US006699453B1
(12) United States Patent
(16) Patent N68
Gorge et al.
(45) Date of Patent:
(54) SPHEROIDALLY AGGLOMERATED BASIC
COBALT(II) CARBONATE AND
(56)
SPHEROIDALLY AGGLOMERATED
References Cited
34,752 A
4,985,318 A
1/1991
Inventors: Astrid Gorge, Goslar (DE); Juliane
5,240,692 A
8/1993 Morifuji ................... .. 423/431
EP
GB
SU
_
_
Notice.
b,
d,
1 _
h
f h,
1/1977 T566 ................... .. 423/4191
219 592
6/1968
OTHER PUBLICATIONS
Chemical Abstracts, vol. 92, No. 8, Abstract No. 61186;
XP002012046 & JP_A 54 131 597'
{gatsmct iisixéengeigé gdjusted under 35
DerWentAN 78—27542; XP 002012047 & JP—A 53 021 099.
(21) Appl. NO.:
( )
y
ays'
DerWentAN 77—86019Y; XP 002012048 & SU—A 548 570.
08/952,913
DerWent AN 92—118237; XP 002012049 & JP—A 04 059
_
622.
(22)
PCT Flled:
May 14’ 1996
Abstract of JP 53—22 193 A2
(86)
PCT NO.:
PCT/EP96/02050
* Cited by examiner
§ 371 (c)(1),
.
_
(2), (4) Date'
(30)
...... .. 429/223
Su Ject to any Isc a1mer,t e term 0 t is
' ' '
(87)
Oshitani et a1.
FOREIGN PATENT DOCUMENTS
PCT/EP96/02050
7/1997
1 437 191
5/1976
(73) Assignee: H.C. Starck GmbH & Co KG, Goslar
(DE)
)
*
....... .. 126/218
4,002,719 A
Meese-Marktsche?'el, Goslar (DE);
*
3/1862 Herrick
THEIR PRODUCTION AND THEIR USE
Dirk Naumann, Ontario (CA); Armin
Olbrich, Seesen (DE); Frank
Schrumpf, Goslar (DE)
(
Mar. 2, 2004
U-S- PATENT DOCUMENTS
C0BALT(II) HYDROXIDE, PROCESS FOR
(75)
US 6,699,453 B1
.
.
Primary Examzner—Stuart L. Hendrickson
NOV‘ 24’ 1997
(74) Attorney, Agent, or Firm—Godfried R. Akorli;
PCT Pub. NO.: WO96/37436
Diderico van Eyl
PCT Pub. Date: Nov. 28, 1996
(57)
ABSTRACT
Foreign Application Priority Data
The present invention relates to basic coba1t(II) carbonate,
agglomerated from ?ne primary particles and of general
May 26, 1995 (DE) ....................................... .. 195 19 326
(51) Int. Cl.7 .............................................. .. C01G 51/06
Composition COKOHbLlCOdl-a, Where 01221209, and
to spheroidal coba1t(II) hydroxide, to a process for produc
(52)
____ __ 423/4191
ing them and to their use.
(58)
Field of Search ......................... .. 423/4191, 420.2;
126/2863, 480
7 Claims, 10 Drawing Sheets
U.S. Patent
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1
2
SPHEROIDALLY AGGLOMERATED BASIC
837. In principle, this process could also be applied to the
element cobalt. HoWever, compared With nickel the process
is made more dif?cult due to the generally knoWn fact that
cobalt(II) in its complexed state is readily oxidised to its
trivalent state. It therefore has to be ensured that atmospheric
COBALT(II) CARBONATE AND
SPHEROIDALLY AGGLOMERATED
COBALT(II) HYDROXIDE, PROCESS FOR
THEIR PRODUCTION AND THEIR USE
oxygen is excluded even more rigorously than in the con
The present invention relates to basic cobalt(II)
ventional precipitation. A general disadvantage of this
carbonate, agglomerated from ?ne primary particles and of
process, Which applies both to nickel and to cobalt, is the
fact that the ?ltrates contain ammonia and complexed metal
cations. A costly effluent treatment procedure cannot there
fore be circumvented.
