treatment of sulfidic tailings, from silver mine operation, tailings impoundment, UPR, ecoinvent 3.6, Undefined

Categories:
ISIC4 categories:
E:Water supply; sewerage, waste management and remediation activities/38:Waste collection, treatment and disposal activities; materials recovery/382:Waste treatment and disposal/3822:Treatment and disposal of hazardous waste
Location:
US - United States
Reference year: 2015 - 2019
Description

Location: US - United States
This dataset represents the activity of waste disposal of sulfidic tailings, from silver mine operation in a tailings impoundment in the United States.
Background: Tailings, a waste material produced during mineral concentration (beneficiation), often contain significant quantities of mobile toxic metals and are typically produced in large quantities. To manage these wastes, tailings are commonly stored behind dammed impoundments, known as tailings ponds. These ponds pose a significant long-term pollution risk as metals may leach out into the surrounding environment, potentially over very long timeframes.
Modelling approach: This dataset was produced using a model developed specifically for assessing the long-term emissions of tailings disposal (see Doka, 2017). The tailings disposal model is based on the modelling framework applied in existing landfill process models used in ecoinvent and is based on a top-down approach. Literature data on measurements of deposited tailings compositions (solids) and measured current concentrations in leachate (liquid) form the basis of the model and are used to characterise pollutant mobility and calculate the currently occurring rate of emissions of the landfill. Heeding chief parameters, such as hydrology, pH development and elemental chemistry, these emissions are then projected into the future. Tailings composition is based on the typical composition of tailings at silver mine sites worldwide; i.e. composition is not region-specific. Land use was calculated following the approach described by Doka (2008). Based on an assumed generic final height of a tailings impoundment of 60 m and an assumed tailings density of 2200 kg/m3, a land area of 7.58E-06 m2 is required per kilogram of sulfidic tailings. The land is assumed to be converted from unknown origin to a disposal site. After an operational phase of 30 years, spontaneous restoration of a consolidated state is assumed to be reached after one hundred years. The total occupation time is therefore 130 years and the land occupation per kilogram tailings is 9.85E-04 m2.
Waste composition (wet, in ppm): H2O 300000; O 621950; H na; C 6145; S 272.23; N 5.0454; P 216.46; B 54.583; Cl 102.61; Br 0.22894; F 772.88; I na; Ag 10.076; As 74.238; Ba 355.2; Cd 4.6448; Co 10.164; Cr 49.843; Cu 590.65; Hg 0.43347; Mn 156.64; Mo 11.524; Ni 14.943; Pb 222.48; Sb 37.083; Se 4.0116; Sn 27.477; V 137.22; Zn 251.39; Be 1.0483; Sc 13.26; Sr 98.041; Ti 114.74; Tl 2.3266; W 9.2739; Si 39024; Fe 9774.1; Ca 2626.4; Al 12044; K 2278.2; Mg 1457.8; Na 1075.8. // Share of carbon in waste that is biogenic 0%.
Activity extent: The dataset includes all potential emissions to the environment and land use changes. Input exchanges of infrastructure, materials, energy, and water are not included here but are accounted for in the activity, silver mine operation.
References
Doka, G. (2008). Life Cycle Inventory data of mining waste: Emissions from sulfidic tailings disposal. Zürich, Switzerland: Doka Life Cycle Assessments.
Doka, G. (2017). A model for waste-specific and climate-specific life cycle inventories of tailings impoundments. Zürich, Switzerland: Doka Life Cycle Assessments.
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.

Technology

This is an inventory for an impoundment of copper ore beneficiation tailings waste. The following assumptions were made concerning technology: final impoundment height is 60 meters; operation phase duration is 30 years; and impoundment leachates are released into the environment untreated.

Process type
Unit
Supported nomenclature
ecoinvent 3.6
LCI modeling approach
Before modeling
Multifunctional modeling
NONE
Format
ECOSPOLD2
Aggregation type
NOT_APPLICABLE
Data provider
ecoinvent
Review status
External
Cost
For sale
License

ecoinvent EULA

Contact
support@ecoinvent.org