U.S. patent application number 11/879814 was filed with the patent office on 2009-01-22 for ion exchanger for winning metals of value.
Invention is credited to Reinhold Klippper, Duilio Rossoni, Michael Schelhaas, Rudolf Wagner, Wolfgang Wambach.
Application Number | 20090022638 11/879814 |
Document ID | / |
Family ID | 40264989 |
Filed Date | 2009-01-22 |
United States Patent
Application |
20090022638 |
Kind Code |
A1 |
Rossoni; Duilio ; et
al. |
January 22, 2009 |
Ion exchanger for winning metals of value
Abstract
The present invention relates to the use of monodisperse,
macroporous anion exchangers of type I or type II in
hydrometallurgical processes for winning metals of value.
Inventors: |
Rossoni; Duilio;
(Langenfeld, DE) ; Klippper; Reinhold; (Koln,
DE) ; Wagner; Rudolf; (Koln, DE) ; Wambach;
Wolfgang; (Koln, DE) ; Schelhaas; Michael;
(Koln, DE) |
Correspondence
Address: |
LANXESS CORPORATION
111 RIDC PARK WEST DRIVE
PITTSBURGH
PA
15275-1112
US
|
Family ID: |
40264989 |
Appl. No.: |
11/879814 |
Filed: |
July 19, 2007 |
Current U.S.
Class: |
423/7 ;
423/1 |
Current CPC
Class: |
Y02P 10/20 20151101;
B01J 41/05 20170101; C22B 60/0265 20130101; B01J 47/014 20170101;
C22B 3/42 20130101; Y02P 10/234 20151101; B01J 41/04 20130101 |
Class at
Publication: |
423/7 ;
423/1 |
International
Class: |
C22B 60/02 20060101
C22B060/02; C22B 3/42 20060101 C22B003/42 |
Claims
1. A method of using monodisperse, macroporous anion exchangers of
type I or type II for winning metals of value, wherein type I
denotes resins whose adsorbing sites are quaternary ammonium groups
which are substituted by alkyl groups, preferably
C.sub.1-C.sub.4-alkyl groups, and wherein type II denotes resins in
which the quaternary ammonium groups have not only alkyl group(s)
but also at least one hydroxyalkyl group, preferably a
hydroxy-C.sub.1-C.sub.4-alkyl group.
2. A method according to claim 1, wherein the metals of value
belong to main groups III to VI or transition groups 5 to 12 of the
Periodic Table of the Elements.
3. A method according to claim 2, wherein the metal of value is
uranium.
4. A method according to any of claims 1 to 3, wherein the
monodisperse macroporous anion exchangers are used in resin in pulp
processes or in in-situ leaching processes or in the work-up of
water containing metals of value.
5. A method according to claim 3, wherein the uranium is present as
uranyl chloride, uranyl phosphate, uranyl acetate, uranyl
carbonate, uranyl sulphate or uranyl nitrate.
6. A process for winning metals of value by the resin in pulp
process or the in-situ leaching process or from water containing
metals of value, wherein monodisperse, macroporous anion exchangers
of type I or type II, preferably of type II, are used, and type I
denotes resins whose adsorbing sites are quaternary ammonium groups
which are substituted by alkyl groups, preferably
C.sub.1-C.sub.4-alkyl groups, and type II denotes resins in which
the quaternary ammonium groups have not only alkyl group(s) but
also at least one hydroxyalkyl group, preferably a
hydroxy-C.sub.1-C.sub.4-alkyl group.
7. A process according to claim 6, wherein the anion exchangers of
type II are functionalized by tertiary amines, preferably
dimethylethanolamine or dimethylmethanolamine.
8. A process according to claim 6 or 7, wherein metals of value of
main groups III to VI and transition group 5 to 12 of the Periodic
Table of the Elements are won.
9. A process according to claim 6, wherein uranium is won as metal
of value.
Description
[0001] The present invention relates to the use of monodisperse,
macroporous anion exchangers of type I or type II in
hydrometallurgical processes for winning metals of value. Type I
denotes resins whose adsorbing sites are quaternary ammonium groups
which are substituted by alkyl groups. Type II denotes resins in
which the quaternary ammonium groups have not only alkyl group(s)
but at least one hydroxyalkyl group.
BACKGROUND OF THE INVENTION
[0002] Due to increasing industrialization in many parts of the
world and globalization, the demand for numerous metals of value
such as cobalt, nickel, zinc, manganese, copper, gold, silver and
also uranium has increased considerably in recent years. Mining
companies and producers of industrial metals are attempting to
satisfy this increasing demand by means of various measures. These
include improving the production processes themselves.
[0003] The metals of value relevant for industrial use are present
in ore-bearing rocks which are mined. The ore which is then present
in relatively large lumps is milled to give small particles. The
materials of value can be leached from these rock particles by a
number of methods. The customary technique is hydrometallurgy, also
referred to as the wet method. If appropriate, the ore is subjected
to a pretreatment to produce soluble compounds (roasting, pyrogenic
treatment) and these are converted by means of acids or alkalis
into aqueous metal salt solutions. The choice of solvent is
determined by the type of metal, the form in which it is present in
the ore, the type of accompanying rock in the ore (gangue) and the
price. The most widely employed solvent is sulphuric acid, and
hydrochloric acid, nitric acid and hot concentrated sodium chloride
solutions are also possible. In the case of ores having
acid-soluble accompanying materials, for example, copper ammoniacal
solutions can also be used, sometimes also under high pressure and
elevated temperature (pressure leaching). Sodium hydroxide is used
for the winning of aluminium oxide; in the case of noble metals,
alkali metal cyanide solutions are used. As an alternative, the
winning of the metals in hydrometallurgy can also be carried out by
precipitation or displacement by means of a less noble metal
(cementation), by means of reduction by hydrogen or carbon monoxide
under high pressure (pressure precipitation) or by electrolysis
using insoluble electrodes or by crystallization (sulphates of
copper, of zinc, of nickel or of thallium), by conversion
(precipitation) into sparingly soluble compounds such as
hydroxides, carbonates or basic salts by means of chalk, milk of
lime or sodium carbonate solution.
