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The separation of beryllium from polyvalent cations with a diallyl phosphate complexing resin
E.
412
BISfIOl’
VOL.
20 (IqjQ)
%USAMIM@NI:ASSUNC f5in titrimetrischcs Analyscvcrfidlren mit cincm willkiirlichcn St:~nclarctgcwicht wurtlc zur Errnittltrng tlcr grtlsstmiigtichcn Gcnauigkcit titrimctrischcr Slcthoclcn vorgcschlagcn. Es hat sic11 hcrausgcstcllt, tlrrss (tic Gcnuriyltcit tlcr an;dytischcn Ergctmissc nrrf Grund physikalischnicclrigcr als die mnximolc chemischcr JCrw5gungcn Ixqgcnzt ist, uncl zwar licgt dicsc <;rcmc mc:cl~;u~ischc Gcnauigkeit clcr Afcssungcn. RJS t~ERt5NCES
3 XI. 4 v.
Ji I?. “ IS. 7
0.
n
13.
Received
Scptembcr
sotll,
1957
INTIIODUC’I’ION
In rcccnt years a number of ion-cscliangc mctl~ocls 11avc been clcvclopccl for separating beryllium from other lxdyvalcnt cations. In tlic carlicr work *v2sclcctive clution of the bcrylliiin~ from other cations aclsorbccl on a sulplionatcd’ exchanger was concluctcd with solutions of inorganic acids or salts. l.Jowcvcr, it is evident that the rclativcly low resin affinity for beryllium, ant1 its low sclcctivity (ratio of ;Lffinity for lxryllium to affinity for other metals) renclcrs sucll scparntions tcclious if a number of diffcrcnt cations arc prcscnt, and often requires a nunibcr of changes in cluting conclitions bcforc LLseparation is complctc. Marc rcccntly ScIiumw CLaL3 have used sulpliosalicylic acid (SSA) at pri .3.5-4,5 for the sclectivc clution of bcrylliuni from clivalcnt cations, hut as pointed. out by these authors, trivalent cations such as aluminium arc also clutccl by SSA in this 1111range. In a few instances, Na2ED’TA or its use suggestcc13 which complcxcs only weakly with Ixqllium~~, has been usdfi as a masking agent for other polyvalcnt cations xncl this allows the beryllium to bc sclcctivcly adsorbccl by the resin. Even in tllis instance it cxn bc espcctccl that the gain in selectivity is likely to 1~ offset consiclcrably by the combinccl cffccts of compctitivc adsorption by the unscclucstcrccl sodium ions and the slight sequcstcring action of NaXI>TA on the wcnkly aclsorhcl lxxyllium. It has now been cstablishcil that the complcxing resin-soclirun cliallyl plxxq~hatc (NaDAP; [(&I-Ir,O)al’(O) 0 Na+J,)” adsorbs beryllium in the lx-csencc of NaaElYTA to saturation capacity (cn. 4.9 mcquiv./g of dry iKid resin) irrespective of the aqueous phase beryllium concentration, while a lnrgc number of cli- and trivalent cations References
fi. 415
arc not adsorbed. ‘1’1~ metlrotl thus allows latter is only a minor or tract coniponcnt the metal from minor coi~t~~lilinntlts.
tllc conccntrntion of l~cryllium when the in a mixture, and also the separation of
‘1‘1~ NaIIAl’ resin was l~rcl)ar~~(las previously doscril)cd6~7. Its sodium -11ydrogc*n c.xchangc capacity was 4.9-j mcquiv./g dry I-1+ form. ‘I’ll0 %t!O-liitrb 225 (S - To:<, divinyl bcnzenc) \\‘ilS obtainctl from Pcrlnutit Co. I,td., I_ondon, and had a sodium lly?rogcii cscllangc capacit). of 4.6s mc!cluiv./g of dry l-l+ form. 1t was finally convcrtcd to tlw sodium form after a nrinil>cr of rcc>*clcs bctwccn hydrocliloric acid (0,5X) and sotlirlin chloritlc (0,5X) solutions.
