Chloride melt Chlorination

Alternatives to the fluidized-bed method process include the chlorination of titanium slags in chloride melts, chlorination with hydrogen chloride, and flash chlorination. The last is claimed to be particularly advantageous for minerals having a high impurity content (133—135,140). The option of chlorinating titanium carbide has also been considered (30). 

Sodium metal is produced commercially on the kilotonne scale by the electrolysis of a fused eutectic mixture of 40% NaCl, 60% CaCh at 580°C in a Downs cell (introduced by du Pont, Niagara Falls, 1921). Metallic Na and Ca are liberated at the cylindrical steel cathode and rise through a cooled collecting pipe which allows the calcium to solidify and fall back into the melt. Chlorine liberated at the central graphite anode is collected in a nickel dome and subsequently purified. Potassium cannot be produced in this way because it is too soluble in the molten chloride to float on top of the cell for collection and because it vaporizes readily... 

Chlorination of ferroalloys (ferroniobium-tantalum) is a more economical and simple alternative [30]. The process is performed on a sodium chloride melt that contains iron trichloride, FeCU. Chlorine is passed through the melt yielding NaFeCl4, which interacts as a chlorination agent with the Fe-Nb-Ta alloy. Chlorination of ferroalloys allows for the production of pure tantalum and niobium pentachlorides, which are used further in the production of high purity oxides and other products. 

In general, the electrolysis of a molten salt at inert electrodes produces the metal at the cathode, e.g., calcium from calcium chloride (melting point 774 °C). The anion is often a halide ion which, on discharge, yields the halogen, e.g., chlorine from calcium chloride. 

In chloride melts, the chlorine electrode (with graphite instead of platinum) is used as a reference electrode (see Table 3.3). 

In an individual molten carbamide, the electrode processes are feebly marked at melt decomposition potentials because of its low electrical conductivity. Both electrode processes are accompanied by gas evolution (NH3, CO, C02, N2) and NH2CN (approximately) is formed in melt. In eutectic carbamide-chloride melts electrode processes take place mainly independently of each other. The chlorine must evolve at the anode during the electrolysis of carbamide - alkali metal and ammonium chloride melts, which were revealed in the electrolysis of the carbamide-KCl melt. But in the case of simultaneous oxidation of carbamide and NH4CI, however, a new compound containing N-Cl bond has been found in anode gases instead of chlorine. It is difficult to fully identify this compound by the experimental methods employed in the present work, but it can be definitely stated that... 

Chloride of Strontium ie in long, six-sided needles, deliquescent in moist air, and soluble in three-qnarter parts of cold water. It imparts an intense crimson color to flame. In alcohol it is also soluble. When heated, the chloride melts and becomes speedily anhydrous. Ignited in air, it loses chlorine and absorbs oxygen. The chloride of strontium is most easily prepared by dissolving the sulphide la water, and decomposing with hydrochloric acid. The symbol for the salt is SrCl, 6 HO. 

Selenium tetrachloride is a colourless solid which on heating vaporises without melting. Sublimation in an atmosphere of chlorine is therefore a convenient method of purification. The density of the vapour (which is yellow in colour) indicates that dissociation occurs to a considerable extent above 200° C., although below this temperature the results are in accordance -with the formula SeCI4.3 The products of dissociation are probably the lower chloride and chlorine. There are indications that at higher temperatures (500° C.) the dichloride, ScCL>, is formed. When the tetrachloride is heated in a sealed tube with selenium, the monochloride is produced.3... 

A synthesis of the monoterpene alkaloid ( )-actinidine has been accomplished through the intramolecular cycloaddition of a substituted pyrimidine (81JCS(P1)1909). Condensation of the diester (756) with formamidine provided the pyrimidine precursor (757) which when heated at its melting point (203 °C) underwent cycloaddition with elimination of isocyanic acid to produce the pyridone (758). Conversion of the pyridone into the chloropyridine was effected with phosphoryl chloride. The chlorine atom was then removed by hydrogenoly-sis over palladium on charcoal to afford the racemic alkaloid (759 Scheme 175). 

All metallic chlorides, except silver chloride and mercurous chloride, are soluble in H.O. but lead chloride, cuprous chloride and thallium chloride are only slightly soluble. Metallic chlorides when heated melt, and volaiilize or decompose, e.g.. sodium chloride, mp 804 (2 calcium, strontium, barium chloride volatilize at red heal magnesium chloride crystals yield magnesium oxide residue and hydrogen chloride cupric chloride yields cuprous chloride and chlorine. Sec also Chlorine Chlorinated Organics. Halides Hypochlorites and Sodium Chloride. 

The distribution of sodium and potassium is not given in the tables. Essentially all of the sodium and potassium in the feed appears in the effluent melt. This is likely caused by the potassium and sodium being converted into the chlorides which are sufficiently volatile to be vaporized along with the zinc chloride. This chlorine is considered irrecoverable. Hence, this method of regeneration is chiefly useful with coals that have relatively low alkali concentrations. 

The choice of the chlorination technique and equipment for the process greatly depends on the compositon of raw stock for chlorination. For shaft furnaces and fluidised layer apparatuses, it is advisable to chlorinate titanium raw stock with relatively small amounts of oxides of calcium, magnesium, manganese and other metals which form low-melting chlorides in chlorination. On the other hand, in chlorination in salt melt these oxides do not have any significant effect on the process. 

Rhenium pentachloride is obtained as black crystals. The solid melts at 261° with decomposition. It fumes in air, evolving hydrogen chloride and chlorine. 

The yield varies with the exposed surface area of the reaction mixture and hence is dependent upon the amount of material and the dimensions of the boat. When the sodium chloride melts, the denser rhodium tends to settle to the bottom of the reaction mixture and is no longer exposed to the chlorine. If the mixture is spread out in the manner shown in Fig. 9, the maximum yield is obtained. 

The kinetics of the chlorine electrode in different chloride melts was studied in the range 190-430°C. Different controlled processes involving the participation of chlorine atoms on graphite have been proposed [82, 83]. 

Chlorination of Methane with Copper Chloride Melts. 

The tendency of an oxidation or reduction half-reaction to proceed can tell us what products to expect in an electrolysis reaction. For example, the reduction potential of sodium is far less (more negative) than that of water, so when we electrolyze a solution of sodium chloride, for example, water is reduced and not sodium ion. Electrolysis of a concentrated solution of sodium chloride produces chlorine along with the hydrogen, whereas electrolysis of a dilute solution of sodium chloride produces oxygen and hydrogen. To get sodium metal, we need to electrolyze molten (melted) sodium chloride in the absence of water altogether. Do not forget that aqueous solutions contain water as well as any solutes. 

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