[0004] U.S. Pat. No. 6,350,420 describes, for example, the
treatment of the ore particles with mineral acids such as sulphuric
acid at high temperatures (e.g. 250-270.degree. C.) under
superatmospheric pressure (high pressure leaching). This gives a
suspension (slurry) of the fine ore particles in sulphuric acid, in
which the leached metals are present in the form of their salts in
more or less concentrated form.
[0005] As an alternative, the leaching of the metals from the rock
can also be effected by other methods. The type of process used
depends on a number of factors, for example on the metal content of
the ore, on the particle size to which the crushed ore has been
milled or on apparatus conditions, to name only a few.
[0006] In the heap leaching process, relatively coarse ore
particles having a low metal content are used.
[0007] In the agitation leaching process, finer ore particles
(about 200 .mu.m) having high metal contents are used in the
leaching process.
[0008] However, the atmospheric leaching process or the
biooxidation process is also used for dissolving the metals from
the ore. These processes are cited, for example, in U.S. Pat. No.
6,350,420.
[0009] The size of the milled ore particles to be used in these
processes is in the range from about 30 to about 250 .mu.m. Because
of the small size of the particles and the large amount of rock, a
classic filtration of the particles from the aqueous phase on
filters is very costly. Separation by the gravitation principle in
decanters by settling of the solid phase in very large stirred
vessels is usually employed industrially. To obtain good separation
and a solution of materials of value which is largely free of
particles, stirred vessels having a diameter of 50 metres and more
are used and a plurality of these are employed in series. Large
amounts of water are required and these are very expensive since
many mines are located in regions in which water is scarce
(deserts). In addition, it is often necessary to use filtration
media which are expensive and pollute the environment to achieve
better removal of the particles.
[0010] In hydrometallurgical plants and mines which are operated in
large numbers worldwide for the winning of materials of value such
as gold, silver, nickel, cobalt, zinc and other metals of value,
the process steps of filtration and clarification account for a
large proportion of the capital cost of the plant and the ongoing
operating expenses.
[0011] Great efforts are therefore made to replace the
abovementioned expensive process steps by other less
capital-intensive processes. New processes of this type are carbon
in pulp processes for silver and gold and the resin in pulp
(R.I.P.) process for gold, cobalt, nickel, manganese.
[0012] For example, U.S. Pat. No. 6,350,420 describes an R.I.P.
process for the winning of nickel and cobalt. A nickel-containing
ore is treated with mineral acids in order to leach out the
materials of value. The suspension obtained by means of the acid
treatment is admixed with ion exchangers which selectively adsorb
nickel and cobalt. The laden ion exchangers are separated from the
suspension by means of screens.
[0013] The ion exchangers used in U.S. Pat. No. 6,350,420 are
resins which are described in U.S. Pat. No. 4,098,867 and U.S. Pat.
No. 5,141,965. Suitable resins are accordingly Rohm & Haas IR
904, a strong base macroporous anion exchanger, Amberlite XE 318,
Dow XFS-43084, Dow XFS-4195 and Dow XFS-4196.
[0014] The ion exchangers described in U.S. Pat. No. 4,098,867 and
U.S. Pat. No. 5,141,965 contain variously substituted
aminopyridine, in particular 2-picolylamine, groups. All ion
exchangers described there display a heterodisperse bead diameter
distribution. In U.S. Pat. No. 5,141,965, the ion exchangers
display bead diameters in the range 0.1-1.5 mm, preferably 0.15-0.7
mm, most preferably 0.2-0.6 mm. The ion exchangers described in
U.S. Pat. No. 4,098,867 display bead diameters in the range 20-50
mesh (0.3 mm-0.850 mm) or larger diameters.
[0015] Rohm & Haas IR 904, a strong base macroporous anion
exchanger, and Amberlite XE 318 are likewise heterodisperse ion
exchangers having bead diameters in the range 0.3-1.2 mm. In the
examples, screens having mesh openings of 30 or 50 mesh (=300 to
600.mu. mesh opening) are used to separate the laden ion exchangers
from the rock particles and the leached solution.
[0016] In the case of uranium as material of value, it is mined
either by open cast methods or underground. In the case of
underground mining, mechanical cutting and, in the case of ores
having a low uranium content, in-situ leaching are used. The
uranium present in the ore is separated by physical and chemical
processes from the remaining rock (liberated). For this purpose,
the ore is comminuted (crushed, finely milled) and the uranium is
leached out. This is achieved by means of acid or alkali with
addition of an oxidant in order to convert the uranium from the
very sparingly soluble chemical 4-valent state into the readily
soluble 6-valent form. In this way, up to 90 percent of the
urnanium present in the ore can be recovered (see
www.nic.com.an/nip.htm).
[0017] Undesirable accompanying materials are removed from the
slurry/solution obtained in a plurality of purification steps by
means of decantation, filtering, extraction, etc.
