Potassium chloride electrolysis

In addition, relatively high concentrations of sodium in the amalgam (>0.5wt%) can cause increased hydrogen evolution in the cells. Potassium chloride electrolysis is considerably more sensitive to both catalysts and high concentration in the amalgam than the sodium chloride process. 

Production. Today, potassium hydroxide is manufactured almost exclusively by potassium chloride electrolysis. The diaphragm, mercury, and membrane processes are all suitable for the production of potassium hydroxide, but the mercury process is preferred because it yields a chemically pure 50 % potassium hydroxide solution. 

Various chemical processes do produce hydrogen as a by-product. Hydrogen is a by-product of sodium or potassium chloride electrolysis that produces chlorine and caustic soda or potash ... 

Strontium is found chiefly as celestite and strontianite. The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Three allotropic forms of the metal exist, with transition points at 235 and 540oC. 

Several methods are available for producing thorium metal it can be obtained by reducing thorium oxide with calcium, by electrolysis of anhydrous thorium chloride in a fused mixture of sodium and potassium chlorides, by calcium reduction of thorium tetrachloride mixed with... 

The electrolysis of potassium chloride [7447-40-7] KCl, to produce chlorine and potassium hydroxide in membrane cells requires similar but unique membranes. Commercial membranes currendy employed in high performance membrane electroly2ers include Du Pont s Nafion 900 series and Asahi Glass s Plemion 700 series. 

Manufacture. Most chlorate is manufactured by the electrolysis of sodium chloride solution in electrochemical cells without diaphragms. Potassium chloride can be electroly2ed for the direct production of potassium chlorate (35,36), but because sodium chlorate is so much more soluble (see Fig. 2), the production of the sodium salt is generally preferred. Potassium chlorate may be obtained from the sodium chlorate by a metathesis reaction with potassium chloride (37). 

The alkali metals are the most violently reactive of all the metals. They are too easily oxidized to be found in the free state in nature and cannot be extracted from their compounds by ordinary chemical reducing agents. The pure metals are obtained by electrolysis of their molten salts, as in the electrolytic Downs process (Section 12.13) or, in the case of potassium, by exposing molten potassium chloride to sodium vapor ... 

The electrolyte is made by in situ chlorination of vanadium to vanadium dichloride in a molten salt bath. Higher valent chlorides are difficult to retain in the bath and thus are not preferred. The molten bath, which is formed by sodium chloride or an equimolar mixture of potassium chloride-sodium chloride or of potassium chloride-lithium chloride or of sodium chloride-calcium chloride, is contained in a graphite crucible. The crucible also serves as an anode. Electrolysis is conducted at a temperature about 50 °C above the melting point of the salt bath, using an iron or a molybdenum cathode and a cathode current density of 25 to 75 A dnT2. The overall electrochemical deposition reaction involves the formation and the discharge of the divalent ionic species, V2+ ... 

The electroextraction process for molybdenum involves the use of its oxides, carbides or sulfides as soluble anodes in a potassium chloride-potassium hexachloromolybdate (K3MoCl6) molten electrolyte. An inert atmosphere electrolytic cell, with a provision for semicontinuous electrolysis, is used for this purpose. The process operation consists of the following steps. 

The only method that has been described for the assay of technical grades of parathion and its formulations is that of Bowen and Edwards (7). The method makes use of the polarograph. The electrolysis is carried out in an acetone-water solution with potassium chloride as the electrolyte and gelatin as the suppressor. An accuracy of 1% is obtained. 

Electrolysis cyclic voltammetry molten salts carbamide potassium chloride ammonium chloride compound adsorbtion. 

Griesheim (1) An early process for producing chlorine by electrolysis, developed by Chemische Fabrik Griesheim-Elektron, in Germany, and commercialized in 1890. The electrolyte was saturated potassium chloride solution, heated to 80 to 90°C. The byproduct potassium hydroxide was recovered. The process was superseded in the United States by several similar electrolytic processes before being ousted by the mercury cell, invented by H. Y. Castner and K. Kellner in 1892. See Castner-Kellner. 

Potassium chloride, 11 122 12 67 20 611-625. See also KCl-langbeinite ore chemical grades of, 20 62It compaction of, 20 621-625 corrosive effect on iron, 7 806 electrolysis of, 20 633 encapsulated, 16 453 froth flotation of, 20 615-616 mining, 20 613-615 refining, 20 615-621 as salt substitute, 22 819-820 separation from sodium chloride, 20 622 therapeutant for aquaculture in U.S.,... 

Strontium metal is not found in its elemental state in nature. Its salts and oxide compounds constitute only 0.025% of the Earths crust. Strontium is found in Mexico and Spain in the mineral ores of strontianite (SrCO ) and celestite (SrSO ). As these ores are treated with hydrochloric acid (HCl), they produce strontium chloride (SrCy that is then used, along with potassium chloride (KCl), to form a eutectic mixture to reduce the melting point of the SrCl, as a molten electrolyte in a graphite dish-shaped electrolysis apparatus. This process produces Sr cations collected at the cathode, where they acquire electrons to form strontium metal. At the same time, Cl anions give up electrons at the anode and are released as chlorine gas Cl T. 

Potassium hydroxide is made by electrolysis of potassium chloride solutions in cells that are exactly analogous to sodium hydroxide production. 

Potassium hydroxide is produced by the electrolysis of potassium chloride solutions. 