Lkrylli~irii wlicn p-cscnt in solution in rclati\~oly lnrgc concentrations and in the ahscncc of fluoride ion, \\‘ilS cstimatcd pJXvimctricall>* as tllc osidc after pwcilGta.tion with ailini
A cc9umn of SalJAP resin (S cm deep X x cm diam.) ~vhich lmd a total sodiumliydrogcn cscliange capacity of 4.19 mcqniv. was constructed. A solution of beryllium nitrate containing 0.68 mg/ml bcq*lliui~l and whose pl1 bar1 been adjusted to 4.0 with ammonja was then passed through at a flow rate of 0.45 ml/min. Analysts of fractions of the cfflncnt indicated the point of l~rcakthrough, and passage of solution was continncd until no more l~cr\*llium was adsorbed. l’hc column was tlicn washed with water and clntion of the l~crylliiim was cffcctcd with ammonium fluoride (20 ml, o.gA’I) * The total lX+ryllium clutcd was 4.1 r nicquiv. No beryllium was detected in solutions obtained on wet Oxidizitlg the resin wit.11 a mixture of sulplmric and nitric acids. Scparatc cspcriments also indicated that nitric acid (20 ml, T.oA~) clutcs the beryllium quantitati\*cly from a similar l,cd of resin. Solutions of Sa2eEI)TA (2.5% w/\*, 25 ml) or SS.4 (o.r.W, 25 ml) at p1.i 4.0 failed to cffcct the elution of dctcctablc l~crylliuin (PT.0 mg) from the saturated resin. A similar cxpcrimcnt with a solution of IXq*llil,lrn (0.6s mg/ml) in the prcscncc of Sap.lS1>TA (2.50/‘;, w/v) gave a l~rcakthrough curve co-inciclcnt with that obtained in its absoncc. .41so the lXXyl!ium capacity of the resin was the same (4.12 mcquiv.). when the l>cryllium concentration of the solution phase was rc~dncccl to O.T mg/ml. Breakthrough CIIWCS u’crc similarly ohtaincd for a column of Zco-karb 225 in the sodium form and of qua! sodium capacity (4.~9 mcquiv.) to that of the column of X:11>.41~in the previous cxprimcnts. ‘I’hc stituration capacities of the resin bed for l~cryllium in the ahscncc and prcscncc of NaeEDTA were 4 .7 and 3.5 mcquiv. rcspcctively. Also clution with extra Na&ISl’A (2.5’j4, w/v, 20 ml) which contained no beryllium effected a complctc removal of the aclsorbed beryllium from the resins. Rcfertmccs
p.
4r5
414
J.
l
V.
J,
WIIEEIXI<
VOL.
20
(1959)
A solution of NadTDTA (2.5%, IOO ml) at per 4.0 atic! containing 2.5 mg of each of the following cations. Be+“, Ca+z, %-+a, Cu+z, %n+z, ITc-c3, Al+” and La+s, was passccl through a column of NaDAP (8 cm deep x T cm cliam.) which had been previously washccl with a solution of NadZTM’A (2.5’:(, w/v, 20 ml). After passage the column was again wasld with Na&D’I’A solution (20 ml). Wet oxidation of the resin with sulphuric and nitric acicls followed by analysts of the resulting solution sl~owecl that the hcryllium was quantitatively adsorbed while no aclsorption of the otllcr cations took place. In separate cxpcrimcnts complete clution of the beryllium was cffcctccl with nitric acid (20 ml, r.oN) or ammonium fluoride (20 ml, 0.5JJ). Analogous tests with solutions of Ctl+z, Hg+z, l’b+s and Tv1n.t”also showed that these cations arc not aclsorbecl by NaDAP in the prcscncc of Na&D’I’A.
