260
J. Kim et al.
Fig. 6 Effect of time on the
lead cementation in alkaline
media at 50 °C (Zn:Pb mole
ratio = 1.0:1.0)
0
20
40
60
80
100
0
2 0
4 0
6 0
8 0
1 0 0
1 2 0
Cementation efficiency (%)
Time (t, min)
Effect of Time on the Cementation of Lead
Firstly, the experiments were carried out to investigate the effect of time on the
cementation behavior of Pb using the Zn powder. After 10 min, the reaction was
almost completed and gave 86.6–88.7% cementation efficiency over a period of 2 h
under the conditions mentioned in Fig. 6 at 1.0:1.0 Zn:Pb mole ratio. To ensure the
reaction to complete under all conditions, 30 min time was chosen for the subsequent
experiments.
Effect of the Quantity of Zn Powder
Figure 7 indicates the effect of quantity of Zn on the lead cementation with the mole
stoichiometric value of Zn in the range 1.0–2.0. The results show that the recovery of
Pb could reach ~100% at 1.2:1.0 mol ratio at 50 °C and 30 min of cementation time.
Therefore, the Zn powder equal to 1.2 times the stoichiometric (mole) requirement
was selected as the Zn dose.
Fig. 7 Effect of quantity of
Zn on the lead cementation
in alkaline media at 50 °C
for 30 min
0
20
40
60
80
100
1:1
1.1:1
1.2:1
1.5:1
2.0:1
Cementation efficiency (%)
Zn:Pb ratio (mole)