DE2753851A1 - IMPROVED METHOD FOR PRODUCING EXCHANGE RESINS AND THE USE THEREOF - Google Patents

Description

The invention relates to the production of resins which, when desired functional groups are incorporated into them, can be used as ion exchange or ligand exchange resins and relates in particular to the production of resins suitable for use in countercurrent ion exchange systems.

In this specification the term "exchange resins" is used for the resins described above. These resins have a grain shape that distinguishes it from resins intended for other purposes.

Countercurrent ion exchange systems have recently been used in ion exchange technology developed. These systems are constructed in such a way that the solution to be treated with a fluidized bed from ion exchange resin is brought into contact. According to one of these known systems, which the present invention is referred to as Based on the prior art, the solution to be treated flows from the bottom up, and the resin flows due to it compared to the solution of higher specific gravity from top to bottom. This process can be batch or continuous be performed. In another embodiment

809823/0862

this system are the resin fluidized beds in a number of horizontally arranged tanks, and the resin flows either intermittently or continuously between the tanks countercurrent to the direction of flow of the solution.

The capacity of such a countercurrent ion exchange system in relation to the system costs is largely determined by the degree of expansion of the fluidized bed of resin particles. This degree of expansion, indicated as —π—, depends on the degree of loosening of the bed

H-Ho ₌ j -to Ho 1-t.

The loosening of the bed is in turn determined by the flow rate of the solution to be treated and the Sedimentation speed of the individual resin grains. This relation can be found in the well-known Richardson Zaki equation indicate

Under practical process conditions, the sedimentation rate can be determined given by the Stokes equation

2 "_ dp

^U "

18 _{/ U}

809823/0862

At a constant flow rate, the expansion of the fluidized bed is therefore essentially due to the density of the Resin, the particle size and the density and viscosity of the solution to be treated is determined. In Figure 1 of the attached Drawing is the effect of resin density on bed expansion for constant particle size, solution density and viscosity the solution illustrated.

The symbols in the formulas given above have the following meanings:

Ho is the height of the fixed resin bed; H is the height of the expanded resin bed; ijo is the porosity of the fixed resin bed t_ is the porosity of the expanded resin bed; Uq is the flow velocity;

U is the unimpeded sedimentation velocity;

η is 4.4 Re _Q ;

Re is

- / ^U

cj (, is the density of the solution; £ S is the density of the resin; £ is the acceleration due to gravity; -u is the viscosity of the solution.

809823/0862

It is known and customary to use exchanger resin granules in a particle size on the order of 0.3 to 1.0 well and with a specific gravity of the order of magnitude from 1.05 to 1.1 are used. Using known methods, resins of higher density and resins with larger particle sizes can also be used but in both cases, when resins prepared in a known manner are used, the rate of absorption is the rate of absorption of ions is reduced by the resin or the capacity or both properties. This adversely affects the Procedure as a whole.

The invention is based on the object of proposing a method for producing an exchange resin of higher density to bring, its kinetic property not given up appreciably and its ion exchange capacity or ligand exchange capacity are not significantly impaired.

The present invention accordingly provides a process for producing an exchange resin by polymerization the starting substances required to form an exchange resin, which are characterized according to the invention is that styrene substituted with bromine and / or iodine on the benzene ring is used as at least one starting substance will.

809823/0862

According to an advantageous embodiment of the method according to the invention, the main amount of the starting substances is Bromostyrene is used together with any desired copolymerizable monomer. Either monobromostyrene or dibromostyrene or a mixture of these two substances can expediently be used as the bromostyrene. The usual monomers can be used as copolymerizable monomers, and in particular crosslinking agents such as divinylbenzene or a brominated or iodinated divinylbenzene can also be used.

If you according to the invention in the starting mixture different proportional amounts of, for example, bromostyrene and Using styrene monomers, you can use copolymers with specific Make weights in the range of 1.05 to 1.35 or even higher depending on the moisture content. The change in specific gravity is a function of the different contents of bromostyrene in the starting mixture for moisture contents of IO%, 3O%, 5O% and 6O% in the accompanying drawing in Figure 2 illustrates.

In this way, according to the invention, the specific gravity and the kinetic properties of the finished ion or ligand exchange resin can be adjusted as desired and the requirements of the specific application for which the material is to be used

809823/0862

is determined, manufactured adapted and the relation of the performance characteristics of the resin can be optimized to the production costs.

