Tgp chi phdn tich Hda, Ly vd Sinh hgc - Tap 19, So 4/2014
NGHIEN Ciru TACH ZIRCONI(IV) KHOI CAC TAP CHAT BANG DI-2-ETYLHEXYLPHOTPHORIC AXIT Bt XAC DINH CHUNG BANG ICP-MS
Din toa sogn 2-6- 2014
Le Ba Thuan, Nguyen Xuan Chien
Viin Cong nghe Xg hiim, Viin Nang lugng Nguyen tir Viet Nam Chu Manh Nhuong
Khoa Hoa hgc, Tru&ng Dgi hgc Suphgm - DH Thdi Nguyen
SUMMARY
SEPARATION OF ZlRCONIUM(rV) FROM IMPURTTIES WITH
DI-2-ETHYLHEXYLPHOSPHORIC ACID FOR DETERMINATION OF THEM BY ICP-MS Investigation of the effects of extraction time, extractant concentration, diluents, acids and loading capacity of the extractant, sunfate with di-2-ethylhexyl phosphoric acid (DEHPA) in toluene on extracting ofZr(V) has been done. The optimal conditions for extraction of 30 mg/mL Zr(IV) are: 2 to 5MHNO3, toluene diluent 50% DEHPA, 1 hrs.
for phase contact time. Extraction efficiency ofZr(V) increase in order: H2SO4 « HCI
< HNO3.
Extraction, stripping ofZr, Hfand scrubbing impurities have been studied and showed that using 3M and 6M HNO3, can scrubbing 95% of almost investigated impurity elements and stripping about 20-26% ofZr(V). Obtained results allow to determine the content of impurities in Zr nuclear materials by ICP-MS technique after removal ofZr using extraction with DEHPA/toluene solvent.
Keywords: extraction, zirconium, HNO3, DEHPA, toluene, impurities, ICP-MS.
1. M d D A U clu quan ttpng cua vat lieu Zr sach hat Zirconi (Zr) va cac hgp kim Zr sach hat nhan la ham lugng cac tap chat kha thap.
nhan dugc su dung chii yeu de chl tao Vi vay, can xac dinh chinh xac ham vat lieu Id phan ling va vd bgc thanh lugng tap chat nham phuc vu cho viec niiien lieu hat nhan do Zr cd tilt dien bit san xuat, danh gia vat lieu Zr diing cho notron nhiet rit nhd va tinh chat hda ly Id phan ling hat nhan.
die thil cua kim loai hgp kun Zr. Yeu
Hien nay cd nhieu phucmg phap phan tich ham lugng tap chit ttong cac vat lieu Zr. ttong dd ICP-MS la mdt phuong phap phan tich hien dai cd dp chinh xac cao, gidi ban phat hien thap cho phep xac dinh dong tbdi nhilu nguyen td. Tac gia Nakane Kiyoshi da sii dung ICP-MS do phan giai cao dl phan tich lugng vet cac tap chit nhu: Na, Mg, Al, Ca, Ti, V, Cr, Mn, Fe, Ni, Sr, Cs, La, Ce, Hf, Pb, Bi cd trong hot Zr02 do sach hat nhan [1]. Nhdm nghien ciiu Zhang va cgng su da su dung ICP-MS dl xac dinh nhieu Ims trong Zr sieu min [2]. Cac tac gia Burger va Riciputi da sii dung ICP-MS dl xac dinh ty le ddng vi cac nguyen td trong mdt so vat lieu bat nhan [3]. Ngoai ra, tac gia Conrad Gregoire va cdng su da su dung ETV-ICP-MS dl xac dinh lugng vet mdt sd nguyen to dat hiem (REEs). U va Th trong quang zircon dan khoang [4]. Dac biet, nhdm tac gia Chen Shi-zhong va cpng sy da phan tich xac dinh 14 REEs bing ICP-MS trong Zr02 sach sau khi tach nin Zr tir mdi trudng HNO3 2M bang tac nhan l-phenyl-3- metyl-4-benzoyl-5-pyrazon (PMPB). Ket qua da tach dugc 99,7% lugng Zr va phan tich dugc ham lugng cua 14 REEs vdi gidi ban phat hien thap va dp lech chuan tuong ddi nhd [5].
