23838 Purolite CHELATION

CHELATIONSYSTEMS

CHELATION RESINS

Ca Cu H Hg PbAg Fe Co

Ca CuH

Hg

Pb

Ag

Fe

Co

The Purolite Company and Purolite International Limited have one of the

most complete lines of ion exchange resins worldwide. For more

information call:

REG NO. 1840987

The Purolite Company and Purolite International Limited, Divisions of the Bro-Tech Group

SALES OFFICES & BUSINESS CENTRES

UNITED KINGDOM Sales & European MarketingPurolite International Limited, Cowbridge Road,Pontyclun, South Wales, CF72 8YL.Tel: 44-1443-235411 Telefax: 44-1443-231113PRODUCTION & ADMINISTRATION

Purolite International Limited, Cowbridge Road, Pontyclun,South Wales CF72 8YL.Tel: 44-1443-229 334 Telefax: 44-1443-222 336.FRANCE

Purolite International Sarl, 11 Avenue Delcassé, 75008 Paris.Tel: 33-1-42 56 45 63 Telefax: 33-1-45 63 38 26 Telex 648856GERMANY

Purolite Deutschland GmbH, Harkort Strasse 25,40880 Ratingen.Tel: 49-2102-46033 Telefax: 49-2102-443663ITALY

Purolite International S.r.l., Viale Coni Zugna 29,20144 Milano.Tel: 39-2-48 18 145 Telefax: 39-2-48 01 23 59 Telex: 335827POLAND

Radus Spolka z.o.o., ul. Przebendowskich 33, 81-543 Gdynia.Tel: 48-58-297 695 / 248 509 Telefax: 48-58-248 118Telex: 54457ROMANIA

Purolite Romania, International Business Centre Modern,Bulevardul Carol No.44-46, Etajul 5, Bucuresti, Sector 2.Tel: 40-1-250 5053 / 250 5028 Telefax: 40-1-250 5999SPAIN

Purolite Iberia SA, Parc Tecnologic Del Valles,Centre Empreses Noves Tecnologies,08290 Cerdanyola (Barcelona).Tel: 34-3-582-0266/7 Telefax: 34-3-582-0268EGYPT

Purolite International Middle East, 12 Obour Gardens, 5th Floor,Apt. 55, Salah Salem Street, Nasr City, Cairo.Tel: 20-2-402 1477 / 403 1967 Telefax: 20-2-402 1478BRASIL

Purolite do Brasil Ltda, Rua Orissanga No.26, Sala 14-10 andar,Edifficio Rubl-Bairro Mirandopolis, 04052-030, Sau Paulo SP.Tel: 55-11-5078 9583 Telefax: 55-11-5078-9583KOREA

Purolite International (Korea), Dae Yeon Building, Room 403,943-30 Daechi-Dong, Kangnam-Gu, Seoul, Korea.Tel: 82-2-3453 7062/3 Telefax: 82-2-3453 7064

WEBSITES - http://www.purolite.com

http://www.puroliteusa.com

U.S.A.

The Purolite Company, 150 Monument Road, Bala Cynwyd,PA 19004Tel: 1-610-668-9090 Freephone: 800-343-1500Telefax: 1-610-668-8139 Telex: 291718CANADA

The Purolite Company, 625 Wabanaki Drive, Unit 2,Kitchener, Ontario N2C 2G3.Tel:1-519-896-6674 Freephone: 1-800-461 1500Telefax: 1-519-896-6679CZECH & SLOVAK REPUBLICS

Purolite International, Masarykova 190,400 01 Usti Nad Labem, Czech Republic.Tel: 420-47-560 38 05 / 420-47-560 38 25Telefax: 420-47-560 38 05RUSSIA

Purolite International, 10th Floor, 36 Lyusinovskaya Street,Moscow 113093.Tel: 7-095-564-8120 Telefax: 7-095-564-8121Satellite Tel: 7-502-222 2120 Telefax: 7-502-222 2121RUSSIAN FEDERATION

Purolite International Limited, 12 Building A, Tambovskaya Street,St Petersburg, 192007 Russian FederationTel: 7-812 327 8350 Telefax: 7-812 327 9079KAZAKHSTAN

Purolite RH Limited, Office 25, 157 Albaya Ave., Almaty 480009Tel: 7-3272 608 449 Telefax: 7-3272 509 475UKRAINE

Purolite International Limited, 2 Korolenko Street, Office No.5,Dnepropetrovsk City, Ukraine 49070Tel: 380-562 32 00 65 Telefax: 380-562 23 12 79SINGAPORE

Purolite International (Singapore) PTE Limited, 300 Beach Road,32-04 The Concourse, Singapore 199555.Tel: 65-297- 0889/297 1453 Telefax: 65-297 1986CHINA

Purolite China Co Limited, Chenguan County, Deqin City,Zhejiang Province, 313200 P.R.China.Tel: (86) 572-842-2908-819 Telefax: (86) 572-842-3954TAIWAN

Purolite International Limited, 16F-2, No.191 Fu-Hsing N Road,Taipei, Taiwan.Tel: 886-2-546 7078 Telefax: 886-2-546 7069MEXICO

Purolite International SA de CV, World Trade Center, Montecito38 Piso 33, Mexico D.F.03810, Mexico.Tel: 52 5488 0904 Telefax: 52 5488 0906

All suggestions and recommendations given above concerning the use of Purolite products are based on tests and data believed to be reliable. However, asPurolite cannot control the use of its products by others, no guarantee is either expressed or implied by any such suggestion or recommendation by Purolite, noris any information contained in this leaflet to be construed as a recommendation to infringe any patent currently valid. D145T/2000

Section Vll. COMMENTS

The Purolite Chelation Resins described in this bulletin are the result ofcontinued development of ion exchange products designed for many industrialprocesses. Further modifications of these products already exist in accordancewith Purolite’s policy to provide their customers with the superior resins forspecific industrial processes.

