Obtaining of high-purity titanium, zirconium, and hafnium by the method of iodide refining in industrial conditions

Article abstract of DOI:10.1134/S0020168510030131

The processes of obtaining high-purity titanium, zirconium, and hafnium by the method of thermal dissociation of iodides are discussed. The data on cleaning of the metals from impurities in glass and metal closed-type vessels are presented. The types of v

Full text of DOI:10.1134/S0020168510030131

ISSN 0020ꢀ1685, Inorganic Materials, 2010, Vol. 46, No. 3, pp. 282–290. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © M.L. Kotsar’, O.G. Morenko, M.G. Shtutsa, S.G. Akhtonov, A.V. Aleksandrov, A.G. Ziganshin, S.I. Indyk, E.N. Kucheryavenko, V.V. Lazarenko,
A.O. Lapidus, V.A. Pogadaev, A.M. Popov, 2010, published in Neorganicheskie Materialy, 2010, Vol. 46, No. 3, pp. 332–340.
Obtaining of HighꢀPurity Titanium, Zirconium, and Hafnium
by the Method of Iodide Refining in Industrial Conditions
a
b
b
b
b
M. L. Kotsar’ , O. G. Morenko , M. G. Shtutsa , S. G. Akhtonov , A. V. Aleksandrov ,
b
c
b
a
a
A. G. Ziganshin , S. I. Indyk , E. N. Kucheryavenko , V. V. Lazarenko , A. O. Lapidus ,
b
a
V. A. Pogadaev , and A. M. Popov
a
OAO AllꢀRussia Research Institute of Chemical Technology, Moscow, Russia
eꢀmail: kotsar@vniiht.ru
OAO Chepetsk Mechanical Plant, Glazov, Russia
b
eꢀmail: post@chmz.net
OAO TVEL, Moscow, Russia
c
eꢀmail: info@tvel.ru
Received February 20, 2009
Abstract—The processes of obtaining highꢀpurity titanium, zirconium, and hafnium by the method of therꢀ
mal dissociation of iodides are discussed. The data on cleaning of the metals from impurities in glass and
metal closedꢀtype vessels are presented. The types of vessels used in industry and the conditions of raw stock
pretreatment and iodide refining of titanium, zirconium, and hafnium are described.
DOI: 10.1134/S0020168510030131
INTRODUCTION
The advantage of the process of iodide refining of metꢀ
als (Ti, Zr, Hf) is that it makes it possible to process various
waste metals resulting from production and, in addition,
to obtain highꢀpurity metals in the form of compact rods
convenient for subsequent treatment.
The aim of this work is to obtain and clean titanium,
zirconium, and hafnium by iodide refining in industrial
The process of iodide refining provides fine cleaning of
titanium, zirconium, and hafnium from impurities and
allows metals to be obtained in a compact form [1],
decreasing their activity to the influence of external facꢀ
tors.
The process of cleaning of titanium, zirconium, and metal vessels of the Tsꢀ40 type.
hafnium from impurities in glass and quartz vessels is
described in [2–5]. In industrial conditions, the process of
THEORETICAL ANALYSIS
iodide refining is implemented in metal vessels made of
nickel–chromium alloys, in particular, of the KhN78T
alloy [6].
The process of iodide refining of metals (Ti, Zr, Hf) is
based on the chemical transport reaction [1]
200–500°C
1100–1500°C
М (sol)+ 2I (gas)
2
МI (gas)
4
4I (gas) + М (sol),
(1)
which is implemented in a closed volume in two differꢀ practice; therefore, the behavior of impurities in the
ent temperature zones. The effect of cleaning from process of iodide refining can be different in each speꢀ
impurities results from the difference of thermodyꢀ cific case and in different vessels.
namic and physicochemical properties of the metal–
iodine and impurity element–iodine systems, in parꢀ
In [4, 5], the linear dependences of the coefficients of
cleaning (Kclean
= Cin imp/Cfin imp) on impurity content in
ticular, Gibbs energies, partial pressures of iodides,
temperatures of their dissociation or disproportionꢀ
ation, and temperatures and rates of interaction with
iodine. The thermodynamic bases of the mechanism
of metal impurity transfer in the process of iodide
refining of zirconium are discussed in [7]. The combiꢀ
initial materials (Cfin imp) of zirconium and hafnium are
found
Kclean
=
a
(
Cin imp
–
Cmin imp) + 1 (Zr),
(Hf).
