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Topic: Hall-Heroult process

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 Bessemer process -- Facts, Info, and Encyclopedia article
The process is carried on in a large ovoid steel container lined with (A very fine-grained soil that is plastic when moist but hard when fired) clay or (A light colored mineral consisting of calcium magnesium carbonate; a source of magnesium; used as a ceramic and as fertilizer) dolomite called the Bessemer converter.
The process is a development of a practice known in (A communist nation that covers a vast territory in eastern Asia; the most populous country in the world) China as early as the (Click link for more info and facts about 200s) 200s.
This process had an enormous impact on the quantity and quality of steel producton and was only made obsolete, a century later, in 1856 by Henry Bessemer's invention of the Bessemer Convertor which allowed the true mass production of steel.
www.absoluteastronomy.com /encyclopedia/b/be/bessemer_process.htm   (775 words)

 Charles Martin Hall - Wikipedia, the free encyclopedia
He is best known for his discovery in 1886 of an inexpensive method for refining aluminum, the Hall-Heroult process (called such because of the nearly simultaneous discovery of the same process by the Frenchman Paul Heroult).
US400664 -- Process of reducing aluminum from its floride salts by electrolysis -- C. Hall
Charles Martin Hall (1863-1914) was a native of Thompson, Ohio.
en.wikipedia.org /wiki/Charles_Martin_Hall   (297 words)

 Electrochemistry Encyclopedia --- Aluminum production
Hall's first electrolytic cells, or "pots," were of cast iron, 24 inches (~61 cm) long, 16 inches (~41 cm) wide and 20 inches (~51 cm) deep, with a 3-inch (~8-cm) baked carbon lining.
Alumina (aluminum oxide) powder, fed to the electrolytic process, is produced by the Bayer process from bauxite ore. Bauxites contain 40-60% alumina, combined with silica (silicon oxide), iron oxide, and titanium dioxide.
In the Bayer process, the alumina is dissolved in hot sodium hydroxide solution and the iron oxide and other oxides are removed as insoluble "red mud." Aluminum hydroxide is precipitated from the clarified solution by cooling and seeding with aluminum hydroxide crystals.
electrochem.cwru.edu /ed/encycl/art-a01-al-prod.htm   (2351 words)

 Paul Héroult, Charles M. Hall, and Julia Brainerd Hall
Charles Martin Hall and the Electrolytic Process for Refining Aluminum - a detailed history with ample technical description of the Hall-Héroult process, from Oberlin College.
The Hall process reduced it to two dollars a pound, and shortly after the company's move to Niagara Falls—the first electrochemical company in that location—to seventy-five cents and then thirty cents.
Hall was just six months out of Oberlin College; his sister Julia, who had also been a chemistry major at Oberlin, was of great assistance to him—helping with experiments, taking laboratory notes, and giving business advice.
www.chemheritage.org /EducationalServices/chemach/eei/hhh.html   (353 words)

 JCE 1997 (74) 1269 [Nov] ACS National Historic Chemical Landmark: Charles Martin Hall's Discovery of the Electrochemical Process for Aluminum
Hall was as adept in overcoming the obstacles to commercialization of his new electrolytic process as he was in discovering it.
Soon after achieving this result, Hall confirmed his earlier belief (expressed to his sister in 1886) that the process could be simplified by using only the resistive heating in the reduction pots to achieve and maintain the molten state.
Hall did not take a formal course in chemistry until three years later - the junior year was the customary time for such study in those years - but, under Jewett's guidance and encouragement, he worked on aluminum chemistry in Jewett's laboratory and in his own laboratory at home.
jchemed.chem.wisc.edu /Journal/Issues/1997/Nov/abs1269.html   (3752 words)

 Aluminium - Open Encyclopedia
Charles Martin Hall received the patent (400655) in 1886, on electrolytic process to extract aluminium.
The invention of the Hall-Héroult process in 1886 made extracting aluminium from minerals inexpensive, and so it is now in common use throughout the world.
However Charles Martin Hall selected the -um spelling in an advertising handbill for his new efficient electrolytic method for the production of aluminium, four years after he had patented the process in 1888.
open-encyclopedia.com /Aluminium   (2027 words)