The object of the present invention Was therefore to
provide a cobalt(II) hydroxide Which does not exhibit the
prior art disadvantages described and Which can be repro
general composition Co[(OH)2]a[CO3]1_a, Where
0.1§a§0.9, and to spheroidal cobalt(II) hydroxide, to a
10
process for producing them and to their use.
Pure-phase cobalt(II) hydroxide is required for a series of
industrial applications. For example, it can be used directly
or after prior calcination to form cobalt(II) oxide as a
component in the positive electrode of modern high-capacity
15
cobalt(II) carbonate having variably adjustable properties,
metal hydride.
It is uniformly distributed in the electrode material, via
such as average agglomerate diameter and speci?c surface
for example, and Which can subsequently be converted into
cobaltates(II) formed as intermediates Which are soluble in
the alkaline electrolyte of the battery (30% by Weight KOH),
20
and is deposited there by oxidation in What is termed the
forming cycle as an electrically conductive CoOOH layer on
disclosed in EP-A 353837. In addition, pure cobalt(II)
oxides are used in electronics and catalyst technology.
Cobalt(II) hydroxide or carbonate is also used for the
other compounds, eg spheroidally agglomerated cobalt(II)
hydroxide, in a series of chemical reactions Whilst retaining
its secondary morphology, can be produced by a technically
simple and economical process.
the nickel hydroxide particles. Proportions of cobalt(II)
Which are present in the starting material do not form soluble
cobaltates and therefore cannot be utilised.
The use of cobalt compounds in alkaline secondary
batteries based on nickel/cadmium or nickel/metal hydride is
ducibly produced by an economical process.
It has noW been found that spheroidally agglomerated
secondary batteries based on nickel/cadmium or nickel/
This cobalt carbonate is a basic cobalt(II) carbonate
25
Which is agglomerated from ?ne primary particles, of gen
eral composition Co[(OH)2]a[CO3]1_a, Where 0.1§a§0.9,
Wherein the agglomerates have a spheroidal habit and the
average agglomerate diameter is 3 to 50 pm. The agglom
erate diameter is preferably 5—20 pm. The basic cobalt(II)
30
production of other cobalt compounds. Amongst others,
carbonate agglomerates according to the invention prefer
ably have tap densities of 2 1.6 g/cm3 and bulk densities of
these include the cobalt salts of Weak acids, Which are
termed metal soaps. These are not only used as driers for
21.2 g/cm3.
lacquers and varnishes, but are also employed as catalysts,
cobalt(II) carbonate agglomerates according to the inven
just like cobalt(II) oxide.
This invention also relates to a process for producing the
35
adipic acid may be cited as an example.
NO3— and/or 1/2 SO 42—, are reacted With aqueous solutions
or suspensions of alkali and/or ammonium carbonates and/or
hydrogen carbonates at temperatures betWeen 40 and 100°
Cobalt(II) hydroxide can be prepared from aqueous
solutions of cobalt(II) salts by precipitation With alkaline
liquors. The resulting precipitates generally have a gel-like
40
?ne structure of the primary crystals and their irregular
agglomeration. Fine primary particles are often desired for
the applications described above, hoWever. Firstly, ?ne
primary particles dissolve more rapidly in acids, and sec
ondly the calcination or reduction of cobalt(II) hydroxides
45
Which are particularly loW in alkali.
This process is preferably carried out continuously With
intensive mixing of the reactants. Residence times in this
50
mode of operation should preferably be betWeen 0.5 hours
and 10 hours, most preferably betWeen 1 and 5 hours.
Depending on the process parameters, particularly
temperature, concentration, pH, residence time and intensity
of stirring, the chemical composition, the siZe of the primary
Acorresponding cobalt(II) hydroxide With a ?ne primary
55
particles, and the siZe and distribution of the secondary
particles, can be adjusted Within Wide limits, as is further
illustrated in Examples 1 to 4 and FIGS. 1 to 4.