Chelation Resins and the associated systems, have already been shown to beindispensible for production of solutions of the high purity needed in specialprocesses. The efficiency of removal of particular species ultimately dependsupon the property of selectivity. However, the advantage of high selectivity hasto be taken into account when considering how best to remove theconcentrated metal from the collecting medium. In some cases resindestruction is economic and useful. In others, it is the change of stability of thechelation complex with the change in conditions between exhaustion andregeneration which ensures near perfect fixation and excellent removal onregeneration. Changes in pH and ionic concentration are often the best meansto ensure efficiency in both parts of the cycle. The use of electrolytic processesfor regeneration can also be considered, particularly for the electrodeposition ofprecious metals.

The need for chelation materials with specific properties tailor made to suitparticular industrial processes is now a commercial reality.

The expertise of Purolite is available, to give recommendations both on specificuses of the chelation products described in this bulletin, and to provide modifiedproducts for evaluation.

a) Extracting heavy metal ions from leachliquors, tailings runoff, or from industrialeffluents. For example, lead may beremoved from oil refinery waste liquors,solvents and aqueous wastes from themanufacture of paints and printing inks, orbattery factory wastes.b) Recovery of zinc from cooling-tower

waters, etc. where it is used as a corrosioninhibitor.

c) Refining of metal salt solutions byselective removal of individual ions.

d) ‘’Polishing’’ of aqueous organic andinorganic solutions for the removal of tracemetals.

20

APPLICATIONS

OPERATING PERFORMANCE

Before attempting to use Purolite S-950for any industrial application, it is stronglyrecommended that laboratory column testsare carried out on the solution which is tobe treated, so as to determine theoperating performance in terms of bothtreated solution quantity and quality oncethe chosen equilibrium cycle conditionshave been established. This may takeseveral cycles.

The curves for copper and nickel forPurolite S-950 given in fig. 3 may serve asa guide to the maximum exchange capacityobtainable from a feed of 2g/l metal as afunction of pH. In practice, lower capacitieswil l usually be obtained, depending,depending upon regeneration level chosen,having regard to the leakage of metalacceptable .

Fig. 3. RESIN CAPACITY

1 2 3 4 5

pH

50

40

30

20

10

0

6-

5-

4-

3-

2-

1-

RES

IN C

APA

CIT

Y g/

l

RES

IN C

APA

CIT

Y lb

/ft3

Cu++

Ni++

The removal of metals from process liquorsis rapidly gaining in importance. Theescalating costs of disposal of wastesolutions, in order that they comply withincreasingly tough regulation, have to betaken into account. Such costs have to beconsidered in conjunction with possiblesavings to be made from recovery.Purolite offers a range of chelation resinswhich will selectively remove particulargroups of metals from solution. Afterpreliminary recovery by precipitation, on theone hand, or where plated metal objectshave been given final rinses, on the otherhand, these metals are usually present inwaste solutions in concentrations of severalparts per million. Such concentrationsalthough low are found to be environ-mentally harmful In many cases.The use of Purolite Chelation Resins forthe purification of these waste aqueousstreams to render them suitable for disposalthrough the domestic sewerage system, ordirect disposal into suitable aquifers, affordsa most suitable and economical means oftreatment, which yields treated solutionscontaining almost undetectable (ppb)concentrations of the undesirable metals.The many-fold increase in concentration ofthe metals on the chelation resin makes

possible the recovery of the metal forreprocessing or effective disposal in a lessharmful form.

Modern industrial chemical processes oftenuse sophisticated techniques which providea more economical route to high qualityproducts. One such process usesmembrane cells for the electrolysis of brineto produce caustic soda and chlorine. Themembrane cells require that the inlet brinecontains less than 20ppb of calcium forefficient operation. Purolite S-940 providesan ideal route to reduce calciumconcentration in brine feed solutions from 1-15ppm, as found in conventionally purifiedsolutions, to well within the requiredspecification, for the smooth operation ofthis process.

As analytical techniques continue toimprove, the study of the effect of tracelevels of impurities on the economics ofindustrial processes is increasingly wellunderstood. The very high selectivity ofchelation resins means that these ionexchange resins will offer many furtherpossibil it ies to remove harmfulcontaminants to provide solutions of therequired purity.

1

Section 1. INTRODUCTION

Chelation Systems

Technical Data

Section II.

Resin Type Functional Group Matrix

Purolite

S-920 Thiouronium Macroporousstyrene-divinyl-

benzene

S-930 Iminodiacetic Macroporousstyrene-divinyl-

benzene

S-940 Aminophosphonic Macroporousstyrene-divinyl-

benzene

S-950 Aminophosphonic Macroporousstyrene-divinyl-

benzene

Principal Applications

Mercury and precious metals removalfrom aqueous solutions

Effluent treatment, hydrometallurgy(Specific for heavy metals)

Brine purification(Removal of calcium etc)

Effluent treatmentHydrometallurgy

During upflow backwash, the resin bedshould be expanded in volume by between50 and 75%, in order to free it from anyparticulate matter from the influent solution,to clear the bed of bubbles and voids, andto reclassify the resin particles as much aspossible, ensuring minimum resistance to

flow. Bed expansion increases with flowrate and decreases with temperature, asshown in Fig. 2. for a typical exhaustedform of the resin. Care should always betaken to avoid resin loss by over-expansionof the bed.

19

AFFINITY ORDER FOR TYPICAL CATIONS.