Nghien ciiu ciia chiing tdi va cac tac gia neu tren cho thay, khi nen mau ldn se anh hudng ldn den ket qua phan tich tap chat bang ICP-MS. Do do. can phai tach nin Zr khdi cac tap chat trudc khi do ham lugng cac tap chit bing ICP-MS [6]. Hien nay, cd nhilu phuang phap khac nhau de tach loai Zr, tuy nhien.
phuong phap chiet dung mdi vdi viec su dung cac tac nhan chiet nhu TBP, DEHPA, Cyanex 272, PC88A,..., dugc danh gia la phuang phap cd nhilu tti&
vgng, ttong dd cac tac nhan chiet DEHPA, PC88A dang dugc nghien ciiu tach Zr ra khdi cac nguyen td khac [7.8].
Trong bai bao nay, cbiing tdi ttinh bay kit qua nghien ciiu kha nang chiet cua Zr(IV) bang tac nhan DEHPA nhlm irng dung dl tach nin Zr(rV) ra khdi cac tap chit khac phuc vu muc dich xac dinh cac tap chit trong vat lieu Zr sach hat nhan bing phep do ICP-MS.
2. V A T LIEU v A PHUONG PHAP NGHIEN CUU
2.1. Hoa chat, dung cu va may mdc Trong nghien ciiu nay, cac dung djch chuln sau dugc sii dung: dung dich Zr;
Hf; Ti (lOOOpg/mL) va dung dich chuln hdn hgp gdm 43 nguyen td (Ag, Al, B, Bi, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, hi, K, Li, Mg, Mn, Na, Ni, Pb, Sr, Tl, Zn, Sc, Y va 14 REEs) lOOOpg/mL;
Tac nhan DEHPA, HCI 36,5%, HCIO4 72%, H2SO4 98%, HNO3 65%, H2O ISMQ, toluen va cac chat pha loang khac deu cd do tinh khiet phan tich cua Merck.
May khdi phd plasma cam iimg (ICP-MS) Aligent 7500a-My, pheu chiet, may lac va cac dung cu thudng dimg ttong phan tich.
2.2. Phugng phap nghiin cmi 2.2.1. Nghien ciiu cdc yiu to dnh hu&ng din hiiu sudt chiet Zr(IV)
Cac yeu td anh hudng dugc khao sat gdm: thdi gian tiep xiic 2 pha (0,1-3 gid), ndng dp tac nhan DEHPA/toluen tir (10-80%), toluen va 5 chit pha loang khac, ndng do cac axit tit (0,5-8M), nong 72
do Zr(IV) tir (10-85 mg/mL), dung lugng chiet cue dai ciia DEHPA 50%/toluen, danh gia mdt so tac nhan giai chiet Zr(IV) ra khdi pha huti co, sd bac chilt thich hgp theo gian do MC Cable-Thiele.
Khao sat hieu suit chilt ciia Zr(IV) va mdt sd nguyen td ttong mdi ttvdng HNO3 bang DEHPA/toluen dugc thuc hien vdi pha nudc la dung dich chira cac dai dien cho timg nhdm nguyen tl, gdm:
Zr, Hf, Ti, K, Mg, Al, Fe(III), Co, Zn, Pb, As(V), Se(VI), La, Er, Tm, Yb, Lu, ndng dp mdi nguyen td diu la 1 mg/mL trong mdi trudng HNO3 (1-3,5M). Pha hilu co la DEHPA 50%/toluen.
2.2.2. Nghien cim tdch Zr(IV) tit mdi tru&ng HNO3 bdng DEHPA/toluen Pha nudc chiia (Zr(rV) 30 mg/mL va 43 tap chSt, ndng do mdi nguyen td tap chat la 0,5 mg/L) ttong mdi tnrdng HNO3 tir (1-3,5M). Pha hilu ca la DEHPA 50%/toluen.
