TITLE:
The Optimization of Lead Electrodeposition from Leachant of Lead Laden Cupels
AUTHORS:
Innocencia S. Mpofu, Edwina Muleya, Washington Mutatu
KEYWORDS:
Cupel, Leaching, Leachant, Electrodeposition, Aceticacid, EDTA
JOURNAL NAME:
Open Access Library Journal,
Vol.3 No.7,
July
26,
2016
ABSTRACT: Disposal of lead laden cupels is proving problematic to mining and
metallurgical companies due to environmental and health issues. In this study
the optimization of operation parameters for the electrode position of lead
metal from acetic acid leachant was carried out. The effects of voltage,
temperature, concentration, size of electrode and the effect of the space between
the electrodes were investigated. Acetic acid (10%) was used as a leachant in
the optimization process. The optimum voltage was found to be 6 V, with the
best operating temperature of 20°C.
The amount of lead deposited increased with increase in
concentration of the lead in solution up to an optimum concentration of 2271.1
ppm. However the extraction efficiencies tended to decrease with increase in
concentration. The optimum inter-electrode distance was observed to be 4 cm
with 0.5 cm radius electrodes that gave the largest extraction efficiency
(70.9%). Acetic acid (10%) was preferred as a leachant compared to EDTA (0.1 M)
because it gave higher leaching and electrode position efficiencies (73.3% vs
68.1) and (95% vs 90.8) respectively. EDTA (0.1 M) was however found to be less
corrosive to the carbon electrodes as observed with acetic acid. Other advantages
of acetic acid are that it is cheaper, can be obtained from renewable sources
and is easy to use because there is no need for constant pH monitoring and
adjustments.