It should be noted that Purolite S-950 iscapable of operating under acidic, neutral, oralkaline conditions; its operating capacity forany of the chelated ions is a function of

CATION SPECIES

CU2 + Pb2 +

Zn2 +

Cd2+, Ca2+

Mg2+, Ni2+ Co2+

pH, and consequently there are minimumvalues of pH below which removal of agiven cation from the influent solution is notfeasable. Relevant figures are given below:

CATION SPECIES

22.53

4.5

Like the S-940, the S-9.50 affinity order varies as a function of solution pH.Acidic pH:H+ > Fe3+ > Pb2+ > Cu2+ > Zn2+ Al3+ > Mg 2+ > Ca2+ > Cd2+ > Ni2+ > Co2+ > Na+

Alkaline pH:Cd2 + Mg2 + > Ca2 + > Sr2 + , Al3 + > Ba2 + >> Na + K+

Fig. 1. PRESSURE DROP VS FLOW RATE Fig. 2. BACKWASH EXPANSION(exhausted form)

0 20 40 60 80

FLOWRATE m/h

FLOWRATE U.S. gpm/ft2

8 16 24 321.0

0.8

0.6

0.4

0.2

0 5 10 15 20

FLOWRATE m/h


2 4 6 8100

50

4-

3-

2-

1-PRES

SUR

E D

RO

P Kg

/cm

2 /m

BED

EXP

AN

SIO

N (%

)

PRES

SUR

E D

RO

Ppsi

/ft b

ed d

epth

10°C

, 50

°F20

°C ,

68°F

40°C

, 10

4°F

10°C

, 50

°F20

°C ,

68°F

40°C

, 104

°F

CONVERSION OF UNITS

1 m/h (cubic metres per square metre per hour) = 0.341 gpm./ft2.= 0.409 U.S. gpm./ft2.

1Kg/cm2 /m (Kilograms per square cm. per metre of bed) = 4.33 psi/ft.= 1.03 atm./m/= 10 ft. H2O/ft

Contents

Section II. Page Nos.

I. INTRODUCTION Chelation Systems 1

II. SUMMARY CHART 1

III. PUROLITE S-920 For the selective removal of mercury 3and precious metals from aqueous solutions.Product Description Standard Operating ConditionsPrinciple of reactionHydraulic CharacteristicsOperating Performance

IV. PUROLITE S-930 For the selective removal of heavy metals. 7Product DescriptionStandard Operating ConditionsPrinciple of reactionApplications Operating PerformanceHydraulic Characteristics

V. PUROLITE S-940 Especially for decalcification of brine solution. 11Product DescriptionOperating Conditions-Brine purificationPrinciples of OperationPrincipal ApplicationOperating PerformanceChemical and Physical StabilityGeneral ApplicationsHydraulic Characteristics (General Applications)Pressure drop and backwash expansion(Brine purification)

VI. PUROLITE S-950 For selective removal of toxic metals from 17aqueous solutions.Product DescriptionStandard Operating ConditionsChemical StabilityHydraulic CharacteristicsAffinity order of typical cationsApplicationsOperating Performances

VII. COMMENTS 21

2

Purolite S-950 is insoluble in acids, alkaliesand all common solvents at normallyencountered temperatures(although oxidizing agents like concentratednitric and perchloric acid at elevatedtemperatures will destroy its structure andsolubilise the resin. Care should be takenwhen using strong nitric acid, as explosive

hazards have been reported onpoly(styrene)-based anion exchange resinswith this reagent). However exposure, evenat ambient temperatures, to certain otherstrong oxidizing agents such as chlorinecauses irreversible damage to this resinand must be kept to the absoluteminimum.

18

The pressure drop (or headloss) across aproperly classified bed of ion-exchangeresin depends on the particle sizedistribution, bed depth, and voids volume ofthe exchange material, and on the flowrateand viscosity (and hence on thetemperature) of the influent solution.Anything affecting any of these parameters,for example the presence of particulatematter filtered out by the bed, abnormalcompaction of the resin bed, or the

incomplete classification of the resinspheres will have an adverse effect, andresult in an increased headloss.

Service flow rates from 8-16 bed volumesper hour, depending on the application, maybe regarded as the normal range used onthis resin, Typical pressure drop figures tobe expected for ordinary aqueous solutions,are given in Fig. 1.

CHEMICAL STABILITY

HYDRAULIC CHARACTERISTICS

STANDARD OPERATING CONDITIONS

Operation Rate Solution Minutes Amount

Service 8- 16BV/h For treatment1-2gpm/ft3

Backwash 5-7m/h Raw Water 5-20 1.5-6BV2-3gpm/ft2 10-35 gal/ft3

Regeneration 3-4BV/h Mineral Acids 30-60 120-200g/l HC10.4-0.5gpm/ft3 (2N-3N) 7.5-1 2.51b/ft3

200-300g/l H2 SO4

12.5-20 Ib/ft3

Slow rinse 3-4BV/h Raw Water 30-40 2-3BV0.4-0.5gpm/ft3 15-20gal/ft3

Conversion to sodium form-as required:3-4BV/h N NaOH 30-60 60-120g/l0.4-0.5 gpm/ft3 (Upflow)* 3.75-7.5 Ib/ft3

Rinse (slow) 3-4BV/h Soft Water 20-40 2-4BV0.4-0.5gpm/ft3 15-30gal/ft3

Backwash expansion 75% (optimum)Design rising space 100%Minimum bed depth 1000mm "gallons"’ refer to U.S. gallons = 3.785 Litres.

*The aim is to achieve the same pH as that of the incoming solution.

Purolite S-920 is a macroporouspolystyrenic based chelating resin, withthiouronium groups designed for theselective removal of mercury.and for therecovery of precious metals from theindustrial effluents. The mercury, inparticular, is strongly bound to the functionalgroups to form highly stable complexes,with high selective affinity compared withthose of other heavy metals. Theseproperties are largely unaffected by highchloride (or sulphate) content of theeffluent. Effluent solutions which maytypically contain 2-20ppm of mercury can betreated to reduce the concentration insolution to less than 0.005ppm. PuroliteS-920 can load up to 200g of mercury, orgold, or 60g approx. of platinum orpalladium for each litre of resin, equivalentto 12.5, and 3.75 Ib/ft3 respectively. PuroliteS-920 is designed for the removal of low

concentrations of soluble mercury saltsfrom waste streams and for the recovery ofprecious metals from rinse waters in thegalvanic and electronic industries. PuroliteS-920 is also used in hydrometallurgy forthe separation of precious metals from acidliquors. Mercury and precious metals are sostrongly held, and run lengths are so long(thousands of hours) that it is not normallyconsidered economic to regenerate theresin for reuse.

Purolite S-920 is more resistant tooxidation than many thiol based resins andcontact with the atmosphere is notdetrimental, however free chlorine andother strong oxidising agents may damagethe resin and their removal from solution byfi ltering through activated carbon isrecommended.

