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Thallium production

Figure 3 - Refined Cadmium Production Figure 4 - Refined Thallium Production... Figure 3 - Refined Cadmium Production Figure 4 - Refined Thallium Production...
Thallium occurs in crooksite, lorandite, and hutchinsonite. It is also present in pyrites and is recovered from the roasting of this ore in connection with the production of sulfuric acid. It is also obtained from the smelting of lead and zinc ores. Extraction is somewhat complex and depends on the source of the thallium. Manganese nodules, found on the ocean floor, contain thallium. [Pg.144]

Selectivity of propylene oxide from propylene has been reported as high as 97% (222). Use of a gas cathode where oxygen is the gas, reduces required voltage and eliminates the formation of hydrogen (223). Addition of carbonate and bicarbonate salts to the electrolyte enhances ceU performance and product selectivity (224). Reference 225 shows that use of alternating current results in reduced current efficiencies, especiaHy as the frequency is increased. Electrochemical epoxidation of propylene is also accompHshed by using anolyte-containing silver—pyridine complexes (226) or thallium acetate complexes (227,228). [Pg.141]

Production and Economic Aspects. Thallium is obtained commercially as a by-product in the roasting of zinc, copper, and lead ores. The thallium is collected in the flue dust in the form of oxide or sulfate with other by-product metals, eg, cadmium, indium, germanium, selenium, and tellurium. The thallium content of the flue dust is low and further enrichment steps are required. If the thallium compounds present are soluble, ie, as oxides or sulfates, direct leaching with water or dilute acid separates them from the other insoluble metals. Otherwise, the thallium compound is solubilized with oxidizing roasts, by sulfatization, or by treatment with alkaU. The thallium precipitates from these solutions as thaUium(I) chloride [7791 -12-0]. Electrolysis of the thaUium(I) sulfate [7446-18-6] solution affords thallium metal in high purity (5,6). The sulfate solution must be acidified with sulfuric acid to avoid cathodic separation of zinc and anodic deposition of thaUium(III) oxide [1314-32-5]. The metal deposited on the cathode is removed, kneaded into lumps, and dried. It is then compressed into blocks, melted under hydrogen, and cast into sticks. [Pg.467]

Demand for thallium has decreased since the early 1980s because, wherever possible, substitute materials are used due to its hazardous nature. Annual production is very small, estimated to be 10,000 kg/yr. The principal domestic producer is Noah Chemical Division, Noah Industrial Corporation. Thallium is available in three grades 99.9%, 99.99%, and 99.999% pure. The 99.9% material is priced at 360/kg ( 17/kg 1969). [Pg.467]

ThaUous sulfate, thaUous nitrate, and thaUous and thaUic oxide are the main compounds produced in bulk quantities by Noah Chemical. Approximately 20 other thallium compounds are also available commercially from Noah Chemical, Cooper Chemical, and Alfa Products, Ventron Division, Thiokol Corporation, in research and production quantities. However, demand for thallium compounds is small and limited to such appHcations as synthetic or analytical reagents. [Pg.468]

Thallium is likewise recovered from flue dusts emitted during sulfide roasting for H2SO4 manufacture, and from the smelting of Zn/Pb ores. Extraction procedures are complicated because of the need to recover Cd at the same time. There are no major commercial uses for T1 metal world production in 1983 was estimated to be 5-15 tonnes p.a. and the price ranged from 60 to 80 per kg depending on purity and amount purchased. [Pg.219]

Lead (13 ppm) is by far the most abundant of the heavy elements, being approached amongst these only by thallium (8.1 ppm) and uranium (2.3 ppm). This abundance is related to the fact that 3 of the 4 naturally occurring isotopes of lead (206, 207 and 208) arise primarily as the stable end products of the natural radioactive series. Only (1.4%)... [Pg.368]

Several derivatives of indolo[3,2-fi]carbazole, such as the system 185, have been claimed to arise from the reaction of suitably substituted simple indoles on treatment with thallium triacetate in acetic acid. A compound having the purported structure of 185 was thus isolated when 2,3-dimethylindole was used as the substrate [78UC(B)422]. Many years later, it was demonstrated that this product is in fact a derivative of indolo[2,3-c]carbazole (cf. Section VI) (99T12595). [Pg.37]

The Teijin oxychlorination, on the other hand, is considered a modern version of the obsolete chlorohydrin process for the production of ethylene oxide. In this process, ethylene chlorohydrin is obtained by the catalytic reaction of ethylene with hydrochloric acid in presence of thallium(III) chloride catalyst ... [Pg.195]

