Location: BR - Brazil
This dataset describes the quarrying and processing of sand, usually applied in construction materials, from alluvial deposits in open pits in Brazil, which represents 30% of Brazilian production of sand for construction (MME, 2009), being the other 70% extracted from river beds. The wet sand mining process involves hydraulic mining of slopes and dredging of the pulp (sand and water) accumulated in the bottom of the pit, which is transported to the cyclone by pipes (therefore conveyor belts are not used in this process). Processing is done with the use of a cyclone for separating water and sand and classifying the sand particles according to its size: fine sand (between 0,15mm and 1,2 mm), medium sand (between 0,3 mm and 2,4 mm) and coarse sand (between 2,4 mm and 4,75 mm) - size classification is a commercial convention, based on the superseded version of ABNT NBR 7211. Sand is not washed and is only air dried (5% of humidity at the end of the process). The dataset includes the quarrying and size classification processes (information regarding weight proportion of sand particles according to its size not available though), as well as equipment maintenance. Machinery is taken into account within the dataset "diesel, burned in building machine", as most machinery runs on diesel. Administration buildings and the quarry’s end of life are not taken into account. Data were collected in 01 quarry located in the state of São Paulo, Brazil, which produces predominantly medium sand, with current technology. The representativeness of the dataset on a national scale is low (<1%).
MME - Ministério de Minas e Energia, 2009. Relatório Técnico 31 - Perfil da areia para construção civil. Available at: <http://www.mme.gov.br/documents/1138775/1256650/P22_RT31_Perfil_de_arei…;. Accessed 29.08.2017.
ABNT - Associação Brasileira de Normas Técnicas. ABNT NBR 7211 - Agregados para concreto - Especificação (National Standard).
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.