The process according to the invention is characterised
technically stable, reproducible and economical method of
production.
The poor ?ltration and Washing behaviour described
above does not occur With spheroidally agglomerated pri
and economic reasons. HoWever, it may also be carried out
using ammonium carbonates in order to obtain products
such as these results in correspondingly ?ne primary par
ticles of cobalt(II) oxide or cobalt metal poWder.
particle structure can only be produced at considerable cost
by conventional processes, hoWever, so that a large discrep
ancy exists betWeen the required property pro?le and a
C., preferably 60 to 90° C., and the resulting basic cobalt(III)
carbonate agglomerates are subsequently ?ltered off and
Washed until they are neutral and free from salts.
The process according to the invention is preferably
carried out With alkali carbonates, both for environmental
consistency, are difficult to ?lter and are thus dif?cult to
Wash to render them neutral and free from salts. Moreover,
they are very sensitive to oxidation in alkaline medium, so
that the ?ltration and Washing processes have to be carried
out With the careful exclusion of atmospheric oxygen.
The cause of the poor ?ltration properties is based on the
tion. This is characterised in that aqueous solutions of cobalt
salts of general formula CoX2, Where X represents Cl—,
The catalytic use of cobalt(II) acetate in the production of
by simple process control. The basic cobalt(II) carbonates
60
according to the invention are insensitive to oxidation by
atmospheric oxygen, Which permits them to be handled
mary particles. For example, spherical nickel hydroxide,
easily. Surprisingly, it has emerged that the basic cobalt(II)
Which is used in modern alkaline secondary batteries, exhib
its excellent ?ltration and Washing behaviour.
The production of spherical nickel hydroxide from aque
ous solutions of nickel salts by precipitation With alkaline
liquors in the presence of ammonia is disclosed in EP-A 353
carbonate agglomerates according to the invention can be
converted in highly concentrated suspension With alkaline
65
liquors into pure-phase cobalt(II) hydroxides Whilst retain
ing the spheroidal secondary morphology; this is described
in more detail in Examples 5 and 6.
US 6,699,453 B1
3
4
This can be effected in a technically simple batch pro
cess. In combination With good sedimentation, ?ltration and
pure cobalt(II) acetate is therefore obtained, Which like-Wise
constitutes a source of high-purity cobalt(II) compounds.
Another industrially important cobalt(II) salt of a Weak
Washing behaviour, the best possible screening from atmo
spheric oxygen can be achieved in this manner, and the
acid is cobalt(II) phosphate. The octahydrate Co3(PO4)
process as a Whole can also be carried out economically on
2.8H2O is a pink poWder and is used to impart a blue
coloration to porcelain and glass and for the production of
an industrial scale Without high costs.
This invention thus also relates to a process for produc
enamels, glaZes and pigments.
ing agglomerated cobalt(II) hydroxide, Wherein the basic
It can be obtained in a compact agglomerated form by the
cobalt(II) carbonate agglomerates according to the invention
reaction of the basic cobalt(II) carbonate according to the
are reacted in suspension With aqueous alkaline liquors
10
invention With aqueous phosphoric acid, as described n
Example 11.
and/or ammonia. The cobalt(II) hydroxide agglomerates
obtainable by the process according to the invention are
Reaction With aqueous oxalic acid solutions can be
characterised in that they consist of spheroidally
effected in an analogous manner, With the agglomerated
agglomerated, polygonal, lamellar primary particles Which
have average diameter to thickness ratios betWeen 3 and 15.
secondary morphology being retained, to form cobalt(II)
15
oxalate, Which in turn can be used for the production of
cobalt metal poWders.
The calcination of agglomerated cobalt(II) oxalate,
optionally assisted or modi?ed by gaseous reducing agents
The spheroidal agglomerates have an average diameter
of 3—50 pm, preferably 5 to 20 pm. Their tap densities are
preferably 21 g/cm3.
