Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 10, pp. 1567−1569.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © A.G. Vodop’yanov, G.N. Kozhevnikov, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 10, pp. 1633−1635.
TECHNOLOGY OF ELECTROCHEMICAL
AND OTHER INDUSTRIES
Recovery of Rhenium and Osmium from Sulfurous Gases
with Solid Carbon
A. G. Vodop’yanov and G. N. Kozhevnikov
Institute of Metallurgy, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia
Received June 26, 2012
Abstract—The possibility of recovering rhenium and osmium from sulfurous gases generated by oxidative roasting
of commercial molybdenite product was examined. When passing through solid carbon packing at a temperature
in the range 288–380°С, higher rhenium and osmium oxides are adsorbed on the surface of the packing to lower
oxides, which allows their hydrochemical separation from the reductant with obtaining potassium perrhenate,
potassium osmate, and osmium sulﬁ de.
Rhenium is a rare and trace element. It is a heavy
high-melting metal exhibiting high wear resistance. It
is used as a component of heat-resistant alloys, electric
contacts, and wear-resistant parts, and also in other ﬁ elds.
The main sources of rhenium are copper–molybdenum
and copper–nickel sulﬁ de ores. In the course of their oxi-
dative roasting, rhenium is released into the gas phase in
the form of the higher oxide Re
(boiling point 359°С).
It is recovered from sulfurous gases to 50–90% by wet
dust trapping. In so doing, sulfuric acid solutions are
formed, from which rhenium is precipitated in the form
of potassium perrhenate or rhenium sulﬁ de .
It should be noted that these ores contain, along with
rhenium, also osmium, a trace platinum element. It is
also used as a component of superhard and wear-resistant
alloys. In oxidative roasting of the raw material, it is
entrained with off-gases in the form of the higher oxide
(boiling point 130°С).
In this study we examined the possibility of dry re-
covery of rhenium and osmium from sulfurous gases by
passing them through solid carbon packing.
Oxidative roasting of commercial molybdenite
product (CMP) with simultaneous recovery of rhenium
and osmium oxide vapors was performed in a labora-
tory installation (Fig. 1). Its main part consisted of two
stainless steel pipes 43 mm in diameter, welded at right
angle. The horizontal and vertical parts of the pipes were
heated with Silit (silicon carbide) and spiral heaters,
respectively. Into the vertical pipe, we inserted a set of
steel grids onto which we placed coke (11–15 g on each
grid). The total amount of the coke loaded was 100.5 g.
The coke temperature in different zones was measured
with a thermocouple by moving it along the vertical. At
temperatures exceeding 400°С, the coke ignited, and the
lower metal oxides underwent oxidation to higher oxides
As raw material we used CMP from Almalyk Mining
and Metallurgical Combine, containing (%) 38.81 Mo,
31.5 S, 7.5 Fe, 3.5 Cu, 10 SiO
, 1.5 CaO, 1.5 Al
5.45 C, 0.088 Re, and 0.0039 Os. As reductant we used
metallurgical coke (fraction 0.4–1.0 mm).
A 12-g portion of CMP was placed in the roasting zone
at 600°С in an air stream (125 l h
). After the roasting
completion, the cinders were replaced by the fresh portion
of the raw material (total mount 70–100 g). The products
obtained were analyzed for the rhenium and osmium con-
tent. The transfer of Mo, Re, and Os into the gas phase
was 5.15–8.33, 82.33–82.44, and 83.2%, respectively.
Figure 2 shows how the degree of vapor deposition of