1 Introduction
2 Methods
2.1 System boundaries
2.2 Global industry representation
2.3 Functional units
Functional unit | Designation | Description |
---|---|---|
High-carbon ferromanganese | HC FeMn | 74–82 wt.% Mn and less than 7.5 wt.% C |
Silicomanganese | SiMn | 65–68 wt.% Mn and less than 2.0 wt.% C |
Refined ferromanganese | Ref. FeMn | 80–85 wt.% Mn and less than 1.5 wt.% C |
Average manganese alloy | Avg. Mn alloy | 40 % HC FeMn 40 % SiMn 20 % Ref. FeMn |
2.4 Life cycle impact assessment categories and environmental indicators
Impact/indicator | Designation | Notes |
---|---|---|
Global warming potential | GWP | Measure of greenhouse gas emissions |
Acidification potential | AP | Measure of acid rain-generating emissions |
Photochemical ozone creation potential | POCP | Measure of smog-forming emissions |
Nitrogen oxides | NOX
| Emissions of controlled and fugitive nitrogen oxides to air |
Sulfur oxides | SOX
| Emissions of controlled and fugitive sulfur oxides to air |
Particulate matter | PM | Emissions of controlled and fugitive particulate matter to air |
Comprehensive energy demand | CED | Total raw energy inputs associated with manganese production, including upstream and downstream processes |
Primary energy demand | PED | Energy delivered to primary manganese production processes only |
Primary water consumption | Water | Water consumption by primary, on-site manganese processes only |
Primary waste generation | Waste | Waste generated by primary, on-site manganese processes only |
2.5 Manganese alloy supply chain description
2.6 Life cycle modeling
2.7 Allocation and co-products
3 Results
Avg. Mn alloy | SiMn | HC FeMn | Ref. FeMn | |
---|---|---|---|---|
GWP (kg) | 6.03 | 6.94 | 5.06 | 6.18 |
AP (g) | 45.0 | 52.4 | 35.4 | 49.6 |
POCP (g) | 3.03 | 3.33 | 2.47 | 3.55 |
NOx (g) | 18.7 | 20.1 | 15.5 | 22.4 |
SOx (g) | 30.9 | 37.5 | 23.9 | 31.5 |
PM (g) | 9.58 | 11.50 | 8.47 | 7.96 |
CED (MJ) | 73.4 | 86.1 | 63.2 | 68.4 |
PED (MJ) | 35.6 | 39.6 | 31.9 | 34.9 |
Water (kg) | 11.3 | 12.9 | 8.8 | 13.0 |
Waste (kg) | 26.5 | 21.9 | 29.2 | 30.3 |