3

Section III. PRODUCT DESCRIPTION

S-920Macroporous Thiouronium

Chelating Resin(For the selective removal of mercury andprecious metals from aqueous solutions)

Technical Data

Typical Chemical & Physical Characteristics

Polymer Matrix Structure ..................................... Macroporous Styrene-divinylbenzenePhysical form & Appearance ..................................................... Opaque Cream SpheresWhole Bead Count ................................................................................................ >95%Functional Groups ....................................................................................... ThiouroniumIonic Form (as shipped) .............................................................................................. H+

Shipping Weight .................................................................... 700 - 735 g/l (44 - 46 lb/ft3)Screen Size range (British Standard Screen) ........................................ 14-52 mesh, wetParticle Size range ............................................................ + 1.2mm <5%, -0.3mm <1%Moisture Retention, H+ Form ............................................................................. 48-54%Reversible Swelling, (H+➔ Hg++) ........................................................................... <5%Specific Gravity. Moist H+ Form .............................................................................. 1.12Specific Gravity. Moist Hg++ Form .......................................................................... 1.40Total Exchange Capacity, H+ Form (wet, volumetric) ..................... 200g Hg/l, 12.5 lb/ft3

Max, Operating Temperature, H+ Form ...................................................... 80°C (176°F)Operating pH Range ................................................................................................. 1-13

Purolite S-950 is a macroporous amino-phosphonic acid chelating resin, designedfor the removal of cations of toxic metalssuch as lead, copper and zinc from industrialeffluents at low ph. At somewhat higher pHvalues, calcium, magnesium and barium, aswell as the toxic metals cadmium, nickel,and cobalt are strongly complexed and maybe separated from quite high concentrationsof univalent cations.Unlike Purolite S-930, the well knowniminodiacetic acid resin, which is selective

for heavy metal ions, but not for commondivalent ions (calcium and magnesium),Purolite S-950 is more highly selective(under the appropriate conditions) for arange of both heavy metal and commondivalent ions. Hence its use may berecommended where it is necessary toremove calcium or magnesium in order toavoid possible precipitation, or where itsselectivity for a particular range of metalsoffers advantages.

17

Section VI. PRODUCT DESCRIPTION

S-950Macroporous Aminophosphonic

Chelating Resin(For the selective removal of toxic metals

from aqueous solutions)

Technical Data


Polymer Matrix Structure ................................Macroporous Styrene-divinylbenzenePhysical Form & Appearance ........................................Opaque light brown spheresWhole Bead Count ............................................................................................>95%Functional Groups ..........................................................................RCH2 N HCH2 P03

ionic Form (as shipped) ........................................................................................Na+

Shipping Weight g/l ...................................................710 - 745 g/l (44.5 - 46.5(lb./ft3))Screen Size Range: British Standard Screen ...................................14-52 mesh, wet

U.S. Standard Screen .......................................16-50 mesh wetParticle Size Range .......................................................+1.2mm <5%, -0.3mm <1%Moisture Retention, Na+ Form ......................................................................60-68%Reversible Swelling, (H+ ➔ Na+) Max. ................................................................45%Specific Gravity, Moist Na+ Form ........................................................................1.13Total Exchange Capacity, Na+ Form (wet, volumetric) ..................2.0 meq./ml., min.

(dry weight)...........................................................5.5 meq./g., min.Exchange Capacity (Na+ Form) .........................24 g. Ca++/l (1.51b/ft3)min at pH 9.5Max, Operating Temperature, Ca++ Form .............................................90°C (195°F)pH Range (operating), H+ Form .............................................................................2-6

Na+ Form ............................................................................................6-11

It is recommended that Purolite S-920 isused in a two column, lead and trail system.In this way, maximum loading of the resin isachieved. When use is for mercury uptake,it is usual to pretreat the solution with lime

neutralisation and to fully oxidise the metalsand sulphites with H2O2. This is followed byflocculation with an inorganic polyelectrolite,sedimentation, sand and activated carbonfiltration .

4


PRINCIPLE OF REACTION


The mercury is strongly complexed by thesulphur and nitrogen groups. When theresin is well rinsed with water before use,the mercury salt as a whole isaccommodated on the resin. In mostinstances the pH of the water to be treatedwill l ie in the range of 3-10, which isgenerally very suitable for highest mercuryuptake and the lowest leakage - typically

much less than 5ppb as Hg. pH may bereduced slightly by the mercury exchange(release of acid held by the weakly basicthiouronium groups) .

In general Purolite S-920 will complexprecious metals when they are present asfree cations. The free cation state isgoverned by the pH of the solution.

The pressure drop (or headloss) across aproperly classified bed of ion-exchangeresin depends on the particle sizedistribution, bed depth, and voids volume ofthe exchange material, and on the flowrateand viscosity (and hence on thetemperature) of the influent solution.Anything affecting any of these parameters,for example the presence of a particulatematter filtered out by the bed, abnormalcompaction of the resin bed, or the

incomplete classification of the bed willhave an adverse effect, and result in anincreased headloss.

Service flow rates from 10-30 bed volumesper hour, depending on the application, maybe regarded as the normal range used onthis resin. Typical pressure drop figures tobe expected for ordinary aqueous solutions,are given in Fig. 1.

Recommended linear flow rate: 6-18 m/hMinimum bed depth: 1000mmBackwash flow rate: 4-8 m/h (see fig. 2), for 20 min.

Mercury Removal

RCH2 S C + Hg++ Cl2 Hg S C

N+H2 Cl -

N+H Cl -

NH2

NH

RCH2

During upflow backwash, the resin bedshould be expanded in volume between 50and 75%, in order to free it from anyparticulate matter from the influent solution,to clear the bed of bubbles and voids, andto reclassify the resin particles as much as

The pressure drop across a bed of resinwhen brine (300g/l) is the influent solution isconsiderably higher than that for more dilutesolutions hence the curves given belowshould be used, see fig. 10.

possible, ensuring minimum resistance toflow. Bed expansion increases with flowrate and decreases with temperature, asshown in fig. 9 for a typical exhausted formof the resin. Care should always be taken toavoid resin loss by over-expansion of thebed.