2.2.3. Quy trinh chiit tdch logi Zr
* 7 2
, M 5 95.2
T ^ 1 - ^ ' 31
iTlDT^^nL 96 1
1
ThMglH.li
Cac dilu kien chilt tach: t>' le V„/Va = 1/1 hoac 2/1, thdi gian tiep xiic pha 1 gid.
thdi gian phan pha 0,5 gid d nliiet do 25±0,5°C. Sau khi phan pha, tach ily phin nude cai va cd can lan I. Tiep tuc cd can lln 2 vdi 5mL hdn hop (HNO3 25%+HC104 20%). Cudi ciing diing HNO3 0,3M dinh miic din 10 mL va do tren may ICP-MS Aligent 7500a. Cac kit qua xac dinh ndng dp dugc diing de tinh hieu suat chiet va danh gia kha nang tach Zr khdi cac nguyen td khac. Cac thi nghiem giai chiet Zr va cac tap chat ciing dugc tien hanh tuong tu.
3. KET QUA VA T H A O LUAN 3.1. Anh hirihig ciia thdi gian tiep xiic pha, nong do t^c nhan chiet, cac chat pha loang, ban chat va nong do axit va nong do muoi sunfat den kha nang chiet Zr
Cac ket qua nghien ciiu dugc chi ra tten hinh(la,lb, lc. Id, le).
« E l
1751
43 .M^U
• ^ i
^ j j 9 B 7 9 1 8 5 6 5 i u
y i 'es 'M ^7-
-•-CHetlian
\-*-Cfk2ar\
DIEHPMolutn (%)
(la) 211 30 40 SD ED 70 SH
(lb)
S7 76 S5
%Ex 9726 -ge
\ 6tS6
Sunfil milniL M '
0 ID 20 30
(le)
Hinh 1- Anh hu&ng cua thai gian tiip xuc pha (a), ndng do tdc nhdn chiit (b), cdc chdt pha lodng (c), bdn chdt vd ndng do axit (d) vd ndng dg mudi sunfat
(e) den khd ndng chiet Zr.
Kit qua thu dugc cho thay rang, hieu suit chilt Zr(IV) ddi vdi he chiia 50%
DEHPA dat dugc kha cao, sau 1-2 lan chiet lugng Zr(IV) len pha hiru eg dat gia tri dung lugng chiet la 29,985 mg/mL Zr(IV). Mat khac, khi ndng do DEHPA/toluen cao ban 50%, thdi gian phan pha dai hem va gay khd khan cho viec xii ly mlu sau khi chiet. Vi vay, ndng dp thich hgp dugc chpn la DEHPA 50%/toluen khi chilt Zr(IV) trong mdi trudng HNO3 2M. Kit qua tten hinh lc cho thiy, tie nhan toluen la thich hgp hon ca khi pha loang DEHPA dimg dl chilt Zr(FV) ttong mdi mrdng HNO3 2M va axit HNO3 cho hieu suit chilt Zr(rV) cao hon ban so vdi cac mdi trudng HCI va H2SO4. Qua dd ciing nhan thay khoang ndng do HNO3 tir 2-5M la thicb hgp hon ca khi chilt Zr(rV) 30 mg/mL bang tac nhan DEHPA 50%/toluen.
Khac vdi axit HNO3, H2SO4 dac va
suit chilt cua ZT(TV). Dieu nay dugc giai thich la do ion Zr(IV) da tao phiic manh vdi ion S04^" gay ra su chiet canh tt-anh vdi tac nhan DEHPA hoac tao ra cac phiic mang dien tich am dang Zr(S04)3^"
khd bi chilt len toluen bdi tac nhan chiet axit nhu DEHPA. Kit qua nay cho thiy, khi su dung axit sunliiric va mudi sunfat dl pha cac mlu Zr thudng gSy anh hudng giam hieu suit chiet Zr(rV). Do dd, cln tim phuang phap pha mlu khac thich hgp hgn, ehlng han nhu su dung bom teflon vdi hdn hgp cac axit dac (HCI+HNO3+HF) dl phan buy mlu.
3.2. Danh gia kha nang giai chiet Zr(rV) bing mot so dung djch axit D I danh gia kha nang giai chilt Zr(IV) ra khdi pha hiru eg DEHPA 50%/toluen (chiia 29,898 mg/mL Zr(IV)), chiing tdi sir dung cac dung dich HCI, H2SO4, HNO3 ttong khoang ndng dp (1-8M) de giai chilt Zr(rV) va kit qua giai chiet dugc chi ra trong bang 1.
