By High Temperature Method

A design of a fluorine generator which is both economical to build and convenient to operate is shown in Fig. 25. The total cost of the material including a supply of the electrodes is about 10. About 2 kg. of electrolyte is required for one charge, and the cell will operate on this quantity for 25 to 50 hours while carrying a current of 10 amp. 

The simplicity of this cell gives it advantages over more complicated designs. The special features that facilitate its operation are as follows  

The copper plate over the top of the heating element protects the latter from the electrolyte. By exposing no material containing silica to possible contact with the electrolyte, it eliminates this source of contamination. 

The open anode side of the cell allows free escape of the hydrogen and permits easy observation of the electrolyte. This reduces the danger of the explosions, should the fluorine stream become stopped in the apparatus in which it is used, and allows possible escape through the anode chamber. Difficulties cannot be encountered in a stoppage of the escape of the hydrogen. 

The large size of the fluorine exit tube and its angle with the horizontal eliminate clogging with solidified electrolyte. Occasional warming with a gas flame will melt out any electrolyte carried into it as spray. 

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Calcium Aluminates. CAS 065997-16-2], Four in number. Iiave been prepared by high-temperature methods and identified. 3CaO- AI>Oi. at l,535aC. decomposes with partial fusion 5CaO- ALOj. nip 1,455 C, CaO AbOt. tnp 1.590°C. 3CaO- AI Oi. mp 1.720 C. 

Calcium Aluminosilicates. Two in number, have been prepared by high-temperature methods and identified 2CaO AhOi SiCL. gehlinile CaO- AI Oi 2SiO . anorthite. 

Ceramic fibers used in composites are usually made by high-temperature methods. Carbon (graphite) fiber, for example, can be made by the thermal decomposition of fibers of polyacrylonitrile, a long-chain organic molecule also used to make the textile Orion ... 

Fluorine, 1 136 as fluorinating agent, 4 137 by high-temperature method, 1 138... 

Borate minerals are common but synthesized examples are relatively rare [11]. We also notice that the borate crystals were usually grown by high temperature methods, exemplified by the high temperature flux and melt techniques [12-14]. There were a few reports on the preparation of borates by using the sol-gel technique. 

The structure of BiSI is built up of (Bi2S2I2) double chains parallel to the c-axis.795 The compound Bii9S27Br3, obtained by high-temperature methods, and the analogous iodide are isostructural, but attempts to prepare the chloride were unsuccessful.796... 

Calcining. Vaporization to complete dryness by high-temperature methods minimizes volume requirements and corrosion. One disadvantage is the poor heat-transfer characteristics of the heat-generating solids. 

Although polymer precursors to non-oxide ceramics offer considerable potential for processing a wide variety of novel shapes, at quite low temperatures with respect to standard ceramics processing methods, very few commercial products based on this approach have been forthcoming [1-5]. Furthermore, very few polymer derived non-oxide ceramics exhibit properties commensurate with those found for the same ceramics produced by high temperature methods. 

Ceramics Stiff, brittle materials that are generally prepared by high temperature methods the resulting materials are insoluble in water. 

D1SS2, Sulfur by high-temperature method D168S, Thiophene in benzene D1988, Mercaptans in natural gas X X X X X X... 

The most common water-soluble initiators are ammonium persulfate, potassium persulfate, and hydrogen peroxide. These can be made to decompose by high temperature or through redox reactions. The latter method offers versatility in choosing the temperature of polymerization with —50 to 70°C possible. A typical redox system combines a persulfate with ferrous ion ... 

Bismuth vanadate can be produced by chemical precipitation, as weU as by high temperature calciaation methods. In the wet process, the acidic solution of bismuth nitrate, Bi(N02)3, is mixed with the alkaline solution of sodium vanadate, Na VO. The gel formed is filtered off on a filter, pressed, washed, and converted to a crystalline form by calciaation at low temperatures of 200—500°C for 1 h (37,38). 

Aluminothermal Method. Calcium metal is produced by high temperature vacuum reduction of calcium oxide in the aluminothermal process. This process, in which aluminum [7429-90-5] metal serves as the reducing agent, was commercialized in the 1940s. The reactions, which are thermodynamically unfavorable at temperatures below 2000°C, have been summarized as ... 

As holds for other cluster systems, certain magic cluster electron counts exist, which indicates for a certain cluster-halide ratio and interstitial present the filling of all bonding molecular orbitals and therefore the thermodynamically most stable situation. For main group interstitial atoms these are 14 cluster-based electrons whereas for transition-metal interstitials the magic number is 18 [1, 10-12]. All of these phases are synthesized by high-temperature solid-state chemical methods. A remarkable variety of different structure types has been... 

Titanium (IV) iodide may be prepared by a variety of methods. High-temperature methods include reaction of titanium metal with iodine vapor,1-3 titanium carbide with iodine,4 titanium(IV) oxide with aluminum (III) iodide,5 and titanium (IV) chloride with a mixture of hydrogen and iodine. At lower temperatures, titanium (IV) iodide has been obtained by the combination of titanium and iodine in refluxing carbon tetrachloride7 and in hot benzene or carbon disulfide 8 a titanium-aluminum alloy may be used in place of titanium metal.9 It has been reported that iodine combines directly with titanium at room temperature if the metal is prepared by sodium reduction of titanium (IV) chloride and is heated to a high temperature before iodine is... 

The disposal and destruction of chlorinated compounds is a subject of great importance. In fact, in 1993, some environmental groups had proposed the need for a chlorine-free economy. The cost of complete elimination of chlorinated compounds is quite staggering with the latest estimate as high as 160 billion/year.46 The most common method to destroy chlorocarbons is by high-temperature thermal oxidation (incineration).47 The toxic chlorinated compounds seem to be completely destroyed at high temperatures however, there is concern about the formation of toxic by-products such as dioxins and furans.48... 

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