The backwash expansion for the calciumform resin at the end of the brinepurification is higher than that for theheavier metals, thus the curves in fig. 11are applicable

16

Brine purification

PRESSURE DROP AND BACKWASH

Fig. 10 PRESSURE DROP VS FLOWRATE Fig. 11 BACKWASH EXPANSION

0 20 40 60 80

FLOWRATE m/h


8 16 24 321.0

0.8

0.6

0.4

0.2

0 5 10 15 20

FLOWRATE m/h


2 4 6 8100

50

4-

3-

2-

1-PRES

SUR

E D

RO

P Kg

/cm

2 /m

BED

EXP

AN

SIO

N (%

)

PRES

SUR

E D

RO

P ps

i/ft b

ed d

epth

40°C , 104°F

60°C , 140°F

80°C , 176°F

10°C

, 50

°F20

°C ,

68°F

40°C

, 104

°F

During upflow backwash, the resin bedshould be expanded in volume by between50 and 75%, to clear the bed of bubbles andvoids, and to classify the resin particles asmuch as possible, ensuring minimumresistance to flow. Bed expansion increases

with flow rate and decreases withtemperature, as shown in Fig. 2. This appliesto unused resin. Since the resin is notregenerated, backwash at exhaustion is notrequired. Care should always be taken toavoid resin loss by over-expansion of the bed.

5

The operating capacity will be higher on thefirst cycle since both lead and trail columnswill use new resin. This cycle wil l becomplete when the lead column issaturated (that is when influent and effluenthave reached equilibrium). The substantialleakage which occurs from the lead columntowards the end of the cycle is of coursetaken out by the trail column. This usescapacity depending upon the conditions ofoperation. In subsequent runs thethroughput obtained from the lead column

will be reduced according to load previouslytaken up while the bed was in the trailposition.

The Fig. 3. gives a typical exhaustion profilefrom the outlet of the trail column in termsof bed volumes throughput for the leadcolumn. In a typical operation as shown thelead column is loaded with a total of 90g/l ofmercury of which 70-85g/l may be loadedwhile the bed is in the lead position.

Fig. 1. PRESSURE DROP VS FLOW RATE Fig. 2. BACKWASH EXPANSION(New resin)


CONVERSION OF UNITS


1Kg/cm2 /m (Kilograms per square cm. per metre of bed) = 4.33 psi/ft.= 1.03 atm./m= 10 ft. H2O/ft

0 20 40 60

FLOWRATE m/h


8 16 241.0

0.8

0.6

0.4

0.2

4-

3-

2-

1-

PRES

SUR

E D

RO

P Kg

/cm

2 /m

0 5 10 15 20

FLOWRATE m/h


2 4 6100

50

BED

EXP

AN

SIO

N (%

)

PRES

SUR

E D

RO

P ps

i/ft b

ed d

epth

5°C

, 40°

F15

°C ,

60°F

30°C

,86°

F 5°C

,40°

F20

°C ,6

8°F

30°C

,86°

F

Purolite S-940 is also suitable forseparation and recovery of heavy metals,including uranium. The leakage of uraniumcan depend on linear flow rate in the resinin pulp process (see Fig. 7).

- Purolite S-940 has a high selectivity forheavy metals and transition metals, moreparticularly, lead, copper and zinc. Theaffinity for copper is higher than for zinc andhence it is possible to separate andconcentrate these metals from a mixture insolution.

- Purolite S-940 may be used to purifysolutions. For example, lead can beremoved from industrial waste streamsetc...

The pressure drop (or headloss) across aproperly classified bed of ion-exchangeresin depends on the particle sizedistribution, bed depth, and voids volume ofthe exchange material, and on the flowrateand viscosity (and hence on thetemperature) of the influent solution.Anything affecting any of these parameters,for example the presence of particulatematter filtered out by the bed, abnormal

compaction of the bed, or the incompleteclassification of the bed wil l have anadverse effect, and result in an increasedheadloss.Service flow rates from 10-30 bed volumesper hour depending on the application, maybe regarded as the normal range used onthis resin. Typical pressure drop figures tobe expected for ordinary aqueous solutions,are given in fig. 8 below.

15

GENERAL APPLICATIONS


Fig. 8 PRESSURE DROP VS FLOWRATE Fig. 9 BACKWASH EXPANSION(Exhausted Forms)

0 20 40 60

FLOWRATE m/h


8 16 241.0

0.8

0.6

0.4

0.2

4-

3-

2-

1-

PRES

SUR

E D

RO

P Kg

/cm

3 /m

0 5 10 15 20

FLOWRATE m/h


2 4 6 8100

50

BED

EXP

AN

SIO

N (%

)

Fig. 7 EXTRACTION OF URANIUM

0 60 120 180 240 300FLOWRATE m/h


24 49 74 98 12370

60

50

40

30

20

10

CO

NC

ENTR

ATI

ON

OF

U4+

ppm

PRES

SUR

E D

RO

P ps

i/ft b

ed d

epth

Influent:-

U4 = 40ppm

Fe2 = 8 g/l

P2O5 = 28%

Flow Rate

= 6 BV/h

10°C

, 50°

F20

°C , 6

8°F

40°C

, 104

°F 10°C

, 50

°F20

°C , 6

8°F

40°C , 104°F

Fig. 3. OPERATING PROFILE: Typical from trail column

10 20 30 40 50

THROUGHPUT BED VOLUMES X 1,000(For lead column)

THROUGHPUT gal/min/ft3 x 1000

2.5 5

20

15

10

5

0

LEA

KAG

E pp

b M

ercu

ry

Inlet Mercury — 2ppmto Lead ColumnTemperature 20°CpH 8.0Flow Rate 8BV/h

6

* Leakage values may be lowerin dotted line region

Purolite S-940 has been exhaustivelytested to demonstrate that it will withstandtemperatures above the maximumrecommended limit of 90°C (194°F) in thepresence of brine solutions at high ionicconcentration (300g/l). It has also beenshown that Purolite S-940 is bothchemically and physically stable to highconcentrations of acid and alkali (20% ofsulphuric acid and 20% of sodium

hydroxide), which are stronger than wouldnormally be used under the most severeconditions of operation. In tests for osmoticand physical stability using a speciallydeveloped rig* which incorporatesmechanical stress and attrition, by pumpingthe resin against a retaining stainless steelmesh, the following results were typicallyobtained after 100 cycles of operation.