(NH4)2S04/NH4HS04) lam giam hieu
Bdng 1. Hieu qud gidi chiit Zr(IV) khoi pha hOu ca (DEHPA, 50%/toluen) bdng mgt so dung dich axit
STT 1 2 3 4 5 6 7 8 9 10
Dung dich HCllM HC12M HC13M HC14M H2SO4 0,5M H2SO4 0.7M H2SO4 IM H2SO4 1.5M HNO32M HNO34M
Mirc dp giai chilt Zr (%)
20,5 26 27,5
28 94,5
95 98,5 98,7 3 4,5
STT 11 12 13 14 15 16 17 18 19 20
Dung dich HNO36M HNO38M HCI IM +H2O2 1%
HCI 2M +H2O2 1%
HCI IM +H2O2 2%
HCI 2M +H2O2 2%
HNO3 2M +H2O2 1%
HNO3 4M +H2O2 1%
HNO3 2M +H2O2 2%
HNO3 4M +H2O2 2%
Mirc dp giai chilt Zr (%)
6 9,5
25 41 35 48 5,5 6,5 6 13 74
Trong ttfdng hgp sii dung dung dich HCI (1-4M), chi giai chilt dugc 20,5- 28% Zr(IV) ra khdi pha hiru co. Khi cd them H2O2 1-2% mirc dd giai chilt tang len tir 25-48%. H2SO4 ttong khoang ndng dp 0,5-1,5M da giai chilt 94,5 - 98,7% Zr(IV). Mirc dp giai chilt ciia cac axit tang theo thir tu sau: HN03<
HC1«H2S04. Tac nhan H2O2 bd sung
\ao cac mdi trudng tten da cai thien dugc phan nao mirc dp giai chiet Zr(IV).
Ket qua nay hoan toan phil hgp vdi ket qua nghien cihi ve anh hudng ciia cac axit den hieu suat chiet Zr(IV) d phan tten.
3.3. Gian dd MC Cable-Thiele trong be Zr(IV)-HN03 2M DEHPA 50%/toluen
Hinh 2 bieu diln gian dd MC Cable-Thiele klii chilt Zr(IV) 50%/toluen.
HNO3 2M- DEHPA
0 5 10 15 20 25 30 35 40 45 50 Hinh 2. Gidn do MC Cabe-Thiele trong hi Zr(lV) (10-85 mg/mL) - HNO3 2M-DEHPA 50%/toluen Gian do hinh 2 cho thay, khi su dvmg
dung mdi DEHPA 50%/toluen d cac the tich pha V(/Va=l/1 va 2/1, can 3 hoac 2 bac chiet tucmg ung dS cd the chilt dugc 98,75% lugng Zr(IV) ban diu. Vi vay, trong cac tbi nghiem sau chiing tdi sir dung ty le thi tich pha VJVi=2n khi chilt Zr(IV) trong HNO3 bing DEHPA.
3.4. Hifu suat chiet ciia cac nguyen t l trong moi trudng HNO3
Anh hudng cua axit HNO3 den hieu suit chiet ciia Zr(rV) va mdt sd nguyen t l tap
chat khao sat dugc trinh bay tren hinh 3.
Ket qua cho thay, hieu suat chiet cua cac nguyen td cd xu hudng giam khi tang ndng do axit. Tuy nhien, mirc do giam khdng gidng nhau. Hieu suat chiet ciia Zr, Hf rat cao va giam khdng dang ke tir (89-99%), Ti, Fe'" (74-93,5%), Tm, Yb, Lu (40,78-91,56%), Y(37-57%), AI(3,3- 7,5%) va cac nguyen td khac cd hieu suit chilt rit nhd tir (0,65%) K den (5,95%) Pb.
H.lls.Kfsm 2n.Co.n laSeM Er
1 1.5 2 Z5 3 3.5 Hinh 3. Hiiu sudt chiit cda Zr(IV) xd mgt so nguyen to trong HNO3
v&i dung mdi 50% DEHPA'toluen.