(2)
(3)
logKclean
=
a
logCin imp + b
nation of necessary conditions of cleaning in closed Equation (2) describes the cleaning of zirconium from
vessels given in [7] cannot always be obtained in actual impurities to the minimum concentration (
Cmin imp) at
282

OBTAINING OF HIGHꢀPURITY TITANIUM, ZIRCONIUM, AND HAFNIUM
283
Kclean = 1; Eq. (3) describes experimental data in a
wider range of impurity concentrations, including the
nickel concentration of 11.5 wt %.
6
7
1
The most complete cleaning of titanium, zirconium,
and hafnium from impurities is obtained after triple iodide
refining [2, 3]. Herein, the amount of impurities in rods
varies from the second refining to the third one much less
than it does from the first to second refining; the refining
effect is shown in the increase in the ratio of electrical
5
resistivities (
98, and from 21 to 33 for titanium, zirconium, and
hafnium, respectively.
ρ
298 K/
ρ
4.2 K) from 140 to 190, from 165 to
1
2
EXPERIMENTAL
Iodide zirconium is obtained in Tsꢀ40 vessels [8]. A Tsꢀ
4
0 industrial vessel, which is applied for iodide refining of
metallic zirconium and its alloys with niobium, is scheꢀ
matically shown in Fig. 1. The raw material in the form of
chippings is placed along the walls of the retort and the
central part of the vessel. A zigzag thread for deposition of
the metal is suspended in the annular gap between the
central part and the retort wall; its diameter is 4–5 mm.
The temperature of the thread during the process is
4
3
Fig. 1. Tsꢀ40 industrial vessel for obtaining iodide zirconium:
) current lead; ( ) central part; ( ) retort; ( ) thread (zircoꢀ
nium wire); ( ) raw material; ( ) vessel head; ( ) ampoule with
iodine.
(1
2
3
4
7
5
6
1
050–1150°С. The required temperature of the raw
material is controlled and maintained by means of a coolꢀ
ing system. Air is used as a coolant; its temperature at the
inlet of the thermostat is equal to that of the environment.
For estimation of quality of initial materials and iodide
In one complete cycle, bars of iodide zirconium with a metals obtained in industrial vessels of the Tsꢀ40 type, the
diameter of 18–20 mm are obtained.
impurity detection techniques from engineering specifiꢀ
cations ES 48ꢀ4ꢀ282ꢀ86, ES 95.46ꢀ97, and GOST (State
Hafnium is obtained in shelfꢀtype vessels (Fig. 2)
developed on the basis of Tsꢀ40. This makes it possible to
use raw material both in the form of chippings and in a
compact form (tablets, pieces, grits, and sheetꢀmaterial
cuttings) and to decrease its charge significantly. Several
threads in the form of wire pins with a diameter of ~4 mm
are arranged in the vessel; there is no raw material charge
in the central part. The temperature of the thread during
the process is 1250–1350°С. This construction allows
rods of iodide of hafnium with a diameter of 18–22 mm to
be obtained.
5
4
6
1
In the 1980s–1990s, iodide titanium was obtained in
Tsꢀ40 industrial vessels. Chippings of VT1ꢀ0 alloy and
chippings from ingots after electronꢀbeam remelting of
titanium sponge were used as a raw material for iodide
refining. The metal was deposited on a titanium wire of
circular or square cross section with a diameter or side of
~4 mm. The wire was suspended on the vessel head in the
3
2
form of several independent loops. The temperature of
the thread during the process was 1150–1250°С. Rods
with a diameter or side up to 19 mm were obtained.
