CLICK ABOVE TO ENLARGE Platinum (chemical symbol Pt), gold was discovered in the sands of Colombia, in 1738. It was so named for its color similar to that of silver, which in English is called "plata" (Note, however, that platinum, when the ingots and is subject to slight bluish reflections). Platinum
a very precious metal and therefore was once widely used, instead of gold, to coin coins. It is currently used in dentistry, in jewelry, in the great scientific instruments of precision, where they are needed extremely thin wires (platinum is very flexible in fact, that may be, with proper processing, pulled wires that reach a diameter of one hundredth of a millimeter ) and finally as a catalyst, in a "platinum black" and "platinum sponge" (in this state is blackish-gray, powder is in the first case, and finely porous and spongy, in the second).
With an alloy of platinum and 90% to 10% of another metal - iridium - were built in Paris in 1889, the meter and the kilogram "champions": the special properties of this alloy ensure that the meter and the kilogram with it set up not undergo significant changes, either by changing temperature, or for the erosion of time.
The most important platinum deposits - it is always found together with gold, silver and other metals - are in the Urals in Russia, Colombia, California, Brazil, Japan, In Australia, South Africa. Its extraction is carried out almost always to "wash the sand platinifere," making that pass these sands in an inclined channel in which flows the water that sweeps away the clay, lighter, while the particles pesanti dei metalli precipitano nel fondo. Di questi metalli, l’oro viene separato amalgamandolo con il mercurio., mentre con l’acqua regia (tre quarti di acido cloridrico e una di acido nitrico) si scioglie il platino. La soluzione così ottenuta si filtra e con successivi trattamenti chimici si ha la spugna di platino; dalla fusione di essa si ottiene il platino quasi puro, che viene infine fuso in lingotti.
a very precious metal and therefore was once widely used, instead of gold, to coin coins. It is currently used in dentistry, in jewelry, in the great scientific instruments of precision, where they are needed extremely thin wires (platinum is very flexible in fact, that may be, with proper processing, pulled wires that reach a diameter of one hundredth of a millimeter ) and finally as a catalyst, in a "platinum black" and "platinum sponge" (in this state is blackish-gray, powder is in the first case, and finely porous and spongy, in the second).
With an alloy of platinum and 90% to 10% of another metal - iridium - were built in Paris in 1889, the meter and the kilogram "champions": the special properties of this alloy ensure that the meter and the kilogram with it set up not undergo significant changes, either by changing temperature, or for the erosion of time.
The most important platinum deposits - it is always found together with gold, silver and other metals - are in the Urals in Russia, Colombia, California, Brazil, Japan, In Australia, South Africa. Its extraction is carried out almost always to "wash the sand platinifere," making that pass these sands in an inclined channel in which flows the water that sweeps away the clay, lighter, while the particles pesanti dei metalli precipitano nel fondo. Di questi metalli, l’oro viene separato amalgamandolo con il mercurio., mentre con l’acqua regia (tre quarti di acido cloridrico e una di acido nitrico) si scioglie il platino. La soluzione così ottenuta si filtra e con successivi trattamenti chimici si ha la spugna di platino; dalla fusione di essa si ottiene il platino quasi puro, che viene infine fuso in lingotti.
* * * * * * * * * * * * * * * * * * * *
0 comments:
Post a Comment