On account of their special properties, such as their high
such as hydrogen, carbon monoxide or dinitrogen monoxide,
bulk densities, de?ned and uniform grain siZe distributions,
then provides cobalt metal poWders Which likeWise exhibit
?oWability, etc., the cobalt(II) carbonates and cobalt(II)
an agglomerated secondary structure but Which are built up
hydroxides according to the invention are alternatives,
Which are of commercial interest, to the corresponding
conventionally produced cobalt compounds Which have an
from small primary particles and Which could therefore be
irregular, non-spheroidal secondary structure.
industrially important.
25
The basic cobalt(II) carbonate agglomerates according to
the invention are suitable starting compounds for various
applications, eg for the production of cobalt(II) salts or for
the production of pure-phase cobalt(II) oxide by calcination,
Which proceeds Whilst retaining the secondary morphology.
As described above for the basic cobalt(II) carbonate, the
cobalt(II) hydroxide according to the invention can also be
used for the production of cobalt(II) salts, or can be calcined
further to form pure-phase cobalt(II) oxide Whilst retaining
its spheroidal secondary structure. This invention thus also
relates to the use of the cobalt(II) hydroxide according to the
invention for the production of pure cobalt(II) salts for use
in bonding agents and catalysts, for the production of
spheroidal, free-?oWing cobalt(II) oxide or higher oxides,
This invention thus also relates to the use of the basic
cobalt(II) carbonate agglomerates according to the invention
for the production of spheroidal, free-?owing cobalt(II)
and as a component of the nickel hydroxide electrode in
oxide and higher oxides by calcination under a protective
alkaline secondary cells.
gas and/or air. The cobalt carbonates are also suitable as 35
This invention also relates to the use of the basic cobalt
starting compounds for the production of other cobalt com
pounds Which can otherWise only be obtained in compact
(II) carbonate agglomerates and/or the cobalt(II) hydroxides
agglomerated form With dif?culty or not at all.
As has already been mentioned in the introduction, a
series of cobalt(II) salts of Weak acids Which cannot be
obtained by the direct reaction of metallic cobalt With the
pigments.
corresponding acids is of considerable industrial impor
tance. Thus, for example, cobalt(II) acetate is usually
products, are described in the folloWing examples, Without
being limited thereto.
obtained by the reaction of conventional cobalt carbonate
precipitates With acetic acid. These precipitations are con
according to the invention for the production of cobalt
The production of the spheroidally agglomerated basic
cobalt(II) carbonates and cobalt(II) hydroxides, and the
further processing thereof to produce diverse secondary
45
ducted in the cold, and rod-shaped precipitates With a high
content of Water of crystallisation and Which scarcely sedi
Examples 1—4
ment out are produced.
Production of Basic Cobalt(II) Carbonate
The basic cobalt(II) carbonate according to the invention
does not exhibit the disadvantages just described, but despite
this has a high reactivity toWards acetic acid for example, so
that it can easily be dissolved in acetic acid and cobalt(II)
Production of the basic cobalt(II) carbonates according to
the invention Was effected in Examples 1 to 4 in a continu
ously operated ?oW reactor With a radial ?oW stirrer, With
the simultaneous addition of aqueous cobalt chloride solu
acetate can be obtained from the solution by crystallisation.
It has noW been found that a heterogeneous reaction of
the spheroidally agglomerated basic cobalt(II) carbonate
EXAMPLE
55
tions and aqueous alkali hydrogen carbonate or alkali car
bonate solutions. The metered addition of the solutions Was
effected using oscillating piston pumps, Which operated very
according to the invention With glacial acetic acid is pos
sible. This produces uniform, acicular crystals of length
accurately and constantly. The temperatures Were held con
10—20 pm and of diameter about 2 pm. This reaction should
stant over the entire duration of the reaction via a regulable
be conducted With an excess of acetic acid so as to be able
thermostat.