14

CHEMICAL AND PHYSICAL STABILITY

Resin % Perfect % Cracks % Pieces % Mis shapesPurolite S-940 97 1 1 1Purolite S-940 100 cycles 96 0 2 1

* Test Rig originally developed by the Scientific Services Division of the Electricity Generating Board of UK.

Fig. 3 CORRECTION FACTOR FORTEMPERATURE

TEMPERATURE °F

120 130 140 150

50 60 70TEMPERATURE °C

1.1

1.0

0.9

0.8

0.7

0.6

CO

RR

ECTI

ON

FA

CTO

R C

2

Fig. 4 CORRECTION FACTOR FOR FLOWRATE

gal/min/ft3

80 160 240 320 400

10 20 30 40FLOWRATE BV/h

1.0

0.8

0.6

0.4

0.2

CO

RR

ECTI

ON

FA

CTO

R C

3

Fig. 5 TYPICAL LEAKAGE OF CALCIUMTHROUGHPUT gal/ft3

50 100 150

500 1000THROUGHPUT - BED VOLUMES

50

40

30

20

10

0

CA

LCIU

M IN

TR

EATE

D B

RIN

E pp

b

Fig. 6 TYPICAL LEAKAGE OF MixedCATIONS

THROUGHPUT gal/ft3

50 100 150

500 1000THROUGHPUT - BED VOLUMES

100

80

60

40

20

0

LEA

KAG

E pp

b

Influent Ca++ 15ppmTemperature 60°C, 140°FpH 10

Influent Ca++ 6ppmSr++ 4ppm

Temperature 60°C, 140°FpH 10.5Flow rate 30BV/h

Ca++

Sr++

Purolite S-930 is a macroporouspolystyrene based chelating resin, withiminodiacetic groups designed for theremoval of cations of heavy metals fromindustrial effluents. These cations may beseparated from high concentrations ofunivalent cations (typically sodium) and alsofrom common divalent cations (such ascalcium). Removal can be achieved bothfrom weakly acidic and weakly basicsolutions depending on the metals to beremoved.

Purolite S-930 finds use in processes forextraction and recovery of metals fromores, galvanic plating solutions, picklingbaths, and effluents even in the presenceof alkaline earth metals (calcium andmagnesium).Further important uses include the refiningof the salt solutions of transition andprecious metals and for the cleaning andpurification of various organic or inorganicchemical products by removal of heavymetals contamination (usually fromaqueous solution).

7

Section IV. PRODUCT DESCRIPTION

S-930Macroporous Iminodiacetic

Chelating Resin(For the selective removal of heavy metals from

aqueous solutions)

Technical Data


Polymer Matrix Structure ..................................... Macroporous Styrene-divinylbenzenePhysical form & Appearance ...................................................... Opaque Beige SpheresWhole Bead Count ................................................................................................ >90%Functional Groups ...................................................................................... IminodiaceticIonic Form (as shipped) ............................................................................................. Na+

Shipping Weight .............................................................. 710 - 745 g/l (44.5 - 46.5 lb/ft3)Screen Size range (British Standard Screen) ........................................ 14-52 mesh, wetParticle Size range .......................................................... + 1.0mm <10%, -0.3mm <1%Moisture Retention, H+ Form ............................................................................. 55-65%Reversible Swelling, (H+➔ Na+) ........................................................................... <20%Specific Gravity. Moist H+ Form .............................................................................. 1.17Total Exchange Capacity, H+ Form (wet, volumetric) ............................... 1.1 eq./l., min.

H+ Form ................................... 35g of Cu ++/l., 2.2 lb/ft3 min.Na+ Form ....................................................... 0.94 eq./l., min.Na+ Form ................................. 30g of Cu ++/l., 1.9 lb/ft3 min.

Max, Operating Temperature, H+ Form ...................................................... 70°C (158°F)pH Range (operating) H+ Form .................................................................................. 2-6

Na+ Form .............................................................................. 6-11

30BV/h

20BV/e

10BV/h

The various applications of Purolite S-940are too numerous to cover individually indetail. Brine softening is the majorapplication. Chlorine gas and alkali metalhydroxides are produced by the electrolysisof brine solutions in chlor-alkali cells. Theindustrial process has used three maintypes of these cells - mercury, diaphragm,and membrane electrolytic cells. Themembrane cells are the most economic andare supported by the most sophisticatedtechnology in their operation. All types needperiodic maintenance as a result of theimpurities in the brine, especially Ca andMg. Membrane cells require the highestpurity brine which should contain less than20ppb calcium and less than 50-100ppb Sraccording to the process specification.

Purolite S-940 is sufficiently selective forstrontium to allow for its containment in thepolishing column when the lead column isoperated to a calcium leakage endpoint.This applies for Sr values up to 20% of thefeed Ca concentration by weight.In this way it is possible to operate at asteady lower voltage, thus saving energyand increasing production.Purification of brine (removal of divalent andtrivalent cations) to the exacting standardsrequired is achieved by using PuroliteS-940 which will remove the majority ofcontaminant metals, even under verydifficult conditions: saturated salt (morethan 300g/l of NaCI), alkaline pH, elevatedtemperature.

13

PRINCIPLE APPLICATION


The operating capacity expressed in g Ca2+ per litre increases with:- pH, optimum >9 (see fig. 1 )- influent calcium concentration, (see correction factor in fig. 2)- temperature of feed, which is best maintained at above 60°C (see fig. 3)- Reduction in flow rate, (see fig. 4)

10-20BV/h is recommended, though rates up to 30BV/h are feasible.

The permanent leakage obtained in treatingbrine using Purolite S-940 is generally veryLow: for example < 50ppb for strontium

and < 20ppb for calcium and magnesium,see fig. 5 and 6.

