Ion exchange-active compositions consisting of water-soluble polyelectrolyte upon ion exchange functional substrate

A new class of ion exchange agents comprises water soluble polymers called polyelectrolytes sorbed onto ion exchange functional substrates.

This invention relates to a new class of ion exchange compositions. In one 
aspect it relates to the preparation of a new class of ion exchange 
compositions. In another aspect the invention relates to a new class of 
ion exchange compositions comprising composites of water soluble polymers 
called polyelectrolytes and a substrate. 
Ionic exchange is the reversible interchange of ions between a solid and a 
liquid in which there is no permanent change in the structure of the solid 
which is the ion exchange material. Ion exchange is used in water 
softening and deionization. It also provides a method of separation that 
is used in many useful chemical processes and analyses. It has special 
utility in chemical synthesis, medical research, food processing, mining, 
agriculture, and a variety of other areas. Ion exchange has been used on 
an industrial basis since the introduction of water softening through 
natural and later synthetic zeolites. 
Most ion exchange resins today are synthetic. They are made totally from 
petroleum chemicals. One problem these resins have is that in order to be 
used, the ions to be exchanged must move from the exchanging fluid into 
the resin, past networks of intertwined and cross-linked polymer chains 
which often have a distinct hydrophobicity. 
Once the ions have migrated to the interior of the resin beads, they 
replace other ions in the beads (hence ion exchange). These other ions are 
often of different radii than their replacement, causing the resin beads 
to shrink or swell during use. This change in bead size can cause plugging 
of the resin bed if the beads get too large. It can also cause some of the 
resin to be washed out of the bed with the fluid if the beads get too 
small. 
Another problem common in large scale operations is the low density of 
synthetic resin beads. Often an upward flow is used in these operations 
and small size beads are unable to remain in the bed and are carried out 
with the fluid. Therefore these processes are limited to large beads, 
which limits the processes capacity and kinetics. 
The instant invention is a composite ion exchange resin which comprises 
low-cost substrate materials. The composite will have the material 
strength and temperature stability of the substrate. The ion exchange 
sites are all at the surface of the substrate or along the length of the 
polyelectrolyte which extends out into the exchanging fluid. The problem 
of shrinking and swelling can be eliminated by the use of a substrate that 
is not subjected to shrinking or swelling. Since the exchange sites are 
all on the outside of the material, the ions will not have to migrate to 
the interior. Also the composites can be relatively dense, simply by 
choosing a dense substrate. Additionally the substrate can also be 
magnetic or magnetically permeable so that magnetic ion exchange bed 
confinement can be employed. 
Therefore, an object of this invention is to produce a new class of ion 
exchange agents. Another object of this invention is to produce an ion 
exchange composite resin of low cost, of high strength, and of better 
temperature stability than conventional ion exchange resins. Still another 
object is to provide ion exchange resin where the exchange sites are in a 
more hydrophilic environment. Another object of this invention is to 
provide ion exchange composite resins that do not shrink or swell on 
loading or regeneration. Another object of this invention is to provide an 
ion exchange composite that can be dense, magnetic or magnetically 
permeable. Other objects of the invention will become clear from the 
following description. 
STATEMENT OF THE INVENTION 
The instant invention is a new class of ion exchange compounds comprising a 
water soluble polymer having multiple ionic functional groups and an ion 
exchange functional substrate. 
In another embodiment this invention is a method of preparing an ion 
exchange compound comprising a water soluble polymer and an ion exchange 
functional substrate. 
DETAILED DESCRIPTION OF THE INVENTION 
A polyelectrolyte is a natural or synthetic polymer substance containing 
either ionic or cationic functional groups. The polyelectrolytes of the 
instant invention can be chosen from any polyelectrolytes of linear or 
cross-linked configuration. The polyelectrolytes that are linear or only 
slightly cross-linked are preferred. Linear polyelectrolytes are most 
preferred. 
The molecular weight range of the polymers useful in accordance with this 
invention is from 2 to 15 million daltons. In general, the molecular 
weight will range from about 1,000 to 15 million daltons. In the most 
preferred embodiment of this invention, molecular weight will range from 
20,000 to 15 million daltons. 
