DE1642805A1 - Procedure for carrying out the ion exchange - Google Patents

Description

Troisdorf, May 26th, 1967

»BELÄE'ÜTEIIGlilSELLSCHJLFT Troisaorf Bez. Cologne

Method for carrying out the ion exchange

'Yemenstand tier invention is a special process for You can manage the home exchange in a phase required Process steps, the displacement of the water -11X13 the exchanger bed, the replacement of the one to be exchanged Ion-jaart through the exchanging type of ion and the displacement of the remaining solution again by water.

In the case of ion exchange processes, the Lon .mart to be exchanged, with which the ion exchanger is loaded, is first replaced by di- · lUotaurjchende, which is supplied with the solution. If min wants to completely replace the ion species to be exchanged, then in known processes it is necessary to use a more or less large excess of AxGr exchanging ion species. Conversely, one can di-; Only completely replace the exchanging ion type of the solution with the ionic type of the ion exchanger to be exchanged if an excess of the latter is used. In a different context, one speaks of ion types that are preferred by the exchanger and others that are less well absorbed,

Bofinoet is now the preferred type of ion absorbed on the AuÄtau.-jcherbett, so is a complete replacement r excess of the less well absorbed ion species

009884/1772

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1S42805

required than in the reverse case ₁ .

But to take advantage of the widest possible Toil to be exchanged and the ions contained in the added solution simultaneously to _r different methods have been applied "In one type of method, multiple exchange beds are successively switched, the first little exchanged and the last-carrying virtually contains only the ions to be exchanged «As soon as a certain amount of the solution of the type of ion to be exchanged has flowed through the exchange chain, the. Liquid flow no longer passed through the first exchanger bed. As a substitute for this Austauschergefäß takes a fresh bed of dasiSnde the chain There _β ea "is achieved by that the exchanging ion of the emerging solution is always largely replaced the jiurch exchanged. If the type of ion to be exchanged is preferred by the exchanger bed, an excess of the ions to be exchanged is used for almost complete removal of the type of ion to be exchanged. In the other case, the same amount of ions is sufficient *

The method with a moving exchanger bed is based on a similar principle. The first layers of the "filling" of such a bed are removed continuously or intermittently on the inlet side of the solution and fresh layers are always introduced at the outlet side of the solution, which are mostly or completely loaded with the ion species to be exchanged.

IS42SOS

For ti I α "ie-i: imxsGfae Itorchführung this T experience values j-.Kiooli Always complex JkpparatTiren t> enö% 3Lg% j what"'KWeii. * <Jlsühne disadvantageous: is because the I-oneaaaTisiausschiiologie ^ chiiologie per se , it is disputed that itiasftauschver- · 'i-uirüii In Etögllchs "fc simple devices diii. At ¥ ei ^v drive with moving situ: ^ generally the flow conditions in the exchanger •> out not favorable, because both at the point," v / q "of the ionic knowledge introduced Trird, as well as where the bad ones are introduced-» 'marry unequal currents, -which the exchange is not actually impaired e, -femgrosserung the apparatus to the settlement of the usually quite high exchange column 1st only cumbersome and also leads to increased sj Verschlelli ^■...:

A similar exchange effect can also be achieved. In αβ:, Ί the solution of the exchanging ions as long as "through the exchange bed jgiSXäSftleitei,. Until the dle_ <dewing ions are completely replaced or until the arti'l are replaced by the exchangeri! © new) whereby in η only ucnjealgeti Part of the resulting solution Sb-fahr, whose seaälii aa attszuauschender ion type corresponds to the necessary>;s' strived Afterwards, the exchange request becomes

Load Xoneftaft ernout * file

~ 4

-. ff -

k 184280S

stored solution: is placed on this bed, wotei dia irt ito cm thai fc · «*« α ctuD.taua0hc5n.dG loKenapt cluroh waiter « iaengen- der to be replaced from zukamsche oaths »The one part of the the solution flowing out, the · the latter lukewarm, in contains the required amount ,, is discharged again · ,,. ■ while the rest is put into storage · Mach the put into storage. Solution becomes a solution: abandoned ,, die- only those who exchange Contains ions. This eieihoi sequence occurs in every cycle repeated in the same way »

