cyanex introduction

8/20/2019 Cyanex Introduction

1/20

Part I Chapter 2: Introduction to Cyanex

13

2.1 Introduction to cyanex compounds

Cyanex extractants are organophosphorous compounds. Depending on their

chemical compositions and structural properties there are different types of

cyanex compounds such as, cyanex 921, cyanex 272, cyanex 301, cyanex 923,

cyanex 471X, cyanex 302, cyanex 925 etc. Cyanex extractants are phosphorus-

based products that act in two different ways:

a) Chelating Extractants

b) Solvating Extractants

a) Chelating Extractants

Cyanex 272 solvent extraction reagent was developed specifically for the

separation of cobalt from nickel by solvent extraction. It is estimated that 40%

of the cobalt in the western hemisphere is produced using cyanex 272 solvent

extraction reagent, at plants Europe, South America , Canada , Africa, China

and Australia. Cyanex 272 solvent extraction reagent can also be used to

separate the rare earth elements from one another. The acid concentration

required for metal stripping is lower than when phosphoric acid or phosphonic

acid are used as extractants. Cyanex 301 solvent extraction reagent is an

analogue of cyanex 272 solvent extraction reagent. Thiophosphinic acid cyanex

301 solvent extraction reagent exhibits interesting extraction characteristics for

the recovery of cobalt and nickel. A potential advantage of the dithiophosphinic

acid cyanex 301 over cyanex 272 is its ability to extract both cobalt and nickel

under very acidic conditions avoiding therefore the need for pH adjustment of

the acidic leach liquors.

b) Solvating Extractants

Cyanex 921 and 923 solvent extraction reagents have potential in a wide

range of applications. Specific applications are the recovery of organic solutes

and inorganic mineral acids from waste effluents, and metal extraction

processes. Unlike its phosphine oxide analogues, cyanex 471X solvent

extraction reagent is a soft Lewis base. Under the HSAB principle, it will only


2/20


14

complex readily with metals that exhibit the characteristics of soft Lewis acids.

Specific characteristics of these so-called soft Lewis acids are their large ionic

radius, their low oxidation state and their ease to be polarized. Examples of

metals falling upon those criteria are Pd(II), Pt(II), Ag(I), Cd(II), Hg(I), Hg (II)

and Au(III).

The cyanex compounds are very useful and effective in case of solvent

extraction of metal ions. Now a days these cyanex compounds are widely used

extractants for separation of metal ions. The detailed information of some of

the cyanex compounds are described [1].


3/20


15

2.2 Properties of cyanex compounds

The properties of different cyanex compounds are shown in Table 2.2.

Table 2.2 Properties of different cyanex compounds

Name of

cyanex

Properties

Cyanex

921

Cyanex 272 Cyanex

923

Cyanex

301

Cyanex

471X

% Purity 93 85 93 75-80

Appearance Off-white,

waxy

solid

colourless to

light amber

liquid

colourless

mobile

liquid

Green

mobile

liquid

Off-white

crystalline

solidMolecular

Weight

386 290 322

Specific

gravity

0.88 at 250C

0.92 at 240C 0.88 at 25

0C

0.95 at 240C

0.91 at 220C

Viscosity 150 cp 37 cp 40 cp at 250C

78 cp at

240C

Solubility

In Distilled

water

16µg/mL at

pH 2.6

10 mg/L 7 mg/L 43µg/mL

at 240C

Boiling

point

>3000C 310

0C at

50 mm Hg

2200C

Pour point -320C -34

0C

Flash point >1080C(closed

cup)

1820C

(Closed

cup

setaflash)

74 0C

(closed

cup)

Specificheat

0.48cal/gm/

0C at

250C

0.45cal/gm/

0C

at 250C

Thermal

conductivit

y

2.7x 10-4

cal/cm/sec./ 0

C

0.000302

cal/cm/sec.