Any material of organic or inorganic composition which has a surface charge 
and which can be utilized as a substrate onto which polyelectrolytes can 
adhere can be used. The substrate holds the polymers immobilized while the 
solution containing valuable ions elutes through the composite. The class 
of substrate has been shown to include any material having an inherent ion 
exchange capacity. Preferred substrate materials include clays, zeolites, 
minerals, charcoals, carbon black and any conventional ion exchange resin. 
The substrate material should be cleaned thoroughly with water or any other 
suitable material to dislodge any foreign material or fines which may have 
adhered to the surfaces. Next, an optional surface pretreatment step may 
be carried out. This step can involve acidization of a mineral substrate 
surface, or ion exchanging cations like protons or barium ions or anions 
like hydroxide ions onto the substrate. If the substrate used is carbon 
black the carbon black can be carbonylated by oxidizing it with ozone, 
nitric acid, nitrogen oxides or hydrogen peroxide. 
The substrate and the polymer solution can be combined in any conventional 
manner, under any suitable conditions. The preferable step is to treat the 
substrate with the polyelectrolyte using an aqueous solution of the 
polyelectrolyte. This process is carried out with the polymer in an 
aqueous solution with a concentration of polymer ranging from about 
0.0000001 to about 10% by weight, based on the weight of the solution, 
preferably in a reasonably dilute solution within that range. 
The polymer can also be applied in a solution in which other organic or 
inorganic salts such as ammonium citrate, sodium benzoate, sodium sulfate, 
tributylammonium chloride, etc., are dissolved. In the case of the 
application of a mixed polyelectrolyte such as poly-(sodium 
acrylate-co-N-acrylamidomethyl-trimethylammonium chloride) it is 
preferable to have such salts also dissolved in the solution being applied 
to the substrate. 
The process of treating the substrate with the polyelectrolyte can be any 
of several conventional processes. The solution of polyelectrolyte can be 
applied to the substrate in a batch fashion or by packing the substrate 
into a column and eluting the solution through the column of substrate. 
Neither method is to be preferred over the other in those cases in which 
the polyelectrolyte is truly chemisorbed onto the substrate. When the 
polymer is less strongly bonded to the substrate, it is preferable to 
apply the polymer solution to the substrate in an upflowing fashion in a 
column packed with substrate. 
After the polymer solution has been applied to the substrate, the composite 
may be used as is, although it should preferably be washed thoroughly with 
water or other suitable material. Whether washed or not, the composite can 
be dried for storage, shipping, and/or use. It is preferable, however, to 
keep the composite moist up through the time of usage. 
Any polyelectrolyte can be used in the present invention. The preferred 
polyelectrolytes are of the group comprising (a) polymers of quaternary 
halide salts of amines, (b) polymers of (1) the sodium salts of acrylic 
acids, (2) the sodium salts of sulfonic acids containing a vinyl group or 
the respective acids of (1) and (2) and copolymers of monomer precursors 
of (a) and (b). The following list of polymers is meant only to be 
illustrative and in no way is it to be construed that they make up all 
possible possible polymers usable in accordance with the invention: 
CATIONIC POLYELECTROLYTES 
poly-(azirinium halides), 
poly-(vinyltropylium halides) 
