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| The Mineral ULEXITE Ulexite, like other borates, is a structurally complex mineral. The basic structure of ulexite contains chains of sodium, water and hydroxide octahedrons linked in endless chains. The chains are linked together by calcium, water, hydroxide and oxygen polyhedra and massive boron units. The basic boron unit has a formula of B5O6(OH)6 and a charge of negative three (-3). It is composed of three borate tetrahedrons and two borate triangular groups. PHYSICAL CHARACTERISTICS: |
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| Boric acid, also called boracic acid or orthoboric acid or Acidum Boricum, is a mild acid often used as an antiseptic, insecticide, flame retardant, in nuclear power plants to control the fission rate of uranium, and as a precursor of other chemical compounds. Preparation: Boric acid is produced mainly from borate minerals by the reaction with sulfuric acid. The largest source of borates in the world is an open-pit mine in Boron, California, USA. Crystal structure: Crystalline boric acid consists of layers of B(OH)3 molecules held together by hydrogen bonds. The distance between two adjacent layers is 318 pm.
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Uses Medicinal uses : It can be used as an antiseptic for minor burns or cuts and is sometimes used in dressings or salves or is applied in a very dilute solution as an eye wash. (1.5% solution or 1 tbsp per quart of boiled water has been suggested for the latter.) Boric acid has the distinction of being the only known acid that is actually beneficial (rather than harmful) to the eyes, and as such is used by ophthalmologists and in some commercial eye drops. Insecticidal use: Boric acid was first registered as an insecticide in 1948 by the EPA for control of cockroaches, termites, fire ants, fleas, silverfish, and many other insects. It acts as a stomach poison affecting the insects' metabolism, and the dry powder is abrasive to the insects' exoskeleton. Boric acid may be used either in an insect bait formulation containing a feed attractant or as a dry powder. The powder may be injected into cracks and crevices, where it forms a fine layer of dust. Insects travel through the boric acid dust, which adheres to their legs. When the insects groom themselves, they then ingest the poison, which causes death three to ten days later of starvation and dehydration. Preservative Use: In combination with its use as an insecticide it also prevents and destroys existing wet and dry rot in timbers. It can be used in combination with an ethylene glycol carrier to treat external wood against fungal and insect attack. Industrial uses : Boric acid is used in nuclear power plants to slow down the rate at which fission is occurring. Fission chain reactions are generally driven by the amount of neutrons present (as products from previous fissions). Natural Boron is 20% Boron-10 and about 80% Boron-11. Boron-10 has a high cross-section for absorption of low energy (thermal) neutrons. In the jewelry industry, boric acid is often used in combination with denatured alcohol to reduce surface oxidation and firescale from forming on metals during annealing and soldering operations. It is also used in the manufacturing of remming mass, a fine silica-containing powder used for producing induction furnace linings and ceramics. Miscellaneous uses: Borates including boric acid have been used since the time of the Greeks for cleaning, preserving food, and other activities. Silly Putty was originally made by adding boric acid to silicone oil. Lithium borate is the lithium salt of boric acid and is used in the laboratory as buffer for gel. TBE buffer is widely used for the electrophoresis of nucleic acids and has a higher buffer capacity than a TAE Buffer. It can be used for DNA and RNA polyacrylamide and agarose gel electrophoresis. It is used in pyrotechnics to prevent the amide-forming reaction between aluminum and nitrates. A small amount of boric acid is added to the composition to neutralize alkaline amides that can react with the aluminum. Boric acid is popularly used among fire jugglers and fire spinners dissolved in methanol to give a deep green flame. It is also used in India and across the world to dust down Carrom boards to decrease friction and increase speed of play. Boric acid is also used in special effects. When Boric Acid is combined with an alcohol (usually ethanol), it produces a green flame when burned. |
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Chemistry: Na2B4O7 -10H2O, Hydrated sodium borate. Borax is a complex borate mineral that is found in playa lakes and other evaporite deposits. The basic structure of borax contains chains of interlocking BO2(OH) triangles and BO3(OH) tetrahedrons bonded to chains of sodium and water octahedrons. PHYSICAL CHARACTERISTICS: |
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Tantalum is a hard, grayish-blue, metallic element. Tantalum was discovered in 1802 by the Swedish scientist Anders Ekeberg. Tantalum is mostly found with the element niobium. The two elements are so similar that they are very difficult to isolate from one another. Tantalum was named after the Greek god, Tantalus. Niobium, discovered before tantalum (1801), was named after the daughter of Tantalus, Niobe. Sources Tantalum is recovered from ore minerals such as columbite and tantalite. About 20% of the tantalum used in the United States comes from recycling. The rest must be imported. Recent major sources for tantalum imports were Australia, Kazakhstan, Canada, China, Thailand, and others. Uses The electronics industry uses most of the tantalum consumed to make electronic components (tantalum capacitors). Since tantalum is so resistant to corrosion, it is used to make surgical instruments and medical equipment such as rods to attach to broken bones, skull plates, and wire meshes to help repair nerves and muscles. Because it has such a very high melting point, it is alloyed (that is, mixed with) other metals to create alloys that are needed for very high temperature applications. Tantalum is also used in camera lenses. Substitutes and Alternative Sources Columbium can be used in place of tantalum to make carbides. Columbium, hafnium, iridium, molybdenum, rhenium and tungsten can be used for high-temperature situations. Aluminum and ceramics can be used in place of tantalum in electronic capacitors. The problem is, however, that most of these substitutes are not as effective as tantalum in some of these applications. Tantalite, [(Fe, Mn) Ta2O6], is a mineral that is close to columbite. Tantalite is black to brown in both color and streak. Manganese rich tantalites can be brown and translucent. Tantalite has been found in Namibia, Nigeria, Canada, Madagascar, northern Europe, and Maine, California, Colorado and Virginia in the United States. Brazil has the world's largest reserve of Tantalite (52.1%). As at 2006, 75% of world tantalite production comes from Australia. |
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