Antimony occurrence

Tartaric acid is noteworthy for a) the excellent way in which the majority of its salts Crystallise, and h) the frequent occurrence of salts having mixed cations. Examples of the latter are sodium potassium tartrate (or Rochelle salt), C4H40 NaK, used for the preparation of Fehling s solution (p. 525), sodium ammonium tartrate, C4H OaNaNH4, used by Pasteur for his early optical resolution experiments, and potassium antimonyl tartrate (or Tartar Emetic), C4H404K(Sb0). The latter is prepared by boiling a solution of potassium hydrogen tartrate (or cream of tartar ) with antimony trioxide,... 

Tin exists in two ahotropic forms white tin (P) and gray tin (a). White tin, the form which is most familiar, crystallizes in the body-centered tetragonal system. Gray tin has a diamond cubic stmcture and may be formed when very high purity tin is exposed to temperatures well below zero. The ahotropic transformation is retarded if the tin contains smah amounts of bismuth, antimony, or lead. The spontaneous appearance of gray tin is a rare occurrence because the initiation of transformation requires, in some cases, years of exposure at —40° C. Inoculation with a-tin particles accelerates the transformation. 

An isotope effect seen in Sb03 by Maddock and Sutin was studied by Hall and Sutin , whose results are shown in Table 3. Again, phenyl radicals were cited as the likely means of reforming the bonds. It was pointed out that owing to the occurrence of isomeric transitions in both of these antimony isotopes, differences in the conversion coefficients could lead to the isotopic differences. 

As might now be expected, certain similar occurrences are present in copper electrolysis. Table IV lists the concentration of antimony analyzed in the copper cathode when various levels of the additives were in the electrolyte. The data indicate a critical concentration of antimony in solution is necessary (approximately 300 ppm) before appreciable amounts are taken into the cathode. Glue does not alter the results for 600 ppm antimony but chloride ion reduces the effective antimony to 200 ppm or less. 

Occurrence. Nearly all the silver ores are compounds of silver with sulphur and the neighbours in the Periodic Table arsenic, antimony and bismuth (argentite Ag2S, the most common silver compound, pyrargyrite Ag3SbS3, proustite Ag3AsS3). Other silver minerals include the halides. Silver is found sometimes as the free metal. Secondary silver (from catalysts, scraps, photographic films, etc.) is an important source. 

Occurrence. Arsenic is associated with sulphide minerals (As4S4 realgar, As2S3 orpiment, FeAsS arsenopyrite, Cu3AsS4, enargite, etc.). Occasionally arsenic is found as free element, usually in ore containing cobalt, antimony, nickel. 

Occurrence. Antimony occurs chiefly as the sulphide, stibnite (Sb2S3). 

Synonym antimony sesquisulfide antimony sulfide Occurrence and Uses... 

The general character of Neumann s chemistry is practical rather than theoretical. It describes plainly and in considerable detail the occurrences, properties and preparations of a large number of mineral, animal, and vegetable products, and the value which it must have possessed at that time as a condensed encyclopedia of chemical facts is manifest. Neumann apparently accepts the phlogiston hypothesis without reservation. In the discussion of metals, which he divides into perfect metals—gold and silver imperfect metals—lead, copper, iron and tin and semimetals (not malleable)—mercury, bismuth, zinc, antimony, arsenic, he has this to say under the head of imperfect metals 7... 

Figure 4.2 shows the SIMS spectrum of a promoted iron-antimony oxide catalyst used in selective oxidation reactions. Note the simultaneous occurrence of single ions (Si+, Fe+, Cu+, etc.) and molecular ions (SiO+, SiOH+, FeO+, SbO+, SbOSi+). Also clearly visible are the isotope patterns of copper (two isotopes at 63 and 65 amu), molybdenum (seven isotopes between 92 and 100 amu), and antimony (121 and 123 amu). Isotopic ratios play an important role in the identification of peaks, because all peak intensities must agree with natural abundances. Figure 4.2 also illustrates the differences in SIMS yields of the different elements although iron and antimony are present in comparable quantities in the catalyst, the iron intensity in the spectrum is about 25 times as high as that of antimony ... 

Solid-state growth of the AlSb layer between aluminium and antimony is due to the occurrence of the following partial chemical reactions ( see Fig. 1.13) ... 

When without the plots of Fig. 3.9b, the microstructure of Fig. 3.9a might provide undisputable evidence for the simultaneous occurrence of all the platinum antimonides between platinum and antimony in the course of isothermal annealing a Pt-Sb reaction couple. Layer thickness-time plots clearly show, however, that this is far from being the case. The PtSi layer is seen to shrink. Therefore, though no crack is visible due to application of pressure, the Pt-Sb couple was evidently split at some (uncertain) moment of time into at least two independent couples in which the other platinum antimonide layers could readily occur. Generally, in perfect reaction couples any compound layer survived in the initial linear stage of interaction can hardly be expected to shrink on its own during the further course of the reaction. 

As antimony sulfide is widely used in primer compositions, sulfur is frequently present in discharge residue particles and can occur at major, minor, or trace level (see Table 19.5). Consequently the occurrence of sulfur at major level is not an accurate indicator of the use of black powder. The particles should be considered as a group and it is clear that the frequent occurrence of both potassium and sulfur at high level is strongly indicative of black powder. However, as can be seen from Table 20.9 the use of black powder does not necessarily yield overall high levels of potassium. Potassium does not normally occur at major level in FDR particles (see Table 19.5) and its presence at major level in any of the particles suggests the use of black powder. 

As we have already mentioned, it was Kennedy who proposed that monomers possessing an allylic hydrogen can be converted into the corresponding allylic cart nium ions through a hydride-ion abstraction promoted by Levns acids. This reaction would not require a cocatalyst and could therefore explain in principle the occurrence of direct initiation. A similar mechanism had previously been claimed by Holmes and Pettit to rationalise the formation of carbenium ions from certain hydrocarbons and antimony pentachloride, e.g. ... 

Information is provided on the occurrence, environmental fate, available analytical methods, and treatment techniques foraldrin, ammonia, antimony, beryllium, boron, chlorpyrifos, isophorone, malathion, p-nitrophenol, phenol, silver, and thallium. 

The problem facing all smelters is that there is a continuous occurrence of antimony in their lead streams, at a time when there is a rapidly declining demand for the element. Declining sales of the alloy, which coincide with increasing use of soft-lead-based alloys, will result in antimony effectively becoming a major contaminant that requires removal. Whilst it is relatively easy for secondary reflners to remove antimony from the bullion, the antimony-rich residue from the process may have to be stockpiled. The residue, which contains around 80 to 90wt.% lead, effectively ties up lead units and can have a major cost impact on the reflnery. 

Occurrence.—To a small extant in the native state. Alloyed with metals in a few minerals. Sometimes in the farm of oxide, but principally in the form of grey antimony ore or ttibnite, which consists of antimonious sulphide. 

Occurrence.—Tn nature u eUbnite or guy antimony ore. Preparation.—1. By beating together antimony and sulphur, or antimonious oxide and sulphur in the proper proportions — 28b, + 88, 2Sb S,. 

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