poly-(azirinium-co-vinyltropylium halides), 
poly-(styrene-co-aziriniun halides), 
poly-(styrene-co-vinyltropylium halides), 
poly-(N-acrylamidomethyl-trimethylammonium halides), 
poly-(N-acrylamidomethyl-trimethylphosphonium halides), 
poly-(N-acrylamidomethyl-trimethylarsonium halides), 
poly-(N-acrylamidomethyl-dimethylsulfonium halides), 
poly-(N-acrylamidomethyl-dimethylselenonium halides), 
poly-(N,N-dimethyl-3,5-dimethylene piperidinium halides), 
poly-(allyltrimethylammonium halides), 
poly-(styrene-co-allytrimethylammonium halides), 
poly-(diallyldimethylammonium halides), 
poly-(vinylbenzyl trimethylammonium halides), 
poly-(vinylbenzyl trimethylphosphonium halides), 
poly-(vinylbenzyl trimethylarsonium halides), 
poly-(vinylbenzyl dimethylsulfonium halides), 
poly-(methyl vinylpyridinium halides), 
poly-(methyl vinylpridinium-co-allyltrimethylammonium halides), 
poly-(methyl vinylphosphorinaninium halides), 
poly-(methyl furaninium halides), 
ANIONIC POLYELECTROLYTES 
poly-(acrylic acid), 
poly-(acrylic acid-co-acrylamide), 
poly-(acrylic acid-co-styrene), 
poly-(styrene sulfonic acid), 
poly-(acrylic acid-co-styrene sulfonic acid), 
poly-(vinylsulfonic acid), 
poly-(methacrylic acid), 
poly-(vinyl phosphonic acid), 
poly-(chloracrylic acid), 
poly-(bromoacrylic acid), 
poly-(vinylbenzoic acid), 
poly-(vinylbutylsufonic acid), 
poly-(sodium acrylate), 
poly-(sodium acrylate-co-styrene), 
poly-(sodium acrylate-co-acrylamide), 
poly-(sodium styrene sulfonate), 
poly-(sodium methacrylate), 
poly-(sodium vinyl phosphonate), 
poly-(sodium chloracrylate), 
poly-(sodium bromoacrylate), 
poly-(sodium vinylbenzoate), 
poly-(sodium vinylbutylsulfonate), 
poly-(sodium tetrastyrylboride), 
poly-(sodium vinylbenzyl triphenylboride) 
MIXED POLYELECTROLYTES 
poly-(acrylic acid-co-azirinium halides), 
poly-(acrylic acid-co-N-acrylamidomethyl-trimethylammonium halides), 
poly-(acrylic acid-co-N,N-dimethyl-3,5-dimethylene piperidinium halides), 
poly-(acrylic acid-co-allyltrimethylammonium halides), 
poly-(acrylic acid-co-diallyldimethylammonium halides), 
poly-(acrylic acid-co-vinylbenzyl trimethylammonium halides), 
poly-(acrylic acid-co-methyl vinylpyridinium halides), 
poly-(styrene sulfonic acid-co-azirinium halides), 
poly-(styrene sulfonic acid-co-N-acrylamidomethyl-trimethyl ammonium 
halides), 
poly-(styrene sulfonic acid-co-N,N-dimethyl-3,5-dimethylene piperidinium 
halides), 
poly-(styrene sulfonic acid-co-allyltrimethylammonium halides), 
poly-(styrene sulfonic acid-co-diallyldimethylammonium halides), 
poly-(styrene sulfonic acid-co-vinylbenzyl trimethylammonium halides), 
poly-(styrene sulfonic acid-co-methyl vinylpyridinium halides), 
poly-(vinylsulfonic acid-co-azirinium halides), 
poly-(poly-vinylsulfonic acid-co-N-acrylamidomethyl-trimethylammonium 
halides), 
poly-(vinylsulfonic acid-co-N,N-dimethyl-3,5-dimethylene piperidinium 
halides), 
poly-(vinylsulfonic acid-co-allyltrimethylammonium halides), 
poly-(vinylsulfonic acid-co-diallyldimethylammonium halides), 
poly-(vinylsulfonic acid-co-vinylbenzyl trimethylammonium halides), 
poly-(vinylsulfonic acid-co-methyl vinylpyridinium halides), 
poly-(methacrylic acid-co-azirinium halides), 
poly-(methacrylic acid-co-N-acrylamidomethyl-trimethylammonium halides), 
poly-(methacrylic acid-co-N,N-dimethyl-3,5-dimethylene piperidinium 
halides), 
poly-(methacrylic acid-co-allyltrimethylammonium halides), 
poly-(methacrylic acid-co-diallyldimethylammonium halides), 
poly-(methacrylic acid-co-vinylbenzyl trimethylammonium halides), 
poly-(methacrylic acid-co-methyl vinylpyridinium halides), 
poly-(sodium acrylate-co-azirinium halides), 