Samples Were taken for Work-up and further processing to
to suspend the solids suf?ciently Well. In the industrial
process, hoWever, this acetic acid is usefully recycled, so
that the process described is also characterised by its eco
form secondary products after the reactor had reached its
stationary state. Work-up Was effected by ?rst alloWing the
nomical nature. A fact Which should be cited as a bene?cial
solids to settle and separating about 80% of them from the
side effect is that ?nal impurities remain in the basic cobalt
carbonate after the reaction in the mother liquor (recycle
liquor) and can be separated from the latter according to the
industrial implementation of the recycling concept. Ultra
mother liquor by decantation. The thickened suspension Was
65
transferred to a suction ?lter, the precipitate formed Was
?ltered off and Washed With about 10 l of Wash Water per kg
of cobalt at the temperature of reaction, and the ?lter cake
US 6,699,453 B1
5
6
Was subsequently dried to constant Weight at 80° C. in a
Example 7
Production of Spheroidally Agglomerated Cobalt(II)
drying oven. The reaction parameters and characteristic
product properties are listed in Table 1.
Oxide From Basic Cobalt Carbonate
TABLE 1
Examples 1—4', production of basic cobalt II carbonates
CoCl soln.
NaHCO3
soln.
1/hour g/l 1/hour
Na2CO3
soln.
Example
g/l
g/l
1/hour
1
150
1.1
80
5.8
—
—
2
103
0.39
—
—
150
0.48
3
150
5.5
80
29.0
—
—
4
103
0.29
—
—
150
0.36
r
4)
stirrer
speed D5U
[hours] [° C.] [rpm] [,um]
BET
[mZ/g]
1)
Co
[% by
C032’
[% by SEM
Weight] Weight] [magn]
2.5
80
1100
10.6
1.3
54.1
29.0
4
90
600
27.6
0.8
58.4
18.3
0.5
80
1000
3.4
53.9
29.5
3
64
1200
7.8
53.3
36.7
29
1.1
FIG.
5000
FIG.
5000
FIG.
5000
FIG.
5000
1 500
x
2 500
x
3 500
x
4 500
x
x
x
x
x
1) determined by the single-point nitrogen method according to DIN 66131
Example 5
500 g basic cobalt(II) carbonate from Example 1 Were
calcined for 2 hours under argon at 650° C. in quartZ boats.
Production of Spheroidally Agglomerated Cobalt(II)
Hydroxide
25
analysis.
100 g basic cobalt(II) carbonate from Example 4 Were
slurried in 200 ml Water and mixed With 80 g NaOH
dissolved in 600 ml Water. The suspension Was then heated
to 85° C. under argon for 1 hour in a rotary evaporator, and
the solid Was ?ltered off by suction and Washed With 2 1
The cobalt content Was determined as 78.58% by Weight.
The SEM photograph shoWs that the spheroidal secondary
30
Water. The ?lter cake Was dried to constant Weight over
85.7 g of pink cobalt(II) hydroxide Was obtained, Which
35
The cobalt content Was determined as 61.7% by Weight.
The Na content Was 85 ppm. The carbonate content Was
determined as 0.2%. In addition to small amounts of a ?ne
40
built up from hexagonal lamellae Which have a diameter of
about 1 pm and thicknesses of 0.1 to 0.2 pm.
Example 6
Production of Spheroidally Agglomerated Cobalt(II)
Oxide From Cobalt(II) Hydroxide
500 g spheroidal cobalt(II) hydroxide from Example 6
Were calcined for 2 hours under argon at 650° C. in quartZ
boats.
fraction, the SEM photograph (FIG. 5) shoWs that the
spheroidal secondary structure of the starting material Was
pre-dominantly retained. The spheroidal agglomerates are
morphology of the starting material Was retained on calci
nation.
Example 8
KOH in a vacuum desiccator.
Was a pure phase according to X-ray diffraction analysis.
