Bismuth arsenates

Antimony, bismuth, arsenic, boron, red phosphorus, silicon [1] and tin [2] all react with incandescence. 

Selenium is extracted as diethyldithiocarbamate complex from the solution containing citrate and EDTA [5]. Ohta and Suzuki [6] found that only a few elements, such as copper, bismuth, arsenic, antimony, and tellurium, are also extracted together with selenium. They examined this for effects of hundredfold amounts of elements co-extracted with the selenium diethyldithiocarbamate complex. An appreciable improvement of interferences from diverse elements was observed in the presence of copper. Silver depressed the selenium absorption in the case of atomisation of diethyldithiocarbamate complex, but the interference of silver was suppressed in the presence of copper. The atomisation profile from diethyldithiocarbamate complex was identical with that from selenide. 

Lead is produced commercially from its principal ore, galena (PbS). The ore is associated with sulfides of several metals including iron, copper, zinc, silver, bismuth, arsenic, antimony and tin. The ore is crushed and ground. It then is selectively separated from gangue and other valuable minerals by one or more processes that include gravity separation and flotation. Selective... 

Selenium and tellurium are converted into their respective tetrachlorides by thionyl chloride, whilst gold, mercury, bismuth, arsenic, antimony, tin and iron give a mixture of the metallic chloride with sulphur dioxide and sulphur monochloride,2 for example ... 

Bismuth Arsenates.—Bismuth Orthoarsenate is obtained as a white crystalline precipitate by the action of arsenic add or an alkali arsenate on a nitric add solution of bismuth nitrate.9 When dried at 100° to 120° C. the product is the hemihydrate, BiAs04. H20, which loses water only at red heat. By evaporating the mixture on a water-bath, de Sehulten10 obtained a product which he described as the anhydrous... 

Disodium hydrogen arsentate reacts in an analogous way the product is the white bismuth arsenate precipitate ... 

A final possibility is that of a semimetal. In this case, there is a zero density of states at the Fermi level, but no band gap. Semimetals differ from semiconductors in that their resistivities have a metallic-like temperamre dependency. Semimetals include selenium, bismuth, arsenic, graphite, and antimony. All of these types of behaviors are illustrated schematically in Figure 6.2, which shows the simplified band picmre and the corresponding DOS for each case. 

AsBi04 (s) BiAs04 (s) Bismuth Arsenate AsBi04 (s) BiAs04 (s)... 

Uranium minerals may be obtained in solution, in a suitable condition for estimation, by the following process. The ore is dissolved in aqua regia, or, if necessary, fused with alkali bisulphate and extracted mth hot hydrochloric acid. After evaporation to drjmess, the residue is taken up with dilute hydrochloric acid, and the solution saturated with hydrogeir sulphide in order to remove any copper, lead, bismuth, arsenic, antimony, or any other metal yielding an insoluble sulphide. The filtrate is concentrated and treated with ammonium carbonate, which precipitates the carbonates of the alkaline earths, iron, and most of the rare earths. The filtrate is neutralised by hydrochloric acid, evaporated to dryness, and the residue ignited to drive off ammonium salts, and then redissolved in dilute acid. The remaining rare earths, and particularly thorium, are next precipitated by the addition of oxalic acid. The filtrate, which contains the uranium in the uranyl condition, may now be precipitated by any of the methods described above. 

Pharmacology and toxicology of organic bismuth, arsenic and antimony... 

Wormser, U. Nir, I. In Chemistry of Organic Arsenic, Antimony and Bismuth Compounds, Patai, S. Ed. Wiley New York, 1994 Chapter 18, Pharmacology and toxicology of organic bismuth, arsenic and antimony compounds, pp 715-723. 

During operation, the electrolyte becomes more concentrated with copper, nickel, and arsenic and depleted with sulfuric acid. Floating slimes are composed of antimony arsenate, SbAsC>4, and bismuth arsenate, BiAsC>4. These can float to the cathode, causing contamination. Soluble impurities are removed from the electrolyte by continuously bleeding a portion of the electrolyte through a purification circuit. The impurity level in the anode determines the volume of electrolyte that must be removed for impurity control. Usually, the elements that control this bleed volume are either arsenic or nickel. The bleed volume is based on the quantity... 

Particulate matter in the waste gas stream will coat the surface of the catalyst, reducing its effectiveness. Certain metals (such as phosphorous, bismuth, arsenic, antimony, mercury, zinc, lead, and tin) can chemically combine with the catalyst. 

Bismuth arsenate BiAsO 4 4,43 10- " Copper(l) chloride CuCl 1.72 10 ... 

Inorganic cathodic Cl are able to restrict corrosion rate of metals via diminishing oxygen concentration in the corrosive medium (sodium sulfite, hydrazine), formation of screening insoluble residues (calcium bicarbonate, zinc sulfate and chloride for steel) on cathodic sites of the metal or by raising overstrain of the cathodic process as a result of reduction of metal cations and their deposition on the metal surface that is being protected (salts of heavy metals, such as antimony, bismuth, arsenic). 

Lead Operations treats zinc plant residues, lead concentrates, recycled batteries, and lead bullion to produce silver, gold, bismuth, arsenic metal, copper sulphate, copper arsenate, sodium antimonate and about 100,000 t/a of refined lead. The lead smelter has been well described previously (2). Key aspects of the lead process flowsheet, as shown in Figure 3, are described herein. 

Any iron present in the leach solution is removed by precipitation as goethite (FeOOH). The solution is then purified by cementation with lead powder to remove copper, silver, bismuth, arsenic and antimony, leaving impurities such as zinc, which do not co-deposit with lead. The purified solution is electrolysed in a diaphragm cell, which uses a coated copper cathode and a titanium mesh anode coated with ruthenium and iridium oxides. An ion permeable membrane separates the cathode and anode compartments. The cathode is fabricated from a dimpled copper sheet coated with an inert adhesive sheet between the dimples, leaving numerous sites of high current density to promote dendritic growth of the lead deposit. The crystalline lead falls from the cathode and is collected in the base of the cell. 

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