^ s has shown that it is advantageous to use the solution what kinds of ions to be exchanged and exchanged; contains to be divided into fractions, in order to achieve a technically useful effect at all. These factions contain usually about the same amount of ions as the one added pure solution. The number of fractions has also been increased in order to achieve the desired loading of the exchange bed with the exchanging ions with the smallest possible excess to reach the exchanging ions. However, it has been shown that theoretical expectations can also be met by the Procedure could not be achieved if one only a variety of fractions used »·

"■■ Ö 0 9.8 84/17 72

Omt - - . ■ - ■ - ■ -

These procedures - have been carried out in two types of facilities carried out. With one of them, the ion exchange ■ container Free space above the exchange bed completely filled with water ;, -during "with another • this hem is partly empty and-only directly above the Exchanger bed a liquid layer is present. The level of the liquid is controlled by a float fixed to a "certain hone of the container" However, the height of the liquid layer is different " lent because the exchange bed "is known to be in one cycle in the meantime assumes different volumes, which depends on the type of ions and also on whether txflt a more or less concentrated solution or Water iiäHäifilrjf fills the bed.

These processes are also disadvantageous Headed parliamentary group sinks in this as a result of their higher specific gravity and is strongly diluted with water, while part of the water, mixed with some solution, remains in the liquid layer « The next fraction also encounters a layer consisting of a more dilute solution. But since these factions are composed differently, namely the ions to be broken up in diminishing and the exchanging ones Ions contained in increasing numbers, shifts their composition as a result of the intermingling in such a way that

more ions exchanging in the former and more to be exchanged Ions get into the rear fractions "

This phenomenon, known as "backmixing," changes the effect considerably * The situation is similar later again if the pure solution of the exchanging. Ions »* art is brought to the l ^ istauscherbett. The bed is then still filled with the last stored fraction in the There are also ions to be exchanged. This faction but is more dilute than the freshly added solution, as will be demonstrated below, and the pure solution falls into this Fraction in as at the beginning the fractions in the water. As a result, parts of the last fraction get with those to be exchanged Ions in the pure solution of the exchanging ion species. And defile them. The exchange effect is worsened by especially if the ions to be exchanged are preferred be included. The exchange bed is now filled with the solution that consists of the pure solution of the exchanging ion species •consists. She is displaced from the bed by water, whereby Water gets into the pure solution. The consequence is that the last i'raktipn always more dilute and also specifically lighter than that added pure solution. . ~

To prevent this harmful intermingling, one can use the Increase the concentration of the last fraction by adding the pure solution in concentrated form to this fraction before its task admits. In this way one can actually achieve that the concentration and also the specific weight of the fractions

009884 / 17T2

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jleieh stays; the admixture. the concentrated solution but the last faction just creates the condition that one wanted to avoid, namely the mixing of the pure. Solution of the ions to be exchanged with the ions to be exchanged. Therefore, this method is also unsuitable To remedy adverse phenomena occurring in factions «

In the known processes, too, there is strong dilution of the fractions compared to the added pure solution of the exchanging ions because of the admixture of large Amounts of water, which is also disadvantageous »exchange reactions

^ between ■■ ■.
to run.! Ions of different valences in concentrated solutions differ from those in dilute solutions. For example, "the calcium ions absorbed during water softening are exchanged in a concentrated solution with better efficiency for ilodium ions, which are given up to regenerate the exhausted cation exchanger." costs due to the presence of large amounts of water considerably ez ^ hÖht be "Y / ith the solution of the exchanged ion as Aofall can _r dissipated e-rixönte vias ^ serprob eme -entstehen * Further! you also need for storing large containers ,, when the volume of a jaden, stored fraction is increased considerably as a result of adding water.