The yield obtained Was 342 g of light broWn cobalt(II)
oxide, Which Was a pure phase according to X-ray diffraction
The yield obtained Was 392 g of light broWn, free-?oWing
cobalt(II) hydroxide, Which Was a pure phase according to
X-ray diffraction analysis. The cobalt content of the material
Was determined as 78.57% by Weight. The spheroidal sec
ondary structure of the starting material Was retained, as
45
Production of Spheroidally Agglomerated Cobalt(II)
shoWn by the SEM photograph (FIG. 7).
Example 9
Hydroxide
Reaction of Spheroidally Agglomerated Basic
2 kg basic cobalt(II) carbonate from Example 1 Were
Cobalt Carbonate With Acetic Acid
slurried under argon in 5 1 Water in a stirred reactor. The
suspension Was mixed With 800 g NaOH dissolved in 3 1
100 g basic cobalt(II) carbonate from Example 1 Were
slurried in 500 ml glacial acetic acid under argon in a 1 liter
Water, and heated for 2 hours at 60° C. With sloW stirring. It
?ask ?tted With a re?ux condenser and a KPG stirrer. The
Was then ?ltered and Washed With 40 1 Warm Water at 60° C.
The ?lter cake Was pre-dried at 40° C. for 12 hours in a 55 temperature of the mixture Was then sloWly increased.
Above about 45° C. the commencement of the reaction Was
vacuum drying oven and then dried to constant Weight at 60°
observed as a rapidly increasing evolution of CO2. The
C. in a drying oven. 1.72 kg of pink cobalt(II) hydroxide Was
obtained, Which Was a pure phase according to X-ray
diffraction analysis.
The cobalt content of the material Was determined as 60
62.1% by Weight. The chloride and sodium contents Were
An aliquot portion of 100 ml of the suspension Was mixed
<100 ppm. The residual carbonate content Was determined
With 200 ml Water and stirred at 80° C. for 5 minutes. A dark
red solution Was formed, from Which red crystals of pure
as 0.2% by Weight.
The spheroidally agglomerated cobalt(II) hydroxide
obtained Was extremely free-?owing. The SEM photographs
(FIG. 6) shoW that the spheroidal structure of the starting
material Was retained almost completely.
reaction temperature Was alloWed to remain at 80° C. for 1
hour and the mixture Was thereafter heated for 1 hour under
re?ux until no more CO2 evolution Was observed.
Thereafter, the reaction mixture Was Worked up as folloWs:
65
cobalt(II) acetate tetrahydrate Were isolated.
The remaining suspension Was ?ltered off through a
suction ?lter and dried by suction for 15 minutes. The ?lter
US 6,699,453 B1
7
8
cake, Which Was of a compact to crumb-like nature, Was
dried to constant Weight at 75° C. in a drying oven. 65.3 of
After the addition Was complete, the mixture Was stirred
for a further 1 hour at the reaction temperature, ?ltered
through a suction ?lter and the product Was Washed With 500
ml Water. After drying the ?lter cake to constant Weight at
pink, pure-phase cobalt(II) acetate Were obtained. The cobalt
content Was determined as 27.7% by Weight.
The SEM photograph (FIG. 8) shoWs uniform, acicular
80° C., 350 g cobalt(II) oxalate dihydrate Were obtained. The
crystals of length 10—20 pm and thickness about 2 pm.
cobalt content Was determined as 30.9% by Weight.
The agglomerated secondary morphology of the starting
Example 10
Reaction of Spheroidally Agglomerated Basic
Cobalt(II) Carbonate With Acetic Acid
material Was retained (FIG. 10).
10
1. Basic cobalt (II) carbonate, agglomerated from ?ne
primary particles and of general composition Co[OH)2]a
20 g basic cobalt(II) carbonate from Example 1 Were
slurried in 600 ml Water under argon in a 1 liter ?ask ?tted
With a re?ux condenser, and Were mixed With 30 ml glacial
acetic acid. The mixture Was then sloWly heated With
stirring. Even With gentle heating, the start of the reaction
could be identi?ed by the commencement of CO2 evolution.
The reaction proceeded considerably more intensely than
the reaction in undiluted glacial acetic acid as in Example 9.
