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Tantalum Chemical Properties
Aug 22, 2017

Tantalum Ta, metal elements, mainly in tantalite, with niobium symbiosis. Tantalum hardness is moderate, rich ductility, can be drawn into thin filament thin film. Its thermal expansion coefficient is very small. Tantalum has a very good chemical properties, with high corrosion resistance. Whether in cold and hot conditions, hydrochloric acid, concentrated nitric acid and "aqua regia" do not respond. Can be used to make evaporative containers, etc., can also do the tube electrode, rectifier, electrolytic capacitor. Medical tissue used to make thin slices or thin lines. Although the corrosion resistance of tantalum is very strong, but its corrosion resistance is due to the surface of the stable tantalum pentoxide (Ta2O5) protective film.

Chemical properties: Tantalum also has a very good chemical properties, with high corrosion resistance, whether in cold and hot conditions, hydrochloric acid, concentrated nitric acid and "aqua regia" do not respond. But tantalum in the hot concentrated sulfuric acid can be corrosive, below 150 ℃, tantalum will not be concentrated sulfuric acid corrosion, only in the temperature above this reaction will be in the 175 degrees of concentrated sulfuric acid in 1 year, the corrosion of the thickness 0.0004 mm, the tantalum into 200 ℃ sulfuric acid soak for one year, the surface damage only 0.006 mm. At 250 degrees, the corrosion rate increased, the corrosion per year for the thickness of 0.116 mm, at 300 degrees, the corrosion rate is faster, soaking for 1 year, the surface was corrosion 1.368 mm. The corrosion rate of fuming sulfuric acid (containing 15% SO3) is more severe than concentrated sulfuric acid, immersed in the solution at 130 degrees for 1 year, and the surface is etched with a thickness of 15.6 mm. Tantalum at high temperatures will be corrosion of phosphoric acid, but the reaction is generally more than 150 degrees occurred in the 250 degrees of 85% phosphoric acid, soak for 1 year, the surface was corrosion 20 mm, in addition, tantalum in hydrofluoric acid and nitric acid Of the mixed acid can quickly dissolve in hydrofluoric acid can also be dissolved. However, tantalum is more afraid of strong alkali, in the 110 degrees 40% concentration of caustic soda solution, tantalum will be quickly dissolved in the same concentration of potassium hydroxide solution, as long as 100 degrees will be quickly dissolved. In addition to the above-mentioned circumstances, the general inorganic salt in the 150 degrees below the general can not corrosion tantalum. Experiments show that tantalum at room temperature, the alkaline solution, chlorine, bromine, dilute sulfuric acid and many other agents do not work, only in the hydrofluoric acid and heat concentrated sulfuric acid under the reaction. This situation is relatively rare in the metal.

But at high temperatures, the oxide film on the surface of tantalum is destroyed, so it can react with a variety of substances, tantalum can react with fluorine at room temperature. At 150 ° C, tantalum is inert to chlorobromide at 250 ° C. Tantalum is still resistant to dry chlorine and is heated to 400 ° C in water containing steam. It remains bright at 500 ° C It began to be corroded, more than 300 degrees tantalum and bromine reaction, iodine vapor when the temperature reached before the red hot were inert. Hydrogen chloride at 410 degrees and tantalum reaction, the production of pentachloride, hydrogen bromide at 375 degrees with tantalum reaction. When heated to a temperature of 200 degrees or less, S can interact with Ta, carbon and hydrocarbons at 800-1100 degrees with tantalum.

Tantalum has the characteristics, so that its application is very broad. In the preparation of a variety of inorganic acid equipment, tantalum can be used to replace stainless steel, life can be improved several times higher than stainless steel. In addition, in the chemical, electronics, electrical and other industries, tantalum can replace the past need to bear the task of precious metal platinum, so that the cost is greatly reduced. Tantalum is made into a capacitive equipment to military equipment. The military industry in the United States is extremely developed and is the world's largest arms exporter. Half of the world's tantalum production is used in the production of tantalum capacitors, the US Department of Defense Logistics Agency is the largest owner of tantalum metal, once bought out of the world one-third of tantalum powder.

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