009884/177 2

* 1S42805

It has now been found that one. then share this subject. ■ avoid can, if one carries out the Ionenatistau-sch The procedural steps required in a phase, the urging of water by a reaction solution of ion exchange and the displacement of the solution again by water,

■ - ■ / '- "whereby the processes are divided into fractions and partially stored separately and in the next cycle one after the other again passed over the exchanger, so that the displacement of the Y / water from the exchanger bed loaded with the ionic acid to be exchanged is first carried out n., makes fractions of solutions with gradually increasing concentration of the ion type to be exchanged and then gives up n ^ fractions of solutions "" which the ion type to be exchanged gradually decreases in concentration to almost cool and the resulting ions in gradually increasing concentration Contain concentration, so that the ion exchange takes place in a solution of practically constant total concentration, with n-fractions of pure solution of the exchanging ions, the exchange is terminated, the ^ concentration corresponding to the total concentration of the "* Hn fractions, then with n. Fractions of a largely pure solution the exchanging ion type in: schr ittwise decreasing concentration displaced and rinsed with n ^ fractions of water and nu _f . n ₂ and n. fractions of the composition corresponding to the inlet, each in the sequence of their -Ablaufs for the next cycle stored separately * ßg * fractions

3 Ö0I884 / T77Z «AC5 ORKSiNAL

'■ ■ '

Water, if necessary, discards small amounts of the ion species to be exchanged and n “fractions of the exchanged ion type as a product solution out of the cycle, in which

ft -! * υ,} η ,, η., n_, n _c and n "in place of a defined 1 * -2 * y 4 ^f 5 '6 7

Number of factions occur

n. can 2 - 20, n ~ 5 - 50, n, 1-8, n. 2 - 10,, n. ■ t -8, η

and ⁿ 7 - ⁿ -z fractions mean

!, Number of y - i fractions j

since the actions corresponding to e · γ are increased or decreased as a result of the change in volume of the exchanger bed. This consideration also applies to the c and o <fractions · The volume of the individual fractions can be the same or different and, based on the bed volume, is variable within a certain range * The volume of the fractions can be within the range of 10 · 100 $ of the bed volume are »the volume, the fractions is not a critical variable of the process according to the invention. . ._ ■ "" - · .. "'_-- .. ■'. - ..".; . ". \. ■ ;; ..- - '; * .: .. _;

Gradual increase or decrease in concentration does not necessarily mean a regular change in concentration, it can also be uneven * /

The invention is based on two basic ideas,

1. the division of the unused solution into a large number of fractions, the total ion content of the individual fractions advantageously being smaller than that of the pure solution added, and

2 * the V ** hind run of the SUr ^ schm ^ tw ^ htn the individual

" ¹⁰

- ye - ■■■ "■■.

Fractions outside and inside the exchanger bed

By dividing it into a large number of small fractions once the overall effect of the added solution is increased because its compositions follow the continuous exchange curve snuggles better than when using a few, large fractions. As a result, more ions are exchanged for the same volume of the stored amount of liquid can.

This effect is only achieved if the fractions are stored in separate vessels, which are then filled or emptied in the same order in each cycle. The result is that the fractions only mix insignificantly. It is also advantageous to keep the height of the liquid layer above the exchanger bed as small as possible, namely so small that the volume of an individual fraction is not reached, but also not smaller than to protect the surface of the exchanger; bed tea is required so that the »Aueta \ i» cher- | material is avoided by the impinging jets of liquid. A layer height of 1.5-3 »5 ° a has proven to be favorable. The effective height of this liquid layer used can depend on a number of factors such as ^; the cross section of the exchanger bed; the volume of the individual fraction of the flow or the Zuflußge3chwindigksit etc * The cheapest value must advertising determined from case to case experimentally \ the. The liquid level also has to adapt to the change in volume of the exchange bed} and lower and raise itself accordingly. The inflowing liquid is mixed in the liquid layer at least reproducibly and evenly * on this

** 009884/1772 ^

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11

.? '. "- ίέίϋ; .'w ^ rcl dj * ü'unerwünschte' \ Toreilen of incoming Flüsnig-; _t: LU U: ILCM whose opeztfisehea weight is greater than that of the ⁷ lür.ni; koitsschicht "Out of bed" avoided.