3.5. Khao sat tach nen Zr(IV) khoi cac t^p chat
Tren co sd khao sat hieu suat chiet cua Zr(IV) va mdt sd nguyen td trong mdi truimg HNO3 d tren, dung mdi DEHPA 50%/toluen dugc sir dung de tach Zr(rV) khdi tap chat tir hdn hgp chiia
Bdng 2a. Stt phdn bd ciia cdc nguyen to & hai pha khi chiit
tit mdi tru&ng HNO3 3M bdng DEHPA 50%/toluen vd gidi chiit I ldn bdng HNO3 6M 7x 30 mg mL % a 43 tap chat ndng dp rieng le 0.5 m g L trong mdi trudng IINO3 3M. Ket qua sau 1 lan chiet bing HNO3 3M va 1-5-2 lan giai chiet bang dung dich HNO5 6M dugc chi ra d cac bans 2a va 2b.
Tap chit Pha nudc. (%) Pha hiru co. (%)
Li. B. Na, K. Rb, Mg, Ca, Sr, Ba, Al, Ga. Tl, Sc. Cd, Ag, Bi, Zn. Pb, Cu,
Co. Ni. Mn. V, As, Se. La. Ce, Pr, Nd. Pm. Sm. Eu, Gd, Tb. Dys Ho. Er
100 Khdng xac dinh dugc
Tm, Yb, Lu 85- 87 13- 15
Y
91 09
Ti, Fe 58
Hf
25 42 75
Zr
20 80 Bang 2b. Suphdn bo cua cdc nguyen to a hai pha khi chiet
tir moi tru&ng HNO3 3M bdng DEHPA 50%/toluen va gidi chiit 2 ldn bdng HNO3 6M
Tap chat
Li, B, Na. K, Rb, Mg, Ca. Sr, Ba, AL Ga, Tl. Sc. Cd. Ag, Bi, Zn, Pb. Cu,
Co. Ni. Mn. V, As. Se, La, Ce, Pr, Nd. Pm, Sm. Eu. Gd. Tb. Dy, Ho. Er Pha nudc. (%) ""*
„. , . ,„ , Khdne xac dinh dugc Pha buu CO. Co)
Tm, Yh.
Lu 95- 96 4-5
Y
96 4
TL Fe 65 35
Hf
32 68
Zr
26 74 76
Tir ket qua d bang 2a va 2b cho thiy, khi su dung dung mdi DEHPA 50%/toluen, qua 1 lan chilt tir mdi ttirdng HNO3 3M va 1^ 2 lln giai chilt bing mdi ttirdng HNO3 6M, da tach dugc tren 95% hiu het cac tap chit ra khdi nin Zr(IV) va lugng Zr(rV) cdn lai chi tir 20-26%.
Theo khao sat do chiing tdi thuc hien, lugng Zr(V) cdn lai d pha nudc se khdng gay anh hudng din phep xac dinh cac tap chit bing phep do ICP-MS, ttir nguyen td Hf, Ti, Fe'"
4. KET LUAN
Da khao sat thuc nghiem va chi ra cac dilu kien tdi uu khi chilt Zr(rV) 30mg/mL bing tac nhan chilt DEHPA nhu sau: mdi trudng chilt HNO3 (2-5M);
DEHPA/toluen vdi ndng do thich hgp la 50%; thdi gian can bing 2 gid; ion S04^"
lam giam hieu suit chilt cua Zr(IV);
Dung lugng ciia dung mdi DEHPA 50%/toluen la 29,985 mg/mL Zr(IV);
HNO3 cd kha nang giai chilt Zr(IV) kem nhit; D I chilt dugc 98,75% lugng Zr(IV) can thuc hien 2 hoac 3 bac chilt vdi V(A'a=2/l hoac 1/1 tuong ling.