/0C

Melting

point

47-520C 58-59

0C


4/20


16

2.3 Cyanex 921 extractant

Cyanex 921 is commonly known as trioctylphosphine oxide (TOPO). It was the

first member of a family of solvent extraction reagents developed by Cytec.

This reagent has been used commercially for many years to recover uranium

from wet process phosphoric acid. It is also used in the extraction of different

metals.

2.3.1 Chemical Structure of cyanex 921

The chemical structure of cyanex 921 is as follows:

CH3(CH

2)7-P-(CH

2)7CH

3

O

(CH2)7CH

3

2.3.2 Stability of cyanex 921

Among trialkylphosphine oxides, cyanex 921 is most stable member of

the group of organophosphorous solvating reagents.

2.3.3 Organic solubility of cyanex 921

The solubility of cyanex 921 is higher in aromatic diluents than the

aliphatic ones.

2.3.4 Toxicity of cyanex 921

The acute oral and acute dermal LD50 values for cyanex 921 extractant

are > 10.0 g/ kg and 2.83 g/ kg, respectively. Marked skin and eye irritation

were produced during primary irritation studies with rabbits. Inhalation of

airborne material may be irritating to the respiratory tract. Cyanex 921 was

determined to be not mutagenic in the Ames Salmonella Assay.


5/20


17

2.3.5 Applications of Cyanex 921

Cyanex 921 is a better extractant because of its higher stability, lower

aqueous solubility and rapid phase engagement. There are numerous

applications of cyanex 921.

1. The solvent extraction method was developed to recover small quqntities of

uranium present in wet process phosphoric acid using cyanex 921.

2. Processes in petrochemical plants, wood pulp mills and other chemical

facilities often generate aqueous effluent streams containing small

concentrations of carboxylic acids; particularly acetic acid. The use of cyanex

921 and others reagents to recover acetic acid from these streams has formed

the subject of informative papers in recent years.

3. Cyanex 921 is used to extract niobium and tantalum from a hydrofluoric-

sulphuric acid leach liquor and then selectively stripped from the loaded

organic phase.

4. Rhenium is an essential element in the production of petroleum reforming

catalysts. Cyanex 921 was used to recover rhenium from these source

materials.

5. Removal of arsenic impurities from copper electrolytes by solvent extraction

with cyanex 921 was carried out. It was found that cyanex 921 is stronger

extractant for arsenic than tributylphosphate.

6. Because of wide applications of lithium in batteries and ceramics a novel

solvent extraction process using cyanex 921 extractant to recover lithium from

its sources was developed.

7. Selective separations can be made depending upon a variety of factors, e.g.

the valence state of metal, the anionic nature of the solution and the

concentration of the extractant in the solvent. Approximately 30 metals were

known to be extracted by cyanex 921.

8. Phenol occurs in aqueous effluent from many processes such as, in the

petroleum, steel and coal gasification industries. Cyanex 921 is a strong

extractant for phenol recovery and offers a lower cost alternative to

conventional phenosolvan technology.


6/20


18

2.4 Cyanex 272 Extractant

Bis(2,4,4- trimethylpentyl)phosphinic acid commonly known as cyanex

272. The active component of cyanex 272 extractant is a phosphoric acid;

metals are extracted through a cation exchange mechanism. Though cyanex

272 is a selective extractant for cobolt in the presence of nickel, a variety of

other cations can be extracted depending upon the solution pH.

2.4.1 Chemical Structure of cyanex 272

The chemical structure of cyanex 272 is as follows

CH3-C-CH

2-CH-CH

2

CH3

CH3

CH3-C-CH

2-CH-CH

2

CH3

CH3

P

O

OH

CH3

CH3

2.4.2 Stability of cyanex 272

The hydrophilic stability of cyanex 272 extractant was examined in several

tests and it was found that cyanex 272 is having highest stability.


Cyanex 272 extractant is totally miscible with common aromatic and

aliphatic diluents, and is extremely stable to both heat and hydrolysis.

