Antimony , aqueous solution

Alaska, Washington, and Nevada. Ores of the Southeast Missouri lead belt and extensive deposits such as in Silesia and Morocco are of the replacement type. These deposits formed when an aqueous solution of the minerals, under the influence of changing temperature and pressure, deposited the sulfides in susceptible sedimentary rock, usually limestone and dolomites. These ore bodies usually contain galena, sphalerite, and pyrite minerals, but seldom contain gold, silver, copper, antimony, or bismuth. 

Stibine Oxides and Related Compounds. Both aUphatic and aromatic stibine oxides, R SbO, or their hydrates, R3Sb(OH)2, are known. Thus both dihydroxotrimethylantimony [19727-41-4], C3H2202Sb, and trimethyl stibine oxide [19727-40-3], C H OSb, have been prepared. The former maybe readily obtained by passing an aqueous solution of dichi orotrimethyl antimony [13059-67-1], C3H2Cl2 > through an anionic-exchange resin (151). 

A.sahi Chemical EHD Processes. In the late 1960s, Asahi Chemical Industries in Japan developed an alternative electrolyte system for the electroreductive coupling of acrylonitrile. The catholyte in the Asahi divided cell process consisted of an emulsion of acrylonitrile and electrolysis products in a 10% aqueous solution of tetraethyl ammonium sulfate. The concentration of acrylonitrile in the aqueous phase for the original Monsanto process was 15—20 wt %, but the Asahi process uses only about 2 wt %. Asahi claims simpler separation and purification of the adiponitrile from the catholyte. A cation-exchange membrane is employed with dilute sulfuric acid in the anode compartment. The cathode is lead containing 6% antimony, and the anode is the same alloy but also contains 0.7% silver (45). The current efficiency is of 88—89%, with an adiponitrile selectivity of 91%. This process, started by Asahi in 1971, at Nobeoka City, Japan, is also operated by the RhcJ)ne Poulenc subsidiary, Rhodia, in Bra2il under Hcense from Asahi. 

Antimony is a metal, in either hydrocarbon or aqueous solution, commonly injected into the fresh feed to passivate nickel. 

Some solids are either too soluble, or the solubility does not vary sufficiently with temperature, in a given solvent for direct crystallisation to be practicable. In many cases, the solid can be precipitated from, say, a concentrated aqueous solution by the addition of a liquid, miscible with water, in which it is less soluble. Ethanol, in which many inorganic compounds are almost insoluble, is generally used. Care must be taken that the amount of ethanol or other solvent added is not so large that the impurities are also precipitated. Potassium hydrogencarbonate and antimony potassium tartrate may be purified by this method. 

For some industrial operations an antimony electrode is used to measure hydrogen-ion concentrations. The electrode consists of a rod of antimony which invariably has a coating of oxide, and placed in an aqueous solution the equilibrium... 

W-Sb oxides were prepared by mixing aqueous solutions of ammonium tungstate and antimony tartarate, followed by drying in an air-circulated oven at 120 C and then calcination at 650 C. 

Electrodeposition of antimony sesquitelluride, Sb2Tc3, or of (Bii xSbx)2Te3 alloys from aqueous solutions is challenging because it is difficult to achieve a sufficiently high concentration of antimony. Complexing agents such as tartaric acid, citric acid, or FUTA have been used to solubilize Sb in water. 

Antimonyl chloride (sometimes called antimony oxychloride) is known as a "basic chloride." It is insoluble in water, but aqueous solutions of the trihalides can be made if enough HX is present to prevent hydrolysis. Adding water to reduce the concentration of acid causes the oxychloride to precipitate. 

In Situ Mdssbauer Studies of Metal Oxide-Aqueous Solution Interfaces with Adsorbed Cobalt-57 and Antimony-119 Ions... 

The procedure for separating Sb-119 from an alpha-irradiated tin target has been described elsewhere (10,11). The amounts of cobalt and antimony coexisting with the nuclides are estimated to have been about 400 ng/mCi and 300 ng/mCi, respectively, i.e., to have been much smaller than that required for monolayer coverage of 30 mg of the hematite sample. About 10 cm3 of an aqueous solution containing 1 - 2 mCi of divalent Co-57 or 0.1 - 1 mCi of pentavalent Sb-119 was adjusted to an appropriate pH value in a Teflon vessel with a 0.5 mm-thick Teflon window at the bottom, and about 30 mg of hematite powder was added to the solution. The suspension was shaken for 30 min at room temperature. After settling of the powder at the bottom of the vessel, the pH was remeasured. 

