1. Used as a polymerization catalyst for dyes and organic synthesis, used for pesticide weeding and separation of defoliants, antibiotics, and also a raw material for the manufacture of cyanide and thiourea
2. Used as an auxiliary raw material for the production of hydrogen peroxide, and also used in dyes, organic synthesis, pesticides, medicines, etc.
3. It is the auxiliary raw material for the manufacture of hydrogen peroxide. Used as a polymerization catalyst for dyes and organic synthesis. Used for separation of pesticides and antibiotics, analytical reagents, etc. It is also a raw material for the manufacture of cyanide, ferrocyanide and thiourea. It is also used for zinc coating, printing and dyeing diffusion agent, electroplating additive.
4. Used as an analytical reagent and also used for the separation of antibiotics
5. Verification and determination of trace iron, determination of silver and mercury, etc., polymerization catalyst, separation of antibiotics, analysis of pesticide content, water quality analysis, preparation of thiocyanate and standard solutions.
||<1 hPa (20 °C)
||Store at RT.
||H2O: 1 M at 20 °C, clear, colorless
||clear colorless or white
|| 4.8-5.8 (50g/l, H2O, 20℃)
|Discoloration of acid-base indicator pH value range
||Stable. Incompatible with strong acids, strong oxidizing agents. Forms explosive mixtures with lead nitrate.
||1762-95-4(CAS DataBase Reference)
|Chemical substance information
||Ammonium thiocyanate (1762-95-4)
||Colorless monoclinic flaky or columnar crystals, shiny. It is easily soluble in water, ethanol, liquid ammonia, acetone, pyridine and liquid sulfur dioxide.
|Solubility in water (g/100ml)
||Dissolved grams per 100ml of water at different temperatures (°C): 120g/0°C; 144g/10°C; 170g/20°C; 208g/30°C; 234g/40°C, 346g/60°C
||Oral-rat LD50: 750 mg/kg; Oral-mouse LD50: 500 mg/kg
|Flammability hazard characteristics
||Heating produces toxic nitrogen oxides, sulfur oxides, cyanide and ammonia fumes.
|Storage and transportation characteristics
||The warehouse is ventilated, low temperature and dry; store separately from potassium perchlorate
||Dry powder, foam, sand, carbon dioxide, misty water
||STEL 5 mg/m3
Ammonium thiocyanate, also known as ammonium thiocyanide or ammonium thiocyanate, is a colorless and shiny monoclinic flaky or columnar crystal, chemical formula NH4SCN, a molecular weight of 76.12, and a rhombohedral crystal at 92°C. It has a melting point of 147°C (decomposition at 170°C), a relative density of 1.3057, and a refractive index of 1.685. It is easily soluble in water, and shows an endothermic reaction when dissolved in water. It is soluble in ethanol, alkali metal hydroxide, acetone, pyridine and liquid sulfur dioxide, but hardly soluble in chloroform (trichloromethane). The solution is red under sunlight. In case of iron salt, blood red iron thiocyanide is formed, which can be colorimetrically determined with the color of the standard solution. When heated to about 140°C, thiourea is formed. 176Chemicalbook ℃ decomposes into ammonia, carbon disulfide and hydrogen sulfide. It is easy to deliquesce in the air and should be sealed and stored away from acids.
Preparation method: Place carbon disulfide and liquid ammonia in a pressurized reactor at a temperature of 30°C for 20 hours, or react sulfur powder, sodium cyanide and ammonium chloride with water at a temperature of about 110°C. Main use: Used as polymerization catalyst for organic synthesis, printing and dyeing diffusion agent, pesticide herbicide, analytical reagent, such as measuring silver mercury and trace iron, and also preparing thiocyanate and thiocyanate complex. It has a certain ability to dissolve silver halide, and its concentrated solution also has the ability to dissolve gelatin. Used in photographic liquids, golden tinting of printing paper, printing of cotton fabrics, pickling of steel, etc.