2.4.4 Toxicity of cyanex 272

The acute oral and acute dermal LD50 values for cyanex 272 extractant

are > 3.5 g/ kg and 2.0 g/ kg, respectively. It is limited to skin and eye irritation

during primary irritation studies with rabbits. Cyanex 272 was determined to be

non-mutagenic in the Ames Salmonella Assay.


7/20


19


1. Cyanex 272 is used as a selectve extractant for the extraction and separation

of cobalt in the presence of nickel.

2. Cyanex 272 is found to be preferentially selective extractant for cobalt in the

presence of calcium.

3. Cyanex 272 can be used to recover cobalt from ammoniacal as well as acidic

solutions.

4. Using cyanex 272 metals like iron, zinc. Copper, manganese, calcium, nickel

from sulphate solutions can be extracted.

2.5

Cyanex 923 Extractant

Cyanex 923 extractant is a liquid phosphine oxide which has potential

applications in the solvent extraction recovery of both organic and inorganic

solutes from aqueous solution, e.g. carboxylic acids from effluent streams and

the removal of arsenic impurities from copper electrolytes.

2.5.1 Compositions of cyanex 923

Cyanex 923 extractant is a mixture of four trialkyl-phosphine oxides as

follows:

(1) Trihexylphosphine oxide (2) dihexylmonooctyl-phosphine oxide

(3) dioctylmonohexyl-phosphine oxide (4) Trioctylphosphine oxide.

R3P(O) R2R’P(O) RR2’P(O) R’3P(O)

Where, R= [CH3(CH2)7]-normal octyl

R’ = [CH3(CH2)7]-normal octyl


Cyanex 923 extractants are completely miscible with all common

hydrocarbon diluents even at very low ambient temperatures. The major benefit

of high solubility lies the ability to prepare concentrated, stable solvents which

can recover solutes (e.g. acetic acid) that are normally only weakly extracted by

this type of reagent.


8/20


20


1. Processes in petrochemical plants, wood pulping mills, and other

chemical facilities often generate aqueous effluent streams containing

carboxylic acids: particularly acetic acid. These carboxylic acids are

recovered by cyanex 923.

2. Phenols, like carboxylic acids are produced during coal liquefaction, coal

gasification and in the petrochemical industry and they can be efficiently

extracted by cyanex 923.

3. Cyanex 923 extractant exhibits a separation factor in ethanol/water

solutions near the maximum useful limit for recovery from continuous

fermentation broths, typically containing 5% ethanol.

4. Removing arsenic, antimony and bismuth impurities from copper

electrolytes by solvent extraction with cyanex 923 improves the quality

of electrolytic copper and consists of improvements in current efficiency.

5. Uranium recovery from wet-process phosphoric acid using synergic

mixtures of phosphine oxides and D2EHPA.

6. Niobium and tantalum are extracted and separated by cyanex 923.

7. Cadmium sometimes occurs as an undesirable impurity in phosphoric

acid and other acids can be removed by cyanex 923.

2.6 Cyanex 301 extractant

Cyanex 301 is a dialkyl dithiophosphinic acid extractant. This sulphur

containing compound is a much stronger acid than its analogous oxy-acid,

cyanex 272. It is capable of extracting many metals at lower pH (


9/20


21

P

S

SHR

R

Where,

R=CH3-C-CH

2-CH-CH

2-

CH3

CH3

CH3

The active component of cyanex 301 is bis(2,4,4-trimethylpentyl)

dithiophosphinic acid.

2.6.2 Applications of cyanex 301

Cyanex 301 extractant is capable of the selective recovery of heavy

metals at low pH in the presence of alkaline earths.

1. Cadmium from wet process phosphoric acid and amino acids from

fermentation broths were capable to extract by cyanex 301.

2. Cyanex 301 was developed to extract and recover zinc from the effluentstreams of viscose rayon plants in the presence of calcium.