Da khao sat hieu suat chiet cua mdt sd nguyen td dai dien tir mdi trudng HNO3 3M bang D2EHPA 50%/toluen. Kit qua cho thay, hieu suat chiet ciia cac nguyen td giam khi tang ndng dp axit; hieu suat chilt ciia Zr, Hf rat cao va giam khdng dang kl tir (89-99%), Ti, Fe"' (74- 93,5%), Tm, Yb, Lu (40,78-91,56%), Y(37-57%i) va cac nguyen td cdn lai cd hieu suit chilt kha nhd (dudi 6%) khi ndng dp HNO3 tang tir 1 din 3,5M.
Vol mlu nghien ciiu chiia (Zr(rV) 30 mg/mL va 43 tap chat 0,5mg/L), sau 1
lan chiet bang HNO3 3M va 1-2 lan giai chiet bang HNO3 6M, da tach dugc tten 95% hau het cac tap chat va luong Zr(IV) di kem chi tir 20-26% se khdng gSy anh hudng din phep xac dinh tap chit bing ICP-MS, trir nguyen td Hf, Ti, Fe'". He chilt nay cd the dugc su dung de tach nen Zr va xac dinh cac tap chat trong vat lieu zirconi sach hat nhan bang phep do ICP-MS.
TAI LIEU THAM KHAO 1. Nakane Kiyoshi Determination of ttace mipurities in high-purity zuconium oxide by high-resolution inductively coupled plasma mass spectrometry. Bunseki Kagaku, Japan. Vol 53, No. 3, pp. 147- 152 (2004).
2. Zhang Xin-quan, Jiang Yu-mei. Yl Yong. Tong Ying-dong. Liu Jing-lei, Su Ya-qin, Li Xiang. Lin Ping. Determination of Multi-Impurities in Superfme Zuconium and Yttrium Oxide by ICP-MS.
J. of Analytical Science 2005-01, pp. 135- 139 (2005).
3. Burger S., Riciputi L.R. . A rapid isotope ratio analysis protocol for nuclear solid materials using nano-second laser- ablation time-of-flight ICP-MS. Journal of Environmental Radioactivity, Vol. 100, Issue 11, pp. 970-976 (2009).
4. Conrad Gregoire D., Kevin M. Ansdell, Douglas M. Goltz, Chuni L. Chakrabarti. Trace analysis of single zircons for rare-earth elements, U and Th by electtothermal vaporization- mductively coupled plasma-mass specttometty (ETV-ICP-MS). Analytical
Spectroscopy in the Earth Sciences.
Vol.124, Issues 1-2, pp. 91-99 (1995).
5. Chen Shi-zhong. Determination of trace rare earth impurities in high purity zirconium dioxide by inductively coupled plasma mass spectrometry after separation by solvent extraction.
Metallurgical Analysis, Vol 26, 03, pp.
7-10(2006).
6. Alan L. Gray. Mass spectrometry with an inductively coupled plasma as an ion source: the influence on ultratrace analysis of background and matrix response. Spectrochimica Acta Part B:
Atomic Spectroscopy, Vol. 41, Isues 1-2.
pp. 151-167(1986).
7. Biswas, Hayat R.K.. Solvent extraction of zu-conium(IV) from chloride media by D2EHPA in kerosene.
Hydrometallurgy 63 (2). pp.149-158 (2002).
8. Ramachandra R. B., Rajesh K. J., Varada R. A., Neela Priya. Solvent extraction of zirconimn (IV) from acidic chloride solutions using 2-ethylhexyl phosphonic acid mono-2-ethyl hexyl ester (PC-88A). Hydrometallurgy 72, pp.
303-307 (2004).
TONG HQfP VA NGHIEN ClTU KHA NANG PHAT QUANG...(^zep theo tr.62) salicylate and o-Phenantroline
incorporated in Silica Matric", Journal of Rare Earths, Vol. 24, pp. 429-433, (2006).
6. Paula C. R. Soares-Santos, Filipe A.
Almeida Paz, et. al., , "Coordmation mode of pyridine-carboxylic acid derivatives in samarium (III) complexes". Polyhedron, Vol. 25, pp.
2471-2482,(2006).
7. Yasuchika Hasegawa, Yuji Wada, Shozo Yanagida, "Strategies for the design pf luminesent lanthanide (III) complexes and their photonic applications". Journal of photochemistry and Photobiology,
Vol.5,pp. 183-202, (2004).
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