Industrial Ammonium Thiocyanate
Industrial ammonium thiocyanate is one of coke oven gas purification products. The pure product is a colorless, shiny monoclinic crystal. Its molecular formula is NH4SCN, and its density is 1.305g/cm3. It is deliquescent in the air and soluble in water. The ammonium thiocyanate production system absorbs a lot of heat), the melting point is 149.6°C, and it decomposes at 170°C. Ammonium thiocyanate is mainly used in the dyeing industry, as well as chemical reagents and herbicides. In the purification process of coke oven gas, when hydrogen cyanide is directly removed from the coal gas with ammonium polysulfide solution, an industrial ammonium thiocyanate product with a content of more than 92% is obtained. The absorption reaction formula of coke oven gas decyanation is: HCN+(NH4)2Sn→HSCN+(NH4)2Sn-1
The ammonia participating in the absorption reaction comes from the coke oven gas itself, so the decyanation device must be located before the coke oven gas recovery process. After the coke oven gas is removed from the tar mist and naphthalene by the electric tar trap, the hydrogen cyanide in the coal gas is removed with an ammonium polysulfide solution to generate ammonium thiocyanate. The absorption liquid continuously circulates the scrubbing gas to increase the concentration of ammonium thiocyanate in the absorption liquid, and at the same time, continuously takes out a part of the absorption liquid to add sulfur for regeneration. The regeneration reaction formula is (NH4)2Sn-1+S→(NH4)2Sn. When the content of ammonium thiocyanate in the absorption solution reaches 250g/L, it can be taken out and sent for processing. After the steps of evaporation and crystallization, industrial ammonium thiocyanate products are produced.
There are two isomers of thiocyanic acid, one is thiocyanate H—S—C≡N, and the other is isothiocyanate H—N—C=S. The free acid has not yet been separated. Most thiocyanates are soluble in water. SCN-ion is a good ligand. A special sensitive reaction of SCN-ion is to form a variety of red complexes with Fe3+. Therefore, potassium thiocyanate or ammonium thiocyanate is often used as a reagent for testing Fe3+.
Colorless and volatile liquid, slightly toxic. Melting point -110°C, relatively stable at 0°C, and rapidly decomposes at room temperature. Easily soluble in water, and the aqueous solution has strong acidity. Its hot solution or concentrated solution is easy to decompose and easy to polymerize. Polymerizes into white crystals at -90～-85℃. Heated in a vacuum to form light yellow thiocyanuric acid soluble in ether, which is easily decomposed into thiocyanic acid. It is prepared by the action of potassium thiocyanate and potassium hydrogen sulfate or the aqueous solution of ammonium thiocyanate through H-type cation exchange resin. It is a reagent for testing iron and quantitatively determining silver in the laboratory by its salt effect.
Potassium thiocyanate is also known as “potassium thiocyanide”. Chemical formula KSCN. The molecular weight is 97.18. Colorless orthorhombic crystals. Deliquescence. Toxic! Irritating to the skin. The melting point is 173.2°C and the relative density is 1.88614. When the melt cools, it turns into brown, green, blue, and white. Easily soluble in water, the aqueous solution is neutral, soluble in acetone, ethanol and liquid ammonia. Decomposes at 500°C. Preparation method: It is obtained by heating potassium cyanide and sulfur powder together, or by reacting ammonium thiocyanate with potassium hydroxide. Uses: used in the production of mustard oil, thiourea, drugs, in the printing and dyeing industry, photography, as a refrigerant, analytical reagents, etc.
The carbon disulfide method mixes carbon disulfide and a slight excess of liquid ammonia with water, and reacts for about 20 hours at a pressure of 5.88×105Pa and a temperature of 100°C to generate ammonium thiocyanate. The reaction solution is evaporated under reduced pressure to remove hydrogen sulfide. At a liquid temperature of 105°C, iron and heavy metals are removed with ammonium sulfide, filtered, the filtrate is concentrated under reduced pressure and then cooled and crystallized in a crystallizer, and then centrifuged and dried to obtain Ammonium thiocyanate. its
In the sulfur method, a proper amount of water and sulfur powder are stirred in a reactor to form a slurry, solid sodium cyanide is slowly added in portions, and the reaction proceeds at a temperature of about 110°C to form sodium thiocyanide, and then solid ammonium chloride is added to react to form sulfur For ammonium cyanate, add barium thiocyanate to the reaction solution to remove impurities and clarify. The supernatant is evaporated under reduced pressure and concentrated to precipitate sodium chloride, and then filtered, cooled and crystallized, separated and dried to obtain ammonium thiocyanate . its