.-IV-V Explanation of the method of operation according to the invention is used in FIG. 1, which schematically shows a phase of the exchange cycle on the basis of the compositions of the inlets and outlets

The ion exchanger initially charges with the ion type A β, while the bed is filled with pure water. The ion type B should be absorbed in preference to A. That. , 7'ts ^ he is displaced from the exchange bed you; ': h n> fractions of A-ion solutions of the series a of gradually increasing concentration In the outflow, there are initially ng fractions of pure water on τ di ^{e ia} i * a very low content of Α-ion are withdrawn and removed from the cycle concentration ^ whose "tjuaiitiitionsetzungen with" phase shift discontinued n> Frakti ori ^ n correspond * Since the off exchanger at this time with the -; loaded 1 oichen ion _r first finds no ion exchange takes "Then n ~ fractions vrerden the series b whose (iosaraticonzentration of pure B-solution corresponds abandoned ■ :: 'ottCi ± aas ion A in gradually decreasing concentration and the Wi \ x supervening Xon B in gradually increasing concentration

v / ird. Since the map concentrations of the "n". Fractians handy stay · "- none of the previous ones rushes ahead, in the outflow there are n ™ fractions of the received, the practiscli only A-lon and under £ ITmetändft spuien des B-I öits contained. This solution represents the won; Product of

BATH ORIGINAL

and is removed from the cycle. The following outflowing n ₂ fractions of series "b ' ¹ are stored. Measuring n _g fractions are always obtained in the same composition and concentration in the outflow. Then n, fractions of series c of the solution of pure B ions are sent through the exchanger bed. These Solution is then displaced by η, fractions of series d of B-ion solutions, with the B-ion being used in a concentration that gradually decreases to almost 0 filled with water 'which only contains small amounts of B-ion

Fractions of the series b ^! , then obtained that of the series d '.

In the following phase of the cycle, which usually consists of 2 or also consists of several phases, the gate passage described can

O-

be repeated accordingly. For example, the

in -.

Loading of the exchange bed with Α ions, the / the above Description used A and B ions only interchanged. The description of the process applies to the case of the cation also of anion exchange. The successive cycles are always carried out in the same way, with each Partial phase the appropriate fractions are used again, which were obtained in the previous cycle. In the steady state, which is achieved after several cycles have been carried out, What remains is the composition of the individual fractions and the liquids removed from the system (feed water and product of ion exchange) unchanged * "

The separation of the water from the solution succeeds when displacing of the water through the solution never completely. A little Some of the ions to be exchanged find their way into the separated water and part of the water dilutes the separated product. ",

" ⁿ " 009884/1772

Depending on the given conditions, one can proceed in such a way that the volume of the flow water is increased and at the same time reduces the volume of the product solution or vice versa »Im times, case, the salinity of the forerun and the concentration decreases the product solution to, in the second is "the change reversed" . ·

The separation of the solution from the water is practically complete . As a result of different hydration, the volume of the exchange bed depends both on the type of ions to be exchanged and on the type of exchange material. If the volume of the bed charged with the ions to be exchanged is greater than after the charge reversal with the exchanging ions, then in the exchange, the former is given by the latter ion. This Viasser enters the fractions in series b with which the exchange is carried out. As a result, the concentration of the first fractions in this series is lower than that of the last and that of the product is lower than that of the pure solution added. This difference cannot be remedied. In the opposite case, in which the volume of the bed loaded with the ions to be exchanged is smaller than the volume of the bed loaded with the ions to be exchanged, water is withdrawn from the solution during the exchange and the first fractions in the series are more concentrated than the last. In this case, a product solution is obtained which is more concentrated than the added solution.

The method according to the invention can also be carried out at above room temperature

en ^Λ lying temperatures can be carried out in the manner described. As a result, the already known advantages are achieved. Because of the higher diffusion rates, the exchange reactions generally run faster and the effect of the exchange becomes greater

, _ias ; 009884/1772

thereby not insignificantly increased »whereby one also with more concentrated Solutions than can work at low temperatures.

The rate of fluid application to the exchanger bed; depends on the apparatus sizes, the exchange resin and the physical properties of the solutions or the water. The volume of the inflowing liquid per unit of time can change as the phase goes through. By known means .vird Measure the amount flowing in so that the described, protective Liquid layer is always retained on the exchanger bed. Different batteries from factions can also use it faster Bed to be applied. These fractions are the fractions of solutions or water that are only present on or in the bed displace, i.e. with which no ion exchange is carried out. ■ By installing valves, etc., this can be done relatively easily Way to achieve »■