3. Dialkyl dithiophoshinic acids, or their salts, have shown to be effective in

extracting a number of alpha amino acids from fermentation broths. The

recovery of L-phenylalanine was done using cyanex 301 extractant.

2.7 Cyanex 471X extractant

Cyanex 471X extractant is a new phosphine –based extractant developed

by Cyanamid for the hydrometallurgical industry. It is particularly useful for

the selective recovery of silver and in the separation of palladium from

platinum.

2.7.1 Chemical Structure of cyanex 471X

The chemical structure of cyanex 471X is as follows


10/20


22

CH3-CH

2-CH

2

CH3

3

P=S

2.7.2 Toxicity of cyanex 471X

The acute oral (rat) and acute dermal (rabbit) LD50 values for the active

phosphine sulphide contained in cyanex 471X extractant are 10,000 mg/kg of

body weight. No significant skin irritation and only mild eye irritation were

produced during primary irritation studies with rabbits. The sulfide was

determined to be non-mutagenic in the Ames Salmonella Assay.

2.7.3 Applications of cyanex 471X

1. Cyanex 471X is a solvating reagent and will extract silver from sulfate,

nitrate and chloride systems.

2. Cyanex 741X extractant has potential in the separation of palladium from

chloride solutions containing platinum(IV) and palladium(II). Palladium

extraction occurs with silver through a solvating mechanism. Stabilized

thiosulfate solutions are an effective strip feed. If present, Ag, Hg(II), Au(III)

will be co-extracted with palladium.

2.8 Scope of Solvent extraction with cyanex compounds

Extraction of metals by cyanex compounds takes place by ion-pair

extraction. In the present days large numbers of cyanex compounds are using

because of their selective extraction properties. In the presence of various

counter anions the extraction properties of cyanex compounds differs and

provides wide variability to extract different metals. Literature survey reveals

the applicability of cyanex compounds in separation of metals by solvent

extraction. The literature survey of cyanex compounds used in the extraction of

various metal ions is given in the following table 2.8.


11/20


23

Table 2.8 Different cyanex compounds used for various metal extractions

under different conditions

Sr.

no.

Cation Technique Cyanex Media Solvent Ref.

No.

1 Ga(III) SE CX-921 HCl Toluene 2

2 Pd(II) SE CX-302 HCl Toluene 3

3 Zn(II) SE CX-923 HCl Solvesso-

100

4

4 Pd(II) Ex-Chrom. CX-302 0.1M HNO3 5

5 Au(III) SE CX-302 HCl Toluene 6

6 Zn(II) SFC CX-302 CO2 7

7 Am(III) Ex-Chrom. CX-301 HNO3 Silica-

Polym.

