Page 103 - Materials Chemistry, Second Edition

84 Life Cycle Assessment of Wastewater Treatment

TABLE 5.3
Inventory: Input and Output Flows of the Hydrometallurgical Process

Flows Quantity Unit Data Source
Input
Batteries BP 105 kg
H 2 SO 4 (R101) 120 (sol. 30%) kg Sulfuric acid (100%), Ecoinvent
H 2 SO 4 (R104) electrolytic 438 (sol. 30%) kg
treatment
KOH (TK 101) 0.51 (solution kg Potassium hydroxide, Ecoinvent,
KOH (R104) 60 g/L, 1 M) PM (Molecular weight) = 56 g/mol
Neutralization electrolytic 1.2 (solution
treatment 60 g/L, 1 M)
K 2 CO 3 (R104) 168 kg Potassium carbonate, Ecoinvent
Neutralization electrolytic
treatment
Ammonium oxalate
(TK104)
Industrial water (R101) 1100 kg Tap water, used as substitute for
Water used to wash the zinc 300 kg mains water, Ecoinvent,
oxalate (R102) Europe, 2000
Electricity consumption
Electricity for the use of 440 kWh Grid electricity, medium voltage,
mixer, reactors, agitators, Italia, Ecoinvent
compressors, evaporators,
pumps, filter, scrubber

Output
Zinc oxalate 118 kg Zinc, Ecoinvent, Europe,
1994–2003
BP final (manganese oxide 66 kg Process data: About 36 kg of
and carbon black) carbon black and 30 kg of MnO 2
K 2 SO 4 solid (S102) 384 kg
H 2 O distilled 3033 kg

in a 30% by mass solution (120 kg of sulfuric acid diluted with water to 1462 L) is
charged. The following reactions take place:

(
4 (
4 (
ZnO solid) + H SO solution) → ZnSO sol) + H O (5.2)
2
2
(
4 (
4 (
) (
Zn OH solid) + HSO solution) → ZnSO sol) + 2HO (5.3)
2
2
2
2 (
4 (
4 (
(
Zn solid) + HSO solution) →β ZnSO sol) + H gas) (5.4)
2
(
4 (
4 (
MnO solid) + HSO solution) → MnSO sol) + H O (5.5)
2
2