Electrolysis Refining of Bauxite Ore for Aluminum Metal

Electrolysis Refining of Bauxite Ore for Aluminum MetalPresented to: Dr. Elie ChalhoubBy: Maamoun Ejjeh Michael Salameh

Outline:General Overview:IntroductionHistory of ProductionRaw Materials Separation Processes

Bayer Process ( Bauxite Ore Aluminum Oxide)Hall-Heroult Process ( Aluminum Oxide Pure Aluminum)ConclusionIntroduction:Aluminum was considered a rare metalHard to extractThird most abundant elementMost abundant metal in Earth crustFound naturally with about 300 different mineralsChief ore of Aluminum is the Bauxite Ore

HistoryIn 1888 Charles Martin Hall and Paul Heroult developed the Hall-Heroult ProcessIt is still the primary technique used todayIn 1887 Carl Joseph Bayer developed the Bayer processIn 1884, 60 kg of aluminum was produced in the United States, and it sold for about the same unit price as silver. In 1995, U.S. plants produced 3.6 million metric tons of aluminum, and the price of silver was seventy-five times as much as the price of aluminum. (http://www.madehow.com/Volume-5/Aluminum.html)

Raw MaterialsBauxite Ore:45-60% aluminum oxideSandIronOther metalsCaustic Soda (NaOH)Cryolite:Sodium AluminumFluorineAluminum FluorideCarbon

Separation ProcessesBayer Process:

Flash tanksSettling tanksCloth filtering and recoveringPrecipitation tanksSettling& washingScrew conveyorHeating and drying Gravity moving2,000 FCoolingAddition of caustic sodaSeparation ProcessesBayer Process:Chemical equations:Al2O3 + 2 NaOH 2 NaAlO2 + H2O 2NaAlO2 + CO2 2 Al(OH)3 + Na2CO3 +H2O2 H2O + NaAlO2 Al(OH)3 + NaOHz2 Al(OH)3 Al2O3 + 3 H2OSeparation ProcessesHall-Heroult Process:

Separation ProcessesHall-Heroult Process:

Chemical Equations:

Separation Processes

Conclusion High amount of energyPollutionAluminum is easily recyclable very high yield (99%-100%)Economically efficient ( usage of by-products) High demand