8

8 Zn(II) SE CX-923 HCl 9

9 Ag(I) BLM CX-471X HNO3 Alkenes +

Isodecanol

10

10 Co(II), Ni(II) SLM CX-

272,301,302

H2SO4 11

11 Cd(II) Ex-Chrom. CX-301 H3PO4 12

12 Am(III), Eu(III) SE CX-301 HNO3 Kerosene 13

13 Cr(III) SE CX-301 HCl Toluene 14

14 As(III), (V) SE CX-925 H2SO4 Toluene 15

15 V(IV) Ex-Chrom. CX-272,

CX-301

Silica Gel 16

16 Ln(III) HPCPC CX-302 HCl 17

17 Ti(IV) SE CX-272 HCl Xylene 18


12/20


24

18 Sc(III) SE CX 923,

CX 925

HCl 19

19 Rh, Pt, Pd SE CX 921 HCl Toluene 20

20 Os, Ru, Ir SE CX 921 HCl 21

21 Sc, Y, La, Gd SE CX 302 HCl 22

22 Ce, Th SE CX 923 H2SO4 n-hexane 23

23 Th(IV) SE CX 272 HNO3 24

24 U(VI) SE CX 272 Salicylate Toluene 25

25 Th(IV) SE CX 272 Salicylate Kerosene 26

26 Cu(II) SE CX 921 HCl Kerosene 27

27 Be(II) SE CX 921 H2SO4 Kerosene 28

28 Ln(III), Y(III) SE CX 925 HNO3 n-heptane 29

29 Eu(III) SE CX 921 HNO3 Toluene 30

30 Al(III) SE CX 272 H2SO4 Exxsol D-80 31

31 Zr(IV), Hf(IV) SE CX 921,

923, 925

HNO3 Kerosene 32

32 Pt(IV) SE CX 921,

925

HCl Toluene 33

33 La(III) SE CX 923 HNO3 Heptane 34

34 U(VI) SE CX 302 HNO3 Kerosene 35

35 Ln(III), Y(III) SE CX 925 HNO3 n-heptane 36

36 Ln(III), Sm(III) SE CX

921,923,925

HNO3 Kerosene 37

37 Cu(II) SE CX 272 H2SO4 38


13/20


25

38 Co(II), Ni(II) SE CX 272 H2SO4 DX 3641 39

39 Zn, Ni SE CX 272,

D2EHPA

H2SO4 Kerosene 40

40 Ni(II) SE CX 272 H2SO4 Kerosene 41

41 Cd(II) SE D2EHPA H2SO4 Toluene 42

42 Zr(IV) SE CX 272 HCl Toluene 43

443 CO(II) SE CX 272 CH3COONa Toluene 44

44 CU(II), Zn(II) SE CX 272,

Versatic 10

acid

H2SO4 Kerosene 45

45 Cd, Ni, Co SE Cx 272,

923, TOPS

HCl Kerosene 46

46 Al, Ni SE TOPS 99,

PC 88 A,

CX 272

H2SO4 Kerosene 47

47 Ga(III), Al(III) SE DBTPA,

DETPA

Kerosene 48

48 Be(II), Al(III) SE CX 921 Cyclohexane 49

49 Cd, Co, Ni SE CX 923 HCl Kerosene 50

50 Cd(II) SLM CX 923 HCl Solvesso

100

51

51 Ti(IV) SE CX 923 HCl Xylene 52

52 Mo(VI), W(VI) SE CX 923 HCl Toluene 53

53 U(VI) SE CX 923 HNO3 Xylene 54

54 Rh, Pt, Pd SE CX 921 HCl Toluene 55

55 Sc(III) SE CX 923, H2SO4 / HCl 56


14/20


26

925

57 Ln(III) SE CX 272 HClO4 57

58 Sn(II) SE CX 925 HCl Toluene 58

59 Zn(II) SE CX 923 NH4Cl Solvesso

100

59

60 U(VI), TH(IV) SE CX 923 HBr Toluene 60

61 U(VI), Th(IV) SE CX 923 HNO3 Xylene 61

62 U(VI),Th(IV),Ce(III),

Ce(IV), Y(III)

SE CX 923 Mineral

acids

Toluene 62

63 Th(IV) SE PC-88A Chloride Dodecane 63

64 Th(IV), Pr(III) SE CX 301,

302

Nitrate Kerosene 64

65 Th(IV) SE CX 272 Nitrate Kerosene 65

66 Ti(IV), V(V), Fe(III) SE CX 923 Kerosene 66

67 U(VI) SE CX 302 HNO3 Xylene 67

68 Sc(II), Zr(IV),

Th(IV), Fe(III),

Lu(III)

