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Determination of rhenium by neutron activation
‘1’1~ ;~lmntla~~c*c of rllcmiuln is very Io~~-~~ in m;ktcri;k r>f ~‘coclxmiical interest except for InolylAmitcs in wliic*ll consiclcral3lc ctnriclirncnt of rlieniurn has 1011~ hen ~“5IIc and I”71lC! isotqx3 Of rhenium, of 100 and 75 lXltXlS, respectively, so lx~ss”“s Ial-gc neutron ac:ti vation cross-sections tliat ;L liigllly sensitive detcrniination of rllcniurn is possil>le by matron activation. Nuclear chta relevant to tllc activittion analysis arc listed in ‘I’ilble I. Neutron ilctivation analysis has previously lxxn alqAiccl to tllc Clctcrnliniltion of rhenium in cms5,
_
nicteoritcs7-‘b ilIlC1 tcktitcsl, and such organic mutcrials iis cnzynicsl” ant1 tiiarincorgarlismsll~l~. Tlicsc nietliocls mostly involve co~n~~licateclcl~eti~ic~l separations inchcling col”‘ecil’itntion, distillation ancl solvent CstrilctiOIl, leading to low cheniical yields. In addition, most of the previous purification lx-occclurcs do not affortl clear r(jcks2.:l.ll,
selmrntion or
comes
of
pritiinry
using of
of
raCli0itctive
from
ii thick
the
rhenium
importniicc duminutn
r)‘l*ll’l’c. ‘I’llesc
mid
~BHhIC)(n,y) ~~%I0 to
rcnmvc
absorber
precautions
‘l’jnl’l’c,
reaction the
wllich
is proclucecl
followxl
conversion
by
electron
or to USC y-spcctroinetry
inevitilbly
cause
a loss
of
bv
a /I-clecny. ilrising to rcniove
uraniuni
fission
Therefore, from tlw
it
rBnllTc
is bJ
Eontribution
sensitivity.
In this work ;L vcq cffcctivc mclioclmiiical proccclurc was clevclolxx~ for rhenium; the singlestep anion eSclliltlgC involved allows a variety of samples to be rapidly analyzed with ;L high cllemical~ yiclc\. ~)l~~lTccm bc completely scparatcd to achieve clircct fi- or I)-counting of rhenium nctivitics without ii loss of sensitivity.
Re BY NEUTI~OS
ACTIVATIOX
19
Standard solzrtiou of rlteuium. Dissolve ca. I: g of potassium perrhenatk: (gig.of’o purity) in 150 ml of 0.5 M hydrochloric acid. Standardize gravim~triciLl!y by a tetraphenylarsonium method. This solution served both xs a carrier and as a comparative standard after nplx-opriate dilution . ,411 other chemicals used wcrc of nnalytical grade quality. ?on-eschan~c: ~01~~2~~. Dowes r--Xx0, 3or.h400 mesh, Cl form, was used. Tlw resin was converted to the t!iiOCyanate fcJrn1 and stored as described lxcviously1:I. Slurry the resin (2 g) wit11 water and pour into a conventional column of diamctcr I.0 cm to form a bed cn. 5 cm long. &fore use pass several column voluincs of 0.025 &I ammonium thiocyanate-o.5 fV1 l~yclrocl~loric acid solution tlirougli the column.
1Veigh out a l~owclercd sainplc of niolybdcnitc (50 mg) or pyrolusitc (zoo mg) and seal in a l~olyctliylcnc tube. Impregnate a smnll piece of filter paper placccl in a polycthylenc bag with an alicluot of the rhenium standard solution (o.ogoG lug Kc) *and seal. For rock samples, weigh ca. 150 lllg in a quartx tube Zintl sfX1. Prelxwc iL comparative standard for rock samples (o.oC)oO klg lie) by placing an aliquot of the stanclard solution in a sepnratc quartz tube, evaporating to dryness under an infrared lamp, and sealing as before. Pack the Sitllll>lC and tlic~coinparntive standard wit11 alun~inun~ foil and position in an nluniinun~ capsule along with aluminum p:ding foil. Ore samples were irrocliatccl for 6 11 in the Tl
lTusc! tllc irracliatcd sample with 1 c: of sodium perosidc in a Sil icntc rock. nic:kcl cruc:il~le. After cooling place the crucilh in a bcakcr containing 4.513 mg lb. Atlcl IO ml of water to leach tllc melt. I
Adjust tllc: suJx!rnatc ol~t~tinccl to 0.025 &I in mimcmiuni tllioc:yxn;itc and Ilyrlrocl~l~~ric acid. I)0 not csceed ii total volunic Cd 3.5 ml. AJlow the ac:idic thioc:yanatc solution to J>ilSS tllrough the ion-cschangc column at a flo\v rate of about 0.5 inl/niin. l’)isc::irCl tl 1c: clnatc. Wash tllc column with 20 ml of the SillllC! acidic 0.5
A/r
in
tlliOc’~~illl~l.tC! 30
ml of
CluiltC!.