The polymerization can be carried out by any suitable reaction; In general, catalysts are used for this purpose, such as benzoyl peroxide, used. Such polymerization techniques are described and owned in the literature to the potential knowledge of the specialist. An example of this literature is the book "Ion Exchange Resins" by Robert Kunin, 2nd edition 1958, published by John Wiley & Sons Inc.

The resins produced according to the invention have a higher density than comparable known resins. This is due to the inclusion of the heavy bromine atoms in the matrix.

The presence of such atoms affects the selectivity of functional groups attached to the resin and the Confer ion exchange or ligand exchange properties, not. Also the kinetics of the exchange reactions that take place between the resin and the solutions in contact with it are not affected, and neither is the Capacity impaired.

809823/0862

The resin matrix can also be manufactured with iodine-containing styrene. Resins of the invention can be macroporous or microporous be.

The novel resins prepared according to the invention can be used for have many uses. You can, for example for water treatment and in hydrometallurgy for the recovery of valuable substances from solutions or slurries. Some specific examples of possible uses are as follows:

(i) New resins prepared according to the invention can be used for Recovery of uranium from aqueous solutions or slurries by leaching uranium-containing materials with acids or alkali accumulate. Such solutions or slurries are usually treated continuously Countercurrent Ion Exchange Process (CIX). If known ion exchange resins are used to extract the If uranium is used from solutions, this process has its limits. One can advantageously use that produced according to the invention Resin, which for this purpose consists of a bromostyrene-containing, high-density matrix with it existing cationic exchange groups (such as a quaternary ammonium compound), use as ion exchange material that can adsorb uranium as an anionic complex from solution. One achieves thus the following special advantages:

809823/0862

- Al-

a) As a result of the relatively high density of the resins according to the invention, higher flow rates and correspondingly greater throughputs of uranium-containing solution to be treated can be used in a CIX system of the same diameter than when using conventional resins. This can be illustrated with reference to FIG. 1 of the accompanying drawing. Therein the expansion of the resin bed —tj— is graphically illustrated against the flow velocity and given for a resin with a specific gravity of 1.05 (that is a standard commercially available resin) and for a resin with a specific gravity of 1.35. It can be seen that in this case the difference between the flow velocity with which one can work is almost 10 times as much for the resin produced according to the invention as compared with the commercially available resin.

b) When one resin according to the invention manufactured using / it is possible to treat solutions or slurries that have a higher content of soluble or unlösli chen substances (the presence of this material increases the overall specific gravity of the solution be treated or the slurry) increases as you can treat them using commercially available resins. As a result of this advantage, it becomes possible to do the solid-liquid separation that is usually done

809823/0862

\ COPY

to separate uranium-containing solutions from waste slurry, thus reducing the overall investment costs for a plant for the recovery of uranium from uranium-containing materials will be to simplify quite considerably.

c) When using the resins prepared according to the invention In CIX systems it is also possible to provide the CIX installation with smaller dimensions, than they do for using commercially available resins to treat equivalent volumes of leach solution or slurry is required.

Any combination of these advantages can be used for a uranium plant designed to use CIX techniques be considered.

(ii) Resins prepared in accordance with the present invention can be used in processing Use of solutions or slurries that occur when leaching copper-containing materials (for example Ores or scrap metal) using appropriate acid or alkali exposure based leaching techniques are. Here too, the same advantages are achieved as have been described in (i) above.

(iii) Resins prepared according to the invention can be used in processing of solutions or slurries, as used in

809823/0862 _C0PY

Leaching of gold-containing ores or materials by means of cyanide occur. The same advantages result here too, as described in (i) above.

(iv) Resins produced according to the invention can be mixed with the same as previously described in (i) advantages for the work-up of solutions used when leaching Metals of the platinum group containing materials are incurred.

(v) The resins prepared according to the invention can also be used for Processing of metals such as zinc, nickel or cobalt-containing leaching solutions or slurries, be used. The same advantages are achieved as described under (i).

(vi) Resins made in accordance with the present invention can still be used in the processing of solutions or slurries containing valuable substances to avoid undesirable impurities (e.g. ferric ions) if such impurities are detected using the CIX techniques either an anionic or a cationic exchange resin can be adsorbed.

809823/0862

(vii) In the form of anion or cation exchange resins, resins prepared according to the invention for water treatment can be used can be used. For example, they are particularly useful where the treatment is to remove impurities should be carried out in order to make the water suitable for feeding into boilers for steam generation. They can also be used for any other industrial application in which the continuous exchange process is useful, especially when considering the presence of particulate matter in the treatment Can tolerate water.

(viii) Resins produced according to the invention can also be used for treatment of solutions can be used by means of conventional fixed-bed ion exchange methods.