SE CX 302,

301

Acidic n-hexane 68

69 Mn(II) SE CX 302 Sulphate Kerosene 69

70 Pb(II) SE CX 302 Phosphoric

acid

Toluene 70

71 Au(III) SE CX 471X HCl 71

72 U(VI) SE CX 302,

Alamine

308, TBP,

HCl/ HNO3 Toluene 72

73 Ce(IV), Th(IV) SE CX 923 H2SO4 n-hexane 73


15/20


27

74 Zr(IV) SE CX 923 Mineral

acids

Toluene 74

75 Ce(III), La(III) SE LIX 54 NaCl n-heptane 75

76 Ti(IV) SE PC-88 A HClO4 Toluene 76

In the present study we have concentrated on the separation of

lanthanides and actinides using cyanex compounds. The lanthanides and

actinides show very close properties. Since, in these elements, the number of

electrons in the outermost as well as the penultimate shell remains the same

and is very difficult to separate from one another [77]. In the present work we

have developed a reliable analytical method for extraction and separation of

uranium, thorium and cerium. Still there were no reports for extraction and

separation of uranium and thorium using cyanex 272 from sodium salicylate

medium in toluene and kerosene respectively. We have also carried out the

study of extraction and separation of cerium using cyanex 923 from sodium

acetate medium in kerosene. In the present work we have studied various

parameters like, concentration of cyanex extractant, concentration of counter

anion, effect of diluents, tolerance limit, multicomponent mixture separation.

The developed methods we have applied for the extraction and separation of

metal ions from real and geological samples.


16/20


28

References

1. www.cytec.com

2. Mishra B.Y., Rokade M.D., Dhadke P.M., Ind. J. Chem., 39A(10),

1114, (2000).

3. Sarkar S.G., Dhadke P.M., Ind. J. Chem. Technol., 7(3),109 (2000).

4. Alguacil F.J., Martinez S., J. Chem. Technol. Biotechnol., 76(3), 298

(2001).

5. Mimura H., Ohta H., Hoshi H., Akiba K., Onodera Y., Sepn. Sci.

Technol., 36(1), 31 (2001).

6. Sarkar S.G., Dhadke P.M., J. Chin. Chem. Soc., 47(4B), 869(2000).

7. Tai C.Y., You G.S.,Chen S.L., J. Supercrit. Fluids., 18(3), 201 (2000).

8. Wei Y., Kumagai M., Takashima Y., Modolo G., Odoj R., Nucl.

Technol, 132(3), 413 (2000).

9. Regel M., Sastre A.M., Szymanowski J., Environ. Sci. Technol, 35(3),

630, (2001).

10. Vajda M., Schlosser S., Kovakova K., Chem. Pap., 54(6B), 423, (2000).

11. Gega, J., Walkowiak, W., Gajda, B., Sep. Purif. Technol., 22 and 23(1-

3), 551 (2001).

12. Reyes, L., H., Medina, I. S., Mendoza, R. N., Vazquez, J. R., Rodriguez,

M. A., Guibal, E., Ind. Eng. Chem. Res., 40(5), 1422 (2001).

13. Wang, Xing-Hai, Jiao, Rong-Zhou, Zhu, Yong-Jun, He Huaxue Yu

Fangshe Huaxue, 22(2), 94 (Chinese) (2000).

14. Khwaja, A.R., Singh, R., Tandon, S.N., J. Environ. Eng. (Reston, Va.),

126(4), 307 (2000).

15. Iberhan L., Wisniewski M., Pr. Nauk. Inst. Technol. Nieorg., Nawozow

Miner. Politech. Wroclaw., 48, 182(Polish) (2000).

16. Saily A., Tandon S.N., Indian J. Chem., Sect. A: Inorg., Bio-inorg.,

Phys., Theor. Anal. Chem., 38A (12), 1300 (1999).

17. Lu J.M., Gengxiang L.D., Hydrometallurgy., Proc. Int. Conf., 3rd ,

Edited by: Yang, Xianwan; Chen, Qiyuan; He, Aiping. International

Academic Publishers: Beijing, Peop. Rep. China. (English) 469 (1998).


17/20


29

18. Saji J., John, K.S., Reddy, M.L.P., Solvent Extr. Ion Exch., 18(5),

877(English) (2000).