Before iodide refining, the raw materials charged into
industrial vessels is subjected to degassing; in the case of
hafnium, this procedure is carried out two times. The
conditions of raw stock degassing and iodide refining of
titanium, zirconium, and hafnium are given in Tables 1
and 2, respectively.
Fig. 2. Shelfꢀtype industrial vessel based on a Tsꢀ40 vessel for
obtaining iodide hafnium: ( ) current leads; ( ) thread
hafnium wire); ( ) retort; ( ) shelves for raw material chargꢀ
ing; ( ) vessel head; ( ) ampoule with iodine.
1
2
(
3
4
5
6
INORGANIC MATERIALS Vol. 46
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284
KOTSAR’ et al.
Table 1. Conditions of degassing of the raw material of titanium, zirconium, and hafnium (shaft furnace; Tsꢀ40 vessel)
Time, h
Leakage,
Pa l/s (μm Hg l/s)
M
tmax
,
°
C
pres, Pa (mm Hg)
total
at tmax
Ti
450–500
400–450
900–950
12
–
–
0.0133 (0.0001)
0.0133 (0.0001)
<0.133 (<1)
<0.133 (<1)
Zr
Hf
8–10
6–16
2
2.0 (0.015)
–
400–450
20–160
–
0.0133 (0.0001)
<0.133 (<1)
Table 2. Conditions of iodide refining of titanium, zirconium, and hafnium (Tsꢀ40 vessel)
Specific power, W/cm2
Retort wall
Raw material Specific rate,
M
Ti
Furnace
Time, h
temperature, °C
weight, kg
g/(m h)
beginning
end
Thermostat
40–43
35
8–9
12–13
550–650
–
60–70
40–46
Zr
Hf
Thermostat
Shaft
6
10
250 ± 15 (170 ± 50)ꢁ 100–150
450–500 60–80
48–56
52–82
ꢁ
Temperature of cooling air.
Standard) 22517ꢀ77 were used for titanium, zirconium, them consists in the heat removal from the raw material by
and hafnium, respectively. The sensitivity level of these the air through the wall. This makes it possible to increase
techniques, which are based, as a rule, on emission specꢀ the specific deposition rate for titanium, zirconium, and
tral, atomic absorption, and neutron activation methods hafnium by a factor of 2, 2.5, and 3 on average, respecꢀ
of analysis, is lower than that of the spark massꢀspectral tively; to extend the duration of processes of iodide refinꢀ
method of detection of impurity content in these metals ing to 35–55 h; and to obtain rods of iodide titanium, zirꢀ
subjected to iodide refining in glass vessels [2, 3].
conium, and hafnium with a diameter of 18–22 mm.
The metallographic examinations of the structural
condition of metals were carried out for rods of titanium,
zirconium, and hafnium after iodide refining. The metalꢀ
lographic samples for analysis were prepared in two stages:
abrading by means of abrasive papers with different abraꢀ
sive grits and polishing with the use of diamond pastes.
The microstructure of rods of each metal was determined
by chemical etching in solutions of different compositions
containing concentrated nitric, hydrofluoric, and sulfuric
acids, glycerol, and water.
Tables 3–5 present the chemical composition of
iodide titanium, zirconium, and hafnium obtained from
approximately equivalent raw material in glass (quartz)
and metal vessels of the KhN78T alloy in laboratory and
industrial conditions. It follows from the given data that
the real amount of impurities in rods of all the metals is
lower than the technical requirements by a factor of 2–4;
the content of individual impurities, as a rule, corresponds
to their detection limit in the applied techniques. In
obtaining hafnium, it appeared to be advantageous to
apply the twoꢀstage degassing of raw material and the linꢀ
ing of shelves with molybdenum foil. This allowed obtainꢀ
ing iodide of hafnium in an industrial vessel with the
amount of impurities lower by a factor of 1.5 than in a
The microstructure was studied with an OLYMPUSꢀ
GXꢀ51 invertedꢀstage microscope and an LECO IAꢀ32
image analyzer in the photo mode at magnifications of
×
50 and
×
100.