[0018] The uranyl ions are removed from the purified solution using
anion exchangers.
[0019] The first publication DE 26 27 540 (=U.S. Pat. No.
4,233,272) discloses a process for the selective separation of
uranium by means of an ion exchanger from acidic solutions which
additionally contain nickel, iron, arsenic, aluminium and
magnesium. A chelating cation exchanger is used here, with both
uranyl UO.sub.2.sup.2+ and U.sup.4+ ions being separated off using
8-12% strength sulphuric acid.
[0020] U.S. Pat. No. 4,430,308 describes a process for the winning
of uranium by means of a heated ion exchanger, with type II resins,
for example Duolite 102 D.RTM., Ionac A-550.RTM., Ionac A-651.RTM.,
IRA 410.RTM., IRA 910.RTM. and Dowex 2.RTM., being able to be used
for this purpose. All of these are heterodisperse, gel-like or
macroporous ion exchangers based on styrene and divinylbenzene as
crosslinker.
[0021] DD 245 592 A1 describes a process for removing uranium by
means of anion exchangers, characterized in that heterodisperse
anion exchangers which are prepared by reaction of crosslinked
alkyl acrylate copolymers with polyamines are used.
[0022] DD 245 368 A1 relates to a process for separating off and
recovering uranium, in particular in the form of its uranium
sulphato complexes by means of heterodisperse ion exchangers which
are prepared from (methyl)acrylic ester copolymers and polyamines
from the series of hydroxyethyl-polyethylenepolyamines.
Furthermore, DD 261 962 A1 discloses a process for preparing
heterodisperse ion exchangers having amino groups and
ortho-hydroxyoxime groups. In Example 1c of this document, uranium
is present in the form of anionic uranyl sulphato complexes and is
bound on a heterodisperse anion exchanger which has been prepared
by the process mentioned.
[0023] DE 101 21 163 A1 describes a process for preparing
heterodisperse chelating exchangers which contain chelating groups
of the formula --(CH).sub.nNR.sub.1R.sub.2 and are used for
removing the heavy metals or noble metals, for instance uranium.
The patent DE 34 28 878 C2 discloses a process for recovering
uranium in an extractive reprocessing procedure for irradiated
nuclear fuels. In this process, use is made of base heterodisperse
anion exchangers based on polyalkyleneepoxypolyamine having
tertiary and quaternary amino groups of the chemical structure
R--NH.sup.+(CH.sub.3).sub.2Cl.sup.- and
R--NH.sup.+(CH.sub.3).sub.2(C.sub.2H.sub.4OH)Cl.sup.-.
[0024] A disadvantage of the ion exchanger used in the prior art
for the winning of uranium and also those for the winning of cobalt
or nickel is the nonuniform loading of the ion exchanger with
uranyl ions, which leads to considerable losses. Due to the ion
exchangers used, the separation of the laden ion exchanger beads
from the slurry via a screen results in further product losses
because part of the beads is lost through the sieve because of
their small diameter. The consequences are losses both of metal of
value, for example uranium, but also of ion exchanger beads.
Furthermore, the washing out of fine ore particles remaining from
the digestion process from the fine beads is very time consuming
and requires large amounts of water. Finally, the ion exchangers to
be used according to the prior art cause high pressure drops and
the nonuniform loading of the ion exchanger beads result in broad
mixing zones in the eluates in the elution of the metal of value
from the beads, which are disadvantageous for further uranium
winning.
[0025] The solution to the problem and thus subject matter of the
present invention is the use of monodisperse, macroporous,
intermediate base or strong base anion exchangers of type I or type
II in the winning of metals of value.
[0026] The monodisperse anion exchangers to be used according to
the invention are preferably used in hydrometallurgical processes,
particularly preferably in resin in pulp processes (R.I.P.
processes) or in in-situ leaching processes or in the work-up of
water containing metals of value.
SUMMARY OF THE INVENTION
[0027] The invention therefore also relates to a process for
winning metals of value from hydrometallurgical processes,
preferably in R.I.P. processes or in in-situ leaching processes or
for the work-up of water containing metals of value, characterized
in that monodisperse, macroporous intermediate base or strong base
anion exchangers of type I or type II, preferably of type II, are
used.
[0028] Compared to the ion exchangers used in the prior art, the
monodisperse, macroporous, intermediate base or strong base anion
exchangers of type I or type II to be used according to the
invention surprisingly display significantly higher adsorption
rates for the metals of value, in particular for uranium, low
pressure drops, have small mixing zones and require significantly
smaller amounts of water.
[0029] In a particularly preferred embodiment, the monodisperse,
macroporous intermediate base or strong base anion exchangers of
type I or type II to be used according to the invention serve to
adsorb uranium from aqueous solutions into which it has been
leached by means of strong acids. When leached by means of strong
acids or by means of concentrated sodium carbonate solutions, the
uranium is preferably present as the uranyl ion (UO.sub.2.sup.2+),
particularly preferably as uranyl chloride, uranyl phosphate,
uranyl acetate, uranyl carbonate, uranyl sulphate or uranyl
nitrate, among which uranyl sulphate obtainable by leaching of the
uranium-containing rock by means of sulphuric acid is particularly
preferred.
[0030] The invention therefore particularly preferably provides for
the use of monodisperse, macroporous intermediate base or strong
base anion exchangers of type I or type II, in particular of type
II, for the adsorption of uranyl ions from the salts of uranium
with strong acids or with sodium carbonate, particularly preferably
from uranyl sulphate or uranyl carbonate.