13rcakthrougl~ of beryllium occurs almost immccliatcly with %co-karb 225 (a monofunctional sulphonatcc! resin) if the solution contains NadZIYI’A. Without the latter breakthrough occurs after the passage of ccz. GA bed volumes of solution and the total capacity of the resin for beryllium was 4.7 mccluiv. that is 0.5 mecluiv. in cxccss of its soclium capacity. This increase in capacity may 1~ due to some of the beryllium existing in tllc resin pllasc as 13c<~H-+. In the case of NaDAP (a monofunctional l~l~osl~horylatcd resin) the breakthrough curve and capacity for hcryllium is not. influcncccl by NadSD’I’A. Although clistribution coefficients (G) for beryllium . between the NaDAP resin and aqueous phases containing Na&D’I’A have not been measurccl, the abscncc of clctcctablc beryllium from NazED’TA solutions which have been passed tlirougll a beryllium saturated column suggests very high Kd values. In conformity with the law of mass action & sl~oulcl increase further to a constant maximum as the beryllium loading on the resin decreases. Also SSA which forms a stable complex with beryllium [log I<& ‘~4.9:]‘” and which rcaclily clutcs it from Dowcx-go (a sulphonatccl resin) 3, fails to clutc it from NaDAP. On the other hand NaJ3D’I’A effects complctc elution of the beryllium from Go-karb 225. As the saturation capacity of NaDAP for beryllium is equal to that for sodium the adsorption mechanism is I%+” -t_ 2NaDAl’
*
13c(l)AY)a
+ 2Na’
l’hc very high affinity of the NaDAP compared to sulphonatcd resins for beryllium also suggests that the latter is bound as a complex to the phosphate functional unit, but speculation on structure of complcs would 1~ prcmaturc at this stage. As well as the polyvalcnt cations listccl hcrc from which beryllium was scparatccl, it is also cviclcnt that it can be scpnratccl from bismuth and polonium(IV) under the same conditions’ *.Iz. Magnesium is not readily elutccl with Na&D’I’A from NaDAP, but it can bc complctcly clutecl with the clisotlium salt of cyclohcxanex,2-cliaminetctraacctic acid which is a stronger scclucstcring agent’“. As with NaalZDD’A, beryllium is not clutccl with this rcagcnt from NaDAP. Uranium(V1) (UOaeC”) like beryllium is also quantitatively aclsorbccl by the resin in the presence of NadZD’I’A. Sodium carbonate howcvcr cffccts its cluantitativc clution, while the beryllium is retained on the resin bed, probably as an insoluble basic carbonate. Rcfercnccs p. 415
VOL.
20 (1959)
COMPLI3SOBlETHIC
SEPARATION
OF l3EIi\-LLfUhI
4x5
SUMMARY The complexing polymer sodium diallyl phosphate (NaDhI’) when usccl in conjunction with disodium ethylene diaminc tctraacctatc (Xa2EIDTh) separates beryllium quantitatively from alkaline earths (Cn and Sr), ferric and tlivalent cations of the first transitional period, aluminium and lanthanicles, cadmium and mcrcury( I I), bismuth ant1 poloniutn( IV). The higl1 affinity of NaDAP for beryllium should permit its concentration by scvcral orders of rnngnitudc, when present as a minor or trace component in a mixture of polyvalcnt cations. The results arc cornpax-cd with tl1ose obtained using sulphonatcd resin.
cn prdscncc cl’dthyl~nccliaininctL’trac6tatc L’allylphosphate dc sodium polymkc, permet clc sCparcr qu:lntitativemcnt Ic glucinium d’avcc dc nomhrcux autrcs cations. tats sont comparbs avcc CL’IIX obtcnus !L l’aitlc cl’unc rdsinc sulfon6c.
