Russian Journal of Applied Chemistry, Vol. 77, No. 5, 2004, pp. 708 710. Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 5,
2004, pp. 712 714.
Original Russian Text Copyright
2004 by Lebedev, Lokshin, Mel’nik, Shchur, Popova.
INORGANIC SYNTHESIS
AND INDUSTRIAL INORGANIC CHEMISTRY
Possibility of Integrated Processing
of the Baddeleyite Concentrate
V. N. Lebedev, E. P. Lokshin, N. A. Mel’nik, T. E. Shchur, and L. A. Popova
Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials,
Kola Scientific Center, Russian Academy of Sciences, Apatity, Murmansk oblast, Russia
Received August 21, 2003; in final form, December 2003
Abstract Main procedures used in integrated processing of baddeleyite, including sintering with calcium
carbonate or oxide, decomposition of the cake with hydrochloric acid, and recovery of zirconium in the form
of zirconium oxochloride, were studied.
The baddeleyite concentrate (BC) from the Kovdor
deposit, which contains no less than 97.5 98.5%
ZrO + HfO , is used without chemical processing in
many fields of technology. Its use for production of
zirconium compounds is considered to be inexpedient
the content of U and Th were determined by radiom-
etry and -ray spectrometry.
2
2
The baddeleyite concentrate was ground in a ball
mill to grain size of less than 0.054 mm, mixed with
CaCO and CaCl in weight ratio of 10 : 8.2 : 1.2, and
3
2
since the cost of ZrO in the concentrate is nearly
2
sintered at 1150 C for 4 h. The cake was dissolved in
twice that in zircon. In view of the decreasing demand
for BC because of the saturation of the market with
zircon-based synthetic materials [1], a necessity arises
for deeper processing of the concentrate. The prof-
itability of such a processing can be substantially
improved by recovery of Sc(III), Ta(V), and Nb(V),
which are present in the BC in amounts whose cost,
at the world prices, is comparable with that of the
concentrate. Previously, the distribution of rare and
radioactive elements in various flowsheets of BC
processing has been studied, and it was shown that
simultaneous synthesis of pure zirconium compounds
and recovery of rare and radioactive elements into
separate concentrates is the most efficient in proces-
hydrochloric acid, and the ZrOCl precipitate was
2
separated and washed with counterflow repulpations
to required purity. The acid consumed for washing
was used to decompose the cake. The degree of con-
centrate decomposition was 95 97%, which consider-
ably exceeds the value in sintering with CaO [2, 3].
The yield of the mother liquor after isolation of
ZrOCl was 150 250 ml per 100 g of BC ( 150 g of
2
1
cake) at a composition (g l ): 40 60 HCl, 120
180 CaO, 2 5 Fe O , 4 8 ZrO , 1.5 3.5 TiO , 1.7
2
3
2
2
3.0 Nb O , 0.25 0.4 Ta O , 0.08 0.18 Sc, 0.15
2
5
2 5
0.6 SiO , 0.06 0.12 U, and 0.05 0.1 Th. Iron finds
2
its way into the BC mainly during grinding and is
present in solution as Fe(III), with other elements also
oxidized to the highest oxidation state.
sing by sintering with CaO or CaCO and subsequent
3
transfer of chlorides or nitrates into solution. Here
we studied methods for recovery of rare elements
Rare elements were primarily recovered using
extraction techniques. It is known that Sc(III) is best
recovered with organophosphorus acids [4, 5]. The
possibility of its recovery with a 0.3 M solution of
di-2-ethylhexyl hydrogen phosphate (HDEHP) in do-
decane was studied. It was found that 99% of Sc(III)
is extracted at a phase ratio o : a = 1 : 10, and 92%,
at o : a = 1 : 50, in the case of agitation for 5 min and
settling for 1 h. The results of a large-scale experi-
ment are listed in Table 1.
into concentrates by sintering of BC with CaCO
3
and recovery of zirconium(IV) in the form of an oxy-
chloride.
EXPERIMENTAL
A baddeleyite concentrate conforming to TU
(Technical Specification) 48-0572 91 was used in the
study. Rare and impurity elements in precipitates were
analyzed by X-ray fluorescence and spectral methods,
and those in solution, by the emission and atomic-
absorption techniques. The specific radioactivity and
The extract was twice washed with a 6 N solution
of HCl at o : a = 1 : 1. Zr(IV) and Sc(III) were not
noticeably washed out; U(VI), Ti(IV), and Fe(III)
1070-4272/04/7705-0708 2004 MAIK Nauka/Interperiodica