[0031] The preparation of monodisperse ion exchangers is known to
those skilled in the art. A distinction is made between, apart from
the fractionation of heterodisperse ion exchangers by sieving,
essentially two direct preparation methods, namely injection or
jetting and the seed feed process in the preparation of the
precursors, the monodisperse bead polymers. In the case of the seed
feed process, a monodisperse feed which can be produced, for
example, by sieving or by jetting is used.
[0032] For the purposes of the present patent application, the term
monodisperse refers to substances in which the uniformity
coefficient of the distribution curve is less than or equal to 1.2.
The uniformity coefficient is the ratio of the parameters d 60 and
d 10. D 60 describes the diameter at which 60% by mass of the
particles in the distribution curve are smaller and 40% by mass are
larger or equal. D 10 refers to the diameter at which 10% by mass
of the particles in the distribution curve are smaller and 90% by
mass are larger or equal.
[0033] The monodisperse bead polymer, viz. the precursor of the ion
exchanger, can be prepared, for example, by reacting monodisperse,
optionally encapsulated monomer droplets comprising a
monovinylaromatic compound, a polyvinylaromatic compound and also
an initiator or initiator mixture and in the case of the present
invention a porogen in aqueous suspension. To obtain macroporous
bead polymers for preparing macroporous ion exchangers, the
presence of a porogen is absolutely necessary. Prior to the
polymerization, the optionally encapsulated monomer droplet is
doped with a (meth)acrylic compound and subsequently polymerized.
In a preferred embodiment of the present invention,
microencapsulated monomer droplets are therefore used for the
synthesis of the monodisperse bead polymer. The various methods of
preparing monodisperse bead polymers both by the jetting principle
and by the seed feed principle are known to those skilled in the
art from the prior art. Reference may at this point be made to U.S.
Pat. No. 4,444,961, EP-A 0 046 535, U.S. Pat. No. 4,419,245 and WO
93/12167.
[0034] The functionalization of the monodisperse bead polymers
obtainable according to the prior art to give monodisperse,
macroporous anion exchangers of type I or type II is likewise known
to those skilled in the art from the prior art.
[0035] Thus, EP-A 1 078 688 describes the preparation of
monodisperse macroporous anion exchangers by the phthalimide
process, in which
[0036] a) monomer droplets comprising at least one
monovinylaromatic compound and at least one polyvinylaromatic
compound and, in the case of the present patent application, a
porogen and/or optionally an initiator or an initiator combination
are reacted to give a monodisperse, crosslinked bead polymer,
[0037] b) this monodisperse, crosslinked bead polymer is
amidomethylated by means of phthalimide derivatives,
[0038] c) the amidomethylated bead polymer is converted into an
aminomethylated bead polymer and
[0039] d) the aminomethylated bead polymer is finally
alkylated.
[0040] In contrast to this ether/oleum variant, the preparation of
monodisperse macroporous anion exchangers by the phthalimide
process using the ester variant is known from EP-A 0 046 535. Here,
the encapsulated bead polymer comprising macroporous,
divinylbenzene-crosslinked polystyrene is converted without prior
removal of the capsule wall into a strongly basic anion exchanger
by the process described in U.S. Pat. No. 3,989,650 by means of
amidomethylation using phthalimidomethyl acetate, alkaline
hydrolysis and quaternization using chloromethane.
[0041] In an alternative embodiment, the monodisperse macroporous
anion exchangers used according to the invention can also be
prepared by the chloromethylation process described in EP 0 051 210
B2, in which the bead polymers are haloalkylated by means of
chloromethyl methyl ether and the haloalkylated polymer is reacted
with ammonia or primary amines such as methylamine or ethylamine or
a secondary amine such as dimethylamine at temperatures of from
25.degree. C. to 150.degree. C.
[0042] The monodisperse macroporous anion exchangers of type I or
type II to be used according to the invention can be synthesized by
means of these three variants.
[0043] The macroporosity required for the anion exchangers to be
used according to the invention is obtained as indicated above by
the use of porogen during the preparation of the bead polymer
precursor. Suitable porogens are organic solvents which do not
readily dissolve or swell the polymer obtained. Examples are
hexane, octane, isooctane, isododecane, methyl ethyl ketone,
butanol or octanol and their isomers. Porogens are in particular
organic substances which dissolve in the monomer but do not readily
dissolve or swell the polymer (precipitants for polymers), for
example aliphatic hydrocarbons (Farbenfabriken Bayer DBP 1045102,
1957; DBP 1113570, 1957).
[0044] As an alternative to aliphatic hydrocarbons, it is also
possible, according to U.S. Pat. No. 4,382,124, to use alcohols
having 4 to 10 carbon atoms as porogens for preparing monodisperse,
macroporous bead polymers based on styrene-divinylbenzene.
Furthermore, an overview of the preparative methods for macroporous
bead polymers is given there.
[0045] The distinction between type I and type II anion exchangers
has been described in U.S. Pat. No. 4,430,308. For the purposes of
the invention, type I resins are resins whose adsorbing sites are
quaternary ammonium groups which are substituted by alkyl groups,
preferably by C.sub.1-C.sub.4-alkyl groups, particularly preferably
by methyl groups.
[0046] In contrast thereto, type II resins are ones in which the
quaternary ammonium groups have not only alkyl group(s) but also at
least one hydroxyalkyl group, preferably a
hydroxy-C.sub.1-C.sub.4-alkyl group. The type II resins are
preferably ones which have methylenehydroxyalkyldimethylammonium
groups as functional groups, with the hydroxyalkyl group having one
or two carbon atoms. The type II anion exchangers which are
preferably used according to the invention can be prepared by means
of the three above-described variants using tertiary amines,
preferably dimethylethanolamine or dimethylmethanolamine, as
amine.