[CO3]1_a, Where 0.1§a§0.9, Wherein the agglomerates
have a spheroidal habit and the average agglomerate diam
15
3. Basic cobalt (II) carbonate agglomerates according to
either one of claim 1 or 2, Wherein they have tap densities
20
of 21.6 g/cm3 and bulk densities of >1.2 g/cm3.
4. Basic cobalt (II) carbonates of claim 1 or 2 as made by
reacting aqueous solutons of cobalt salts of the general
formula CoX2, Where X is selected from the group consist
ing of Cl—, NO3— and 1/2 SO 42— With aqueous solutions
25
Reaction of Spheroidally Agglomerated Basic
Cobalt(II) Carbonate With Phosphoric Acid
200 g basic cobalt(II) carbonate from Example 1 Were
suspended in 1 1 Water.
eter is 3 to 50 pm.
2. Basic cobalt (II) carbonates according to claim 1,
Wherein the agglomerate diameter is 5—20 pm.
The temperature Was then carefully increased to 80° C. After
about 0.5 hour, a clear, red cobalt(II) acetate solution had
been formed.
Example 11
We claim:
30
The mixture Was heated to 60° C. and mixed over 1.5
or suspensions of carbonates selected from the group con
sisting of alkali carbonates, ammonium carbonates and
hydrogen carbonates at temperatures betWeen 40 and 100°
C., the reactants being mixed intensively With residence time
of mixing operation, at said temperature range, of 0.5 to 10
hours, ?ltering the residue basic cobalt (II) carbonates and
subsequently Washing these until they are neutral and free
from salts.
hours, With stirring, With 140 g H3PO4 (85% by Weight)
5. Basic cobalt (II) carbonate agglomerates according to
dissolved in 1 1 Water. The mixture Was stirred for a further
claim
1 or 2 Wherein the spherical habit agglomerates are
0.5 hour at the reaction temperature, and Was then ?ltered
through a suction ?lter and the product obtained Was Washed 35 made up of polygonal lamellar primary particles Which have
average diameters (spans) of 0.3 pm to 1.5 pm and diameter
With 500 ml Water.
(span) to thickness ratios betWeen 3 and 15.
After drying the ?lter cake to constant Weight at 80° C.,
6. Basic cobalt (II) carbonate agglomerates according to
307 g of a pink product Was obtained, Which Was free
?oWing after de-agglomeration, Which it Was possible to
effect easily. The cobalt content Was determined as 35.7% by
claim 3 Wherein the spherical habit agglomerates are made
40
average diameters (spans) of 0.3 pm to 1.5 pm and diameter
Weight. X-ray diffraction analysis shoWed the diffraction
(span) to thickness ratios betWeen 3 and 15 .
spectrum of pure-phase cobalt(II) phosphate octahydrate.
It can be seen from the SEM photograph (FIG. 9) that the
agglomerated secondary morphology of the starting material
45
Was predominantly retained.
ing of Cl—, NO3— and 1/2 SO42— With aqueous solutions
50
subsequently Washing these until they are neutral and free
from salts.
The mixture Was heated to 70° C. and mixed over 2 hours,
2 1 Water.
sisting of alkali carbonates, ammonium carbonates and
hydrogen carbonates at temperatures betWeen 40 and 100°
C., the reactants being mixed intensively With residence time
of mixing operation, at said temperature range, of 0.5 to 10
hours, ?ltering the resulting basic cobalt (II) carbonates and
200 g basic cobalt(II) carbonate from Example 1 Were
suspended in 1 1 Water.
With stirring, With 266 g oxalic acid dihydrate dissolved in
7. Basic cobalt (II) carbonates of claim 3 as made by
reacting aqueous solutions of cobalt salts of the general
formula CoX2, Where X is selected from the group consist
or suspensions of carbonates selected from the group con
Example 12
Reaction of Spheroidally Agglomerated Basic
Cobalt(II) Carbonate With Oxalic Acid
up of polygonal lamellar primary particles Which have
55