XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3005
Next, cementation experiments were carried out using
ZVI powder as a reductant to recover extracted Pb2+ as
zero-valent Pb. Effects of the ZVI addition and cementa-
tion time on recovery of extracted Pb2+ in the leachate were
investigated after PbSO4 extraction using CH3COONH4
3.5 M for 30 min (Figure 2). Almost all extracted Pb2+ was
recovered with more than 0.1 g of ZVI for 24 h, and with
ZVI 0.5 g within 1 h. To confirm the recovery of Pb2+ on
ZVI, the residue obtained from the cementation experi-
ment using 1 g/10 mL of ZVI for 24 h was analyzed using
SEM-EDS, suggesting that the extracted Pb2+ was reduc-
tively deposited on ZVI via the following cementation
reaction
Pb^CH COO Fe Pb 2CH COO Fe
3 2
0 0
3
2+ +=++-^aq h h
Coupled Extraction-Cementation of PbSO4 Using
NaCl-HCl and Zero-Valent Fe
First, the extraction experiments of PbSO4 were conducted
using 5 M of NaCl acidified with 0.1 M of HCl (NaCl-
HCl) at solid-liquid (S/L) ratio of 0.5 g/10 mL and the
extraction efficiency of PbSO4 was ~40%. Extraction of
PbSO4 with Cl− would occur as illustrated in following
equations (Farahmand 2009 Zhang 2019)
PbSO Cl PbCl SO
4 4
2- +=+-+
PbCl Cl PbCl
2 .+=+-
PbCl2 Cl PbCl
3 +=--
PbCl Cl PbCl
3 4
2- +=--
Figure 1. The extraction efficiency of Pb (a) after 24 h with different concentrations of
CH
3 COONH
4 (0−6.5 M), (b) after 0−60 min with CH
3 COONH
4 3.5 M
Figure 2. The Pb recovery in the leachate after PbSO
4 extraction using CH
3 COONH
4 3.5 M for
30 min (a) after 24 h with different amount of ZVI (0.1−0.5 g/10 mL), (b) after 0−2 h with ZVI
0.5 g/10 mL
Next, cementation experiments were carried out using
ZVI powder as a reductant to recover extracted Pb2+ as
zero-valent Pb. Effects of the ZVI addition and cementa-
tion time on recovery of extracted Pb2+ in the leachate were
investigated after PbSO4 extraction using CH3COONH4
3.5 M for 30 min (Figure 2). Almost all extracted Pb2+ was
recovered with more than 0.1 g of ZVI for 24 h, and with
ZVI 0.5 g within 1 h. To confirm the recovery of Pb2+ on
ZVI, the residue obtained from the cementation experi-
ment using 1 g/10 mL of ZVI for 24 h was analyzed using
SEM-EDS, suggesting that the extracted Pb2+ was reduc-
tively deposited on ZVI via the following cementation
reaction
Pb^CH COO Fe Pb 2CH COO Fe
3 2
0 0
3
2+ +=++-^aq h h
Coupled Extraction-Cementation of PbSO4 Using
NaCl-HCl and Zero-Valent Fe
First, the extraction experiments of PbSO4 were conducted
using 5 M of NaCl acidified with 0.1 M of HCl (NaCl-
HCl) at solid-liquid (S/L) ratio of 0.5 g/10 mL and the
extraction efficiency of PbSO4 was ~40%. Extraction of
PbSO4 with Cl− would occur as illustrated in following
equations (Farahmand 2009 Zhang 2019)
PbSO Cl PbCl SO
4 4
2- +=+-+
PbCl Cl PbCl
2 .+=+-
PbCl2 Cl PbCl
3 +=--
PbCl Cl PbCl
3 4
2- +=--
Figure 1. The extraction efficiency of Pb (a) after 24 h with different concentrations of
CH
3 COONH
4 (0−6.5 M), (b) after 0−60 min with CH
3 COONH
4 3.5 M
Figure 2. The Pb recovery in the leachate after PbSO
4 extraction using CH
3 COONH
4 3.5 M for
30 min (a) after 24 h with different amount of ZVI (0.1−0.5 g/10 mL), (b) after 0−2 h with ZVI
0.5 g/10 mL