[0047] Metals of value to be isolated according to the invention by
means of the monodisperse, macroporous anion exchangers are
preferably metals of main groups III to VI and of transition groups
5 to 12 of the Periodic Table of the Elements. Preference is given
to winning mercury, iron, titanium, chromium, tin, lead, cobalt,
nickel, copper, zinc, cadmium, manganese, uranium, bismuth,
vanadium, the platinum group elements ruthenium, osmium, iridium,
rhodium, palladium, platinum and also the noble metals gold and
silver. According to the invention, particular preference is given
to using the monodisperse, macroporous anion exchangers for winning
uranium.
[0048] Preferred processes for the use of the monodisperse,
macroporous anion exchangers to be used according to the invention
are resin in pulp processes or in-situ leaching processes,
particularly preferably in-situ leaching processes, or the work-up
of any water containing metals of value.
[0049] The monodisperse, macroporous anion exchangers to be used
according to the invention are used in appropriate plants of
exploration companies. In the case of the winning of uranium which
is particularly preferred according to the invention, the pages
http://www.uraniumsa.org/processing/insitu.leaching.htm,
http://www.nrc.gov/materials/fuel-cycle-fac/ur-milling.htm or
IAEA-TECDOC-1239, "Manual of acid in situ leach uranium mining
technology" of the IAEA (International Atomic Energy Agency) of
August 2001 give examples of possible configurations of apparatus
of existing mines which employ the in-situ leaching process.
[0050] As indicated above, the monodisperse, macroporous anion
exchangers of type I or type II, in particular of type II, to be
used according to the invention surprisingly display a
significantly higher adsorption rate for the abovementioned metals
of value, in particular for the winning of uranium from in-situ
leaching processes, compared to the prior art.
EXAMPLES
Example 1
[0051] a) Preparation of the monodisperse, macroporous bead polymer
based on styrene, divinylbenzene and ethylstyrene
[0052] 3000 g of deionized water were placed in a 10 l glass
reactor and a solution of 10 g of gelatin, 16 g of disodium
hydrogenphosphate dodecahydrate and 0.73 g of resorcinol in 320 g
of deionized water was added and mixed in. The temperature of the
mixture was brought to 25.degree. C. A mixture of 3200 g of
microencapsulated monomer droplets having a narrow particle size
distribution and comprising 3.6% by weight of divinylbenzene and
0.9% by weight of ethylstyrene (used as commercial isomer mixture
of divinylbenzene and ethylstyrene containing 80% of
divinylbenzene), 0.5% by weight of dibenzoyl peroxide, 56.2% by
weight of styrene and 38.8% by weight of isododecane (industrial
isomer mixture having a high proportion of pentamethyl-heptane) was
subsequently added while stirring, with the microcapsule comprising
a formaldehyde-cured complex coacervate of gelatin and a copolymer
of acrylamide and acrylic acid, and 3200 g of an aqueous phase
having a pH of 12 are added. The mean particle size of the monomer
droplets was 460 .mu.m.
[0053] The mixture was polymerized while stirring by increasing the
temperature according to a temperature programme commencing at
25.degree. C. and finishing at 95.degree. C. The mixture was
cooled, washed on a 32 .mu.m sieve and subsequently dried at
80.degree. C. under reduced pressure. This gave 1893 g of a
spherical polymer having a mean particle size of 440 .mu.m, a
narrow particle size distribution and a smooth surface.
[0054] The polymer was chalky white in appearance and has a bulk
density of about 370 g/l.
[0055] 1b) Preparation of the amidomethylated bead polymer
[0056] 2400 ml of dichloroethane, 595 g of phthalimide and 413 g of
30.0% strength by weight formalin were placed in a reaction vessel
at room temperature. The pH of the suspension was adjusted to 5.5-6
by means of sodium hydroxide. The water was subsequently removed by
distillation. 43.6 g of sulphuric acid were then added. The water
formed was removed by distillation. The mixture was cooled. At
30.degree. C., 174.4 g of 65% strength oleum was added, followed by
300.0 g of monodisperse bead polymer prepared according to process
step 1a). The suspension was heated to 70.degree. C. and stirred at
this temperature for a further 6 hours. The reaction liquor was
taken off, deionized water was added and residual amounts of
dichloroethane were removed by distillation.
[0057] Yield of amidomethylated bead polymer: 1820 ml
[0058] Elemental composition determined by analysis: carbon: 75.3%
by weight; hydrogen: 4.6% by weight; nitrogen: 5.75% by weight.
[0059] 1c) Preparation of the aminomethylated bead polymer
[0060] 851 g of 50% strength by weight sodium hydroxide solution
and 1470 ml of deionized water were added to 1770 ml of
amidomethylated bead polymer from Example 1b) at room temperature.
The suspension was heated to 180.degree. C. and stirred at this
temperature for 8 hours.
[0061] The bead polymer obtained was washed with deionized
water.
[0062] Yield of aminomethylated bead polymer: 1530 ml
[0063] The total yield, extrapolated, was 1573 ml
[0064] Elemental composition determined by analysis: carbon: 78.2%
by weight; nitrogen: 12.25% by weight; hydrogen: 8.4% by
weight.