 Aluminum production utilizing positively charged alumina - Patent 6221233
The process 300 begins with a reaction step 308 wherein the aluminum hydroxide is fed, either as a wet cake or as a dry powder, with a slurry water 310 and an acid 312 into a pressure cooker.
In the step 354, the off-gases from step 350 are processed through a conventional acid plant by: a) lowering the temperature for water vapor and sulfur trioxide adsorption with concentrated sulfuric acid, b) conversion of sulfur dioxide to the trioxide, and c) absorbing such sulfur trioxide in a concentrated sulfuric acid.
The process is, in essence, a "zero-discharge" facility excepting a small purge stream 306 which removes impurities that may have been introduced with the feed stock 302.
www.freepatentsonline.com:9003 /6221233.html   (5920 words)

 American Metal Market: Industry changes match competition - aluminum industry
The basic electrolytic process for producing aluminum became known as, and is still called, the Hall-Heroult process.
Hall continued to improve his smelting process, and was able to lower the price of ingot from approximately $5 a pound in 1888 to under $1 a pound by 1895.
It was there that Hall, in 1888, found six industrialists willing to risk some of their capital to promote his new smelting process.
www.findarticles.com /p/articles/mi_m3MKT/is_v94/ai_4521614   (1058 words)

 Process for accurately maintaining a low alumina content in an electrolytic smelting cell for the production of aluminum - Patent 4654129
Process according to claim 1, 2, 3 or 4, wherein the required value Po of the regulation parameter P expressed in micro-ohms per second and percent weight per hour is fixed between 2/100.J and 10/100.J, wherein J is the electrolysis current expressed in kA.
Process according to claim 1, wherein after step (b) of over-supply, a phase of normal supply CN is maintained for a few minutes before reducing the rate to C-.
Process according to claim 1, wherein after step (b) of over-supply, a rate approximating the nominal rate CN is maintained for a few minutes.
www.freepatentsonline.com /4654129.html   (3740 words)

 Charles Martin Hall: Electrolysis of Aluminium - Cryolite - John Mc Clarey, Loreto Coleraine
The same electrolytic process was discovered concurrently by the French chemist Paul L.T. Heroult and is therefore known as the Hall-Heroult process.
23, 1886, Hall found that molten cryolite, which is the mineral sodium aluminium fluoride, was the solvent he needed for the process; using the cryolite and aluminium oxide and homemade batteries, he produced his first small globules of aluminium.
Hall spent the rest of his life developing both his process and the aluminium industry.
www.ifa.ukf.net /hallcell/hall.htm   (453 words)

 Aluminum electrolysis (Don Wilkins)
Hall was 22 years old at the time and his process is essentially what is in use currently.
Hall (and presumably Heroult) was aware of this problem and did use pure alumina.
The Bayer process using bauxite is a chemical process for extracting pure alumina from bauxite.
yarchive.net /metal/aluminum_electrolysis.html   (516 words)

The one that has had the greatest impact, fluoride evolution from the Hall-Heroult process, is the subject of another paper at this Conference.
Of course, this is an oversimplification and the factors of inspiration, innovation, discovery and evaluation have all been evident in the growth and maturity of knowledge characterizing electrolytes for the Hall-Heroult Process.
Charles Martin Hall and Paul L. Heroult were fortunate that the development of suitable carbon anode and cathode materials in commercial quantities preceded their independent discoveries, in 1886, of a commercially successful electrolytic method for producing aluminum.
doc.tms.org /servlet/ProductCatalog?category=02-5409   (1614 words)

 Bayer process -- Facts, Info, and Encyclopedia article
The Bayer process is the principal industrial means of producing (Any of various forms of aluminum oxide occurring naturally as corundum) alumina, itself important in the (Click link for more info and facts about Hall-Heroult process) Hall-Heroult process for producing (A silvery ductile metallic element found primarily in bauxite) aluminum.
In the Bayer process, bauxite is washed with a hot solution of (A strongly alkaline caustic used in manufacturing soap and paper and aluminum and various sodium compounds) sodium hydroxide, NaOH, at 250°C. This converts the alumina to (White crystalline compound that occurs naturally as the mineral gibbsite) aluminum hydroxide, Al(OH)
The Bayer process was developed in 1888 by the German chemist Karl Bayer.
www.absoluteastronomy.com /encyclopedia/b/ba/bayer_process.htm   (288 words)

 Floating cathode elements based on electrically conductive refractory material, for the production of aluminum by electrolysis - Patent 4532017
In a process of manufacturing aluminum by the Hall-Heroult process employing a molten cryolite-base bath as electrolyte, the improvement comprising a cathodic element of an electrically conductive refractory material as the active cathodic material which floats at the electrolyte-aluminum interface.
Also disclosed therein is a cathode for carrying the process into effect, characterised in that it comprises a carbon substrate covered by a plurality of titanium diboride elements which are not connected to the substrate and which are not connected to each other, forming a bed of regular thickness on said substrate.
The process of claim 10 wherein the relative density of TiB.sub.2 and graphite support is lower than the relative density of the aluminum produced.
www.freepatentsonline.com /4532017.html   (3633 words)

