Potassium thiocyanate, commonly known as potassium roseate and potassium rose palmate, is an inorganic substance with the chemical formula KSCN. It is mainly used to synthesize resins, insecticides, fungicides, mustard oil, thiourea and drugs, and can also be used as a chemical reagent3+）It is used as a common indicator to generate a blood red flocculent complex after being added;It is also used to prepare thiocyanate (thiocyanide) solution, test iron ion, copper and silver, urine test, tungsten chromogenic agent, and indicator for volumetric titanium;It can be used as refrigerant and photographic thickener.
It is easily soluble in water and cooled due to a large amount of heat absorption.Also soluble in alcohol and acetone
Density (g/mL, 25/4 ℃)
one point eight eight six
Melting point (º C)
one hundred and seventy-three
Boiling point (º C, normal pressure)
five hundred
Flash point (º C)
five hundred
Refractive index
one point six six zero[7]
chemical property
KSCN has unstable chemical properties at room temperature, and is prone to deliquescence in the air and absorbs a lot of heat to cool down.The chemical property is stable at - 29.5 ～ 6.8 ℃, and the semi aqueous crystal can be obtained at low temperature.It turns blue when it is heated to about 430 ℃, and becomes colorless again after cooling.[1]
2. If potassium thiocyanate is placed in acid solution for a long time, it will be mixed with acid (such ashydrochloric acid）React and produce yellow precipitate（sulfur）And highly toxicHydrogen cyanideGas:[3]
3. In acid solution, potassium thiocyanate can be absorbed by metal (such aszinc）Decompositionhydrogen sulfideAnd hydrogen cyanide gas:[3]
Reaction of potassium thiocyanate with vinyl carbonate
Function and use
Announce
edit
For manufacturingThiourea、Mustard oil, configuringElectroplating solutionEtc.Used as refrigerant and steel analysis reagent.It is also used in the production of dyes and drugs.Used in electroplating industryDeplating agent，cryogen。It is also used in dye industry, photography industry, pesticide and steel analysis.[1]
Add potassium thiocyanide to the test tube
SCN-Energy and Fe3+Coordination formation [Fe (SCN)n]3-nIt can be observed that the solution is blood red:
。When diluted with water, the blue color fades to red, so it needs to react in concentrated solution to get obvious results.joinAmyl alcohol(or amyl alcohol andEtherThe amyl alcohol layer is blue.This method is often used to test Co in solution2+, very sensitive.[5]
synthetic method
Announce
edit
1. It can be generated by the reaction of potassium cyanide and sulfur or by the pressure synthesis reaction of carbon disulfide and ammonia waterAmmonium thiocyanate, and thenPotassium carbonateReaction.
Ammonium thiocyanate conversion method is used to synthesize carbon disulfide and ammonia water under pressure to generate ammonium thiocyanate and by-product ammonium thiocyanate. After desulfurization and evaporation, ammonium thiocyanate is decomposed into hydrogen sulfide and removed. When the liquid temperature is 105 ℃, potassium carbonate solution is slowly added to generate potassium thiocyanate.A large amount of carbon dioxide and ammonia will be produced in the reaction process.Ammonia can be recovered for use. The reaction solution is filtered, insoluble matter is removed, and then evaporated under reduced pressure. After cooling, crystallization, and centrifugation, industrial potassium thiocyanate is prepared.[8]The reaction formula is as follows:
2. The crude product is prepared by the double decomposition reaction of potassium salt and ammonium thiocyanate. The refining method is to recrystallize it for many times in boiling ethanol, then dry it at 100 ℃ under reduced pressure, and store it in a dryer with concentrated sulfuric acid.
3. Ammonium thiocyanate conversion method: pressure synthesis of sulfur dioxide and ammonia water to generate ammonium thiocyanate and by-product ammonium thiocyanate, and then through desulfurization and evaporation to decompose ammonium thiocyanate into hydrogen sulfide for removal. Slowly add potassium carbonate solution at the liquid temperature of 105 ℃ to generate potassium thiocyanate.[2]
matters needing attention
Announce
edit
Hazard Overview
Health hazard: acute poisoning caused by misuse will cause gastrointestinal dysfunction such as nausea, vomiting, abdominal pain, diarrhea, blood pressure fluctuation, and slow heart rate.Severe poisoning can cause obvious damage to renal function.Chronic effect, can inhibit thyroid function, can make women's menstrual period longer and more.
Environmental hazard: It is harmful to the environment and can cause pollution to the water body.
Flammability hazard: This product is incombustible.
Security risk terminology
Safety terminology
S13：Keep away from food, drink and animal foodstuffs.
Keep away from food, drink and animal feed.
S36/37：Wear suitable protective clothing and gloves.
Wear appropriate protective clothing and gloves.
S61：Avoid release to the environment. Refer to special instructions / safety data sheets.
Avoid release to the environment.Refer to Special Instructions/Safety Data Sheet.
Risk terminology
S61：Avoid release to the environment. Refer to special instructions / safety data sheets.
Avoid release to the environment.Refer to Special Instructions/Safety Data Sheet.
R32：Contact with acid liberates very toxic gas.
Contact with acid releases extremely toxic gas.
R52/53：Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment.
It is harmful to aquatic organisms and may have long-term adverse effects on the water environment.
First aid measures
Contact part
First aid measures
Skin contact
Take off contaminated clothes and wash with plenty of flowing water.
Eye contact
Lift the eyelids and wash them with flowing water or normal saline.Get medical attention.
inhalation
Leave the site to fresh air.Get medical attention.
Ingestion
Drink enough warm water to induce vomiting.Gastric lavage and catharsis.Get medical attention.
Fire fighting measures
Hazard characteristics: It is subject to high thermal decomposition and emits toxic cyanide and sulfide smoke.
Extinguishing method: Move the container from the fire site to an open place as far as possible.
Leakage emergency treatment
Emergency treatment: isolate the leakage contaminated area and restrict access.It is recommended that emergency personnel wear dust masks (full face masks) and gas suits.Flush with a large amount of water, and put the diluted washing water into the waste water system.In case of large leakage, collect and recycle or transport to waste disposal site for disposal.
Operational disposal
Precautions for operation: closed operation, full ventilation.Operators must be specially trained and strictly abide by the operating procedures.It is recommended that operators wear self-priming filter type dust mask, chemical safety goggles, anti poison penetration work clothes and anti chemical gloves.Avoid dust generation.Avoid contact with acids.Load and unload gently during transportation to prevent damage to packaging and containers.Provide leakage emergency treatment equipment.Empty containers may leave harmful substances.
Precautions for storage: store in a cool, dry and well ventilated warehouse.Keep away from kindling and heat sources.Keep container sealed.It shall be stored separately from acids, etc., and mixed storage is strictly prohibited.The storage area shall be equipped with appropriate materials to contain leakage.