The transfer of the results obtained in the laboratory of the invention Procedure on an industrial scale takes place in the '.Veise, in which the relation of the quantities of the individual fractions, based on the volume of the exchanger bed and its composition. Due to the different flow conditions. Will there is a certain shift in the composition of the fractions take place, but the steady state It is nevertheless reached relatively quickly. A change in composition of the fractions from the laboratory tests./ When the process according to the invention is carried out on an industrial scale, it is possible. Several exchange beds can also be used in phase shift. In this case one comes' with a set of inputs

storage batteries off.
*) is therefore unnecessary

■ " ¹⁵ " .. 00988 A / 1 7 7 2

BATH ORIGINAL

The inventive method can be in various Devices are carried out »Two institutions will always have these in common for practical purposes. The one institution is used to regulate the height of the liquid layer on the exchanger bed "" This can be controlled by two floats reach, one of which is on the surface of the exchanger bed floats while the other is in the liquid. The relative position of these swimmers to each other is used to regulate » -

Another facility ensures that the parliamentary groups Λ do not mix before they are relinquished. They are passed through a funnel onto the exchanger bed. The funnel is dimensioned so that it can take up the volume of a fraction. The individual fraction containers are provided with drains through which the liquid flows off faster than it is transported further, so that the liquid collects in the funnel triggered pulse is used in a known manner to open the

Closing organs of the fraction container used. '

A device was used to carry out the following examples which is shown schematically in Figs. The exchange vessel 5 of FIG. 2 contains the ion exchange resin 6, which is covered by a low liquid layer 48 is · At a certain distance from this liquid layer there is a distributor device 8. The incoming fractions pass via the line 7 into a vessel 49, which is dimensioned in such a way that a volume of a fraction is added men wordon can »In the vessel 49 Taefindet to control the

^ ^ ,, 00 9 884/1772

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Valves 17 ′ - a float 50. The drains pass through line 9 to a 3- ^ tap 22, which is used to control the out of the circuit to be channeled out and used for the fractions retained in the circuit; feed water and product solution pass via line 23 to a further 3-way valve 24. Via lines 25 and

26 - the feed water or the product solution is discharged. The fractions remaining in the circuit pass through lines 10 and 11 to the corresponding container batteries 12 - 16,

27 - 33 and 34 - 36. The 3-way cocks 38 are used to divert the individual factions. The fractions of the container batteries 12 - 16, 27 - 33 and 34 - 36 are filled into the container 49 and by means of a pump 19 via line 18 to the exchanger bed brought. The containers 3 and 4 are used to hold water or pure solution of the exchanging ion. The factions of the Water or the pure solution were stored in container batteries 20 a-c or 37 a-c before being placed on the bed. Above the line 21 and 39, these fractions flow into the receiving funnel 49 and then onto the bed. ·

The distributor 8 of FIG. 2 consists of a flat, cylindrical vessel with a perforated plate 4I ³ ^ ⁸ bottom. The reference numeral 42 is intended to indicate the position of the holes. -

Below the distributor there is a second perforated plate 43, the holes 45 of which are offset with respect to 42. The holes 45 are surrounded by small ear pieces 46 that prevent the liquid from splashing should prevent.

The pipe sections 47 below the perforated plate 43 carry an installation that a rib-shaped dripping of the liquids is guaranteed

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00 98 84/1772

ORIGINAL

d.urxjs £ ienuiße procedure achieved effects:

• *

Example 1;

The aim is to replace the ammonium ions of a cation exchanger with potassium ions, which are released in the form of a potassium chloride solution. The reaction can be described by the following equation! ^r

KCl- .. + NH. s R ₁ -> ο NH „C1 _T .. + K solution 4.1 4 solution

As JL · a cation exchanger based on a modified Polystyrene with sulphonic acid residues as active groups of the usual. Grain size used. The resin used is commercially available available under the name lewatit S 100.