[0065] Number of mol of aminomethyl groups per litre of
aminomethylated bead polymer: 2.13
[0066] Number of mol of aminomethyl groups in the total yield of
aminomethylated bead polymer: 3.259
[0067] A statistical average of 1.3 hydrogen atoms per aromatic
ring originating from the styrene and divinylbenzene units were
replaced by aminomethyl groups.
[0068] 1d) Preparation of a monodisperse, macroporous anion
exchanger having dimethylaminomethyl groups=type I
[0069] 1995 ml of deionized water and 627 g of 29.8% strength by
weight formalin solution were added to 1330 ml of aminomethylated
bead polymer from Example 1c) at room temperature. The mixture was
heated to 40.degree. C. It was subsequently heated to 97.degree. C.
over a period of 2 hours. A total of 337 g of 85% strength by
weight formic acid were added at this temperature. The pH was
subsequently set to 1 by means of 50% strength by weight sulphuric
acid over a period of 1 hour. At pH 1, the mixture was stirred for
another 10 hours. After cooling, the resin was washed with
deionized water and freed of sulphate and converted into the OH
form by means of sodium hydroxide solution.
[0070] Yield of resin having dimethylamino groups: 1440 ml
[0071] The total yield, extrapolated, is 1703 ml
[0072] The product contains 2.00 mol of dimethylamino groups/litre
of resin.
[0073] The total number of mol of dimethylamino groups in the total
yield of product having dimethylamino groups was 3.406.
Example 2
[0074] Preparation of a monodisperse intermediate base macroporous
anion exchanger having dimethylaminomethyl groups and
trimethylaminomethyl groups=type I
[0075] 1220 ml of bead polymer bearing dimethylaminomethyl groups
from Example 1d), 1342 ml of deionized water and 30.8 g of
chloromethane were placed in a reaction vessel at room temperature.
The mixture was heated to 40.degree. C. and stirred at this
temperature for 6 hours.
[0076] Yield of resin bearing dimethylaminomethyl groups and
trimethylaminomethyl groups: 1670 ml
[0077] The extrapolated total yield was 2331 ml.
[0078] Of the nitrogen-containing groups of the product, 24.8% were
present as trimethylaminomethyl groups and 75.2% were present as
dimethylaminomethyl groups.
[0079] The utilizable capacity of the product was: 1.12 mol/litre
of resin.
[0080] Stability of the resin in the original state: 98 perfect
beads in 100
[0081] Stability of the resin after the rolling test: 96 perfect
beads in 100
[0082] Stability of the resin after the swelling stability test: 98
perfect beads in 100
[0083] 94 percent by volume of the beads of the final product had a
size in the range from 0.52 to 0.65 mm.
Example 3
[0084] Preparation of a monodisperse strong base macroporous anion
exchanger having hydroxyethyldimethylaminomethyl groups=type II
[0085] 1230 ml of the resin having dimethylaminomethyl groups
prepared as described in Example 1d) and 660 ml of deionized water
were placed in a reaction vessel. 230.5 g of 2-chloroethanol were
added thereto over a period of 10 minutes. The mixture was heated
to 55.degree. C. A pH of 9 was set by pumping in 20% strength by
weight sodium hydroxide solution. The mixture was stirred at pH 9
for 3 hours, the pH was subsequently set to 10 by means of sodium
hydroxide solution and the mixture was stirred at pH 10 for a
further 4 hours. After cooling, the product was washed with
deionized water in a column and 3 bed volumes of 3% strength by
weight hydrochloric acid were then filtered through.
[0086] Yield: 1980 ml
[0087] The utilizable capacity of the product was: 0.70 mol/litre
of resin.
[0088] Stability of the resin in the original state: 96 perfect
beads in 100
[0089] Stability of the resin after the rolling test: 70 perfect
beads in 100
[0090] Stability of the resin after the swelling stability test: 94
perfect beads in 100
[0091] 94 percent by volume of the beads of the end product had a
size in the range from 0.52 to 0.65 mm.
Example 4
[0092] Preparation of a heterodisperse, strong base macroporous
anion exchanger having trimethylammonium groups based on
styrene-divinylbenzene according to the prior art
[0093] 4a) Preparation of the bead polymer--use of the initiator
dibenzoyl peroxide
[0094] 1112 ml of deionized water, 150 ml of a 2% strength by
weight aqueous solution of methylhydroxyethylcellulose and 7.5 gram
of disodium hydrogenphosphate.times.12 H.sub.2O were placed in a
polymerization reactor at room temperature. The total solution was
stirred at room temperature for one hour. The monomer mixture
comprising 59.61 g of 80.53% strength by weight divinylbenzene,
900.39 g of styrene, 576 g of isododecane and 7.70 g of 75%
strength by weight dibenzoyl peroxide was subsequently added. The
mixture was firstly left to stand at room temperature for 20
minutes and was then stirred at room temperature at a stirring
speed of 2000 rpm for 30 minutes. The mixture was heated to
70.degree. C., stirred at 70.degree. C. for a further 7 hours, then
heated to 95.degree. C. and stirred at 95.degree. C. for a further
2 hours. After cooling, the bead polymer obtained was filtered off
and washed with water and dried at 80.degree. C. for 48 hours.
[0095] The diameter of the beads was in the range from 0.32 to 0.71
mm.