Fig. 1 CAPACITY FOR CALCIUM REMOVAL(as a function of pH)

7 8 9 10 11 12

pH

25

20

15

10

5O

PER

ATI

NG

CA

PAC

ITY

Ca

g/l

Fig. 2 CORRECTION FACTOR FORINFLUENT CALCIUM CONCENTRATION

0 5 10 15 20 25

CALCIUM INFLUENT CONCENTRATION ppm

1.2

1.1

1.0

0.9

0.8

0.7

OPE

RA

TIN

G C

APA

CIT

Y C

1

The iminodiacetic functional groups, ineither the sodium or the hydrogen form, willchelate heavy metals by ion attraction to the

dicarboxylic functionality and electrondonation from the nitrogen:

8

PRINCIPLE OF REACTION

APPLICATIONS

Purolite S-930 is particularly suitable for theremoval of heavy metals (as weakly acidicchelated complexes) which are heldaccording to the following order of

selectivity.Cu>>Ni>Zn≥Co≥Cd>Fe(ll)>Mn>CaThe macroporous resin structure ensuresexcellent diffusion of ions thus affording


Operation Rate Solution Minutes Amount

Service 8 - 16BV/h For treatment1-2gpm/ft3

Backwash 5-7m/h Raw Water 5-20 1.5-6BV/h2-3gpm/ft2 10-35 gal/ft3

Regeneration 3-4BV/h Mineral Acids 30-60 140-200g/l HCL or0.4-0.5gpm/ft3 (2N-3N) 12.5-20lb/ft3

200-320g/l H2SO4

Slow rinse 3-4BV/h Raw Water 30-40 2-3BV/h0.4-0.5gpm/ft3 15-25gal/ft3

Conversion to sodium form as required:-3-4BV/h 1/2N NaOH 40-60 40-60g/l0.4-0.5gpm/ft3 (Upflow)* 2.5-3.75lb/ft3

Rinse 3-4BV/h Soft or Demin 20-40 2-4BV/h0.4-0.5gpm/ft3 Water 15-30gal/ft3

Backwash expansion 75% (optimum)Design rising space 100%Minimum bed depth 1000m"gallons refer to U.S. gallons = 3.785 Litres.

*The aim is to achieve the same pH as that of the incoming solution.

Purolite S-930:- These operating con-ditions are given as a general example.However regeneration conditions andflow rates should be chosen for the

particular application. For furtherrecommendations please contact yourlocal sales office

CH2 --- C = O

R --- CH2 --- N ONaONa

CH2 --- C = O

CH2 --- C = O

R --- CH2 --- N

CH2 --- C = O

+ M2+ M + 2Na+O

O

Purolite S-940 may also be used in thehydrogen form for heavy metals removal.The above operating conditions may beadapted as follows. The regeneration iscarried out using HCI, as above (or 2NH2SO4 may also be used at 200-300g/l;12.5-19lb/ft3). The objective of the sodium

conversion is to optimise the pH of solutionto maximise capacity and reduce leakage.The aim should be to achieve the same pHas that of the incoming solution. Operationflow rates of 8-16 BV/h (1-2 gpm/ft3) may beused, and displacement prior to backwasheliminated or modified.

12

PRINCIPLES OF OPERATION

The capacity of this resin is dependent uponpH; it is able to operate in neutral, acidic oralkaline media, however the relativeaffinities for metals vary as a function of pHand ionic concentration, hence it is

recommended that laboratory trials (columntests) are carried out to prove the process.The list of relative affinities will help serveas guide in such trials.

- Acidic pH Pb2+ > Cu2+ > U4+, Zn2+, Al3+ >Mg2 + > Sr2 + , Ca2 + , Na + , Ba2 +

-Alkaline pHCd2+ Mg2+ > Ca2+ > Sr2+ Al3+ > Ba2+ > , Na+ K+

In the particular case of brine purification by softening the feed solution of chloralkalielectrolysis cells, the characteristic reactions are described as follows:—

-Service2RCH2NH CH2PO3 Na2 + Ca2+ (RCH2NH CH2PO3 )2 CaNa2 .

- Regeneration to H+ form(RCH2NH CH2PO3)2 CaNa2 + 4HCI 2RCH2NH CH2PO3 H2 + CaCI2 + 2NaCI

-Conversion to sodium formRCH2NH CH2PO3H2 + 2Na OH RCH2NH CH2PO3Na2 + 2H20


Operation Rate Solution Minutes Amount (Temp)

Service 8-30BV/h Brine * 1.25 * (at 60—90°C)1-4gpm/ft3

Brine Displacement 4 BV/h Soft water 60—90 1.30 4—6BV (roomtemp, RT)

0.5gpm/ft3 30—45 gals /ft3

Backwash 8-12m/h Soft water 30 - - (RT)3-5 gpm/ft2

Regeneration 2-6BV/h HCI (Normal) 30-60 1.0 100-150g/l (RT)0.25-0.75gpm/ft3 6.25-9.5 Ib/ft3

Rinse 2-4BV/h Soft water 30-60 1.0 2BV(RT)0.25-0.5gpm/ft3 1 5gal/ft3

Sodium Conversion 2-4BV/h NaOH (Normal) 15-60 1.45 20-80g/l (RT)0.25-0.5 gpm/ft3 (Upflow) 1.25-5 Ib/ft3

Rinse 2-4BV/h Soft water 30-60 1.45 2BV (RT)0.25-0.5 gpm/ft3 15 gal/ft3

* Exhaustion time and volume of treated brine depend upon the operating conditions(see Figures 1-4) “gallons” refer to US gallons =3.785 litres

efficient exhaustion and regeneration.Recovery of heavy metals from effluentsfrom the plating industry is achieved byconcentration and is particularly usefulwhere full demineralisation and recycling ofthe rinse water is not practised. Thesimplest case is where only one heavymetal is present, when volumes of rinsewater are low, waste water fees may below, and raw water has a low salt content.Purolite S-930 can be used to reduceresidual toxic heavy metals to below themaximum admissible concentration levelswhich are often far below those obtainableafter precipitation reactions. It may also beused to remove similar residuals from

demineralised rinse water circuits.Purolite S-930 is also used to separate andconcentrate heavy metals in hydro-metallurgical processes (ore dressing andscrap recovery). It is particularly suitablewhere metals are present in lowconcentrations. Separation techniques maybe carried out according to the order ofselectivity given above. However changesin the sequence occur with change in pHand in the presence of certain anions(including higher concentrations of chlorideand sulphate). The sequence given above isapplicable for neutral and weakly acidicsolutions.