19. Li D., Wang C., Hydrometallurgy, 48(3), 301(1998).

20. Mhaske A.A., Dhadke P.M., Hydromettalurgy, 61(2), 143 (2001).

21. Mhaske A.A., Dhadke P.M., Hydromettalurgy, 63(2), 207 (2002).

22. Wu D., Niu C., Li D., Bai Y., J. Alloys Comp., 347(1-2), 442 (2004).

23. Jun L., Zhenggui W., Dequin L., Gengxiang M., Zucheng J.,

Hydromettalurgy, 50(1), 77 (1998).

24. Karve M., Belwalkar S., Rajgor R., Indian J. Chem., 45A, 406 (2006).

25. Madane N. S., Nikam G. H., Mahanwar K. R., Mohite B. S., J.

Radioanal. Nucl. Chem., 288, 285-290 (2011).

26. Madane N. S., Mohite B. S., J. Radioanal. Nucl. Chem., 290, 649-654

(2011).

27. Mishra S., Devi N., Hydrometallurgy, 107(1-2), 29-33 (2011).

28. Zaki E. E., Ismail Z.H., Daoud J.A., Aly H.F., Hydrometallurgy, 80(4),

221-231 (2005).

29. Wei Li, Xianglan Wang Hui, Zhang Shulan, Meng, Deqian Li, J. Chem.

Technol. Biotech., 82, 376-381 (2007).

30. Awwad N.S., Gad H.M.H., Aly H.F., Intern. J. Phyc. Sci., 3(1), 22-27

(2008).

31. Tsakiridis P.E., Leonardou S.A., Hydrometallurgy, 80(1-2) 90-97

(2005).

32. Nayl A.A., El-Nadi Y.A., Daoud J.A., Sep. Sci. Technol., 44, 2956-2970

(2009).

33. Mhaske A.A., Dhadke P.M., J. Chem. Eng. Japan, 34(8), 1052-1055

(2001).

34. Tong Hul, Li De-qian, Wang Yi-ge, Lel Jai-heng, Wuhan Univ., J. Nat.

Sci., 8(3A), 871-874 (2003),

35. Rahman N.A., Daoud J.A., Aly H.F., J. Radioanal. Nucl. Chem., 25(3),

597-603 (2003).


18/20


30

36. Wei Li, xianglan Wang, Hui Zhang, Shulan Meng, Deqian li, J. Chem.

Tech. Biotech., 82, 376-381 (2007).

37. El-Nadi Y.A., El-Hefny N.E., Daoud J.A., Sol. Ext. Ion Exch., 25(2),

225-240(16) (2007).

38. Sole K.C., Hiskey J.B., Hydrometallurgy, 37(2), 129-147 (1995).

39. Fu Xun, Golding J.A., Sol. Ext. Ion Exch., 5(2), 205-226 (1987).

40. Silva J.E., Pavia A.P., Soares D., Labrincha A., Castro F., J. Hazard.

Mater., B120, 113-118 (2005).

41. Leszek, Gotfryd, Physicochemical problemes of meneral processing, 39,

117-128 (2005).

42. Asrafi F., Feyzbakhsh A., Entezari Heravi N., Intern. J. Chem. Tech.

Research, 1(3), 420-425 (2009).

43. Reddy B.R., Kumar J.R., Reddy A.V., Anal. Sci., 20(3), 501 (2004).

44. Nikam G.H., Mohite B. S., Res. J. Chem.sci., 2(1), 75-82 (2012).

45. Sinha M.K., Sahu S.K., Meshram P., Pandey B.D., Kumar V., 15th

Inter. Confer. On “ Non-ferrous metals” held at Hotel Oberoi Grand,

Kolkata, 8-9th July 2011.

46. Neela P.D., eprints.csirexplorations.com/97/1/Abstract.doc , 1-14

(2007).

47. Rao S.V., Yang D.H., Sohan J.S., Kim S. K., The scientific world J .,

2012, Doi: 10.1100/2012/286494 (2012).