The microhardness was determined by a PMTꢀ3 quartz vessel.
microhardness gage at a load of 0.49 N according to
GOST 9450ꢀ76.
Figure 3 depicts the physical form of rods of iodide of
titanium, zirconium, and hafnium; Fig. 4 shows the
microstructure of their cross section.
RESULTS AND DISCUSSION
The structure of a titanium rod is granular (polyheꢀ
The comparison of the conditions of experiments on dral), homogeneous in cross section. The analysis of the
iodide refining of titanium, zirconium, and hafnium in titanium rod structure revealed elongated pores extending
glass (quartz) [2–5] and metal vessels (KhN78T alloy, Tsꢀ radially from the periphery to the center at a depth up to
40 vessel) shows that the fundamental difference between oneꢀhalf of the radius of the cross section. The microꢀ
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OBTAINING OF HIGHꢀPURITY TITANIUM, ZIRCONIUM, AND HAFNIUM
285
Table 3. Chemical composition, coefficients of cleaning from impurities, and microhardness of titanium obtained in the proꢀ
cess of iodide refining in glass and metal (Tsꢀ40) vessels (IT stands for iodide titanium)
Impurities, wt %
Impurities, wt %
Chippings
Impurities, wt %
Mgꢀreꢀ
duced
Kclean
Kclean
GOST
19807ꢀ91ꢁ
IT
IT
ITꢀ1
ITꢀ2
Element
sponge
Iodide refining of titanium
in a glass vessel
Iodide refining of VT1ꢀ0 alloy wastes
in a Tsꢀ40 vessel
ES 48ꢀ4ꢀ282ꢀ86ꢁꢁ
Nitrogen
0.02
0.000012
0.0022
–
1670
4.5
0.04
–
0.11
0.0043
–
0.0018
0.0018
0.0001
0.0014
61
2.4
–
–
Aluminum
Hydrogen
Iron
0.010
–
0.005
–
0.02
–
–
0.008
0.15
0.10
0.08
–
0.05
0.04
0.04
0.07
0.004
–
0.00093
0.024
54
1.6
0.018
0.2
13
0.005
–
0.05
–
Oxygen
<0.01
>20
Silicon
0.0001
0.001
400
70
0.0073 <0.0008
9.1
0.009
0.004
0.004
–
0.01
0.02
0.015
–
Magnesium
Manganese
Copper
–
–
<0.001
<0.001
<0.001
0.0088
0.009
–
–
0.0034
0.00064
0.000012
0.000018
0.000074
0.00087
1.2
–
–
–
1330
1110
1080
–
–
–
–
Nickel
0.016
0.02
0.08
–
–
0.012
0.019
–
1.4
2.1
–
0.005
0.01
–
0.015
0.03
–
Carbon
0.05
–
Chlorine
Chromium
–
0.0062
8
0.00085
12
7.3
–
0.005
8
0.03
8
Number of detected
impurities
10
12
–
6
Amount of impuriꢀ
ties
0.350
–
0.03328
10.5
0.328
–
0.3768 <0.0376
<10
≤
0.047
–
≤
0.19
–
Microhardness,
By Vickers
746 (76)
–
–
–
–
1090–1178
(111–120)
–
–
2
MPa (kgf/mm
)
ρ298 K/
ρ
–
190ꢁꢁꢁ
–
–
–
–
4.2 K
ꢁ
Maximum values.
ꢁ Term of validity expired on January 1, 1991.
ꢁꢁ After triple iodide refining of a magnesiumꢀreduced sponge.
ꢁ
ꢁ
hardness values across the rod section vary from 1090 to metal along the rod’s cross section ranges from 1080
2
2
1
178 MPa (111–120 kgf/mm ).
to 1444 MPa (110–147 kgf/mm ).