[0096] 4b) Preparation of the amidomethylated bead polymer
[0097] 1331 ml of 1,2-dichloroethane, 493.9 g of phthalimide and
347.4 g of 29.6% strength by weight formalin were placed in a
reaction vessel at room temperature. The pH of the suspension was
adjusted to 5.5-6 by means of sodium hydroxide. The water was
subsequently removed by distillation. 36.2 g of sulphuric acid were
then added. The water formed was removed by distillation. The
mixture was cooled. At 30.degree. C., 132.3 g of 65% strength oleum
was added, followed by 317.1 g of heterodisperse bead polymer
prepared according to process step 4a). The suspension was heated
to 70.degree. C. and stirred at this temperature for a further 6.5
hours. The reaction liquor was taken off, deionized water was added
and residual amounts of dichloroethane were removed by
distillation.
[0098] Yield of amidomethylated bead polymer: 1410 ml
[0099] Elemental composition determined by analysis: carbon: 76.8%
by weight; hydrogen: 5.0% by weight; nitrogen: 5.4% by weight.
[0100] 4c) Preparation of the aminomethylated bead polymer
[0101] 1515.75 g of 24.32% strength by weight sodium hydroxide
solution were added to 1385 ml of amidomethylated bead polymer from
Example 4b) at room temperature. The suspension was heated to
180.degree. C. over a period of 2 hours and stirred at this
temperature for a further 8 hours.
[0102] The bead polymer obtained was washed with deionized
water.
[0103] Yield of aminomethylated bead polymer: 1200 ml
[0104] Elemental composition determined by analysis: carbon: 79.3%
by weight; nitrogen: 11.2% by weight; hydrogen: 8.4% by weight;
balance oxygen.
[0105] Aminomethyl group content of the resin: 2.34 mol/l
[0106] A statistical average of 1.17 hydrogen atoms per aromatic
ring originating from the styrene and divinylbenzene units were
replaced by aminomethyl groups.
[0107] 4d) Preparation of the heterodisperse, strong base,
macroporous anion exchanger having trimethylammonium groups
[0108] 1160 ml of aminomethylated bead polymer from Example 4c)
were introduced into 1950 ml of deionized water in an autoclave at
room temperature. 501.6 g of chloromethane were added and the
suspension was heated to 40.degree. C. At 40.degree. C., the
suspension was stirred at a stirring speed of 200 rpm for a further
16 hours. The autoclave was cooled and vented. The resin was
filtered off on a sieve, washed with water and transferred to a
column. 200 ml of 5% strength by weight aqueous sodium chloride
solution were added while swirling. The resin was subsequently
classified to remove soluble and solid constituents.
[0109] Volume yield: 1620 ml
[0110] Stability of the resin in the original state: 99% of whole
beads
[0111] Stability of the resin after the rolling test: 96% of whole
beads
[0112] Stability of the resin after the swelling stability test:
98% of whole beads
[0113] The diameter of the beads was in the range from 0.35 to 0.85
mm.
Example 5
[0114] Preparation of a monodisperse, strong base macroporous anion
exchanger having trimethylammonium groups based on
styrene-divinylbenzene
[0115] 1513 ml of deionized water were placed in a reactor. 900 ml
of aminomethylated bead polymer from Example 1c) and 263 ml of 50%
strength by weight sodium hydroxide solution were added thereto at
room temperature. 357 g of chloromethane are subsequently added and
the suspension was heated to 40.degree. C. The suspension was
stirred at 40.degree. C. for 16 hours and subsequently cooled to
room temperature.
[0116] The suspension was poured onto a sieve and subsequently
washed with deionized water. The anion exchanger was then
introduced into a column provided with a glass frit. 1500 ml of 3%
strength by weight aqueous HCl were filtered through. The anion
exchanger was then classified by means of water to remove solid and
dissolved particles.
[0117] Volume yield: 1560 ml
[0118] Stability of the resin in the original state: 99% of whole
beads
[0119] Stability of the resin after the rolling test: 97% of whole
beads
[0120] The diameter of the beads was in the range from 0.57 to 0.67
mm.
Example 6
[0121] Determination of the uptake capacity of a heterodisperse,
strong base macroporous anion exchanger having trimethylammonium
groups based on styrene-divinylbenzene
[0122] 500 g of a zinc(II) chloride solution which was adjusted to
pH 1 by means of hydrochloric acid were placed in a polyethylene
bottle. The solution contained 4.2 g of zinc per litre of solution.
10 ml of a heterodisperse, strong base macroporous anion exchanger
having trimethylammonium groups based on styrene-divinylbenzene
were added to the solution. The mixture was stirred at room
temperature for 24 hours.
[0123] Samples were taken after 5 hours and 24 hours and analysed
to determine their zinc content.
[0124] Sample taken after 5 hours: zinc content=4.2 g of zinc per
litre of solution--based on the initial concentration, 0% of zinc
was taken up.
[0125] Sample taken after 24 hours: zinc content=4.1 g of zinc per
litre of solution--based on the initial concentration, 2.5% of zinc
was taken up.
Example 7
[0126] Determination of the uptake capacity of a monodisperse,
strong base macroporous anion exchanger having trimethylammonium
groups based on styrene-divinylbenzene
[0127] 500 g of a zinc(II) chloride solution which was adjusted to
pH 1 by means of hydrochloric acid were placed in a polyethylene
bottle. The solution contained 4.2 g of zinc per litre of
solution.
[0128] 10 ml of a monodisperse, strong base macroporous anion
exchanger having trimethylammonium groups based on
styrene-divinylbenzene were added to the solution. The mixture was
stirred at room temperature for 24 hours.
[0129] Samples were taken after 5 hours and 24 hours and analysed
to determine their zinc content.
