Credit for the modern rediscovery of platinum is usually given to Antonio de Ulloa. Platinum is a soft, dense, ductile metal that is very resistant to corrosion. It is used to make jewelry, wire, electrical contacts and laboratory vessels. Platinum expands at nearly the same rate as soda-lime-silica glass, so it is used to make sealed electrodes in glass systems.
Platinum is used to coat missile nose cones, jet engine fuel nozzles and other devices that must operate reliably for long periods of time at high temperatures.
Platinum resistance wires are used in high temperature electric furnaces. Furthermore, a nickel matte with a deficiency of sulphur is an excellent collector of the platinum group metals; therefore under suitable conditions a nickel matte can be produced that is low in copper and will contain the platinum group metals.
At Brimsdown this operation is mainly carried out in a blast furnace, although six-ton reverberatory furnaces are also used. The first stage of the smelting operations is a blast furnace treatment to separate nickel matte containing very small amounts of copper and practically all of the platinum metals.
The copper tops are then either poured into a five-ton reverberatory holding furnace or directly into a horizontal-type copper converter. The converter is lined with magnesite brick and capable of taking charges up to five tons.
By blowing air through the molten top considerable heat is generated and sodium sulphate is first formed. This is tapped off as a watery liquid and used again in the blast furnace.
Silica is then added to the converter to flux iron oxide and any excess soda; this slag is also poured off and the residual copper sulphide blown down to blister copper in the normal way. The blister copper is tapped into a ladle and poured directly into one of three small reverberatory furnaces. The copper is then further refined and cast into moulds to make anodes for the electro-refinery.
The ground nickel matte is roasted in this battery of oil-fired furnaces. The nickel oxide produced is then reduced to metal and cast into anodes. In the meantime, nickel matte from the blast furnace operation is broken, crushed and ground in ball mills to 20 mesh. This material is then roasted to nickel oxide in oil-fired feet diameter Herreschoff type furnaces with two hearths separated by an air gap. After cooling, the resultant nickel oxide is briquetted with anthracite coal and sand.
These briquettes are next charged into an oil-fired reverberatory type furnace, where the oxide is reduced to metal and tapped into anode moulds. These anodes, which contain practically all the platinum metals, are then passed into the electrolytic nickel refinery. Copper anodes from the converter process are dissolved electrolytically using an acid copper sulphate solution as an electrolyte.
The products of this operation are pure copper cathodes and an anode slime which may contain gold and small quantities of the platinum group metals. The cells are constructed of rubber-lined concrete.
The warmed electrolyte is fed in at one end and overflows from the other into a launder running between the lines of cells. From the launder the liquid is pumped to overhead tanks where its heat is maintained, and by gravity flows to a manifold which feeds it back to the cells.
During electrolysis the electrolyte tends to accumulate nickel and quantities have to be bled off occasionally and replaced by pure copper sulphate. The impure electrolyte is treated for recovery of the copper sulphate and the nickel sulphate is passed to the nickel refinery. The quantity of anode slime formed by the dissolving of these anodes is small and falls to the bottom of the cells, where it is periodically recovered.
A platinum flotation circuit. In a process called flotation separation , air bubbles are blown through the mixture and carry platinum particles to the surface of the bath. The platinum-rich froth is skimmed from the bath and allowed to dry into a concentrated powder.
One ton of dried powder may contain between 3 and 30 ounces 85 to grams of PGMs. Froth generated at the top of a flotation cell concentrates the platinum particles. The dried powder is then heated to extremely high temperatures to remove impurities. Air is blown over the matte that remains after smelting to eliminate unwanted iron and sulfur. At this point, the PGM content of the matte is now about 50 ounces 1.
Further chemical processing will remove any base metals remaining in the matte, such as copper and nickel. At this stage, the mineral concentrate contains about 15 to 20 percent PGMs. In the final stage, the mineral concentrate is treated with aqua regia to dissolve the platinum. The solution is filtered, purified, and burned to produce pure platinum metal.
Molten matte containing palladium and platinum is emptied from the furnaces at the Stillwater mine in North America. Platinum deposits are located in only a few areas of the world. For every ten gold mines there is only a single platinum mine. All the platinum ever mined would fill a room no more than 25 feet square.
Today, world platinum production hovers at about seven million troy ounces per year. Russia is the second largest producer of platinum. Blue Sapphire Engagement Rings. White Sapphire Engagement Rings. Pink Sapphire Engagement Rings. Purple Sapphire Engagement Rings.
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Other Colors of Sapphire Engagement Rings. View All Sapphire Rings. Blue Sapphire Rings. About half of platinum's demand is actually for use in catalytic converters for transportation vehicles like buses, cars and trucks, in large part because it's adept at converting harmful engine emissions into less damaging waste. Platinum is also used as a catalyst to make chemicals like silicone, nitric acid and benzene. In fact, the six platinum group metals iridium, palladium, platinum, rhodium, ruthenium and osmium are all known for their impressive catalytic skills meaning these metals increase the rate of chemical reaction between substances without changing their physical properties.
In the healthcare field, platinum compounds are a component of some chemotherapy drugs, and are also used in pacemakers and even dental fillings. The electronics industry has various applications for platinum, too — for instance, computer hard disks.
From a defense standpoint, platinum has been long valued for its strength, which goes far beyond simple scratch resistance. The metal holds up well under high temperatures, boasts stable electrical properties and is highly resistant to chemical attacks.
For example, coating jet engine blades with platinum-based products protects them where temperatures can reach 2, degrees C 3, degrees F. Even today, platinum is so important to economic and defense efforts that it was listed as one of the 35 minerals "deemed critical to U. With a resume like that, it appears that platinum's reputation and price tag are well-deserved, indeed. Ironically, Spaniards who discovered platinum in Colombia were less than impressed, tossing it by the wayside as an impurity in the coveted silver they were mining.
So disdainful of the metal were they that they dubbed it "platina," which means "little silver.
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