disodiquc, I,cs r&111-
Polymercs Diallyl-natriumphosphat, in Gcgcnwnrt tics IX11atriumsalzcs tlcr Athylcndiamintctracssigsiurc crtnhglicht cinc quantitative Ahtrcnnung tics I3Crylliums von anl1lrcicl1en mchrwcrtigcn Kationcn. Die Ergcbnissc wcrtlcn mit dcnjcnigen, tlic tnit 1Iilfc cincs sulfonicrtcn Harzcs crhaltcn wurdcn, vcrglichcii. IIEl’EIIlSNCJS 1 I-I. KAKIHANA. J. Clrem. Sot. Jnpan, Pure Clrctn. Std.. 72 (1951) 200. 2 M. I-Io~1>n, J_ C/rem. Sot. Jupnn, Pure Chorr. Sect., 72 (19.51) 361. 3 J. SCHUl1l?R’r, h. I,INDI~SIMUW ANI) W. \VI?STFALL, J. Whys. C~WVI., 62 (~c)gH) 390. 4 l-l.V. &'tECK AND V. HANKS, A7rnl. C/rem., 22 (1950) 151-z. n ht. N. NADKAHNI, XI. S. VARDE AND V. T. A~r1rr\vhtE,.4)1ul.Cl1i~~1.~lcfu, 16 (1957) r)2f. 0 J. KISSNEDY, Ijrif. Pd. 777. 248, (1957). 7 J. I
Reccivcd
SOLUBILITY
Depnrfmenl
PRODUCT RELATIONS IN THE HYDROUS HYDROXIDES of Chcn1islvy, Univcrsify
of il~liclrigun,
rl ?iw Arbor,
Scptembcr
RARE
Mid;.
rgth,
rgg8
EARTH
(U.S.A.)
‘This paper is being prcscntccl to consider tllc solubility products of the rare earth hydroxides. A considcrablc amount of work has hccn dircctcd to this topic]. ‘I’hr: diffcrcncc bctwcen “new” and “old” precipitated hyclroxidcs has already been well established and seems to be a kinetic phenomenon in which a more soluble material undergoes ripening through dehydration and further crystalization to bccomc more insoluble. However, there has been some clucstiorl regarding the solubility product * Present address: ** Present address:
, Rcferetrces
9. 4x8
P.O. Box 806, Tavaros, Ma., U.S.A. Ikpartmcnt of Chemistry, Purdue University,
.
Lafayette,
Ind.,
U.S.A.
412
BISfIOl’
VOL.
20 (IqjQ)
%USAMIM@NI:ASSUNC f5in titrimetrischcs Analyscvcrfidlren mit cincm willkiirlichcn St:~nclarctgcwicht wurtlc zur Errnittltrng tlcr grtlsstmiigtichcn Gcnauigkcit titrimctrischcr Slcthoclcn vorgcschlagcn. Es hat sic11 hcrausgcstcllt, tlrrss (tic Gcnuriyltcit tlcr an;dytischcn Ergctmissc nrrf Grund physikalischnicclrigcr als die mnximolc chemischcr JCrw5gungcn Ixqgcnzt ist, uncl zwar licgt dicsc <;rcmc mc:cl~;u~ischc Gcnauigkeit clcr Afcssungcn. RJS t~ERt5NCES
3 XI. 4 v.
Ji I?. “ IS. 7
0.
n
13.