The microstructure of iodide zirconium along the
The microstructure of a rod of iodide hafnium is granꢀ
cross section of the rod is also homogeneous. The ular. The grain growth direction from the center to the
peripheral and central zones of the rod’s cross secꢀ periphery is revealed. A hafnium thread is seen in the cenꢀ
tion hardly differ at all. The microhardness of the tral zone (Fig. 4). A discontinuity of the metal of the rod
INORGANIC MATERIALS Vol. 46
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286
KOTSAR’ et al.
Table 4. Chemical composition, coefficients of cleaning from impurities, and microhardness of zirconium in the process of ioꢀ
dide refining in glass and metal (Tsꢀ40) vessels (IZ stands for iodide zirconium)
)
Impurities, wt % Impurities, wt %
Chippings of
Impurities,
wt %
Kclean
briquettes of
sintered elecꢀ
trolytic powꢀ
der
Kclean
Electrolytic
powder
IZ
IZ
Element
Iodide refining of zirconium in
a glass vessel [5]
Iodide refining of zirconium
in a Tsꢀ40 vessel
ES 95.46ꢀ97
Nitrogen
0.045
0.14
0.00015
0.00094
–
300
148.9
–
0.0045
<0.002
0.001
0.0003
<0.00003
–
>2.2
0.005
0.005
0.001
0.00005
–
Aluminum
Beryllium
Boron
0.0011
<0.003
0.000042
–
1
–
–
–
–
>1.4
–
1
Tungsten
Hafnium
Iron
0.006
0.0019
0.018
–
0.004
1.5
1
0.0029
0.0048
–
0.034
0.0081
–
0.03
0.05
0.03
0.00005
–
3.75
0.004
0.00003
–
2
Cadmium
Potassium
Calcium
Oxygen
–
122.6
1564
511
–
–
11
8
0.00038
0.0061
0.87
0.0000031
0.0000039
0.0017
0.00091
–
0.016
0.0036
0.056
0.004
–
0.00032
0.007
0.002
0.0001
–
0.02
0.05
0.008
0.0002
–
Silicon
0.0061
–
6.703
2
Lithium
Magnesium
Manganese
Copper
–
–
–
1
0.0013
0.0012
0.0055
–
0.000052
0.0000038
0.00041
–
25
–
315.8
13.42
–
0.0003
0.0003
–
0.0003
0.0003
0.003
0.004
<0.006
0.0013
0.003
0.002
0.003
–
0.001
0.003
0.005
0.01
0.01
0.05
0.005
0.005
0.008
–
1
Molybdenum
Nickel
–
0.0012
0.002
0.014
0.000011
0.01
0.00064
0.00091
0.000021
0.000011
0.001
1.875
2.198
666.7
1
0.003
–
0.75
Niobium
Tin
–
–
–
–
1.3
–
–
1
–
Lead
<0.003
<0.003
0.0046
0.017
0.0033
0.0032
19
Titanium
Carbon
10
0.0016
0.24
0.00011
0.00062
0.000031
–
14.54
387.1
Fluorine
Chlorine
Chromium
0.5
16129
–
–
–
–
–
<0.003
21
0.02
21
Number of detectꢀ 20
ed impurities
20
–
Amount of impuriꢀ
ties
1.8703
0.01922
97.3
<0.168
<0.0644
2.6
≤0.2863
Microhardness,
By Vickers
628 (64)
1080–1444
(110–147)
2
MPa (kgf/mm
)
ρ298 K/
ρ
–
220
–
–
–
–
–
4.2 K
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OBTAINING OF HIGHꢀPURITY TITANIUM, ZIRCONIUM, AND HAFNIUM
287
Table 5. Chemical composition, coefficients of cleaning from impurities, and microhardness of hafnium in the process of iodide
refining in quartz and metal (based on Tsꢀ40) vessels (IH stands for iodide hafnium)
Impurities,
Impurities, wt %
Impurities, wt %
wt %
Kclean
Kclean
ES 95.2195ꢀ
Element
Chippings
IH
Chippings
IH
(
GFIꢀ1)
90ꢁ
Iodide refining of hafnium
in a quartz vessel [5]
Iodide refining of hafnium coils in an industrial GOST 22517ꢀ
shelfꢀtype vessel
77ꢁ
Nitrogen
0.01
0.003