 Aluminum Production -- the Hall - Héroult Process -- Electrolysis of Aluminum Fluoride
In this process the elimination of the silica is accomplished by combination of the silicon with the fluorin of the flused fluorid; forming silicon fluorid, which escapes into the atmosphere as a gas...
This method of process has been found to be impracticable in the treatment of large quantities of material on account of the great cost of metallic sodium.
In such processes the mixture always contains a considerable proportion of silica and also some carbonate of soda, either introduced originally as an impurity or formed by exposure of the caustic-soda solution to the air.
www.fluoride-history.de /p-aluminum.htm   (3020 words)

 2G products - Aluminium information.
The Hall-Heroult process is used toreduce alumina to aluminum metal by electrolytic reduction.
The refining (Bayer process) and the reduction (Hall-Heroult) process are seldom accomplished at the same facility.
Emissions from aluminum reduction processes are primarily gaseous hydrogen fluoride and particulate fluorides, alumina, carbon monoxide, carbon dioxide, volatile organics, and sulfur dioxide from the reduction cells.
www.2gproducts.co.uk /aluminium_info_01.htm   (1452 words)

Hall filed patents in the USA and Héroult in France but Hall was eventually credited with being the earlier inventor due to the slightly earlier patent application that he made.
Working in a woodshed in Ohio, Charles Martin Hall made the same discovery that metallurgist Paul Lois Toussaint Héroult made in a makeshift laboratory in Gentilly: both men dissolved aluminium oxide in molten cryolite and then extracted the aluminium by electrolysis.
It is only 160 years since the element aluminium was discovered and only 100 years since a viable production process was established, and today more aluminium is produced each year than all other non-ferrous metals combined.
www.eaa.net /material/history.htm   (958 words)

There is little doubt that Heroult and Hall made their discoveries independent of each other on different sides of the ocean and very close in time.
Heroult himself visited the area and assisted in the technical installation of the furnace.
Paul Heroult's electric furnace invention is the watershed of the current mini-mill steel industry plants in the United States.
www.ggc-asmi.ucdavis.edu /Other/Heroult.htm   (849 words)

 "Parivesh", a Newsletter of CPCB, Delhi
In the Hall-Heroult process, aluminium oxide is dissolved in an electrolytic bath composed mainly of cryolite, sodium aluminium fluoride and aluminium fluoride.
The manufacture of aluminium involves two important stages (i) refining bauxite to aluminium oxide (alumina) by the Bayer process and (ii) reducing alumina in Hall-Heroult electrolytic cells to the aluminium metal.
The precipitated material is removed from the process stream by filtration and calcined to produce aluminium oxide.
envfor.nic.in /cpcb/newsletter/techind/min.html   (1092 words)

 The Main
Other metals may be separated from their ores by a mechanical FLOTATION PROCESS, such as the CYANIDE PROCESS used for gold, or by an electrolytic process such as the Hall-Heroult process.
Another important extraction process is the production of alumina from bauxite by the Bayer process, and the production of ALUMINUM from alumina by the Hall-Heroult process.
Because the cementation process of making crucible steels was very costly for large-scale consumption, the predominant structural metal at that time was WROUGHT IRON; it remained so until the invention of the Bessemer converter in 1855 by another English scientist, Sir Henry BESSEMER.
chemserv.venturacollege.edu /doliver3/chem1b/notes/Chap22new.htm   (1584 words)

 Aluminum Now Online
Hall and Heroult's process, however, made aluminum's production commercially viable.
When Charles Martin Hall in 1886 invented the electrolytic process that would make aluminum production economically viable, manufacturers did not beat a path to his door looking for ways to put his invention to use.
Hall's subsequent work with the Pittsburgh Reduction Company—securing bauxite to produce alumina and hydroelectric power for smelting, and establishing a fabricating business—single him out as the "father" of the modern aluminum industry.
www.aluminum.org /ANTemplate.cfm?IssueDate=09/01/2003&Template=/ContentManagement/ContentDisplay.cfm&ContentID=7083   (1111 words)