Electrolytic reduction and thermal decomposition have not yet been apphed in large scale commercial methods. Electrolysis of alkali or alkaline earth borates produces boron in low purity. Electrolytic reduction of fused melts of boron trioxide or potassium tetrafluroborate in potassium chloride yield boron in high purity. Also, boron tribromide or boron hydrides may be thermally dissociated hy heating at elevated temperatures. 

Also high purity lanthanum may be produced by electrolysis of a molten mixture of anhydrous lanthanum chloride and sodium chloride or potassium chloride at elevated temperatures. 

Lithium metal is produced commercially by electrolysis of a fused eutectic mixture of hthium chloride-potassium chloride (45% LiCl) at 400 to 450°C. The eutectic mixture melts at 352°C in comparison to the pure LiCl melting at 606°C. Also, the eutectic melt is a superior electrolyte to LiCl melt. (Landolt, P.E. and C. A. Hampel. 1968. Lithium. In Encyclopedia of Chemical Elements.C. A. Hampel, Ed. Reinhold Book Corp. New York.) Electrolysis is carried out using graphite anodes and steel cathodes. Any sodium impurity in hthium chloride may be removed by vaporizing sodium under vacuum at elevated temperatures. All commercial processes nowadays are based on electrolytic recovery of the metal. Chemical reduction processes do not yield high purity-grade metal. Lithium can be stored indefinitely under airtight conditions. It usually is stored under mineral oil in metal drums. 

Lithium chloride is used in the production of lithium metal by electrolysis. It also is used in metallurgy as a eutectic melting composition with potassium chloride (LiCl 41 mol% KCl 59 mol%). Other applications are in low temperature dry-cell batteries as a dehumidifier in air conditioning in welding and soldering flux as a desiccant in fireworks and in mineral waters and soft drinks. 

Electrolysis processes have been known since Davy first isolated the metal in 1807. Electrolysis, however, suffers from certain disadvantages. A major problem involves miscibility of the metal with its fused salts. Because of this molten potassium chloride, unlike sodium chloride, cannot be used to produce the metal. Fused mixtures of potassium hydroxide and potassium carbonate... 

Potassium hydroxide is produced commerically by electrolysis of a saturated solution of potassium chloride in brine using mercury cells consisting of a titanium anode and mercury cathode. Potassium reacts with mercury forming the amalgam which, on treatment with water, forms potassium hydroxide and hydrogen. 

Praesodymium metal can be obtained from its anhydrous halides by reduction with calcium. The metal also may be prepared by electrolysis of fused praesodymium chloride at elevated temperatures (about 1,000°C). Alternatively, an eutectic mixture of praesodymium chloride, potassium chloride, and sodium chloride may be electrolyzed. In such electrolysis graphite is the anode and tungsten the cathode. 

MetaUic strontium is produced by electrolysis of a mixed melt of strontium chloride and potassium chloride in a graphite crucible using an iron rod as cathode. The upper cathodic space is cooled and the strontium metal coUects over the cooled cathode and forms a stick. 

Electrolytic processes for the perchlorates.—F. von Stadion found that if an aq. soln. of chlorine dioxide be included in Volta s circuit, at first very little gas is developed, but after some hours, oxygen and chlorine appear at the anode, and hydrogen at the cathode. The volume of hydrogen so obtained is nearly twice that of the oxygen. After some time the soln. is decolorized, and transformed into perchloric acid. In 1857, A. Riche 18 prepared perchloric acid by the electrolysis of hydrochloric acid, or of an aq. soln. of chlorine and ten years earlier, H. Kolbe prepared potassium perchlorate by the electrolysis of an aq. soln. of potassium chloride—acidified with sulphuric acid—and of potassium trichloro-methyl-sulphonate. H. Kolbe (1846), a pioneer in the electrolytic preparation of compounds, specially noted that the formation of perchloric acid is always preceded by that of chloric acid, and stated ... 

Uses Of the Stassfurt salts.—The magnesium compounds in the Stassfurt salts are used for the preparation of magnesium and of its salts. The potash salts are an essential constituent of many fertilizers used in agriculture, etc. 22 and potassium chloride is the starting-point for the manufacture of the many different kinds of potassium salts used in commerce—carbonate, hydroxide, nitrate, chlorate, chromate, alum, ferrocyanide, cyanide, iodide, bromide, etc. Chlorine and bromine are extracted by electrolysis and other processes from the mother liquids obtained in the purification of the potash salts. Boric acid and borax are prepared from boracite. Caesium and rubidium are recovered from the crude carnallite and sylvite. 

The general methods for the production of the alkali metals are (1) Electrolytic processes involving the electrolysis of (a) the fused hydroxide, or (b) a fused salt— chloride, nitrate, cyanide, etc. (2) Chemical processes involving the reduction of hydroxide, or carbonate, or other salt with carbon, metal carbide, iron, calcium, magnesium, aluminium, etc. W. Spring 5 claims to have reduced a little potassium chloride by passing hydrogen over the salt at a red heat. 

In order to obtain metallic lithium, A. Guntz electrolyzed a mixture of equal arts of lithium and potassium chlorides and 0. Ruff and 0. Johannsen obtained etter results with a mixture of lithium bromide with 10 to 15 per cent, of the chloride. The electrolysis is conducted in a graphite retort with a thick iron wire as cathode, and a current of 100 amps, at 10 volts gave an 80 per cent, yield. 

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