An exchange bed of 65 liters with a filling height of 1 m was used used ^ ''

The potassium ions are preferentially absorbed in this exchange "

The exchange was first IAIT a 3.8 η KCl solution by a known simple exchange process performed The Dürchsatzgeschv / indigkeit of the KCl solution was 6 volume solution / volume AüstaaschQr per hour, ä's were about I70 ° / o of the full capacity 'of Austauacherbettes to potassium ions erforderlieh to all Aimuoniumionen to replace 40 "/ the bed volume was obtained as a pure 'Ya α ο-he liachdem *, NH Cl appeared. in solution. This reached abfjr after more ^r i85 ⁰ Jo the bed volume the Eingangskonaentration, ao that about 25 fo the bed volume of water in the solution

- ■ · -. ■ 00988A / 1772

¹¹ Iu *

jel'ingte. When the KCl solution was displaced, it took up a further 10 .0 dea bed volume of water until the potassium chloride content in the outlet became negligible.

The total outflowing solution therefore had a concentration of only 2.3 η instead of 3.8 η and the concentration of NH Cl was only 1.35 n _{e therein}
] Invention method;

'As was first the water from the Austauscherhett displaced "To this was added 10 (= n ..) fractions of the battery A (FIG. 1) whose volume was 30 ^liters ß> of the bed volume and in · which the concentration of NH. Cl's gradually increased from 0.4 η to 2.8 η. Then 25 (= n ") fractions of the battery h were given up, the volume of which was 15 ° of the bed volume *

The total concentration of these fractions was 3j8 η and the. The concentration of the potassium ions rose gradually from 0.2 η to 3.65 η, while that of the ammonium ions resulted from the difference between 3.8 η and these values. Pure KCl solution was then added in 4 C = ³¹ O fractions, the concentration of which corresponded to 3> 8 η and the total potassium content of which corresponded to the capacity of the exchanger bed (here 2.2 eq / l bed volume). ; To displace this solution was added 6 (-ή.) Fractions using a 'solution of which the volume per 20 <fo the Bettvolxunens was gradually and its concentration of 3> to 6 on ö, o4 decreased. Finally, 4 (= n, -) fractions of pure water, each of 18 / o of the bed volume, were added,

First (»n) fractions of pure V / asaor, which at the end contained some NH.Cl, flowed out of the exchange bed. The volume of these fractions e ¹ was 65 ^c / o of the bed volume and the amount of NH lost. Cl's accounted for 3 "ß> of the exchanger capacity. When the concentration _{t of} the outflowing solution reached 0.3 η, the first one

00 9 88 4/1772 BAD original

Fraktion dor a'-Batterie ™ * hw «.

- ¹ * - 16A280S

abjezv / eigt and poured into the corresponding storage container. After this battery was replenished, the product of the Auatiusch reaction, a solution of NH-Cl with a concentration of 3165 η and an alkaline content of 0.014 in 4 "(= ⁿ ₇ ) fractions was drawn off and removed from the circuit. Thereafter followed n _? and n, fractions of the series b ¹ and d ¹ and composition of the series, the number of batteries b and d corresponding to all fractions were collected, this phase was over.

In the following phase, the exchange bed was loaded with ammonium ions _e

Example 2; '

The calcium ions of a cation exchanger are supposed to pass through '.Yasstoff'ionen be replaced - which in the form of hydrochloric acid. is abandoned. The reaction can be described by the following equation τ / earth:

^{2 HC1} solution ^{+ approx} . ^) ₂ - * ^CaC1 2 ⁺² H = R ₂ As the cation exchanger, the usual grain size, "a similar exchanger was used as in Example 1, which is commercially available under the name Dowexy.

At üiöseia Austauach the calcium ions are preferentially

Y he falsehood -

The exchange was carried out with a 2 η HCl solution, ie a simple exchange. The throughput rate was 6 volumes of fluid / fluid exchanger per hour. To remove 21 ij if.val Ca ions from 150 ml exchange bed niui3te raan 466 mval 2 η IiGl vurv / ends or 224 lh the stoichiometric length of the removed Ga ions.