solution 0.5
Acltl
111
to
ant1
tlisc:iLJYl
the
tllioc:~;~t~;~t~-(~,~
tllis
S
ml
of
in (i h/l hydrc~chl~~ric: ;idcl,
A4
acid,
Ilyclrochloric
ilnC1 2
ml
of
lhmiovc
cluntc.
IiydroclJloric
20’7;
tllc
rlicniutn
by clution
with
xicl solution. Collect tllc whole I nil of 35’%, tin(II) chloride solution
potassium
tliiocyanatc
solution.
‘I’t-ansfcr
cstract the rhenium by shaking with 20 ml of ethyl ctlirtr for x nlin. Transfer the ether layer to a conical beaker and cvaJx)ratc to dryness. Add IO ml of 0 n/r IlycJrochloric acid to the rcsiclue and wnrm. While shaking, aclcl I~ydrogcn Jxxosidc dropwise to the sdution to dcconiposc tlic tliiocyanate. .3’)‘);J If iL yellowish I~l~C~\Vll 01 blnclcisl~ bmwn precipitate appr5U-s, Jnakc the Solution alkdinc! with :llnlllOlliil and warm until the prcciJ)itate turns yellow. Add n few drops of inctliyl orange solution ant1 ncutralizc with iunnioniuin I~yclrcjsiclc or I1ydrochloric acid, tlcJx2ncling on the Jxcvious step. Digest for 5 niin on a stcarn hat11 ztncl filter. Add 3 nil of ilC~l.lCOUS x(7:) tctr~~~~lieiiylarsc~nium chloride solution to the filtrate and tligcst for x0 min. Cool and filter through iL wcighccl smxll filter paJxr. Wash wit11 w;itcr :ind tlicn with cthnnol. Dry at x roe for IO min, cool ;lnCI weigh. Mount for the activity nieasurcnients. ‘l’rcat the comparative standard in a siniilar way. to
:L SCJXIKltOry
I(J:SUJ,‘J’S
ANIj
fuillic!~
ilnd
IjJSC:CJSSI<)N
Althougll scvcr~il raClicJcllClnicill J~roccclures arc nvailablc for rlicnium, a iilc~tliocl is still lacking. Ib’)rll’l’c:,Jxoclucccl by uranium fission or 1)~ tlccay of :lCtiViItC!tl lllOl_~lXlC?tlulll, bchnvcs very similarly to rhenium in most raCJiochemica1 scJxuatioris. Aluminum absorbers must 1x2 cmJ~loycC1 in racliometric IKSiL>‘S to absorb conversion clc~~trons arising from tlic isonicric transition (c/y very 1iKgC) and y (e/y, 0.1~) decay of t)l)rll’l\~.\Vith y-sJxxtromctry, the 0.14-McV y-peak of ‘)Onl’l’~ interferes wit11 tllc Jdtn;uy y-peaks at 0.137 McV for In(lRc nncl :lt 0.155 MeV for ln”l
sJxxific
L’(W), ‘I’c(VII). One cm thus expect to bc rtblc to isolate ELpure rhenium frnc‘Table II shows the results tion in ;I single step by this anion-eschange lxocess. for the determination of rhenium in several molybdenites, pyrolusites, molybdenum sulfide (of chemically pure quality) and the standard rock W-I from Centcrville, Virginia. The errors reported are tile standartl deviations hased on the final result not on the counting data. Colorirnetric values for the Yamanashi molybclcnitc and
of tllc ilVC!IXgC WilllC?S IXinolybdcnum sulfide are included in Table II *, ilgrc~IIlcnt twccn colorimctry and activation analysis is satisfactory. MOI
i
i
of 1We
number
scparatcd
Channel
from molvbdenitr.
