Location: IAI Area, Russia & RER w/o EU27 & EFTA - IAI Area, Russia & Europe outside EU27 & EFTA
Data on Al(OH)3 extraction and calcination to Al2O3 was aggregated on original source (International ALuminium Institute 2015 LCI survey, IAI personnal communication in 2017). In- and outputs of Al(OH)3 are calculated according to the stoichiometry (1.530 kg Al(OH)3 --> 1.000 kg Al2O3 + 0.530 kg H2O). Separate energy data was provided by IAI for production of hydrate and calcination processes. The Al(OH)3 extraction process involves adding milled bauxite to a hot caustic soda (NaOH) solution, dissolving the aluminium-bearing minerals (gibbsite, böhmite and diaspore) present to form a sodium aluminate supersaturated solution or “pregnant liquor”. Flocculants are added to aid settling and the solution is progressively cooled causing aluminium hydroxide crystals to precipitate. Further information can be found at http://bauxite.world-aluminium.org/refining/process.html.
Two sources were used in the creation of this dataset: IAI 2015 Survey data (officially published in 2017); and original ecoinvent 2 data (Althaus, 2007) for exchanges unreported by IAI.
Undefined unit processes (UPRs) are the unlinked, multi-product activity datasets that form the basis for all of the system models available in the ecoinvent database. This is the way the datasets are obtained and entered into the database by the data providers. These activity datasets are useful for investigating the environmental impacts of a specific activity (gate-to-gate), without regard to its upstream or downstream impacts.