[0130] Sample taken after 5 hours: zinc content=3.5 g of zinc per
litre of solution--based on the initial concentration, 16.7% of
zinc was taken up.
[0131] Sample taken after 24 hours: zinc content=3.3 g of zinc per
litre of solution--based on the initial concentration, 26.7% of
zinc was taken up.
[0132] Methods of examination:
[0133] Number of perfect beads after preparation
[0134] 100 beads are viewed under the microscope. The number of
beads which have cracks or display spalling is determined. The
number of perfect beads is the difference between the number of
damaged beads and 100.
[0135] Determination of the stability of the resin after the
rolling test
[0136] The bead polymer to be tested is distributed in a layer of
uniform thickness between two plastic cloths. The cloths are placed
on a firm, horizontal substrate and subjected to 20 cycles in a
rolling apparatus. One cycle consists of one forward and back
movement of the roller. After rolling, the number of unscathed
beads in 100 beads is determined on representative samples by
counting under the microscope.
[0137] Swelling stability test
[0138] 25 ml of anion exchanger in the chloride form are introduced
into a column. 4% strength by weight aqueous sodium hydroxide
solution, deionized water, 6% strength by weight hydrochloric acid
and once again deionized water are introduced in succession into
the column, with the sodium hydroxide solution and the hydrochloric
acid flowing downwards through the resin and the pure water being
pumped through the resin from below. The treatment is sequenced by
means of a control apparatus. One cycle takes one hour. 20 cycles
are carried out. After the end of the cycles, 100 beads are counted
out from the resin sample. The number of perfect beads which are
not damaged by cracks or spalling is determined.
[0139] Utilizable capacity of strong base and intermediate base
anion exchangers
[0140] 1000 ml of anion exchanger in the chloride form, i.e. the
nitrogen atom bears chloride as counterion, are introduced into a
glass column. 2500 ml of 4% strength by weight sodium hydroxide
solution are filtered through the resin over a period of 1 hour.
The resin is subsequently washed with 2 litres debasified, i.e.
decationized, water. Water having a total anion hardness of 25
degrees of German hardness is then filtered through the resin at a
rate of 10 litres per hour. The eluate is analysed to determine the
hardness and also the residual amount of silicic acid. Loading is
complete at a residual silicic acid content of .gtoreq.0.1
mg/l.
[0141] The number of gram of CaO taken up by one litre of resin is
determined from the amount of water filtered through the resin, the
total anion hardness of the water filtered through and the amount
of resin installed. The number of gram of CaO represents the
utilizable capacity of the resin in the unit gram of CaO per litre
of anion exchanger.
[0142] Volume change chloride/OH form
[0143] 100 ml of anion exchanger bearing basic groups are rinsed
into a glass column by means of deionized water. 1000 ml of 3%
strength by weight hydrochloric acid are filtered through over a
period of 1 hour and 40 minutes. The resin is subsequently washed
free of chloride with deionized water. The resin is rinsed under
deionized water in a tamping volumeter and jiggled in until the
volume was constant--volume V1 of the resin in the chloride
form.
[0144] The resin is again transferred into the column. 1000 ml of
2% strength by weight sodium hydroxide solution are filtered
through. The resin is subsequently washed free of alkali with
deionized water until the eluate has a pH of 8. The resin is rinsed
under deionized water in a tamping volumeter and jiggled in until
the volume is constant--volume V2 of the resin in the free base
form (OH form).
[0145] Calculation: V1-V2=V3
[0146] V3:V1/100=swelling change chloride/OH form in %
[0147] Determination of the amount of basic aminomethyl groups in
the aminomethylated, crosslinked polystyrene bead polymer
[0148] 100 ml of the aminomethylated bead polymer are jiggled in on
a tamping volumeter and subsequently rinsed into a glass column by
means of deionized water. 1000 ml of 2% strength by weight sodium
hydroxide solution are filtered through over a period of 1 hour and
40 minutes. Deionized water is subsequently filtered through until
100 ml of eluate admixed with phenolphthalein have a consumption of
not more than 0.05 ml of 0.1 N (0.1 normal) hydrochloric acid.
[0149] 50 ml of this resin are admixed with 50 ml of deionized
water and 100 ml of 1 N hydrochloric acid in a glass beaker. The
suspension is stirred for 30 minutes and subsequently introduced
into a glass column. The liquid is drained. A further 100 ml of 1 N
hydrochloric acid are filtered through the resin over a period of
20 minutes. 200 ml of methanol are subsequently filtered through.
All eluates are collected and combined and titrated with 1 N sodium
hydroxide against methyl orange.
[0150] The amount of aminomethyl groups in 1 litre of
aminomethylated resin is calculated according to the following
formula: (200-V)20=mol of aminomethyl groups per litre of
resin.
[0151] Determination of the degree of substitution of the aromatic
rings of the crosslinked bead polymer by aminomethyl groups
[0152] The amount of aminomethyl groups in the total amount of the
aminomethylated resin is determined by the above method.
[0153] The number of mol of aromatics present in the amount of bead
polymer used, A in gram, is calculated from this amount by division
by the molecular weight.
[0154] For example, 950 ml of aminomethylated bead polymer
containing 1.8 mol of aminomethyl groups per litre are prepared
from 300 gram.
[0155] 950 ml of aminomethylated bead polymer contain 2.82 mol of
aromatics.
[0156] 1.8/2.81=0.64 mol of aminomethyl groups are then present per
aromatic.
[0157] The degree of substitution of the aromatic rings of the
crosslinked bead polymer by aminomethyl groups is 0.64.
* * * * *
References