Hall process

Mining and metallurgical Zinc roaster Zinc smelter Copper roaster Copper reverberatory furnace Copper converter Aluminum-Hall process Aluminum-Soderberg process Ilmenite dryer Titanium dioxide process Molybdenum roaster Ore beneficiation... 

FIGURE 14.24 In the Hall process, aluminum oxide is dissolved in molten cryolite and the mixture is electrolyzed in a cell with carbon anodes and a steel cathode. The molten aluminum flows out of the bottom ot the cell. 

The annual production of aluminum in the United States in 2000 was 3.6 Mt (1 Mt = 1.0 X 109 kg). What mass of carbon, lost from the anode of the electrolysis cell, was required to produce this amount of aluminum by the Hall process ... 

Hall process (Hall-Herault process) The production of aluminum by the electrolysis of aluminum oxide dissolved in molten cryolite, haloalkane An alkane with a halogen substituent. 

Haber, F., 357, 385 Hahn, O., 717 half-cell, 492 half-life (chemical), 543 half-life (radioactive), 712 half-reaction, 484 halide, nomenclature, 763 Hall, C., 598 Hall process, 598 haloakane, F36, 739, 756 nomenclature, 763 halogen, F20, 639... 

Chemical research is driven by many goals, and it progresses in many different ways. The essential traits of a good researcher are curiosity, creativity, flexibility, and dedication. Some chemical advances come from a direct assault on a known problem. A classic example is the development of the Hall process for refining aluminum from its ores, which we describe in Chapter 21,. As a contemporary example, many scientists around the world are working at a feverish pace to develop a vaccine against the AIDS virus. 

Calculate the number of moles of A1203 needed to prepare 5000g of A1 metal in the Hall process ... 

Aluminum suboxide, effect of formation on aluminum yield in Hall process, 2 295... 

Hall process Electrolytic production of aluminum metal from a molten solution of A1203 and cryolite (Na3AlF6). 

When it was first isolated, aluminum was a rare and expensive metal. During the nineteenth century, it so symbolized modern technology that the Washington Monument was given an expensive aluminum tip. That rarity and expense was transformed by electrochemistry. Aluminum metal is now obtained on a huge scale by the Hall process. In 1886,... 

The alumina is then reduced to pure aluminum metal in the Hall process (Section 14.13). 

In the production of 1.0 X 103 kg of aluminum by the Hall process, what mass of carbon is lost at the anode ... 

Aluminum (Al) Aluminum is a silvery white metal with a relatively low density of 2.7 g/cm3. For this reason, aluminum is a popular material for construction. Alloying aluminum with other metals improves its strength. Elemental aluminum does not occur in nature, and must be synthesized by the energy-intensive Hall process. Compounds containing aluminum are found in antiperspirants (aluminum chloride) and antacids (aluminum hydroxide). 

Using the Hall process exclusively, the aluminum industry in the United States alone produces more than 150,000 tons of aluminum each year, and it is impossible to estimate the magnitude of probable future production. The commercial product obtained directly by electrolysis has a purity greater than 99%. It is of interest to note that a few months following the discovery of the Hall process an identical method was discovered independently by the French chemist Paul-Louis-Toussaint Heroult. 

Although AI2O3 is the source of aluminum in the Hall process for obtaining the metal, it is a very useful material in its own right. Activated alumina is used as an adsorbent for many gases and is effective in their removal. Alumina is also an important constituent in abrasives and polishing compounds, catalysts, ceramics, and electrical insulators. 

Practice Problem 17.7 Calculate the time required to produce 1.00 X 10 g of aluminum metal by the Hall process (See Practice Problem 17.5) with a current of 500 A. ... 

Hall process— A process for the production of aluminum metal by passing an electric current through a mixture of aluminum oxide dissolved in cryolite (sodium aluminum fluoride). 

Figure 12.4 Schematic representation of electronic transitions, including Shockley-Read-Hall processes for a deep-level state.

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