Received
Scptembcr
sotll,
1957
INTIIODUC’I’ION
In rcccnt years a number of ion-cscliangc mctl~ocls 11avc been clcvclopccl for separating beryllium from other lxdyvalcnt cations. In tlic carlicr work *v2sclcctive clution of the bcrylliiin~ from other cations aclsorbccl on a sulplionatcd’ exchanger was concluctcd with solutions of inorganic acids or salts. l.Jowcvcr, it is evident that the rclativcly low resin affinity for beryllium, ant1 its low sclcctivity (ratio of ;Lffinity for lxryllium to affinity for other metals) renclcrs sucll scparntions tcclious if a number of diffcrcnt cations arc prcscnt, and often requires a nunibcr of changes in cluting conclitions bcforc LLseparation is complctc. Marc rcccntly ScIiumw CLaL3 have used sulpliosalicylic acid (SSA) at pri .3.5-4,5 for the sclectivc clution of bcrylliuni from clivalcnt cations, hut as pointed. out by these authors, trivalent cations such as aluminium arc also clutccl by SSA in this 1111range. In a few instances, Na2ED’TA or its use suggestcc13 which complcxcs only weakly with Ixqllium~~, has been usdfi as a masking agent for other polyvalcnt cations xncl this allows the beryllium to bc sclcctivcly adsorbccl by the resin. Even in tllis instance it cxn bc espcctccl that the gain in selectivity is likely to 1~ offset consiclcrably by the combinccl cffccts of compctitivc adsorption by the unscclucstcrccl sodium ions and the slight sequcstcring action of NaXI>TA on the wcnkly aclsorhcl lxxyllium. It has now been cstablishcil that the complcxing resin-soclirun cliallyl plxxq~hatc (NaDAP; [(&I-Ir,O)al’(O) 0 Na+J,)” adsorbs beryllium in the lx-csencc of NaaElYTA to saturation capacity (cn. 4.9 mcquiv./g of dry iKid resin) irrespective of the aqueous phase beryllium concentration, while a lnrgc number of cli- and trivalent cations References
fi. 415
arc not adsorbed. ‘1’1~ metlrotl thus allows latter is only a minor or tract coniponcnt the metal from minor coi~t~~lilinntlts.
tllc conccntrntion of l~cryllium when the in a mixture, and also the separation of
‘1‘1~ NaIIAl’ resin was l~rcl)ar~~(las previously doscril)cd6~7. Its sodium -11ydrogc*n c.xchangc capacity was 4.9-j mcquiv./g dry I-1+ form. ‘I’ll0 %t!O-liitrb 225 (S - To:<, divinyl bcnzenc) \\‘ilS obtainctl from Pcrlnutit Co. I,td., I_ondon, and had a sodium lly?rogcii cscllangc capacit). of 4.6s mc!cluiv./g of dry l-l+ form. 1t was finally convcrtcd to tlw sodium form after a nrinil>cr of rcc>*clcs bctwccn hydrocliloric acid (0,5X) and sotlirlin chloritlc (0,5X) solutions.
Lkrylli~irii wlicn p-cscnt in solution in rclati\~oly lnrgc concentrations and in the ahscncc of fluoride ion, \\‘ilS cstimatcd pJXvimctricall>* as tllc osidc after pwcilGta.tion with ailini
A cc9umn of SalJAP resin (S cm deep X x cm diam.) ~vhich lmd a total sodiumliydrogcn cscliange capacity of 4.19 mcqniv. was constructed. A solution of beryllium nitrate containing 0.68 mg/ml bcq*lliui~l and whose pl1 bar1 been adjusted to 4.0 with ammonja was then passed through at a flow rate of 0.45 ml/min. Analysts of fractions of the cfflncnt indicated the point of l~rcakthrough, and passage of solution was continncd until no more l~cr\*llium was adsorbed. l’hc column was tlicn washed with water and clntion of the l~crylliiim was cffcctcd with ammonium fluoride (20 ml, o.gA’I) * The total lX+ryllium clutcd was 4.1 r nicquiv. No beryllium was detected in solutions obtained on wet Oxidizitlg the resin wit.11 a mixture of sulplmric and nitric acids. Scparatc cspcriments also indicated that nitric acid (20 ml, T.oA~) clutcs the beryllium quantitati\*cly from a similar l,cd of resin. Solutions of Sa2eEI)TA (2.5% w/\*, 25 ml) or SS.4 (o.r.W, 25 ml) at p1.i 4.0 failed to cffcct the elution of dctcctablc l~crylliuin (PT.0 mg) from the saturated resin. A similar cxpcrimcnt with a solution of IXq*llil,lrn (0.6s mg/ml) in the prcscncc of Sap.lS1>TA (2.50/‘;, w/v) gave a l~rcakthrough curve co-inciclcnt with that obtained in its absoncc. .41so the lXXyl!ium capacity of the resin was the same (4.12 mcquiv.). when the l>cryllium concentration of the solution phase was rc~dncccl to O.T mg/ml. Breakthrough CIIWCS u’crc similarly ohtaincd for a column of Zco-karb 225 in the sodium form and of qua! sodium capacity (4.~9 mcquiv.) to that of the column of X:11>.41~in the previous cxprimcnts. ‘I’hc stituration capacities of the resin bed for l~cryllium in the ahscncc and prcscncc of NaeEDTA were 4 .7 and 3.5 mcquiv. rcspcctively. Also clution with extra Na&ISl’A (2.5’j4, w/v, 20 ml) which contained no beryllium effected a complctc removal of the aclsorbed beryllium from the resins. Rcfertmccs
p.