Many different types of resin can be used with the exchange resins according to the invention Organic and inorganic substances are grown to produce the resulting ion or ligand exchange resin to impart diverse skills for the exchange of cations or anions or for the formation of complexes from solutions. Examples of such organic substances are those known as primary, secondary, tertiary or quaternary amines Substances that are commonly used to make the resin

809823/0862

To impart anion exchange properties, carboxylic acid residues, that give the resin cation exchange properties, including sulfonic acid residues that impart cation exchange properties, and complexing compounds that make the resin suitable for the selective adsorption of metals.

To illustrate the advantages of the method according to the invention a number of ion exchange resins according to the invention Methods were synthesized and their adsorption properties were measured.

In the examples below, the term " bromostyrene" refers to monobromostyrene in which the bromine is attached to the benzene ring.

Anion resins

For the synthesis of anion exchange resins, the following was used

Method showing process stages used:

(i) An emulsion copolymerization was carried out using a suspension of bromostyrene or mixtures of styrene and bromostyrene as starting substances and divinylbenzene using benzoyl peroxide as the polymerization

809823/0862

catalyst carried out. The conditions were chosen so that either a resin gel or with the addition of a Pore former a macroporous resin was produced and the polymer particles have a size in the range of 3OO up to 500 microns.

(ii) By reacting this basic body with chloromethyl ether under the usual conditions for the formation of resins these resin particles were chloroethylated.

(iii) The chloromethylated resins were reacted with triethylamine, and in this way an anion exchange group was introduced in the form of the strong base, the uranium as able to adsorb anionic complex compounds from solutions, or it was reacted with dimethylamine and so on introduced a weakly basic anion exchange group.

The specific weight of the product and its capacity were determined on samples of the resin produced in this way. As a The capacity of uranium uptake and the corresponding uptake rate were examples of the adsorption capacity for metal checked. In the same way and under the same conditions as for the production of the invention

809823/0862

resin according to the invention was made using only styrene as the starting material for comparison purposes a common resin made. The test conditions and the results obtained are summarized in Table 1.

It can be seen that the resins prepared according to the invention are a have significantly higher specific gravity than the conventional comparative resin and that in general their capacity and their kinetic properties are very similar to those of the conventional one Resin. It can also be seen that by changing the percentages of bromostyrene and styrene in depending on the starting material, the specific gravity and the capacity and kinetic properties of the resins in a desired manner can be varied according to the production technology used. It is known that by crosslinking (i.e. the proportion used Amount of divinylbenzene) the density of the resin can be influenced by changing the moisture content. But this is nowhere near as significant as the effect of the bromostyrene, as can be seen from Table 2.

809823/0862

Table 1

Experimental results for anion resins

Resin type

common styrene resin (strong base)

j bromostyrene resin (strong base)

1: 2 styrene / bromostyrene resin (based on mole fraction) (strong base)

Bromostyrolhar2 (weak base)

DVB content%

chloride form

3.5 (wt.%)

3.5 (wt.%)

3.0 (MoI.%)

3.3 specific dich-r capacity
te of the resin in j equivalents

1.22

1.20

1.24

per liter of
Resin in
Chloride form

1.41

1.30

1.4:

1.34

Uranium capacity
g U ₃ O ₈ per

liter

51

52

si.

relative loading speed
age

1.02

0.7 '

Table 2 Effect of crosslinking on density

Art

% DVB density g / ml

Bromostyrene

Styrene
Styrene

commercially available |
Resin based
of styrene

10 8 6 6 4 2 1.29 1.23 1.25 1.24 1.21 .1.11 1.17

1.12

809823/0862

Cation resins

As described above under (i) on page 16 and with subsequent A resin according to the present invention was prepared using conventional chlorosulfonation, and a resin was used for comparison common sulfonic acid resin made. The results are given in Table 3.

comparison from Table 3 5
3 1.46
1.20 Resins density
(Na form) sulfonic acid-containing 1, 18
1, 29 Resin type DVB content capacity ⁺
% Equivalents / 1
(Na form) Styrene
Bromostyrene 4,
3,

determined by titration of the hydrogen cations on the hydrogen form of resin; the titration was carried out with a standard sodium hydroxide solution made up with sodium chloride, as described in the reference given above.

Chelating resins

A resin made with bromostyrene in accordance with the present invention was obtained as a chelating resin with iminodiacetate residues by treating chloromethylated polybromostyrene resin grains with hexamine, Hydrolyze the resulting product with concentrated

809823/0862

Hydrochloric acid at reflux temperature and reaction of the product made with sodium chloroacetate. This resin was used for copper adsorption and made with a styrene-based one compared to usual resin. The results are shown in Table 4.

