Lead tungstate

Stannic and stannous, see under Tin Stibine, see Antimony hydride Stibnite, see Antimony(III) sulflde Stolzite, see Lead tungstate(VI)(2—)... 

Although molybdenite was for several years the only known source of molybdenum, the Abbe F. X. Wulfen in 1785 described a lead mineral from Carinthia which had previously been regarded as lead tungstate, and when M. H. Klaproth analyzed a specimen of it from Bleyberg in 1792-94, he found it to be lead molybdate (76). Two years later, Charles Hatchett examined a larger specimen of it and confirmed Klaproth s conclusion. This mineral is now known as wulfenite. 

Most of his scientific research was done during the decade 1796 to 1806. His first paper in the Philosophical Transactions described his analysis of the Carinthian lead molybdate (4). The celebrated Scheele, said he, in 1778 read before the Academy of Sciences at Stockholm an essay in which he proved. . . that the mineral called Molybdaena was composed of sulfur and a peculiar metallic substance, which, like arsenic and tungsten, was liable by super-oxygenation to be converted into a metallic acid which in its properties differed from any other that had been previously discovered. Hatchett mentioned the confirmatory researches of B. Pelletier, P. J. Hjelm, and Mr. Islmann [J. C. Ilsemann], and added But the existence of this substance was known to be only in that mineral which Scheele had examined. This lead mineral from Carinthia had been described by the Abbe F. X. Wulfen and by N. J. Jacquin. For several years it was believed to be lead tungstate, but Klaproth proved it to be lead molybdate. Since Klaproth had had an insufficient amount of the mineral, Hatchett made a complete analysis of it and investigated the properties of molybdic add. 

Tkachenko et al reported that compacts in iron, copper, nickel or cobalt matrices had operating temperature limits between 200 and 600 C, but compacts in molybdenum gave satisfactory friction and wear to 900 C in vacuum. A satisfactory composite for high-temperature aircraft brakes was described as containing 25% molybdenum disulphide, alumina and lead tungstate in a nickel matrix . The composites were pressed at 880 to 1080 MPa and sintered at 1010 C for two hours in vacuum. 

In different hydrothermal conditions, Ti02 nanocrystallites (anatase and rutile) with nine kinds of morphologies have been prepared [1, 2]. CdW04 nanorods [3], which showed very strong photoluminescence at 486 nm (Aex = 253 nm) at room temperature, were prepared by a hydrothermal method at 130 °C. Lead tungstate... 

PbW04 LEAD TUNGSTATE 1310 Pu203 DIPLUTONIUM TRIOXIDE (ALPHA) 1353... 

Barium group Tungsten group Lead tungstate Tungsten white Colour Index (1971) 77128 Salter (1869) 414-415... 

Lead tunstate, PbW04, appears to have had limited use in its synthetic form as a pigment. There are also two lead tungstate minerals, the tetragonal stolzite and monoclinic raspite qq.v. both PbW04) however it is not known what crystal system the synthetic pigment takes. 

Lead tungstate (. v.) has been synthesised as a white pigment, as described by Riffault et al. (1874), although it is unknown what crystal system the synthetic form takes. It is sometimes referred to as tungsten white, although this is also apphed to barium tungstate (qq.v.). 

Lead group Tungsten group Barium tungstate Lead tungstate Stolzite Tungsten white... 

Lead group Tungsten group Albite Barium tungstate Lead tungstate Muscovite Quartz Raspite Scheelite Tungsten white Bersch (1901) 128 Bywater(1983) Kilias Konnerup-Madsen (1997) Plakhov et al. (1971) Riffault et al (1874) 159-160 Salter (1869) 414 15... 

Tungsten gronp Tungsten oxides and hydroxides group Barium tungstate Lead tungstate... 

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