 Primary Aluminium Production — The Process, Production Trends and Major Aluminium Producing Regions
Primary aluminium is produced in reduction plants (or ‘smelters’), where pure aluminium is extracted from alumina by the Hall-Héroult process.
This process takes place in electrolytic cells (or “pots”), where carbon cathodes form the bottom of the pot and act as the negative electrode.
Anodes (positive electrodes) are held at the top of the pot and are consumed during the process when they react with the oxygen coming from the alumina.
www.azom.com /details.asp?ArticleID=2113   (425 words)

 "Crown Jewels"
In 1886 both Charles Martin Hall of Ohio and Paul Heroult of Paris, discovered the electrolytic process for producing aluminum.
Their method, now known as the Hall-Heroult process, is still used today.
Hall’s patent was taken up by a group of Pittsburgh entrepreneurs, and the resulting company is today Alcoa.
www.cmoa.org /aluminum/pages/catalog_html/19.htm   (90 words)

 Nat' Academies Press, Decreasing Energy Intensity in Manufacturing: Assessing the Strategies and Future Directions of the Industrial Technologies Program (2005)
The projects within one smelting focus area are based on the chemistry of the Hall-Héroult process, including new concepts such as inert anode and wetted cathode that would require a different cell design.
Process steps such as solidification and fabrication are, however, identified by the roadmap as having top-priority RandD needs, while the bandwidth analysis identifies rolling, extrusion, and shape (presumably shape casting) as having some opportunity for improvement.
Forming, as such, is neither identified as a process step with top-priority RandD needs in the 2003 Aluminum Industry Roadmap, nor is this process identified as having a large opportunity for improvement by the bandwidth analysis.
www.nap.edu /openbook/0309095743/html/28.html   (950 words)

 Metallurg Aluminium presents the Age of Aluminium
There are two successive stages: first, a chemical process extracts alumina or anhydrous aluminium oxide from the bauxite, followed by the Hall-Héroult electrolytic process to reduce the alumina to aluminium.
While the mining process is relatively simple, the process to extract the aluminium from the bauxite is quite complex.
What followed was a long and painstaking process to unlock the secrets of the metal, which never occurs in its pure form in nature, but exists only in combination with other materials – silicates and oxides.
www.metallurgaluminium.com /ageofaluminium.html   (1007 words)

 AllRefer.com - aluminum, Compound & Element (Compounds And Elements) - Encyclopedia
Commercially, aluminum is prepared by the Hall-HEroult process, which consists essentially of the electrolysis of alumina prepared from bauxite and dissolved in fused cryolite.
However, it was not until 1886 that the process by which aluminum is produced today was discovered independently by C. Hall, a student at Oberlin College, and Paul HEroult, a French metallurgist.
The process depends critically on the availability of cheap hydroelectric power.
reference.allrefer.com /encyclopedia/A/alumin.html   (570 words)

 History of Aluminium
1827 Friedrich Wöhler (Germany) describes a process for producing aluminium as a powder by reacting potassium with anhydrous aluminium chloride.
1889 Karl Josef Bayer (Austria), son of the founder of the Bayer chemical company, invented the Bayer Process for the large scale production of alumina from bauxite.
It took many years of painstaking research to "unlock" the metal from its ore and many more to produce a viable, commercial production process.
www.world-aluminium.org /history   (491 words)

 USGS Open-File Report 01-197
The Hall-Héroult process (figure 28) is a reduction process where alumina is dissolved by passing an electric current through a molten electrolyte contained within an electrolytic cell or "pot," which requires large amounts of electricity, at least 13 kilowatt-hours per kilogram of aluminum, to break the aluminum-oxygen chemical bond (International Primary Aluminium Institute, 2000).
A chemical process to commercially produce alumina from bauxite, the Bayer process was patented by Karl Bayer, of Germany, in 1888 (B, figure 24).
In this chemical process, bauxite is washed, ground, and dissolved in caustic soda (sodium hydroxide) at high pressure and temperature.
pubs.usgs.gov /of/2001/of01-197/html/app2.htm   (3521 words)

Aluminum is produced throughout the world using the Héroult-Hall process which consists in the electrolysis of alumina dissolved in cryolite melts.
At last, a lot of research works were and are currently performed on the chemistry involved in the Héroult-Hall process.
These researches were extended both to determine the stabilities of aluminum oxychloride and alumina (11) and to analyze the role of fluoride anion on the conditional solubility of alumina in chloride melts (12) with the idea of a possible mixed chloride-fluoride based process of aluminum electrowinning.
www.elsevier.com /homepage/saa/eccc2/paper59/paper59.html   (4374 words)

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