poly-(sodium acrylate-co-N-acrylamidomethyl-trimethylammonium halides), 
poly-(sodium acrylate-co-N,N-dimethyl-3,5-dimethylene piperidinium 
halides), 
poly-(sodium acrylate-co-allyltrimethylammonium halides), 
poly-(sodium acrylate-co-diallydimethylammonium halides), 
poly-(sodium acrylate-co-vinylbenzyl trimethylammonium halides), 
poly-(sodium acrylate-co-methyl vinylpyridinium halides), 
poly-(sodium styrene sulfonate-co-azirinium halides), 
poly-(sodium styrene sulfonate-co-N-acrylamidomethyl-trimethylammonium 
halides), 
poly-(sodium styrene sulfonate-co-N,N-dimethyl-3,5-dimethylene piperidinium 
halides), 
poly-(sodium styrene sulfonate-co-allyltrimethylammonium halides), 
poly-(sodium styrene sulfonate-co-diallyldimethylammonium halides), 
poly-(sodium styrene sulfonate-co-vinylbenzyl trimethylammonium halides), 
poly-(sodium styrene sulfonate-co-methyl vinylpyridinium halides), 
poly-(sodium vinylsulfonate-co-azirinium halides), 
poly-(sodium vinylsulfonate-co-N-acrylamidomethyl-trimethylammonium 
halides), 
poly-(sodium vinylsulfonate-co-N,N-dimethyl-3,5-dimethylene piperidinium 
halides), 
poly-(sodium vinylsulfonate-co-allyltrimethylammonium halides), 
poly-(sodium vinylsulfonate-co-diallyldimethylammonium halides), 
poly-(sodium vinylsulfonate-co-vinylbenzyl trimethylammonium halides), 
poly-(sodium vinylsulfonate-co-methyl vinylpyridinium halides), 
poly-(sodium methacrylate-co-azirinium halides), 
poly-(sodium methacrylate-co-N-acrylamidomethyl-trimethylammonium halides), 
poly-(sodium methacrylate-co-N,N-dimethyl-3,5-dimethylene piperidinium 
halides), 
poly-(sodium methacrylate-co-allyltrimethylammonium halides), 
poly-(sodium methacrylate-co-diallyldimethylammonium halides), 
poly-(sodium methacrylate-co-vinylbenzyl trimethylammonium halides), 
poly-(sodium methacrylate-co-methyl vinylpyridinium halides), 
MOST PREFERRED CATIONIC POLYELECTROLYTES 
poly-(N-acrylamidomethyl-trimethylammonium chloride), 
poly-(N,N-dimethyl-3,5-dimethylene piperidinium chloride), 
poly-(allyltrimethylammonium chloride), 
poly-(diallyldimethylammonium chloride), 
poly-(vinylbenzyl trimethylammonium chloride), 
poly-(methyl vinylpyridinium chloride), 
MOST PREFERRED ANIONIC POLYELECTROLYTES 
poly-(acrylic acid), 
poly-(styrene sulfonic acid), 
poly-(vinylsulfonic acid), 
poly-(methacrylic acid), 
poly-(sodium acrylate), 
poly-(sodium styrene sulfonate), 
poly-(sodium vinylsulfonate), 
poly-(sodium methacrylate), 
MOST PREFERRED MIXED POLYELECTROLYTES 
poly-(sodium acrylate-co-N-acrylamidomethyl-trimethylammonium chloride), 
poly-(sodium acrylate-co-N,N-dimethyl-3,5-dimethylene piperidinium 
chloride), 
poly-(sodium acrylate-co-allyltrimethylammonium chloride), 
poly-(sodium acrylate-co-diallyldimethylammonium chloride), 
poly-(sodium acrylate-co-vinylbenzyl trimethylammonium chloride), 
poly-(sodium acrylate-co-methyl vinylpyridinium chloride), 
poly-(sodium styrene sulfonate-co-N-acrylamidomethyl-trimethylammonium 
chloride), 
poly-(sodium styrene sulfonate-co-N,N-dimethyl-3,5-dimethylene piperidinium 
chloride), 
poly-(sodium styrene sulfonate-co-allyltrimethylammonium chloride), 
poly-(sodium styrene sulfonate-co-diallyldimethylammonium chloride), 
poly-(sodium styrene sulfonate-co-vinylbenzyl trimethylammonium chloride), 
poly-(sodium styrene sulfonate-co-methyl vinylpyridinium halides). 
The following examples further describe this invention but are not intended 
to limit the invention.

EXAMPLES 
It is well known that clays generally have some ion exchange capacity. 
Indeed, many of the most important ion exchange adsorbents used in 
industry are clays--for example, zeolites, mordenite and Fuller's earth. 
