basic information

ammonium sulfate Numbering system

ammonium sulfate Physical and Chemical Properties

Appearance and characteristics:

White crystalline powder

Density:

one point seven six

Boiling point:

330ºC at 760 mmHg

Melting point:

280ºC

Refractive index:

n20/D 1.396

Stability:

Stable. Contact with strong oxidizers may cause fire or explosion. Incompatible with strong bases.

Storage conditions:

The warehouse is ventilated, low-temperature and dry, and stored separately from potassium nitrate and potassium nitrite

security information

Safety instructions:

S26-S37/39

Hazard category code:

R36/37/38

Dangerous goods transportation code:

UN 1170 3/PG 3

Customs code:

three billion one hundred and two million two hundred and ten thousand

Dangerous goods signs:

Xi

Production method and purpose

Production method

1. The neutralization reaction between ammonia and sulfuric acid is carried out at about 100 ℃, and the resulting ammonium sulfate crystal slurry is separated by centrifugation and dried to obtain the finished ammonium sulfate product. The recycling method involves recovering ammonia gas from coking furnace gas and then neutralizing it with sulfuric acid.

2. Dissolve ammonium sulfate in cold water until the relative density is 1.20. Add an appropriate amount of ammonia water to adjust the pH of the solution to 8-9, let it stand, absorb the supernatant, add a small amount of activated carbon to the clear solution, heat and boil, and keep it at 60 ℃. Add more ammonia water until the pH value reaches 9-10. Let it stand and cool to room temperature. Filter and evaporate the filtrate until crystals precipitate, then dry at 70 ℃ to obtain pure ammonium sulfate.

3. Under stirring and ice water cooling conditions, add 270mL of concentrated nitrogen water (with a relative density of 0

Add 850mL of 20% H2SO4 to 91). After adding sulfuric acid, the solution should still have an ammonia odor, otherwise ammonia water needs to be added. Boil the obtained solution and filter it. Evaporate and crystallize the filtrate according to the above method.

4. Purification method of ammonium sulfate: Dissolve 150g of industrial ammonium sulfate in 260mL of water, heat to boiling, and add 1-2g of ammonium persulfate or 30% hydrogen peroxide. Continue boiling for a few minutes until the divalent iron is completely oxidized. The K3 [Fe (CN) 6] solution can be used to test whether the divalent iron in the solution has been completely oxidized. If no blue precipitate is generated after adding the K3 [Fe (CN) 6] solution, it indicates complete oxidation. Otherwise, ammonium persulfate or hydrogen peroxide needs to be added. After complete oxidation, add ammonia water to the solution to make the pH value of the solution about

8 0. Boil and filter to remove sediment. After adding a small amount of EDTA solution to the filtrate, heat and evaporate until a large amount of crystals appear. After cooling to room temperature, filter and wash several times with cold distilled water, then dry at 30-50 ℃.

5. After neutralization with ammonium hydroxide and sulfuric acid, it is obtained by crystallization, centrifugal separation, and drying.

6. Add 300kg of distilled water to 200kg of industrial ammonium sulfate, heat with steam, and stir until completely dissolved. Cool the dissolved solution to 50 ℃, add an appropriate amount of ammonium sulfide solution according to the heavy metal, iron, and arsenic content in the raw materials, stir evenly, let it stand for 3-4 hours, check for complete precipitation of heavy metal sulfides, and then filter. Add sulfuric acid to the obtained filtrate until pH=2, stir thoroughly to complete the arsenic ion precipitation reaction in the solution, add 200 grams of activated carbon for decolorization, and after confirming the arsenic content is qualified, perform filtration or pressure filtration. Heat the clarified filtrate to 70-80 ℃ to remove hydrogen sulfide, let it stand and cool. When it cools to 50-60 ℃, add ammonia water, stir evenly, adjust the pH to 9, and then add 200g of activated carbon. After passing the iron test, filter or press the filtrate. Heat, evaporate, concentrate and crystallize the clear liquid, centrifuge and spin dry the crystals, and dry them in a 100 ℃ oven. The mother liquor can be recycled and reused. To obtain high-purity ammonium sulfate, simply prepare it by using analytical pure ammonium sulfate, conductive water, high-purity ammonium sulfide, high-purity sulfuric acid, high-purity ammonia water, and treated activated carbon according to this process.

7. Prepare high-purity ammonium sulfate by neutralizing high-purity ammonia water with high-purity sulfuric acid: Place a hard beaker containing 1350ml of high-purity ammonia water with a density of 0.9 in an ice bath and let it stand for 15 minutes. Slowly add 4350ml of 20% high-purity dilute sulfuric acid while stirring. The prepared solution should maintain an ammonia odor. Stop heating when the solution is evaporated and concentrated to a syrup like state, cool and crystallize, filter and wash once with conductive water, and then dry to obtain high-purity ammonium sulfate.

use to

Glass etchants, wood and wine preservatives, disinfectants, analytical reagents, zirconium drop reagents, fiber mordants, and reagents for extracting rare elements.

toxicity