(A) Lower cncrgv mngc;
(13) higher rncrgv
mnec.
Fig. 2. Ikca~
curw of induced rhenium activities obtained from the irradiated ruolybdenitc. (In, I In) Gross dccay of rhcniutu activities obtaiurd from the sample and con~parativc standard, rcspcctiwly. (lb, Ilb) Decay of ‘We (S&S h) obtained from the srmplc and comparative standard, rcspcctivcl~. (Ic, Ilc) Decay of *BsRc (16.7 h) obtained b\- suhtmction of the long-livctl *““Rc fraction in thr sample and comparative standard, rcspcctivcly.
Fig. I. y-Spcctm
4
loon
62 KeYOSK r-ray
C Y
:
2G
5
I
ACTIVATION
23
resonance capture. However no sign of neutron shielding was found esperimentally. so far as the specific activities produced on less than 0.x pg Re wcrc concerned. ‘i’he effect of neutron self-shielding in the samples does not appear to be significant. because of the small sample size used and the low absorption cross-section of the However, if the samples contain apprcciablc amounts of major matris materials. arising from self-shielding must he considered. This rhenium, possible intcrfcrencc Esperimentally, so-mg portions of commercially will be the case for molybdenites. available molybdenum disulfide containing 9.3 p.p.m. I~ leading to the formation c)f lH(Il
7)
lH5\\1
IHII\jT(n,y)lH?\.V
‘wh(l1
,p)
5
lH”l
!*
ln71
18”lb
irracliation conclitions It can be shown by CillcUlation 15 that under the neutron produced by I ,ug of tungsten correfor rocks in the present work, the lH~~l
r\ neutron activation method is proposed for the determination of rhcniunl in rocks and ores. After the irradiation, the radiochemical separation consists of a one-step anion cschnnge; @ctivities of radiochemically pure 1flcJRe or lnoI
On propose unc mfthode par activntion du rhenium clans des roches et des minerais.
au moyen de neutrons pour le dosage La separation racliochimiclue consistc
24
I<. ISHIDA,
I<. KUIIOI)A,
K.
KAWARUCHI
en un dchange cl’anions; on compte lcs activitds-/I de l”fiIle ou IRaRe, radiochimiqucment purs. Ix renclcment chimiclue cst cn moyenne de 75”i;,; le gain cle temps est consiclfrahlc. Des r&ultats sont dorm& pour dcs tencurs en rh&nium de x-die standard W-x, pliisieurs molybd~nitcs ct pyrolusitcs.
Die Neutroncn~lktivicrun~s~n~~lyse wircl fiir die J3cstimmung von l
_
nicteoritcs7-‘b ilIlC1 tcktitcsl, and such organic mutcrials iis cnzynicsl” ant1 tiiarincorgarlismsll~l~. Tlicsc nietliocls mostly involve co~n~~licateclcl~eti~ic~l separations inchcling col”‘ecil’itntion, distillation ancl solvent CstrilctiOIl, leading to low cheniical yields. In addition, most of the previous purification lx-occclurcs do not affortl clear r(jcks2.:l.ll,
selmrntion or
comes
of
pritiinry
using of
of
raCli0itctive
from
ii thick
the
rhenium
importniicc duminutn
r)‘l*ll’l’c. ‘I’llesc
mid
~BHhIC)(n,y) ~~%I0 to
rcnmvc
absorber
precautions
‘l’jnl’l’c,
reaction the
wllich
is proclucecl
followxl
conversion
by
electron
or to USC y-spcctroinetry
inevitilbly
cause
a loss
of
bv
a /I-clecny. ilrising to rcniove
uraniuni
fission
Therefore, from tlw
it
rBnllTc
is bJ
Eontribution
sensitivity.
In this work ;L vcq cffcctivc mclioclmiiical proccclurc was clevclolxx~ for rhenium; the singlestep anion eSclliltlgC involved allows a variety of samples to be rapidly analyzed with ;L high cllemical~ yiclc\. ~)l~~lTccm bc completely scparatcd to achieve clircct fi- or I)-counting of rhenium nctivitics without ii loss of sensitivity.