Trithiadiazepine 4 is readily thalliated by thallium(III) trifluoroacetate the product 19 reacts in situ with potassium iodide, copper(I) cyanide, and methanol/carbon monoxide300 to give 20a-c, respectively.33 ... [Pg.483]

The solution of the thallium derivative 19 in MeCN was treated with KI (0.246 g, 1.5 mmol) in H,0 (1 mL) and the product was extracted into tt20. The extract was washed with H20, dried (MgS04) and chromatographed (silica gel, petroleum ether) to give 20c as pale-yellow plates [yield 0.037 g (80% based on unrecovered 4) mp 92-94 C (petroleum ether)], followed by starting material 4 (0.005 g, 17%). [Pg.483]

Selectivity to primary metathesis products is usually less than 100%, as a consequence of side reactions, such as double-bond migration, dimerization, oligomerization, and polymerization. The selectivity can be improved by adding small amounts of alkali or alkaline earth metal ions, or, as has recently been shown, thallium 40), copper, or silver ions (41)-... [Pg.138]

The equation for a net chemical reaction represents the overall transformation of reactants into products. Thus, thallium Ill) ions oxidize iron(II) ions according to Eq. (1-1), and a secondary amine reacts with an aryl chloride as in Eq. (1-2). [Pg.2]

Indeed, the rate of reaction between iron(II) and thallium Ill) in Eq. (1-1) is not proportional to the product [Fe2+]2[T13+], The experimental data, taken over a range of concentrations so as to reveal the dependences, show that the rate is given by... [Pg.3]

The organic solvent is removed by distillation under reduced pressure to give 4,4 -dimethyl-l,T-biplienyl contaminated with a small amount of bis(4-methylphenyl)thallium bromide. The crude product is dissolved in 30 ml. of benzene, and the solution is filtered through a short column of alumina (Note 7) using a total of 250 ml. of benzene as eluent. Distillation of the benzene under reduced pressure leaves 19-21 g. (80-83%) of 4,4 -dimethyl 1,1 -biphenyl as a colorless solid, m.p. 118-120° (Note 8). [Pg.49]

Let us consider first the low-energy fission of the lighter fissionable elements, in the neighborhood of Pb208. These elements (gold, thallium, lead, bismuth), when bombarded with particles such as 20-Mev deuterons, undergo symmetric fission, the distribution function of the products having a half width at half maximum of 8 to 15 mass-number units (20). [Pg.822]

When the reaction is run with potassium fert-butoxide in THF at -5°C, one obtains (after hydrolysis) the normal Knoevenagel product (32), except that the isocyano group has been hydrated (16-65). With the same base but with DME as solvent the product is the nitrile (33). When the ketone is treated with 31 and thallium(I) ethoxide in a 4 1 mixture of absolute ethanol and DME at room temperature, the product is a 4-ethoxy-2-oxazoline (34). Since 33 can be hydrolyzed to a carboxylic acid and 34 to an a-hydroxy aldehyde, this versatile reaction provides a means for achieving the conversion of RCOR to RCHR COOH, RCHR CN, or RCR (OH)CHO. The conversions to RCHR COOH and to RCHR CN have also been carried out with certain aldehydes (R = H). [Pg.1227]

The reaction of 1,2-dithiolanes with 2- and 4-picolyllithium has been examined <96PS(112)101> and the reactions of thioanhydrides such as 94 with both thiols <95JOC3964> and amines <96TL5337> have been reported. Treatment of 1,2-dithiolium salts with lithium or thallium cyclopentadienide results in formation of a variety of bi-, tri- and tetracyclic products <96LA109>. Reaction of 95 with trimethyl phosphite gives some of the desired coupling product but also the phosphonates 96 <96PS(109)557>. [Pg.199]


See other pages where Thallium production is mentioned: [Pg.396]    [Pg.175]    [Pg.396]    [Pg.175]    [Pg.391]    [Pg.75]    [Pg.175]    [Pg.406]    [Pg.467]    [Pg.468]    [Pg.471]    [Pg.157]    [Pg.505]    [Pg.57]    [Pg.140]    [Pg.158]    [Pg.7]    [Pg.22]    [Pg.31]    [Pg.168]    [Pg.181]    [Pg.218]    [Pg.223]    [Pg.207]    [Pg.633]    [Pg.291]    [Pg.189]    [Pg.300]    [Pg.719]    [Pg.569]    [Pg.998]    [Pg.1050]    [Pg.148]   
See also in sourсe #XX -- [ Pg.221 ]

See also in sourсe #XX -- [ Pg.221 ]

See also in sourсe #XX -- [ Pg.467 ]




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