Physical and chemical properties:
Product name: Potassium Permanganate
Alias: Potassium permanganate Molecular formula: KMnO4
Molecular weight: 158.034 CAS No.: 7722-64-7 EINECS No.: 231-760-3
Boiling point: decomposition water-solubility: 6.38g /100 mL (20 ℃)
Outer view: dark purple slender diagonal columnar crystal with metallic luster
Storage conditions: Room temperature RTECS No. : SD6475000
Chemical properties
1. Oxidize and decompose ethanol and hydrogen peroxide.
2. Potassium permanganate is one of the strongest oxidants. As an oxidant, it is greatly affected by pH and has the strongest oxidation ability in acidic solution. Its corresponding acid HMnO4 and anhydride Mn2O7 are both strong oxidants, which can automatically decompose into heat and cause combustion in contact with organic matter.
3. Potassium permanganate has a strong oxidation, in the laboratory and industry is commonly used as an oxidant, when ethanol is decomposed. In an acidic medium, it will slowly decompose into manganese dioxide, potassium salt and oxygen. Light catalyzes this decomposition and is often stored in brown bottles in the laboratory. It can be seen from the electric potential diagram of elements and the oxidation state diagram of free energy that it has very strong oxidation property. In alkaline solution, the oxidation is not as strong as in acidic solution. As an oxidant, the reduced products vary with the acidity or alkalinity of the medium.
4. When the product encounters organic matter, it releases primary ecological oxygen and manganese dioxide, but no free oxygen molecules are released, so there is no bubble. Primary ecological oxygen has sterilization, deodorization, detoxification, potassium permanganate antibacterial deodorization than hydrogen peroxide solution strong and lasting. Manganese dioxide can combine with protein to form a gray-black complex, which shows convergence at low concentration and irritation and corrosion at high concentration. Its bactericidal ability increases with the increase of concentration,0.1% can kill the majority of bacteria reproduction,2% ~ 5% solution can kill the bacteria within 24 hours. The bactericidal action can be significantly enhanced under acidic conditions. For example, the addition of 1.1% hydrochloric acid in 1% solution can kill anthrax spores within 30 seconds.
5.Potassium permanganate is decomposed by heat
Uses
It is widely used as an oxidant in chemical production, such as saccharin, vitamin C, isoniazid and benzoic acid. Used as preservatives, disinfectants, deodorants and antidotes in medicine; In the water purification and wastewater treatment, as a water treatment agent, to oxidize hydrogen sulfide, phenol, iron, manganese, organic, inorganic and other pollutants, control odor and decolorization. It is also used as bleach, adsorbent, colorant and disinfectant. It is widely used in smelting, military industry, printing and dyeing, electroplating, electronics, medicine and other industries.
Preparation methods
There are two common preparation methods:
(1) Manganese dioxide and potassium hydroxide obtained from ore are heated in the air or mixed with potassium nitrate (providing oxygen) to produce potassium manganate, and then electrolyzed with oxidant in alkaline solution to obtain potassium permanganate;
(2) It is produced by the reaction of Mn ion with strong oxidants such as lead dioxide (PbO2) or sodium bismuth (NaBiO3);
There are various industrial production methods:
(1) Open hearth furnace method: The production principle is to mix pyrolusite with high temperature alkali reaction, after cooling, grinding powder roasted in open hearth furnace. The process is fully open, manganese dust, smoke and alkali fog have great environmental pollution, great labor intensity, low thermal efficiency and high energy consumption. The Ministry of Industry and Information Technology no. 122 of 2010 required to phase out open hearth furnace production process by the end of 2010;
(2) Brick kiln method: The roasting process is put into the rotary kiln, and the air is injected to oxidize the potassium manganate. The oxidation reaction condition of this method is harsh, the reaction is easy to be incomplete, the noise is big, the coking is easy, the equipment maintenance is big, the energy consumption is high. At present, has been basically eliminated by the market;
(3) Liquid phase oxidation method: add alkali to the liquid phase reaction pot, add pyrolusite in proportion, pass into the theoretical oxygen demand to make potassium manganate. This method has simple equipment, less manganese dust and short reaction time. But the raw material requirements are high, also belongs to the intermittent production, the production cost is high;
(4) Patented technology continuous production method: using patented tower equipment, continuous feeding, reaction and discharge to produce products. It has the advantages of large production capacity, short reaction time, high conversion rate of raw materials, low labor intensity, no manganese dust, no dust, no alkali fog pollution and so on. This technology is a major breakthrough in the production of potassium permanganate, which is praised as "a revolution of inorganic salt" by professionals.
Dangerous characteristic
Strong oxidant, in the presence of concentrated sulfuric acid, ammonium salt can explode; Glycerin can cause spontaneous combustion. Risk of combustion explosion when in contact with or mixed with organic matter, reductants, inflammables such as sulfur or phosphorus.
Extinguishing method: using water, mist water, sand.
Emergency treatment
Isolate the leaking contaminated area and restrict access. Emergency responders should wear dust mask (full cover) and gas suit. Do not contact the leakage directly, small amount of leakage with sand, dry lime or soda ash mixed, with a clean shovel collection in a dry, clean, covered container. Large quantities of leakage are collected for recovery or transported to waste disposal sites for disposal.
Operational considerations
Closed operation, enhanced ventilation. Operators must be specially trained, strictly observe the operating rules and stay away from fires and heat sources. Smoking, eating and drinking water are strictly prohibited in the workplace. Avoid contact with reducing agent and active metal powder. Pay attention to light loading and unloading in handling to prevent damage to packaging and containers. Equipped with the appropriate variety and quantity of fire fighting equipment and leakage emergency treatment equipment.
Application field
Smelting and military industry
Printing and dyeing pigments
Weaving and tanning leather
Electroplating and corrosion protection
The electronics industry
Water treatment and environmental protection
Cultivation and breeding
Chemical raw materials
Medicine
New energy and new products
Other
|