Re BY NEUTI~OS
ACTIVATIOX
19
Standard solzrtiou of rlteuium. Dissolve ca. I: g of potassium perrhenatk: (gig.of’o purity) in 150 ml of 0.5 M hydrochloric acid. Standardize gravim~triciLl!y by a tetraphenylarsonium method. This solution served both xs a carrier and as a comparative standard after nplx-opriate dilution . ,411 other chemicals used wcrc of nnalytical grade quality. ?on-eschan~c: ~01~~2~~. Dowes r--Xx0, 3or.h400 mesh, Cl form, was used. Tlw resin was converted to the t!iiOCyanate fcJrn1 and stored as described lxcviously1:I. Slurry the resin (2 g) wit11 water and pour into a conventional column of diamctcr I.0 cm to form a bed cn. 5 cm long. &fore use pass several column voluincs of 0.025 &I ammonium thiocyanate-o.5 fV1 l~yclrocl~loric acid solution tlirougli the column.
1Veigh out a l~owclercd sainplc of niolybdcnitc (50 mg) or pyrolusitc (zoo mg) and seal in a l~olyctliylcnc tube. Impregnate a smnll piece of filter paper placccl in a polycthylenc bag with an alicluot of the rhenium standard solution (o.ogoG lug Kc) *and seal. For rock samples, weigh ca. 150 lllg in a quartx tube Zintl sfX1. Prelxwc iL comparative standard for rock samples (o.oC)oO klg lie) by placing an aliquot of the stanclard solution in a sepnratc quartz tube, evaporating to dryness under an infrared lamp, and sealing as before. Pack the Sitllll>lC and tlic~coinparntive standard wit11 alun~inun~ foil and position in an nluniinun~ capsule along with aluminum p:ding foil. Ore samples were irrocliatccl for 6 11 in the Tl
lTusc! tllc irracliatcd sample with 1 c: of sodium perosidc in a Sil icntc rock. nic:kcl cruc:il~le. After cooling place the crucilh in a bcakcr containing 4.513 mg lb. Atlcl IO ml of water to leach tllc melt. I
Adjust tllc: suJx!rnatc ol~t~tinccl to 0.025 &I in mimcmiuni tllioc:yxn;itc and Ilyrlrocl~l~~ric acid. I)0 not csceed ii total volunic Cd 3.5 ml. AJlow the ac:idic thioc:yanatc solution to J>ilSS tllrough the ion-cschangc column at a flo\v rate of about 0.5 inl/niin. l’)isc::irCl tl 1c: clnatc. Wash tllc column with 20 ml of the SillllC! acidic 0.5
A/r
in
tlliOc’~~illl~l.tC! 30
ml of
CluiltC!.
solution 0.5
Acltl
111
to
ant1
tlisc:iLJYl
the
tllioc:~;~t~;~t~-(~,~
tllis
S
ml
of
in (i h/l hydrc~chl~~ric: ;idcl,
A4
acid,
Ilyclrochloric
ilnC1 2
ml
of
lhmiovc
cluntc.
IiydroclJloric
20’7;
tllc
rlicniutn
by clution
with
xicl solution. Collect tllc whole I nil of 35’%, tin(II) chloride solution
potassium
tliiocyanatc
solution.
‘I’t-ansfcr
cstract the rhenium by shaking with 20 ml of ethyl ctlirtr for x nlin. Transfer the ether layer to a conical beaker and cvaJx)ratc to dryness. Add IO ml of 0 n/r IlycJrochloric acid to the rcsiclue and wnrm. While shaking, aclcl I~ydrogcn Jxxosidc dropwise to the sdution to dcconiposc tlic tliiocyanate. .3’)‘);J If iL yellowish I~l~C~\Vll 01 blnclcisl~ bmwn precipitate appr5U-s, Jnakc the Solution alkdinc! with :llnlllOlliil and warm until the prcciJ)itate turns yellow. Add n few drops of inctliyl orange solution ant1 ncutralizc with iunnioniuin I~yclrcjsiclc or I1ydrochloric acid, tlcJx2ncling on the Jxcvious step. Digest for 5 niin on a stcarn hat11 ztncl filter. Add 3 nil of ilC~l.lCOUS x(7:) tctr~~~~lieiiylarsc~nium chloride solution to the filtrate and tligcst for x0 min. Cool and filter through iL wcighccl smxll filter paJxr. Wash wit11 w;itcr :ind tlicn with cthnnol. Dry at x roe for IO min, cool ;lnCI weigh. Mount for the activity nieasurcnients. ‘l’rcat the comparative standard in a siniilar way. to
:L SCJXIKltOry
I(J:SUJ,‘J’S
ANIj
fuillic!~
ilnd