<0.01
–
3.3
–
–
–
1
0.005
0.005
–
0.0035
0.042
–
<0.002
>1.7
>14
0.005
0.005
–
Aluminum
Hydrogen
Tungsten
Iron
<0.01
–
<0.003
<0.0008
–
–
–
–
–
0.01
0.04
0.01
0.05
0.005
0.004
0.0005
0.005
0.01
0.02
0.01
0.005
0.01
0.003
1.0
–
–
0.03
–
0.03
–
0.071
0.16
0.01
0.01
0.095
–
<0.007
<0.003
<0.007
<0.003
<0.003
<0.0003
–
>10
>53
0.04
0.01
–
Calcium
Oxygen
–
0.01
0.003
0.002
0.004
0.02
–
<0.01
<0.003
0.002
0.0003
0.002
–
>1
>1.4
>3.3
>32
Silicon
>1
1
0.005
0.004
0.0005
–
Magnesium
Manganese
Copper
13
10
–
–
–
0.002
0.002
–
Molybdenum
Nickel
<0.003
<0.003
<0.006
<0.003
<0.006
<0.003
<1
–
0.1
0.007
–
0.003
–
2.3
–
0.05
–
Niobium
Titanium
Carbon
–
–
–
0.05
0.018
0.001
0.75
13
0.009
0.01
0.001
0.75
13
5.5
1.8
1
–
–
0.005
0.01
0.003
1.0
0.01
0.001
>1.7
–
Chromium
Zirconium
1
<1
12
–
Number of detectꢀ
ed impurities
–
17
16
–
13
Amount of impuriꢀ
ties (without Zr)
£
0.165
–
£
0.0833
2
<0.1925
0.4065
<0.0531
>7.6
–
≤
0.1375
(
without Zr
and Mo
–
)
Microhardness,
2187 (220)
By Vickers
767 (180) [3]
–
–
–
–
–
–
1757–1934
(179–197)
MPa (kgf/mm
)
1
ρ298 K/
ρ
–
36 [3]
–
–
–
4.2 K
ꢁ
Maximum values.
INORGANIC MATERIALS Vol. 46
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288
KOTSAR’ et al.
(а)
(b)
(c)
Fig. 3. Physical form and macrostructure of rods of iodide of titanium (a), zirconium (b), and hafnium (c):
×
100 (a, b) and
×
50 (c).
2010
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OBTAINING OF HIGHꢀPURITY TITANIUM, ZIRCONIUM, AND HAFNIUM
а)
289
(
(b)
(
c)
Fig. 4. Microstructure of the cross section of rods of iodide titanium (a), zirconium (b), and hafnium (c): ×100 (a, b) and ×50 (c).
of iodide hafnium around the thread is observed in the size and shape of deposited crystals can vary (from a round
form of pores of various configurations: round, dropꢀ
shaped, and extended (elongated). The formation of the
discontinuity zone around the thread (wire) is apparently
related to different temperature conditions of metal depꢀ
shape to a dendriteꢀlike one), which affects the density of
their coalescence.
The measurements of microhardness along the cross
osition at the starting moment of the process of iodide section of the rod of iodide hafnium showed that it varies
2
refining. Depending on temperature of the thread, the from 1757 to 1934 MPa (179–197 kgf/mm ).
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2
90
KOTSAR’ et al.
2. Elyutin, A.V., Denisova, N.D., Baskova, A.P., and
CONCLUSIONS
The conditions of iodide refining of titanium, zircoꢀ
Bystrova, O.P., Behavior of Impurities under Obtaining of
HighꢀPurity Titanium by the Method of Iodide Refining,
in Nauchnye trudy GIREDMETa (Transactions of
GIREDMET), Moscow: Metallurgiya, 1981, vol. 106,
pp. 3–9.
nium, and hafnium in laboratory glass (quartz) and indusꢀ
trial metal (KhN78T alloy) vessels are compared. It is
shown that the fundamental difference between them
is the heat removal from the raw material by the air
through the wall, which decreases excessive heating.
