Molten magnesium

Electrolytic plant producing magnesium and chlorine from molten magnesium chloride. 

Molten magnesium chloride can be formed by the direct carbochlofination of magnesium oxide obtained from the calciaation of magnesium carbonate ores or magnesium hydroxide [1309-42-8]. 

Russian production may be going to a flow line cell concept (35). In this process, dehydrated camaOite is fed to a chamber where it is mixed with spent electrolyte coming from the electrolytic cells. The spent electrolyte first enters a metal collection chamber, where the molten magnesium is separated. The electrolyte is then enriched with camaOite and any iasoluble impurities are allowed to settle. The enriched electrolyte is then returned to the electrolytic cells. The result is that most of the remaining impurities are removed ia the first electrolytic cell. 

Equipment. The standard equipment in magnesium foundries consists of large stationary brick-lined reverbatory furnaces which can hold up to 10—15 t of molten magnesium. Reverbatory furnaces are furnaces in which heat is suppHed by burning a fuel in a space between the reactants and the... 

Condensation of metal vapors followed by deposition on cooler surfaces yields metal powders as does decomposition of metal hydrides. Vacuum treatment of metal hydrides gives powders of fine particle size. Reaction of a metal haHde and molten magnesium, known as the KroU process, is used for titanium and zirconium. This results in a sponge-like product. 

Heated zirconium is readily chlorinated by ammonium chloride, molten stannous chloride, zinc chloride, and chlorinated hydrocarbons and the common chlorinating agents. It is slowly attacked by molten magnesium chloride in the absence of free magnesium, which is always present in the KroU process. 

The TiCU is fractionally distilled from FeCls and other impurities and then reduced with molten magnesium in a sealed furnace under Ar,... 

Use of Air/C02/Sp6 Mixtures for the Improved Protection of Molten Magnesium-Couling , Proc. IMA World Magnesium Conference, Oslo, June (1979)... 

Early experimental work in electrorefining at Los Alamos by Mullins et-all ) demonstrated that americium could be partitioned between molten plutonium and a molten NaCl-KCl salt containing Pu+3 ions, and Knighton et-al(8), working at ANL on molten salt separation processes for fuel reprocessing, demonstrated that americium could be extracted from Mg-Zn-Pu-Am alloys with immiscible molten magnesium chloride salts. Work... 

FIGURE 12.12 A schematic representation of the electrolytic cell used in the Dow process for magnesium. The electrolyte is molten magnesium chloride. As the current generated by the external source passes through the cell, magnesium ions are reduced to magnesium metal at the cathode and chloride ions are oxidized to chlorine gas at the anode. 

Sf.lf-Tksi 12.15A Determine the mass (in grams) of magnesium metal that can be obtained from molten magnesium chloride, by using a current of 7.30 A for 2.11 h. What volume of chlorine gas at 25°C and 1.00 atm will be produced at the anode ... 

Titanium metal is obtained by reduction of TiClq with molten magnesium metal at high temperature. The reaction gives solid titanium metal (mp = 1660 °C) and liquid magnesium chloride (mp = 714 °C) ... 

The above reaction shows that the oxychloride decomposes at the sublimation temperature into the volatile tetrachloride and the nonvolatile oxide. Reduction starts as soon as the chloride vapour contacts the molten magnesium, and this exothermic reaction raises the temperature of the reaction mixture. The temperature of the reduction crucible is maintained in the range of 800 to 875 °C. The process is carefully controlled by matching the sublimation rate of zirconium tetrachloride with the reduction rate. The conclusion of the reduction is indicated by a fall in temperature and pressure. 

Reduction of the oxide by heated sodium or potassium proceeds with incandescence, and explosion occurs in contact with molten magnesium. 

Interaction with molten magnesium at 651°C is explosive, and more so with calcium at 200° C. 

Used industrially as a catalyst in organic synthesis, to protect molten magnesium and its alloys from oxidation, as a flux for soldering magnesium manufacture of specialty electronics as a fumigant and in ionization chambers for detection of weak neutrons. 

Calculate the mass of magnesium that can he plated onto the cathode hy the electrolysis of molten magnesium chloride, using a current of 3.65 A for 55.0 min. 

Spills of molten magnesium yielded results similar to those of aluminum, but fires often followed the event. 

Purified HfCh is sublimed and reduced with magnesium by passing the vapors through molten magnesium heated in an electric furnace ... 

Although many commercial processes have heen developed since the first electrolytic isolation of Mg metal hy Davy and Faraday, and Bussy, hy chemical reduction, the principles of the manufacturing processes have not changed. At present, the metal is most commonly manufactured by electrolytic reduction of molten magnesium chloride, in which chlorine is produced as a by-product. In chemical reduction processes, the metal is obtained by reduction of magnesium oxide, hydroxide, or chloride at elevated temperatures. 

The Kroll process involves heating molten magnesium and zirconium tetrachloride vapor in a sealed furnace in the absence of air under a helium atmosphere. The reaction forms zirconium sponge and magnesium chloride ... 

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