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Graphite retort

In order to obtain metallic lithium, A. Guntz electrolyzed a mixture of equal arts of lithium and potassium chlorides and 0. Ruff and 0. Johannsen obtained etter results with a mixture of lithium bromide with 10 to 15 per cent, of the chloride. The electrolysis is conducted in a graphite retort with a thick iron wire as cathode, and a current of 100 amps, at 10 volts gave an 80 per cent, yield. [Pg.449]

The USA used 37 ktonnes of natural graphite in 1989, nearly all imported in addition, over 300 ktonnes of graphite was manufactured. Natural graphite is used in refractories (27%), lubricants (17%), foundries (14%), brake linings (12%), pencils (5.3%), crucibles, retorts, stoppers, sleeves and nozzles (4.0%) etc. [Pg.271]

Perhaps the first practical application of carbonaceous materials in batteries was demonstrated in 1868 by Georges Le-clanche in cells that bear his name [20]. Coarsely ground MnO, was mixed with an equal volume of retort carbon to form the positive electrode. Carbonaceous powdered materials such as acetylene black and graphite are commonly used to enhance the conductivity of electrodes in alkaline batteries. The particle morphology plays a significant role, particularly when carbon blacks are used in batteries as an electrode additive to enhance the electronic conductivity. One of the most common carbon blacks which is used as an additive to enhance the electronic conductivity of electrodes that contain metal oxides is acetylene black. A detailed discussion on the desirable properties of acetylene black in Leclanche cells is provided by Bregazzi [21], A suitable carbon for this application should have characteristics that include (i) low resistivity in the presence of the electrolyte and active electrode material, (ii) absorption and retention of a significant... [Pg.236]

Muffle Furnaces or Retorts of Graphite or Silicon Carbide. The metal is fed into the furnace either batchwise as a solid or continuously as a liquid. The heat of vaporization is supplied by heating the outside of the retort with a burner. The nonvolatile residues (iron and lead in the case of dross from smelting) accumulate in the retort and must be removed at intervals. This is facilitated by tipping the retorts. [Pg.80]

Graphite is made electrically from retort or petroleum coke (Fig. 3). Temperatures on the order of 2700°C are necessary. [Pg.144]

The principal foreign sources, of graphite are Ceylon, Canada, Mexico and Madagascar. In the United States the chief sources of the mineral are to be found in Alabama, New York and Pennsylvania. Artificial graphite is produced in the electric furnace, and a soft variety known as kish is the product of the blast furnace. Possible sources of carbon which may be used in this connection are retort graphite formed in gas retorts and the carbon resulting from the decomposition of hydrocarbons. [Pg.512]

In European practice both coke and retort graphite have been admixed with the natural graphite for making crucibles. The practice is not desirable for steel melting,... [Pg.512]

After the reactor was cooled to room temperature, it was opened and the mass of metal was mechanically freed of frozen slag. Ninety percent of the zinc in the alloy was removed by distillation in a retort heated to 1150°C at a vacuum lower than 0.2 Torr. The retort was then filled with argon or helium to prevent oxidation of the spongy thorium and cooled to room temperature. The thorium was transferred to a beryllia crucible in an induction-heated vacuum furnace for melting, evaporation of the residual zinc, and casting into a graphite mold. Thorium metal yield was 94 to 96 percent. [Pg.313]

Carbon Electrode carbon, retort graphite, graphite (clay-bonded)... [Pg.13]

S. Tennant, like W. Wollaston, dissolved crude platinum in aqua regia. At the bottom of the retort he discovered a black precipitate with metallic lustre. This phenomenon had been observed previously in experiments with platinum, but the precipitate was believed to be graphite. In summer 1803 Tennant suggested that the precipitate most likely contained a new metal. In autumn of the same year the French chemist H. Collet-Descoties also concluded that the precipitate contained a metal that precipitated from ammonium platinum salts and yielded red colour. In his turn, L. Vauquelin heated the black powder with alkali and obtained a volatile oxide. Vauquelin believed that it was an oxide of the metal mentioned by H. Descoties. Tennant s experiment set off a series of investigations. Tennant himself continued his research and in spring 1804 he reported to the British Royal Society that the powder contained two new metals which could be separated fairly easily. In 1805 he published the article On Two Metals Found in the Black Powder Formed after Dissolution of Platinum . The names osmium and iridium were mentioned in the article for the first time. [Pg.86]

Furnaces are constructed using an induction heated crucible of graphite or silicon carbide, contained within a refractory lined vacuum vessel. The zinc condenser may be external, in the vacuum train, or may be contained within the lid of the containment vessel. Seals are by rubber O rings in water-cooled flanges and the ability to maintain vacuum is a critical aspect of efficient operation. Target operating pressure is around 80 mbar absolute. The final temperature of the retort bullion (impure silver) formed within the retort at the end of a batch is in the range of 1100 to 1200°C. The detection of the end point of the batch distillation is also an important aspect of operation and usually is determined by the vacuum pressure and the temperature of the residual metal. Typical performance is shown in Table 12.2. [Pg.216]

The commercial manufacture of pyrolytic graphite products is a relatively new division of the graphite industry. Though this material has been known for some 50 years (glance coal, deposited carbon in gas retorts, etc.), it is only within the last 10-15 years that the necessary production techniques have been developed. [Pg.777]


See other pages where Graphite retort is mentioned: [Pg.29]    [Pg.122]    [Pg.13]    [Pg.20]    [Pg.29]    [Pg.122]    [Pg.13]    [Pg.20]    [Pg.46]    [Pg.562]    [Pg.480]    [Pg.380]    [Pg.381]    [Pg.449]    [Pg.801]    [Pg.27]    [Pg.386]    [Pg.289]    [Pg.199]    [Pg.227]    [Pg.449]    [Pg.801]    [Pg.231]    [Pg.242]    [Pg.504]    [Pg.513]    [Pg.620]    [Pg.426]    [Pg.352]    [Pg.761]    [Pg.275]   
See also in sourсe #XX -- [ Pg.13 ]




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