Калия перманганат химические свойства, назначение, производство
Описание
Potassium permanganate, is composed of dark purple, odorless crystals with a blue metallic sheen. It is soluble in water, decomposes at 465°F (240°C), and is a powerful oxidizing material. Potassium permanganate is a dangerous fire and explosion risk in contact with organic materials. Potassium permanganate is incompatible with sulfuric acid, glycerin, and ethylene glycol. The four-digit UN identification number is 1490. The primary uses of potassium permanganate are as an oxidizer, bleach, or dye; during radioactive decontamination of the skin; and in the manufacture of organic chemicals.
Химические свойства
Potassium permanganate is a dark purple crystalline solid with a sweet taste that decompose at 240°C and explode in contact with oxidizable materials.Used as a disinfectant and analytical reagent, in dyes,bleaches,and medicines,and as a chemical intermediate.
Физические свойства
Dark purple rhombohedral crystal; density 2.703 g/cm3; stable in air;decomposes at about 240°C; moderately soluble in cold water, 6.38 g/100mL at 20°C, soluble in hot water, 25 g/100mL at 65°C; decomposed by alcohol, acetone and many organic solvents causing their oxidation; also decomposed by concentrated acids.
Использование
Potassium permanganate (KMnO4) is a dark purple-bluish sheen crystal with a slightly sweet
taste. It is produced by oxidizing manganate in an electrolytic cell or by passing carbon dioxide
through a hot solution of manganate and then cooling until permanganate crystals form. It is
a strong oxidizing agent, particularly with organic matter, which makes it a good disinfectant,
deodorizer, bleach, and antiseptic.
Определение
potassium permanganate: A compound,KMnO4, forming purple crystalswith a metallic sheen, soluble inwater (intense purple solution), acetone,and methanol, but decomposedby ethanol; r.d. 2.70; decompositionbegins slightly above 100°C and iscomplete at 240°C. The compound isprepared by fusing manganese(IV)oxide with potassium hydroxide toform the manganate and electrolysingthe manganate solutionusing iron electrodes at about 60°C.An alternative route employs productionof sodium manganate by a similarfusion process, oxidation withchlorine and sulphuric acid, thentreatment with potassium chloride tocrystallize the required product.Potassium manganate(VII) is widelyused as an oxidizing agent and as adisinfectant in a variety of applications,and as an analytical reagent.
Подготовка
Potassium permanganate is produced from manganese ore containing at least 60% manganese dioxide, MnO2. The finely ground ore is mixed with 50%potassium hydroxide and heated at about 350°C in rotary kilns. This converts manganese dioxide to potassium manganate:
MnO22+ 4KOH + O2→2K2MnO4+ 2H2O
Potassium manganate obtained above is oxidized to the permanganate either by electrolysis or by chemical oxidation. Electrolytic oxidation is more common. Electrolytic cells have cathodes made of iron rods and nickel-plated anodes. Potassium manganate melt is extracted with water prior to its elec-trolysis and then electrolyzed at a cell voltage of 2.3V and current of about 1,400 amp. Permanganate is produced at theanode and water is reduced to gaseous hydrogen and hydroxyl ions at the cathode:
2K2MnO44+ 2H2O →2KMnO4+ 2KOH + H2.
Показания
Potassium permanganate (KMnO4) is an oxidizing agent that is rapidly rendered
inactive in the presence of organic material. The oxidizing action of the chemical
is purportedly responsible for its germicidal activity. It is also an astringent and a fungicide. This preparation stains the skin and clothing, and undissolved
crystals will cause a chemical burn. It is used less commonly now (primarily
as an antifungal agent) and may be little better than water as a wet dressing.
A 1:4,000 to 1:16,000 dilution is used on weeping or denuded surfaces (one
crushed 65-mg tablet dissolved in 250 to 500 mL; one 330-mg tablet dissolved
in 1,500 mL to 3,000 mL). For use as a medicated bath, 8 g (approximately 2
tsp) should be dissolved in 200 L (a full bathtub) of water to produce about a
1:25,000 dilution. Skin stains may be removed with a weak solution of oxalic
acid or sodium thiosulfate.