4r5
414
J.
l
V.
J,
WIIEEIXI<
VOL.
20
(1959)
A solution of NadTDTA (2.5%, IOO ml) at per 4.0 atic! containing 2.5 mg of each of the following cations. Be+“, Ca+z, %-+a, Cu+z, %n+z, ITc-c3, Al+” and La+s, was passccl through a column of NaDAP (8 cm deep x T cm cliam.) which had been previously washccl with a solution of NadZTM’A (2.5’:(, w/v, 20 ml). After passage the column was again wasld with Na&D’I’A solution (20 ml). Wet oxidation of the resin with sulphuric and nitric acicls followed by analysts of the resulting solution sl~owecl that the hcryllium was quantitatively adsorbed while no aclsorption of the otllcr cations took place. In separate cxpcrimcnts complete clution of the beryllium was cffcctccl with nitric acid (20 ml, r.oN) or ammonium fluoride (20 ml, 0.5JJ). Analogous tests with solutions of Ctl+z, Hg+z, l’b+s and Tv1n.t”also showed that these cations arc not aclsorbecl by NaDAP in the prcscncc of Na&D’I’A.
13rcakthrougl~ of beryllium occurs almost immccliatcly with %co-karb 225 (a monofunctional sulphonatcc! resin) if the solution contains NadZIYI’A. Without the latter breakthrough occurs after the passage of ccz. GA bed volumes of solution and the total capacity of the resin for beryllium was 4.7 mccluiv. that is 0.5 mecluiv. in cxccss of its soclium capacity. This increase in capacity may 1~ due to some of the beryllium existing in tllc resin pllasc as 13c<~H-+. In the case of NaDAP (a monofunctional l~l~osl~horylatcd resin) the breakthrough curve and capacity for hcryllium is not. influcncccl by NadSD’I’A. Although clistribution coefficients (G) for beryllium . between the NaDAP resin and aqueous phases containing Na&D’I’A have not been measurccl, the abscncc of clctcctablc beryllium from NazED’TA solutions which have been passed tlirougll a beryllium saturated column suggests very high Kd values. In conformity with the law of mass action & sl~oulcl increase further to a constant maximum as the beryllium loading on the resin decreases. Also SSA which forms a stable complex with beryllium [log I<& ‘~4.9:]‘” and which rcaclily clutcs it from Dowcx-go (a sulphonatccl resin) 3, fails to clutc it from NaDAP. On the other hand NaJ3D’I’A effects complctc elution of the beryllium from Go-karb 225. As the saturation capacity of NaDAP for beryllium is equal to that for sodium the adsorption mechanism is I%+” -t_ 2NaDAl’
*
13c(l)AY)a
+ 2Na’
l’hc very high affinity of the NaDAP compared to sulphonatcd resins for beryllium also suggests that the latter is bound as a complex to the phosphate functional unit, but speculation on structure of complcs would 1~ prcmaturc at this stage. As well as the polyvalcnt cations listccl hcrc from which beryllium was scparatccl, it is also cviclcnt that it can be scpnratccl from bismuth and polonium(IV) under the same conditions’ *.Iz. Magnesium is not readily elutccl with Na&D’I’A from NaDAP, but it can bc complctcly clutecl with the clisotlium salt of cyclohcxanex,2-cliaminetctraacctic acid which is a stronger scclucstcring agent’“. As with NaalZDD’A, beryllium is not clutccl with this rcagcnt from NaDAP. Uranium(V1) (UOaeC”) like beryllium is also quantitatively aclsorbccl by the resin in the presence of NadZD’I’A. Sodium carbonate howcvcr cffccts its cluantitativc clution, while the beryllium is retained on the resin bed, probably as an insoluble basic carbonate. Rcfercnccs p. 415
VOL.