9


HYDRAULIC CHARACTERISTICS (General Applications)

The information below may be taken as ageneral guide. However, before any plantdesign is contemplated, the user shouldascertain the exact operating performanceunder the proposed conditions of use, byway of column testing of the feed solutionto be treated.The operating capacity is a function of pH,

and inlet concentration solution for eachmetal. Fig. 1 gives the exchange capacityobtainable when using the operatingconditions given above, as a function of pH.This capacity is a function of ionicconcentration, hence the multiplicationfactor given in fig. 2 should be applied.

The pressure drop (or headloss) across aproperly classified bed of ion-exchangeresin depends on the particle sizedistribution, bed depth, and voids volume ofthe exchange material, and on the flow rateand viscosity (and hence on the

temperature) of the influent solution.Anything affecting any of these parameters,for example the presence of particulatematter filtered out by the bed, abnormalcompaction of the resin bed, or theincomplete classification of the bed will

Fig. 1. Exchange capacity for metalsas a function of pH.

1 2 3 4 5pH

25

20

15

10

5

0

EXC

HA

NG

E C

APA

CIT

Y FO

R M

ETA

LS g

/l

Fig. 2. Correction factor for ionicconcentration

IONIC CONCENTRATION %

1 2 3 4 5IONIC CONCENTRATION g/l

1.5

1.0

0.5

CO

RR

ECTI

ON

FA

CTO

R C

1

Cu

Ni

Fe

RelativeVolumeChange

Purolite S-940 is a chelating resin ofmacroporous structure, with a polystyrenematrix crosslinked with divinylbenzene(DVB) substituted with weakly acidicaminophosphonic active groups. Thischemical structure facilitates the formationof complexes with metall ic ions. Theaminophosphonic chelating resins have a

greater affinity for certain cations, and formmore stable complexes with cations of lowatomic mass metals than their iminodiaceticresin counterparts. Hence Purolite S-940 iscapable of fixing one or more specificcations from a larger range even fromsolutions which are highly concentrated.

11

Section V. PRODUCT DESCRIPTION

S-940Macroporous Aminophosphonic

Chelating Resin(Especially for decalcification of

brine solutions)

Technical Data

NOTE: Purolite S-940 is susceptible tooxidation. Hence direct treatment of brinesolutions containing free chlorine should beavoided, for instance by preliminary reactionwith sulphur dioxide, sulphite or, by use of atreatment with activated carbon. Brinesolution can often contain significant

concentrations of chlorates. In this case it isnecessary to ensure that the displacementrinse prior to the acid regeneration isefficient, so as to avoid the formation offree chlorine from contact of chlorates inthe brine solution with the regenerant acid.


Polymer Matrix Structure ..................................... Macroporous Styrene-divinylbenzenePhysical form & Appearance ..................................................... Opaque Cream SpheresWhole Bead Count ................................................................................................ >95%Functional Groups .................................................................................. -CH2NHCH2PO3Ionic Form (as shipped) ............................................................................................. Na+Shipping Weight ...............................................................710 - 745 g/l (44.5 - 46.5 lb/ft3)Screen Size Range

(British Standard Screen) ........................................................ 18-36 mesh(U.S. Standard Screen) ........................................................... 20-40 mesh

Particle Size range ...................................................... + 0.85mm <2%, -0.425mm <2%Moisture Retention, Na+ Form ........................................................................... 55-65%Reversible Swelling, (H+ Na+) Max ................................................................. <50%

(H+ Ca++) Max ............................................................... <20%Specific Gravity. Moist Na+ Form ............................................................................. 1.11Total Exchange Capacity, (Na+ Form) ...................... 20 g Ca/L (1.24 lb/ft3) min at pH 9,5Max, Operating Temperature, °C (°F) .......................................................... 90°C (195°F)Solubility .................................... Insoluble in water, acids and bases, common solvents

have an adverse effect, and result in anincreased headloss. Service flow rates from8-16 bed volumes per hour, 1-2gpm/ft3,depending on the application, may beregarded as the normal range used on thisresin.

Typical pressure drop figures to beexpected for ordinary aqueous solutions,are given in fig. 3., below. This is applicableto the freshly regenerated H+ Form. As theresin is converted to the metal form thepressure drop will decrease slightly.

10

During upflow backwash, the resin bedshould be expanded in volume by between50 and 75%, in order to free it from anyparticulate matter from the influent solution,to clear the bed of bubbles and voids, andto reclassify the resin particles as much as

possible, ensuring minimum resistance toflow. Bed expansion increases with flowrate and decreases with temperature, asshown in fig. 4, for a typical exhausted formof the resin. Care should always be taken toavoid resin loss by over-expansion of thebed.

CONVERSION OF UNITS


1Kg/cm2 /m (Kilograms per square cm. per metre of bed) = 4.33 psi/ft.= 1.03 atm./m/= 10 ft. H2O/ft

Fig. 3 PRESSURE DROP VS. FLOWRATE Fig. 4 BACKWASH EXPANSION(Exhausted Form)

0 20 40 60 80

FLOWRATE m/h


8 16 24 321.0

0.8

0.6

0.4

0.2

0 5 10 15 20

FLOWRATE m/h


2 4 6 8100

50

4-

3-

2-

1-PRES

SUR

E D

RO

P Kg

/cm

2 /m

BED

EXP

AN

SIO

N (%

)

PRES

SUR

E D

RO

Ppsi

/ft b

ed d

epth

5°C

,40°

F15

°C ,6

0°F

30°C

,86°

F

5°C

,40°

F

15°C

,60°

F30

°C ,8

6°F

40°C

104°

F

Documents

23838 Purolite CHELATION