48. Imre Toth, Emo Brucher, Talanta, 37(12), 1175-1178, (1990).

49. Mishra B.Y., Dhadke P.M., Sep. Sci. Tech., 33(11), 1681-1692 (1998).

50. Reddy B.R., Priya D.N., J. Power Sources, 161(2), 1428-1434 (2006).

51. Rodriguez A.M., Gomez-Limon D., Alguacil F.J.,

digital.csic.es/bitstream/10261/36800/1/cdmem3.doc P.1-10 (2005).

52. Saji Jihn k., Saji J., Reddy M.L.P., Ramamohan t.R., Rao T.P.,

Hydrometallurgy, 1(4), 9-18 (1999).

53. Talla R.G., Gaikwad S.U., Pawar S.D., Indian J. Chem. Tech., 17, 436-

440 (2010).


19/20


31

54. Reddy M.L.P., Vani T.J.S., P.Rama S.Reddy, Reddy Krishna L., Reddy

A.V.R., Rao Krishna K.S.V., Int.J. Res. Chem. Environ., 1(1), 55-59

(2011).

55. Mhaske A.A., Dhadke P.M., Hydrometallurgy, 61(2), 143-150 (2001).

56. Deqian Li, Chun Wang, Hydrometallurgy, 48(3), 301-312 (1998).

57. Swain B., Otu E.O., Sep. Sci. Purif. Tech., 83, 82-90, (2011).

58. Mhaske A., Dhadke P.M., Sol. Ext. Ion Exch., 20(1), 127-137 (2002).

59. Franciso Jose Alguacil, Susana Martinez, J. Chem. Eng. Japan, 34(11),

1439-1442 (2001).

60. Ghag, S.M., Pawar S.D., J. Serb. Chem. Soc., 75(11), 1549-1557 (2010).

61. Sahu S.K., Reddy M.L.P., Ramamohan T.R., Chakravortty V.,

Radiochim. Acta, 88, 33-37 (2000).

62. Gupta B., Malik P., Deep A., J. Radioanal. Nucl. Chem., 251(3), 451-

456 (2002).

63. Singh D.K., Singh H., Gupta C.K., Mathur J.N., J. Radioanal. Nucl.

Chem., 250(1), 123-128 (2001).

64. El-Hefny N.E., Daoud J.A., J. Radioanal. Nucl. Chem., 26(2), 357-363

(2004).

65. El-Dessouky S.I., El-hefny N.E., Daoud J.A., Radiochim. Acta, 92(1),

25-29 (2004).

66. Remya P.N., Reddy M.L., J. Chem. Tech. Biotech., 79(7), 734-741

(2004).

67. Karve M., Gaur C., J. Radioanal. Nucl. Chem., 273(2), 405-409 (2007).

68. Wang C., Li D., Sol. Ext. Ion Exch., 13(3), 503-523 (1995).

69. Devi N.B., Mishra S., Hydrometallurgy, 103, 118-123 (2010).

70. Menoyo B., Elizalde M.P., Almela A., Sol. Ext. Ion Exch., 19(4), 677-

698 (2001).

71. Martinez S., Navarro P., Sastre A.M., Alguacil F.J., Hydrometallurgy,

43(1-3), 1-12 (1996).

72. Senol A., J. Radioanal. Nucl. Chem., 258(2), 361-372 (2003).


20/20


73. Lu Jun, Wei zhenggui, Li Deqian, Ma Gengxiang, Jiang Zucheng,

Hydrometallurgy, 50(1), 77-87 (1998).

74. Gupta B., Malik P., Mudhar N., Sol. Ext. Ion Exch., 23(3), 345-357

(2005).

75. Urbanski T.S., Fomari P., Abbruzzese C., Hydrometallurgy, 40(1-2),

169-179 (1996).

76. Singh R.K., Dhadke P.M., J. Serb. Chem. Soc., 67(7), 507-521 (2002).

77. Puri B.R., Sharma L.R., Kalia K.C., “Principles of Inorganic

Chemistry”, 13th

ed., 705-719 (2006).

cyanex introduction

Documents