IjJSC:CJSSI<)N
Althougll scvcr~il raClicJcllClnicill J~roccclures arc nvailablc for rlicnium, a iilc~tliocl is still lacking. Ib’)rll’l’c:,Jxoclucccl by uranium fission or 1)~ tlccay of :lCtiViItC!tl lllOl_~lXlC?tlulll, bchnvcs very similarly to rhenium in most raCJiochemica1 scJxuatioris. Aluminum absorbers must 1x2 cmJ~loycC1 in racliometric IKSiL>‘S to absorb conversion clc~~trons arising from tlic isonicric transition (c/y very 1iKgC) and y (e/y, 0.1~) decay of t)l)rll’l\~.\Vith y-sJxxtromctry, the 0.14-McV y-peak of ‘)Onl’l’~ interferes wit11 tllc Jdtn;uy y-peaks at 0.137 McV for In(lRc nncl :lt 0.155 MeV for ln”l
sJxxific
L’(W), ‘I’c(VII). One cm thus expect to bc rtblc to isolate ELpure rhenium frnc‘Table II shows the results tion in ;I single step by this anion-eschange lxocess. for the determination of rhenium in several molybdenites, pyrolusites, molybdenum sulfide (of chemically pure quality) and the standard rock W-I from Centcrville, Virginia. The errors reported are tile standartl deviations hased on the final result not on the counting data. Colorirnetric values for the Yamanashi molybclcnitc and
of tllc ilVC!IXgC WilllC?S IXinolybdcnum sulfide are included in Table II *, ilgrc~IIlcnt twccn colorimctry and activation analysis is satisfactory. MOI
i
i
of 1We
number
scparatcd
Channel
from molvbdenitr.
(A) Lower cncrgv mngc;
(13) higher rncrgv
mnec.
Fig. 2. Ikca~
curw of induced rhenium activities obtained from the irradiated ruolybdenitc. (In, I In) Gross dccay of rhcniutu activities obtaiurd from the sample and con~parativc standard, rcspcctiwly. (lb, Ilb) Decay of ‘We (S&S h) obtained from the srmplc and comparative standard, rcspcctivcl~. (Ic, Ilc) Decay of *BsRc (16.7 h) obtained b\- suhtmction of the long-livctl *““Rc fraction in thr sample and comparative standard, rcspcctivcly.
Fig. I. y-Spcctm
4
loon
62 KeYOSK r-ray
C Y
:
2G
5
I
ACTIVATION
23
resonance capture. However no sign of neutron shielding was found esperimentally. so far as the specific activities produced on less than 0.x pg Re wcrc concerned. ‘i’he effect of neutron self-shielding in the samples does not appear to be significant. because of the small sample size used and the low absorption cross-section of the However, if the samples contain apprcciablc amounts of major matris materials. arising from self-shielding must he considered. This rhenium, possible intcrfcrencc Esperimentally, so-mg portions of commercially will be the case for molybdenites. available molybdenum disulfide containing 9.3 p.p.m. I
7)
lH5\\1
IHII\jT(n,y)lH?\.V
‘wh(l1
,p)
5
lH”l
!*
ln71
18”lb
irracliation conclitions It can be shown by CillcUlation 15 that under the neutron produced by I ,ug of tungsten correfor rocks in the present work, the lH~~l
r\ neutron activation method is proposed for the determination of rhcniunl in rocks and ores. After the irradiation, the radiochemical separation consists of a one-step anion cschnnge; @ctivities of radiochemically pure 1flcJRe or lnoI
On propose unc mfthode par activntion du rhenium clans des roches et des minerais.
au moyen de neutrons pour le dosage La separation racliochimiclue consistc
24
I<. ISHIDA,
I<. KUIIOI)A,
K.
KAWARUCHI
en un dchange cl’anions; on compte lcs activitds-/I de l”fiIle ou IRaRe, radiochimiqucment purs. Ix renclcment chimiclue cst cn moyenne de 75”i;,; le gain cle temps est consiclfrahlc. Des r&ultats sont dorm& pour dcs tencurs en rh&nium de x-die standard W-x, pliisieurs molybd~nitcs ct pyrolusitcs.
Die Neutroncn~lktivicrun~s~n~~lyse wircl fiir die J3cstimmung von l