Search results
Results from the WOW.Com Content Network
Bauxite is the main source of the rare metal gallium. [17] During the processing of bauxite to alumina in the Bayer process, gallium accumulates in the sodium hydroxide liquor. From this it can be extracted by a variety of methods. The most recent is the use of ion-exchange resin. [18]
The liquid aluminium is removed from the cell via a siphon every 1 to 3 days in order to avoid having to use extremely high temperature valves and pumps. Alumina is added to the cells as the aluminum is removed. Collected aluminium from different cells in a factory is finally melted together to ensure uniform product and made into metal sheets.
Aluminium (or aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air.
An electrolytic cell is made of a steel shell with a series of insulating linings of refractory materials. The cell consists of a brick-lined outer steel shell as a container and support. Inside the shell, cathode blocks are cemented together by ramming paste. The top lining is in contact with the molten metal and acts as the cathode.
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer.Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al 2 O 3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. [1]
Mining for aluminum and the subsequent industrial usage disrupts the natural burial processes of the aluminum cycle. By the year 2050 the need for aluminum is expected to increase by 200-300%. [7] Aluminum is mined in the form of bauxite ore. Bauxite is only 40-60% aluminum oxide. [8] The elements that make up the rest of bauxite are also very ...
He realized that by passing an electric current through a bath of cryolite and aluminum oxide, the then semi-rare metal aluminum remained as a byproduct. [8] This discovery, now called the Hall–Héroult process, along with the Bayer process, are the dominant processes for production of aluminum from bauxite ore. [citation needed]
Some non-ferrous materials are also used in the iron and steel industries. For example, bauxite is used as flux for blast furnaces, while others such as wolframite, pyrolusite, and chromite are used in making ferrous alloys. [3] Important non-ferrous metals include aluminium, copper, lead, tin, titanium, and zinc, and alloys such as brass.