009884/1772

Method according to the invention;,

This example was carried out using an exchange bed of 150 ml. Fractions of 30 ml each, the CaGl content of which increased from 0.2 η to 1.0 η, were applied as a battery a J C = Cl,). Battery b consisted of 18 (= n ₂ =) fractions of 50 ml each, which had a total concentration of 2.05 to 1.96 η decreasing, in which the concentration of Ca ions from 1 / 8..η to 0 , 02 η gradually increased. The hydrochloric acid was added in 1 (= n,) fraction of 150 ml, the concentration of which was 1.96 η. The battery of the displacement ^{fractions consisted of 3 (= η} /) fractions, which contained pure hydrochloric acid (some calcium chloride contaminated); their concentration increased from 1.2 η to 0.07 ^{n & 1} ° · Then Y / ater was given up until the last fraction of hehe d ¹ was filled again. For this purpose 90 ml v / ater were consumed. 80 ml Y / ater with 3 meq CaCl ₂ content were drawn off and removed as a forerun. Then followed the IL battery. Factions. Thereafter, 150 ml (n “= 1) product of the exchange with a total concentration of 1.82 η and a calcium content of 210 meq were subtracted. So the acid consumption was 135 ° i ^aer stöchiometJtschen. Amount of calcium ions removed ”. Compared to the simple process, the process according to the present invention ^{saved more than 35 c} / ° hydrochloric acid

Base pieI 5; -

The chloride ions of an anion exchange conquer are supposed to pass through. Hydroxyl ions are replaced, v / which appear as sodium hydroxide vsrerden. The reaction can be expressed by the following equation has been described: -

NaOII ... 4- R _x = Gl ■ - ► NaCl ₁ ,., + R, = OH. ■ Solution 3 · Solution 5 ■ "--- ■ -"

A strongly basic type II anion exchanger was used as R the usual grain size is used, which is commercially available under the name Dowex II is available. Ground this replacement the chloride ions preferentially absorbed * \

Comparison attempt:. *

The exchange will be carried out with a 1 η NaOH solution. In a simple exchange with an exchanger bed with 200 ml, the lye was transferred at a throughput rate of 6 volumes of solution /

Volume exchangers per hour abandoned. 320 ml of lye were required in order to be able to bind 157 meq chloride ions in the subsequent exchange with a n / 20 solution of HaCl

Urfinäun -; according to the procedure ;

The first battery a of the fractions consisted of 3 ('-Hi) fractions with a volume of 35 ml each, the NaCl content of which rose from 0.15 η to 0.6 η} Then the fractions of the second battery b were 17 ( = n ₂ ) Fractions of equal volume given up, their. Total concentration was 1 η and the chloride content decreased from 0.9 η to 0.12 η. Now 210 ml ( ^;> n ^ = l) 1 η NaOH solution were given up. This was followed by 5 (= n.) Fractions of 35 ml volume, the NaOH content of which decreased from 0.9 to 0.05 ή. Finally, 140 ml v / water were added to replenish the fractions.

From the solution flowing out, 10 5 ml (= n / · = · 1) were first removed as a forerun, which contained only 0.2 meq NaCl. Then the fractions a ¹ were returned. The 210 ml product was then withdrawn and discharged. Then followed the fractions of batteries b ^r and d ¹ which corresponded to b and d. In the water content of the exchange bed there was still an alkali concentration of 9.03 n.

^ ^Λ? 0 09 884/177 2 bai

The method according to the invention would achieve .that only

2-10 ml of 1 "η NaOH solution tenoti ^ t -wurden, around 157 meq Remove Gl ions. . ■.

009 884/17 72

Claims (1)

Process for carrying out the process steps required for ion exchange in a phase, displacing Jasüor by a reaction solution of the ion exchange and displacing the solution again by water, the processes being divided into fractions and partially stored separately and in the next cycle one after the other again through the exchanger »characterized in that the displacement of the water from the exchange bed loaded with the type of ion to be exchanged is initially carried out by nv fractions of solutions with gradually increasing concentration of the ion type to be exchanged and then n ~ fractions of solutions are given up which contain the ion type to be exchanged in concentration gradually decreasing to almost zero and contain the exchanging ions in a gradually increasing concentration, so that the ion exchange takes place in a solution of practically constant total concentration, with n, fractions of ruined solution g of the exchanging ions ends the exchange, ■ .vobioi whose concentration corresponds to the total concentration of the n "fractions, then displaced with n. n "and η. Fractions at the inlet correspond to their composition in the sequence of their outlet s separately stored for the next cycle, n fractions of water with possibly small amounts of the ion type to be exchanged are discarded and n fractions of the exchanged ion type are used as product solution out of the cycle _o SADORfQiNAU 009684/1772 Blank page