98ba3733-fa5f-4cc7-bfe5-76c317f7ea70Alumina productionprimary productionconsumption mix, at plantMaterials productionMetals and semimetalsData was collected through the Aluminum Association and the International Aluminum Institute.110Includes both imports and domestic production. The fraction of alumina imports to total alumina consumed for primary aluminum production is approximately 40%. The imports of alumina from Australia and Suriname accounted for approximately 80% of the total alumina imports to the U.S.Alumina refining comprises the conversion of bauxite to aluminum oxide Al2O3 (alumina) using the Bayer process. Most refineries use a mixture of blended bauxite to provide feedstock with consistent properties. The mixture is ground and blended with recycled plant liquor. This liquor contains dissolved sodium carbonate and sodium hydroxide recovered from previous extraction cycles plus supernatant liquor recycled from red mud holding ponds. The slurry is heated and pumped to digesters, which are heated in pressure tanks. In digestion, iron and silicon impurities form insoluble oxides called red mud. The red mud settles out and a rich concentration of sodium aluminates is filtered and seeded to form hydrate alumina crystals in precipitators. These crystals are then heated in a calcination process. The heat in the calciners drives off combined water leaving alumina.
This step of manufacturing begins with the processing of beneficiated bauxite and ends with the output of alumina to be subsequently processed in the smelter. The operations associated with this unit process include (AA, 1999; IAI, 2005):
# bauxite grinding, digestion, and processing of liquors,
# alumina precipitation and calcination,
# maintenance and repair of plants and equipment, and
# treatment of process air, liquids, and solids.Alumina to be used in aluminium production.Partly terminated systemAttributionalNoneAllocation - market valueAllocation - exergetic contentAllocation - massNoneAll data used in the calculation of the LCI results refer to net calorific value.None1% cut-off criteria applied for non-hazardous inputs & outputs except alloying elements which are not considered. - No cut-off criteria for hazardous products emissions (ex. PAH, PFC, BaP, etc.) - Infrastructure not included. All ancillary processes (electricity, caustic soda, etc.) included.
Cut-off rules for each unit process: Coverage of at least 95 % of mass and energy of the input and output flows, and 98 % of their environmental relevance (according to expert judgement).
For further details please see the document "GaBi Databases Modelling Principles"NoneFor details please see the document "GaBi Databases Modelling Principles"NoneFor details please see the document "GaBi Databases Modelling Principles"NoneLife Cycle Impact Assessment of aluminum Beverage CansLife Cycle Inventory Data Primary Aluminium, 200595.02006The data set represents a cradle to gate inventory. It can be used to characterise the supply chain situation of the respective commodity in a representative manner. Combination with individual unit processes using this commodity enables the generation of user-specific (product) LCAs.No statementthinkstepAAThis background LCI dataset can be used for any type of LCA studiesAAthinkstep2019-02-01T00:00:00.000ILCD format 1.1thinkstep2019-02-01T00:00:00.00000.00.001Data set finalised; entirely publishedAAtrueOtherGaBi (source code, database including extension modules and single data sets, documentation) remains property of thinkstep AG. thinkstep AG delivers GaBi licenses comprising data storage medium and manual as ordered by the customer. The license guarantees the right of use for one installation of GaBi. Further installations using the same license are not permitted. Additional licenses are only valid if the licensee holds at least one main license. Licenses are not transferable and must only be used within the licensee's organisation. Data sets may be copied for internal use. The number of copies is restricted to the number of licenses of the software system GaBi the licensee owns. The right of use is exclusively valid for the licensee. All rights reserved.Aluminium oxide (alumina)Output1.01.00Mixed primary / secondaryUnknown derivationvaluable