In the course of leaching uranium ore fines (&lt;30 mesh) from a New Mexico 
ore, conventional acid leaching under relatively harsh conditions reduced 
the uranium content (as U.sub.3 O.sub.8) from 0.445 to only 0.137 weight 
percent. Under the assumption that the uranium might be held to the clay 
matrix of the fines by ion exchange trapping, another sample of the ore 
fines was first treated with Cla-sta, a commercial cationic 
polyelectrolyte marketed by Haliburton Co., and acid leached as before but 
with surprising results. Rather than an improvement in uranium extraction, 
the treatment had the opposite effect--uranium content was reduced from 
0.445 to 0.398 percent, just over 10 percent leached. Thus, it appeared 
that cation exchange capacity of the ore for uranium had been enhanced. 
This observation then led to the invention that the ion exchange capacity 
of solids with limited capacity can be enhanced by treatment with suitable 
linear polymers having multiple functional groups. 
In carrying out the laboratory experiments (see table) to demonstrate the 
utility of the invention, the solids to be treated were slurried with 
water into which the treating agents had been dissolved. Agitation at room 
temperature continued for 30 minutes after which the sample was washed, 
filtered and the filter cake or portions thereof similarly contacted for 
either further treatment or retesting for ion exchange capacity. In the 
experiments involving Nuchar charcoal, the agitation period was one hour, 
and in the runs with zeolite the agitation period was about 18 hours. 
TABLE 
__________________________________________________________________________ 
Cake 
Run 
Sample 
Sample Filter Cake 
Analysis 
No. 
Designation 
Weight (g) 
Reagents Designation 
Weight % 
__________________________________________________________________________ 
Barren Uranium Ore Fines 
A 4-1 200 200 g. H.sub.2 O, 4 g Cla-sta, (see note) 
4-2 &lt;0.01 S 
(see note) 24 g. (NH.sub.4).sub.2 SO.sub.4 
B 4-2 10 20 g H.sub.2 O, 2 g DDBS (see note) 
4-3 0.24 S 
C 4-2 10 10 g. 1 M Na.sub.2 S.sub.4 
4-6 0.38 S 
D 4-1 10 20 g. H.sub.2 O, 2 g. DDBS 
4-7 0.054 S 
E 4-1 10 10 g. 1 M Na.sub.2 S.sub.4 
4-9 0.097 S 
F 2-4-5 100 100 g. H.sub.2 O, 3 g., PAA, 
5-2 &lt;0.003 Cu 
(see note) 2 g. NaOH 0.873 Fe 
G 5-2 10 20 g. H.sub.2 O, 2 g. DDBS 
4-8 &lt;0.01 S 
H 5-2 20 20 g. H.sub.2 O, 2 g. Fe.sub.2 (SO.sub.4).sub.3 
5-3 &lt;0.003 Cu 
1.020 Fe 
I 5-2 20 20 g. H.sub.2 O, 2 g. CuSO.sub.4 
5-4 0.299 Cu 
0.741 Fe 
J 4-4 20 20 g. H.sub.2 O, 2 g. CuSO.sub.4 
5-5 0.100 Cu 
(see note) 0.744 Fe 
K 2-4-5 20 20 g. H.sub.2 O, 2 g. CuSO.sub.4 
5-7 0.0676 Cu 
Nuchar-Charcoal Solids 
L 8-1 None &lt;0.02 Cl 
&lt;0.003 Cu 
M 8-1 1 100 g. H.sub.2 O, 2 g. NH.sub.4 Cl 
8-2 &lt;0.30 Cl 
N 8-1 2 100 g. H.sub.2 O, 4 g. PAA, 
8-3 &lt;0.02 Cl 
4 g. NaOH 
O 8-3 1 100 g. H.sub.2 O, 2 g. NH.sub.4 Cl 
8-4 &lt;0.01 Cl 
P 8-3 1 100 g. H.sub.2 O, 2 g. CuSO.sub.4 
8-5 0.657 Cu 
Na--Y--Zeolite Solids 
Q 13-1 30 300 g. H.sub.2 O, 30 g. 
13-3A 8.98 Fe 
(see note) 
K.sub.3 Fe(CN).sub.6, plus 
52.85 org. C 
250 g. H.sub.2 O, 30 g. K.sub. 3 Fe(CN).sub.6 
R 13-0 133.87 
500 g. H.sub.2 O, 69.17 g 
13-2 0.065 Fe 
(see note) 
sample 13-1 0.747 org. C 
S 13-2 30 300 g. H.sub.2 O, 30 g. 