Общее описание
A purplish colored crystalline solid. Noncombustible but accelerates the burning of combustible material. If the combustible material is finely divided the mixture may be explosive. Contact with liquid combustible materials may result in spontaneous ignition. Contact with sulfuric acid may cause fire or explosion. Used to make other chemicals and as a disinfectant.
Реакции воздуха и воды
Soluble in water.
Профиль реактивности
Potassium permanganate is a very powerful oxidizing agent, particularly in acidic surroundings. Reacts with incandescence with aluminum carbide [Mellor 5:872. 1946-47]. Grinding with antimony or arsenic causes ignition of the metals [Mellor 12:322. 1946-47]. Mixtures with acetic acid or acetic anhydride may explode if not kept cold [Von Schwartz 1918. p. 34]. Explosions can occur when acidified solutions come in contact with benzene, carbon disulfide, diethyl ether, ethyl alcohol, petroleum, or organic matter. Contact with glycerol may produce an explosion [Pieters 1957. p. 30]. Contact with concentrated hydrogen peroxide solution can produce an explosion [Haz. Chem. Data 1973. p. 230]. Contact with solid hydroxylamine produces an immediate white flame [Mellor 8:294. 1946-47]. Transport through a polypropylene tube ignited the tube [MCA Case History 1842. 1972]. Mixing with concentrated sulfuric acid in a vessel containing moisture caused an explosion (due to formation of manganese heptoxide) [Delhez 1967].
Опасность
Dangerous fire and explosion risk in contact
with organic materials, powerful oxidizing agent.
Угроза здоровью
Burns and stains the skin dark brown. If ingested will cause severe distress of gastro-intestinal system. May be fatal if over 4 oz. are consumed.
Пожароопасность
Behavior in Fire: May cause fire on contact with combustibles. Containers may explode.
Промышленное использование
This is a crystalline substance with a deep purple color, extremely soluble in water
(60 g/L). At a temperature above 200 °C, KMnO4 decomposes according to the following
reaction:
2KMnO4 +Heat?
K2MnO4 + MnO2 + O2
Potassium permanganate has a depressing effect on most sulfide minerals including
sphalerite, pyrrhotite and chalcopyrite. It has been used to depress pyrrhotite and arsenopyrite
in a pyrite flotation alkaline circuit. Studies were carried out on the depression of copper
in copper–molybdenite separation with promising results. There is very little known
about the depressing action of KMnO4 in relation to pH.
Возможный контакт
Potassium permanganate is used
in solutions as a disinfectant, topical antibacterial agent;
deodorizer, bleaching agent; and in air and water
purification.
Перевозки
UN1490 Potassium permanganate, Hazard Class:
5.1; Labels: 5.1-Oxidizer.
Методы очистки
Crystallise it from hot water (4mL/g at 65o), then dry it in a vacuum desiccator over CaSO4. Phillips and Taylor [J Chem Soc 4242 1962] cooled an aqueous solution of KMnO4, saturated at 60o, to room temperature in the dark, and filtered it through a No.4 porosity sintered-glass filter funnel. The solution was allowed to evaporate in air in the dark for 12hours, and the supernatant liquid was decanted from the crystals, which were dried as quickly as possible with filter paper.
Несовместимости
Potassium permanganate is a powerful
oxidizing agent, that is, it will initiate a fire or explosion if
brought into contact with reducing materials; combustibles,
organic materials; strong acids; or oxidizable solid, liquid
or gas; glycerin, ethylene glycol; polypropylene, hydroxyl-
amine, hydrogen trisulfide; antimony, arsenic, sulfuric acid;
hydrogen peroxide; phosphorus, and any finely divided
combustible material. It will decompose, and release
oxygen, if brought into contact with heat, alcohol, acids,
ferrous salts; iodides and oxalates.
Утилизация отходов
React with reducing agent,
neutralize and flush to sewer
Калия перманганат препаратная продукция и сырье
сырьё
препарат