20 (1959)
COMPLI3SOBlETHIC
SEPARATION
OF l3EIi\-LLfUhI
4x5
SUMMARY The complexing polymer sodium diallyl phosphate (NaDhI’) when usccl in conjunction with disodium ethylene diaminc tctraacctatc (Xa2EIDTh) separates beryllium quantitatively from alkaline earths (Cn and Sr), ferric and tlivalent cations of the first transitional period, aluminium and lanthanicles, cadmium and mcrcury( I I), bismuth ant1 poloniutn( IV). The higl1 affinity of NaDAP for beryllium should permit its concentration by scvcral orders of rnngnitudc, when present as a minor or trace component in a mixture of polyvalcnt cations. The results arc cornpax-cd with tl1ose obtained using sulphonatcd resin.
cn prdscncc cl’dthyl~nccliaininctL’trac6tatc L’allylphosphate dc sodium polymkc, permet clc sCparcr qu:lntitativemcnt Ic glucinium d’avcc dc nomhrcux autrcs cations. tats sont comparbs avcc CL’IIX obtcnus !L l’aitlc cl’unc rdsinc sulfon6c.
disodiquc, I,cs r&111-
Polymercs Diallyl-natriumphosphat, in Gcgcnwnrt tics IX11atriumsalzcs tlcr Athylcndiamintctracssigsiurc crtnhglicht cinc quantitative Ahtrcnnung tics I3Crylliums von anl1lrcicl1en mchrwcrtigcn Kationcn. Die Ergcbnissc wcrtlcn mit dcnjcnigen, tlic tnit 1Iilfc cincs sulfonicrtcn Harzcs crhaltcn wurdcn, vcrglichcii. IIEl’EIIlSNCJS 1 I-I. KAKIHANA. J. Clrem. Sot. Jnpan, Pure Clrctn. Std.. 72 (1951) 200. 2 M. I-Io~1>n, J_ C/rem. Sot. Jupnn, Pure Chorr. Sect., 72 (19.51) 361. 3 J. SCHUl1l?R’r, h. I,INDI~SIMUW ANI) W. \VI?STFALL, J. Whys. C~WVI., 62 (~c)gH) 390. 4 l-l.V. &'tECK AND V. HANKS, A7rnl. C/rem., 22 (1950) 151-z. n ht. N. NADKAHNI, XI. S. VARDE AND V. T. A~r1rr\vhtE,.4)1ul.Cl1i~~1.~lcfu, 16 (1957) r)2f. 0 J. KISSNEDY, Ijrif. Pd. 777. 248, (1957). 7 J. I
Reccivcd
SOLUBILITY
Depnrfmenl
PRODUCT RELATIONS IN THE HYDROUS HYDROXIDES of Chcn1islvy, Univcrsify
of il~liclrigun,
rl ?iw Arbor,
Scptembcr
RARE
Mid;.
rgth,
rgg8
EARTH
(U.S.A.)
‘This paper is being prcscntccl to consider tllc solubility products of the rare earth hydroxides. A considcrablc amount of work has hccn dircctcd to this topic]. ‘I’hr: diffcrcncc bctwcen “new” and “old” precipitated hyclroxidcs has already been well established and seems to be a kinetic phenomenon in which a more soluble material undergoes ripening through dehydration and further crystalization to bccomc more insoluble. However, there has been some clucstiorl regarding the solubility product * Present address: ** Present address:
, Rcferetrces
9. 4x8
P.O. Box 806, Tavaros, Ma., U.S.A. Ikpartmcnt of Chemistry, Purdue University,
.
Lafayette,
Ind.,
U.S.A.