Table 4 for density Comparison of chelating resins
Copper adsorption 1.
1 Resin type DVB content Cu ²⁺ capacity ⁺
% g / l (Na form) , 12
, 36 Styrene
Bromostyrene 6.5 40
3.9 32

determined by bringing 10 ml of des into contact for 4 hours
Resin with 40 ml copper sulfate solution (15 g / l Cu in water).

A chelating agent based on bromostyrene according to the invention Picolylamine type resin was prepared as follows:

As in the previous example, the polybromostyrene matrix was prepared and chloromethylated. This matrix was rated at 6.8
% By weight divinylbenzene produced as a crosslinking agent.

809823/0862

12 ml of methyl alcohol was added to 0.05 moles of the resin in a round bottom flask equipped with a reflux condenser, thermometer and stirrer, and the resin was allowed to swell for 15 minutes. The excess alcohol was then removed and, over a period of 3 minutes, 30 ml of an aqueous aminomethylpyridine (AMP) solution containing 21.6 g of AMP were added ^{with stirring at a temperature of 10 ° C.} The mixture was then refluxed at 40 ° C. for 8.5 hours and then heated at 80 ° C. for 3 hours after the reflux condenser was removed. The resulting resin grains were washed first with water, then with 1 molar HCl and then washed again with water until the excess HCl was removed.

The specific gravity of the resulting granules was found to be 1.31. The capacity of the resin became 1.83 equivalents per kg or, based on copper, to 0.6 equivalents

2+
Cu per liter of the moist sedimented resin (chloride form)

measured.

The above results show that those made in accordance with the present invention Exchange resins had very much improved specific gravity. This can also be seen from the in Figure 2 of curves visible in the accompanying drawing.

me: bü

809823/0862

Claims (14)

UEXKULL & STOLBERG Hi M ι (. «". ΙΙ'Λ ·. .1 .1? Ο00 HAMH 'ιΐίί ι ¹ SJ PATENT LAWYERS DN JD FRHH by UEXKULl DR ULRICH GRAF STOLBCRG UIPL. ING. JÜRGEN SUCHANTKE SENTRACIIEM LIMITED Sentrachem Building 47, Main Street, Johannesburg, Transvaal Province South Africa (1'ri.o: December 5, 1976 ZA 76/7216 - 14595) Hamburg, November 30, 1977 Improved process for the production of exchange resins and their use Claims Process for the production of an exchange resin by polymerizing the required starting substances a resin, characterized in that as at least one starting substance with bromine and / or iodine on the Benzene ring substituted styrene is used. 2. The method according to claim 1, characterized in that bromostyrene, preferably mono- and / or dibromostyrene is used as one of the starting substances. 809823/0862 ORIGINAL INSPECTED 2 7 b 3 8 b Ί 3. The method according to claim 1 or 2, characterized in that unsubstituted as at least one other starting substance Styrene is used. 4. The method according to claim 3, characterized in that the starting substances in a resin with a specific weight from about 1.05 to 1.35 and relative amounts yielding a suitable moisture content are used will. 5. The method according to any one of the preceding claims, characterized in that a catalyst is used and denzoyl peroxide is used for this. 6. The method according to any one of the preceding claims, characterized in that a crosslinking agent is used together with the starting substances. 7. The method according to claim 6, characterized in that divinylbenzene is used as the crosslinking agent. 8. Exchange resin, characterized in that it is produced by the process of any one of claims 1 to 7 has been. ORIGINAL INSPtCiEO 809823/0862 9. exchanger resin according to claim 8, characterized in that that functional groups are attached to the resin which give the resin anion or cation character or chelate L properties give. 10. Exchange resin according to claim 9, characterized in that that as functional groups on it amines, sulfonic acid and / or iminodiacetate sit. 1 . Procedure for carrying out a guided in Geyenstroin Exchange process, characterized in that an exchange resin according to one of claims 9 or 10 is used. 12. The method according to claim 11, characterized in that the extraction of uranium from the exchange process Leaching of uranium-containing materials from solutions or slurries is carried out. 13. The method according to claim 11, characterized in that the resin used for the extraction of copper from during leaching Solutions or slurries from copper-containing materials are used. ORIGINAL INSPECTED 809823/0862 14. The method according to claim 11, characterized in that the resin for the extraction of gold from the leaching Solutions or slurries from gold-containing material are used. 809823/0862