Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 4, pp. 602−606.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © A.G. Morachevskii, T.V. Butukhanova, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 4, pp. 566−570.
OF SYSTEMS AND PROCESSES
On the Limiting Activity Coefﬁ cient
of Arsenic in Liquid Lead
A. G. Morachevskii and T. V. Butukhanova
St. Petersburg State Polytechnical University, St. Petersburg, Russia
Received February 25, 2011
Abstract—The available published data on thermodynamic properties of liquid arsenic–lead alloys were analyzed
and mathematically treated on which basis the limiting activity coefﬁ cients of arsenic in liquid lead were calculated
for several temperatures.
Arsenic is a characteristic impurity in lead both
recovered from ores  and obtained by secondary lead
processing [2, 3]. Thermodynamic substantiation of the
process of lead treatment to remove the arsenic impurity
requires knowledge of the activity of arsenic in liquid
lead at very low As content.
The phase diagram of the As–Pb system is of the
eutectic type with the eutectic point at 291°C and
mole fraction of arsenic x
as low as 0.0685 . The
thermodynamic properties of the arsenic–lead system
were the focus of several studies [5–14], in particular,
by the EMF method using molten salt electrolytes
[5, 8, 9, 14] and heterogeneous equilibrium method
, as well as by calorimetric measurements [7, 12]
and saturated arsenic vapor determination [7, 10, 11].
Table 1 summarizes the data from those studies which
mostly cover limited composition ranges and whose
results are not entirely consistent across them . The
data reported by Rtskhiladze et al. [11, 12] were not
included in Table 1, because they do not contain reliable
Moriyama et al.  reported on signiﬁ cant positive
Table 1. Summary of thermodynamic quantities of liquid arsenic–lead liquid alloys
Arsenic content x
EMF 723–873 0.130–0.647 
Vapor pressure 976 0.01–0.09 
Heterogeneous equilibrium 913 To 0.80 
Calorimetry 793 To 0.18 
EMF To 953 0.05–0.70 
EMF 753–943 0.10–0.70 
Vapor pressure 737–855 0.10–0.50 
EMF 710–910 0.10–0.55 
No numerical data were reported.