13-3 0.076 Fe 
K.sub.3 Fe(CN).sub.6, plus 
250 g. H.sub.2 O, 30 g. K.sub.3 Fe(CN).sub.6 
0.240 org. C 
T 13-2 30 300 g. H.sub.2 O, 30 g. NaBr, 
13-4 0.006 Br 
plus 250 g. H.sub.2 O, 30 g. NaBr 
U 13-2 30 300 g. H.sub.2 O, 30 g. NaI, plus 
13-5 0.11 I 
250 g. H.sub.2 O, 30 g. NaI 
V 13-2 30 300 g. H.sub.2 O, 30 g. 
13-6 27.54 org. C 
NaB(C.sub.6 H.sub.5).sub.4, plus 
250 g. H.sub.2 O, 30 g. NaB(C.sub.6 H.sub.5).sub.4 
__________________________________________________________________________ 
Footnotes to Table 
Samples 41 and 24-5 are two different batches of barren uranium ore fines 
(&gt;30 mesh). 
Sample 44 is a portion of sample 41 which had been treated with PAA. Whil 
it was not analyzed for Cu, it can be assumed to be free of Cu. 
Sample 81 is Nuchar, grade WVW charcoal distributed by West Virginia Pulp 
and Paper, Chem. Div. 
Clasta is a cationic polyelectrolyte of proprietary composition 
distributed by Haliburton Co. 
DDBS is dodecylbenzenesulfonate, the sodium salt. 
PAA is polyacrylic acid (MW 2000), available in 65 percent solution, 
neutralized to the sodium salt. 
Sample 130 is sodiumy-zeolite. 
Sample 131 is poly(N,N--dimethyl3,5-dimethylenepiperidinium chloride), 
21.6% Cl. 
Comments on the Table 
Run A demonstrates that treatment of barren ore with Cla-sta and ammonium 
sulfate adds essentially no sulfur to the ore, but in Run B the Cla-sta 
treated ore trapped DDBS as indicated by the cake analysis of 0.24% S. 
This result contrasts with Run D wherein barren ore treated with DDBS 
retained only 0.054% S. 
The results of Run C demonstrate the ability of the Cla-sta treated ore to 
retain polysulfide with a cake analysis of 0.38% S, whereas in control Run 
E the untreated ore exhibited low capacity for polysulfide with only 
0.097% in the cake. 
A second sample of barren uranium ore fines designated 2-4-5 was treated 
with the anionic polyelectrolyte PAA plus caustic in Run F and analyzed 
for Cu and Fe. In Run G, it is demonstrated that such treated ore does not 
trap sulfonate (&lt;0.01% S). Run H was made to test the ability of the 
PAA-treated ore to pick up ferric ions. While there was some increase, 
this may not be too significant since the ore was already rich in iron. In 
Run I, however, the same PAA-treated ore was tested with cupric sulfate 
and significant retention of copper was demonstrated with 0.299% Cu versus 
near zero in the starting adsorbant. The corresponding barren ore adsorbed 
only 0.0676% Cu in Run K. In Run J another ore sample which had been 
treated with the acrylate anionic polyelectrolyte exhibited good retention 
of Cu (0.100%). Run K is a control demonstrating that the barren ore used 
in Runs F, G, H and I has little affinity for Cu. 
Run L simply shows that Nuchar contains essentially no Cl or Cu, and Run M 
demonstrates that the charcoal has some capacity for chloride ion. In Run 
N the charcoal was treated with the anionic acrylate polymer and Run O 
indicates that such treatment eliminates the ability of the charcoal to 
absorb chloride. Run P, however, shows that the treated charcoal has good 
capacity for Cu cations. 
Runs Q through V demonstrate that 
poly(N,N-dimethyl-3,5-dimethylenepiperidinium chloride) has high affinity 
for ferricyanide anion (Run Q), but this capacity is largely lost when the 
polymer is composited with Na-Y-zeolite (Runs R and S). The composite has 
no affinity for bromide (Run T), but high capacity for iodide (Run U) and 
tetraphenylboride anion (Run V).