Platinum malleability

English chemist and physicist Discoverer of palladium and rhodium Inventor of a process for making platinum malleable. Famous for his researches on force of percussion, gout, diabetes, columbium (niobium), tantalum, and titanium, and his scale of chemical equivalents. 

Baron Carl von Sickingen devises a process for making platinum malleable. 

Death of Dr. Wollaston in London. His specifications for making platinum malleable were circulated at the same time as the news of his death. 

Platinum is a beautiful silvery-white metal, when pure, and is malleable and ductile. It has a coefficient of expansion almost equal to that of soda-lime-silica glass, and is therefore used to make sealed electrodes in glass systems. The metal does not oxidize in air at any temperature, but is corroded by halogens, cyanides, sulfur, and caustic alkalis. 

At the start of the nineteenth century, platinum was refined in a scientific manner by William Hyde WoUaston, resulting in the successful production of malleable platinum on a commercial scale. During the course of the analytical work, WoUaston discovered paUadium, rhodium, indium, and osmium. Ruthenium was not discovered until 1844, when work was conducted on the composition of platinum ores from the Ural Mountains. 

Platinum, a bluish-white metal, is soft, tough, ductile, and malleable. It has a melting point of 1773°C. The coefficient of thermal expansion is... 

Frenchman P. F. Chabeneau, and subsequently in London by W. H. Wollaston/ who in the years 1800-21 produced well over 1 tonne of malleable platinum. These techniques were developed because the chemical methods used to isolate the metal produced an easily powdered spongy precipitate. Not until the availability, half a century later, of furnaces capable of sustaining sufficiently high temperatures was easily workable, fused platinum commercially available. 

Both rhodium (m.p. 1976°C, b.p. 3730°C) and iridium (m.p. 2410°C, b.p. 4130°C) are unreactive silvery metals, iridium being considerably more dense (22.65gem-3) than rhodium (12.41 gem-3), the densest element known apart from osmium. Both form fee (ccp) lattices and, like the other platinum metals, are ductile and malleable. Neither is affected by aqua regia and they only react with oxygen and the halogens at red heat. 

Platinum. Pt aw 195.09 silver-gray, lustrous, malleable and ductile metal face-centered... 

Pure platinum is malleable and ductile with excellent corrosion resistance. When alloyed with cobalt, it has good magnetic properties (76.7 W% Pt, 23.3 W% Co). 

A metal is an electropositive element. There are over 70 metals in the earth s crust. Examples include copper, gold, iron, platinum, silver and tungsten. Chemically, in solution, a metal atom releases an electron to become a positive ion. In bulk metals are solids and tend to have high melting and boiling points (an exception is mercury). They are lustrous, relatively dense, malleable, ductile, cohesive and highly conductive to both electricity and heat. 

Sobolcvsky A process for converting native platinum to malleable platinum by pressing and heating. Developed by P. G. Sobolevsky in Russia in the 1820s. 

The catalyst is normally contained on a ceramic substrate. These ceramics are extruded in a malleable state and then fired in ovens. The process consists of starting with a ceramic and depositing an aluminum oxide coating. The aluminum oxide makes the ceramic, which is fairly smooth, have a number of bumps. On those bumps a noble metal catalyst, such as platinum, palladium, or rubidium, is deposited. The active site, wherever the noble metal is deposited, is where the conversion will actually take place. An alternate to the ceramic substrate is a metallic substrate. In this process, the aluminum oxide is deposited on the metallic substrate to give the wavy contour. The precious metal is then deposited onto the aluminum oxide. Both forms of catalyst are called monoliths. 

Platinum (Pt, [Xe + 4/ l4]5r/96.s 1), name from the Spanishplatina (silver). Known and used by the pre-Columbian South-American Indians since ancient times. Re-discovered and noticed by the Western scientists in 1735 (Antonio de Ulloa). Silvery, white solid, ductile and malleable metal. 

Palladium is a soft, silvery-white metal whose chemical and physical properties closely resemble platinum. It is mosdy found with deposits of other metals. It is malleable and ductile, which means it can be worked into thin sheets and drawn through a die to form very thin wires. It does not corrode. Its melting point is 1,554°C, its boiling point is 3,140°C, and its density is 12.02 g/cm. ... 

Iridium is a hard, brittle, white, metallic substance that is almost impossible to machine. It is neither ductile nor malleable. Iridium will only oxidi2e at high temperatures and is the most corrosive-resistant metal known. This is why it was used to make the standard meter bar that is an alloy of 90% platinum and 10% iridium. 

Platinum is classed by tradition and commercial usefulness as a precious metal that is soft, dense, dull, and silvery-white in color, and it is both malleable and ductile and can be formed into many shapes. Platinum is considered part of the precious metals group that includes gold, silver, iridium, and palladium. It is noncorrosive at room temperature and is not soluble in any acid except aqua regia. It does not oxidize in air, which is the reason that it is found in its elemental metallic form in nature. Its melting point is 1,772°C, its boiling point is 3,827°C, and its density is 195.09g/cm. ... 

When you see Dr. Wollaston give him a thousand compliments from me and then ask him if it would be possible to have a little malleable platinum, not separated from its natural alloy with palladium, rhodium, etc, to make a crucible. The crucibles I have bought recently from Cary are of a metal noticeably purer than those which I formerly had, and for that very reason infinitely more susceptible to attack by other substances (5). 

According to W. T. Brande, Wollaston also discovered a separate ore, consisting of iridium and osmium, among the grains of crude platinum. Its specific gravity is 19.5 it is hard, not malleable, and very brilliant (120, 124). Osmium occurs in laurite and in osmiridium. A kind of iridosmium (osmiridium high in iridium) called irite was discovered... 

It did truly look like silver. Furthermore, it was malleable enough to be made into jewellery, and resisted the corrosion that gradually turned real silver black. In this respect palladium closely resembles platinum, which sits below it in the Periodic Table. It is in fact one of the so-called platinum-group metals, all of which were found lurking in natural platinum around the turn of the nineteenth century by Wollaston and his colleague Smithson Tennant. ... 

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