This makes it possible to increase the specific depoꢀ
sition rate for titanium, zirconium, and hafnium by a
factor of 2, 2.5, and 3 on average, respectively; to
extend the duration of processes of iodide refining to
3. Elyutin, A.V., Denisova, N.D., Baskova, A.P., and
Bystrova, O.P., Behavior of Impurities in the Process of
Iodide Refining of Zirconium and Hafnium, in Nauchnye
trudy GIREDMETa (Transactions of GIREDMET), Mosꢀ
cow: Metallurgiya, 1980, vol. 96, pp. 63–69.
4
. Kotsar’, M.L., Nikonov, V.I., Fedorov, V.D., et al., Iodide
Refining of CalciumꢀThermic Reduced Zirconium, Vopr.
At. Nauki Tekh., Ser. Fiz. Radiats. Povrezhdenii Radiats.
Materialoved., 2002, issue 6, pp. 100–105.
3
5–50 h; and to obtain rods of iodide titanium, zirꢀ
conium, and hafnium with a diameter of 18–22 mm.
The requirements on the chemical composition of
rods of iodide titanium, zirconium, and hafnium are
defined in ES 48ꢀ4ꢀ282ꢀ86, ES 95.46ꢀ97, and GOST
5. Evstyukhin, A.I., Leont’ev, G.A., Kotsar’, M.L., et al.,
Cleaning from Impurities in the Process of Iodine Refining
of Hafnium and its Alloys with Nickel, in Konstruktsionnye
materialy v atomnoi tekhnike: Sbornik nauchnykh trudov
MIFI (Engineering Materials in Nuclear Engineering:
Collection of Scientific Papers of MEPhI), Moscow:
Energoatomizdat, 1987, pp. 15–24.
2
2517ꢀ77, respectively. The real amount of impurities in
bars of all the metals is lower than the technical requireꢀ
ments by a factor of 2–4; the content of individual impuꢀ
rities, as a rule, corresponds to their detection limit in the
applied techniques.
6
. Belomestnykh, B.V., Golubev, M.V., Golubo, S.V., et al.,
Advances in Technology of Iodide Refining of Zirconium,
Tezisy dokladov VI Otraslevoi konferentsii po gidrometalꢀ
lurgii i metallurgii tsirkoniya (Abstracts of Papers of VI
Industry Conf. on Hydrometallurgy and Metallurgy of Zirꢀ
conium), Dneprodzerzhinsk, 1986, p. 169.
The efficiency and extent of the cleaning of titanium
from impurities in glass (quartz) and metal (KhN78T
alloy) vessels are approximately the same. The cleaning of
zirconium raw material from impurities in a Tsꢀ40 indusꢀ
trial vessel is lower than that in a laboratory glass vessel.
The cleaning of hafnium in a metal vessel lined with
molybdenum foil is higher than that in a quartz vessel.
7. Evstyukhin, A.I., Leont’ev, G.A., and Shulov, V.A., Study
of the Mechanism of Metal Impurity Transfer in the Proꢀ
cess of Iodide Refining of Zirconium., Materialy soveshꢀ
chaniya po voprosam polucheniya i issledovaniya svoistv
chistykh metallov (Proc. Meeting on Problems of Obtaining
and Study of Properties of Pure Metals), Kharkov, 1977,
pp. 13–16.
REFERENCES
1
. Rolsten, R.F., Iodide Metals and Metal Iodides, New York:
Wiley, 1961 [Moscow: Metallurgiya, 1967, pp. 86–89].
8. Moiseev, V.G., Morenko, O.G., Pogadaev, V.A., et al., RF
Patent 2261287, Byull. Izobret., 2005, no. 27.
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2010