The word bismuth is derived from the German word Weissmuth, or white substance. It is the heaviest stable element of the periodic table. Even though it carries the status of heavy metal, this metal is rated as relatively nontoxic and noncarcinogenic, unlike its neighboring elements (in the periodic table) like arsenic, antimony, lead, and tin, which are highly toxic. This nontoxicity arises from the insolubility of its salts in neutral aqueous solutions such as biological fluids, which... 

Hydrogen sulfide forms precipitates of several metal sulfides when passed through an aqueous solution of metal salts. Under acid conditions, several metals including arsenic, antimony, bismuth, cadmium, copper, lead, mercury, and tin are precipitated as their sulfide e.g. ... 

Potassium chlorate is an oxidizing agent in matches, fireworks and explosives. The head of safety matches is coated with potassium chlorate which is struck on a surface consisting of red phosphorus, antimony(lII) sulfide and an adhesive to light the fire. It also is used in laboratory preparation of oxygen. Its dilute aqueous solution is an antiseptic. 

Of the various synthetic processes that are available, two are of most relevance in the present context - precipitation from aqueous solution and melt forming. These methods are used where it is not possible to produce adequate products directly from natural sources. This will be because there is no suitable mineral, due to the chemical nature of the product, of particle size and shape requirements, or to purity considerations. The other principal synthetic method in use for filler production is pyrolysis/combustion. This type of process in which the particles are formed in the gas phase is used where very small particles are required, such as with carbon blacks and some silicas. This type of filler is not widely used in thermoplastics and so these processes are not discussed in any detail here, although some information specific to the production of antimony oxide will be found later. 

Zinc chloride is much less reactive than aluminum chloride and usually requires higher reaction temperatures. However, it has the advantage that, unlike aluminum chloride, it is less sensitive to moisture and can sometimes even be used in aqueous media.88 Concentrated aqueous solutions of ferric chloride, bismuth chloride, zinc bromide, stannous chloride, stannic chloride, and antimony chloride are also alkylation catalysts, particularly in the presence of hydrochloric acid.89... 

Of the heavy metals, iron is the only one which pre- cip States antimony completely from the aqueous solution of tartar emetics. - Hydrochloric, nitric, and sulphuric acids precipitate a basic hydrochloyata, nitrate, and sulphate of the oxide of antimony, - ... 

Basic sulphates are obtained when the normal sulphates of antimony, bismuth and mercury are treated with water, sulphuric acid being produced simultaneously. These salts are insoluble in water. Many other metals, for example copper,6 aluminium 8 and tin,7 yield precipitates of basic sulphates on the addition of alkali to aqueous solutions of their normal sulphates. 

Aqueous solutions of the salts, or of tellurium dioxide in acids, easily undergo reduction.to elementary tellurium. Phosphorus, phosphorous acid,-7 hypophosphorous acid,8 sulphurous acid,9 thiosulphuric acid,10 hyposulphurous acid,11 hydriodic acid,12 hydrogen sulphide,13 ferrous salts, stannous salts,14 hydrazine 15 and phenylhydrazine, as well as various metals,18 e.g. zinc, iron, tin, cadmium, antimony and copper, are able to effect this reduction. 

Precipitation of the coating from aqueous solutions onto the suspended Ti02 particles. Batch processes in stirred tanks are preferred various compounds are deposited one after the other under optimum conditions. There is a very extensive patent literature on this subject. Continuous precipitation is sometimes used in mixing lines or cascades of stirred tanks. Coatings of widely differing compounds are produced in a variety of sequences. The most common are oxides, oxide hydrates, silicates, and/or phosphates of titanium, zirconium, silicon, and aluminum. For special applications, boron, tin, zinc, cerium, manganese, antimony, or vanadium compounds can be used [2.40], [2.41],... 

Antimony Arsenite.—When powdered antimony is digested with a concentrated aqueous solution of arsenic acid, and the solution then diluted with water, a precipitate forms, which was described by Berzelius 6 as antimony arsenite. He obtained a similar product by heating a mixture of arsenic and antimony pentoxide it remained as a transparent vitreous mass. The exact composition of these products does not appear to have been investigated. 

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