chapter - i: introductionshodhganga.inflibnet.ac.in/bitstream/10603/11765/2/02_table of cont… ·...

INDEX

School of Science, SVKM’s NMIMS University

INDEX

Abbreviations ...................................................................................................................... i

List of figures .....................................................................................................................iv

List of tables .......................................................................................................................vi

CHAPTER - I: Introduction

I.1 Background .............................................................................................................. 1

I.1.1 Man and metals ............................................................................................ 1

I.1.2 Need for separation techniques ..................................................................... 1

I.1.3 Choice of analytical method ......................................................................... 2

I.2 Motivation ................................................................................................................ 3

I.2.1 Nickel .......................................................................................................... 4

I.2.2 Cobalt .......................................................................................................... 9

I.2.3 Zinc ............................................................................................................ 14

I.3 Scope and objectives of the thesis ........................................................................... 19

I.4 Organization of thesis ............................................................................................. 20

I.5 Works cited............................................................................................................. 21

CHAPTER - II: Theoretical

II.1 Introduction to gravimetric analysis ........................................................................ 24

II.2 Precipitative gravimetry .......................................................................................... 25

II.3 Ideal conditions for precipitative gravimetry ........................................................... 25

II.4 Operations involved in precipitative gravimetry ...................................................... 25

II.4.1 Sample pretreatment ............................................................................... 26

II.4.2 Precipitation ........................................................................................... 26

II.4.2.1 Factors affecting precipitation ................................................................. 27

II.4.2.2 Mechanism of precipitation ..................................................................... 28

II.4.2.3 Purity of the analytical precipitate ........................................................... 29

II.4.2.4 Types of precipitate ................................................................................ 30

II.4.3 Digestion or ageing ................................................................................ 30

INDEX


II.4.4 Testing for completion of precipitation .................................................. 30

II.4.5 Filtration................................................................................................ 31

II.4.6 Washing of precipitate ........................................................................... 31

II.4.7 Drying and ignition of precipitates ......................................................... 31

II.4.8 Weighing ............................................................................................... 32

II.4.9 Calculations ........................................................................................... 32

II.5 Errors in chemical analysis..................................................................................... 33

II.6 Significant developments in gravimetry ................................................................. 35

II.7 Applicability of gravimetry and its advantages ....................................................... 35

II.8 Problems associated with the practice of gravimetry ............................................... 36

II.9 Selection of organic ligand ..................................................................................... 37

II.10 2-Mercaptobenzothiazole ........................................................................................ 37

II.10.1 Introduction ............................................................................................ 37

II.10.2 Literature review .................................................................................... 38

II.11 Works cited ............................................................................................................ 40

CHAPTER - III: General experimental

III.1 Glasswares .............................................................................................................. 44

III.2 Balance ................................................................................................................... 44

III.3 pH meter ................................................................................................................. 44

III.4 Preparation of double distilled water ....................................................................... 44

III.5 Chemicals and reagents ........................................................................................... 44

III.6 Treatment of G3 sintered-bed crucible..................................................................... 45

III.7 Standardization of acids and alkalies ....................................................................... 45

III.8 Purification of solvents ........................................................................................... 45

III.9 Complex matrices for spiked and actual samples ..................................................... 45

III.10 Preparation of solutions of anions ........................................................................... 46

III.11 Preparation and standardization of solution of cations ............................................. 46

III.12 Works cited ............................................................................................................ 64

INDEX


CHAPTER - IVa: Development of a new, rapid and selective method for the separation

and estimation of nickel(II) by (substoichiometric) precipitation technique employing

2-mercaptobenzothiazole in ethyl alcohol

IVa.1 Introduction ......................................................................................................... 65

IVa.2 Experimental ....................................................................................................... 66

IVa.2.1 Procedure ........................................................................................... 66

IVa.2.2 Optimization of parameters of precipitation ........................................ 66

IVa.2.3 Study of interference of anions and cations using excess of reagent ..... 67

IVa.2.4 Evaluation of stoichiometry of metal to reagent .................................. 67

IVa.2.5 Study of interference of cations at substoichiometric level .................. 67

IVa.2.6 Metal analysis in the complex ............................................................. 68

IVa.3 Results and discussion ......................................................................................... 68

CHAPTER - IVb: Application of the developed method for the estimation of nickel(II)

with 2-mercaptobenzothiazole in ethyl alcohol in spiked and actual samples

IVb.1 Introduction ......................................................................................................... 92

IVb.2 Experimental ....................................................................................................... 92

IVb.2.1 Estimation of Ni(II) in spiked samples ................................................ 92

IVb.2.2 Estimation of Ni(II) in actual samples ................................................. 95

IVb.3 Results and discussion ......................................................................................... 96

IVb.4 Summary and conclusions .................................................................................... 99

IVb.5 Works cited ....................................................................................................... 101

CHAPTER - Va: Development of a new, rapid and selective method for the separation

and estimation of cobalt(II) by (substoichiometric) precipitation technique employing


Va.1 Introduction ....................................................................................................... 104

Va.2 Experimental ..................................................................................................... 105

Va.2.1 Procedure ......................................................................................... 105

Va.2.2 Optimization of parameters of precipitation ...................................... 105

INDEX


Va.2.3 Study of interference of anions and cations using excess of reagent ... 105

Va.2.4 Evaluation of stoichiometry of metal to reagent ................................ 106

Va.2.5 Study of interference of cations at substoichiometric level ................ 106

Va.2.6 Metal analysis in the complex ........................................................... 106

Va.3 Results and discussion ....................................................................................... 107

CHAPTER - Vb: Application of the developed method for the estimation of

cobalt(II) with 2-mercaptobenzothiazole in ethyl alcohol in spiked and actual samples

Vb.1 Introduction ....................................................................................................... 131

Vb.2 Experimental ..................................................................................................... 132

Vb.2.1 Estimation of Co(II) in spiked samples.............................................. 132

Vb.2.2 Estimation of Co(II) in actual samples .............................................. 134

Vb.3 Results and discussion ....................................................................................... 137

Vb.4 Summary and conclusions .................................................................................. 140

Vb.5 Works cited ....................................................................................................... 143

CHAPTER - VIa: Development of a new, rapid and selective method for the separation

and estimation of zinc(II) by (substoichiometric) precipitation technique employing


VIa.1 Introduction ....................................................................................................... 145

VIa.2 Experimental ..................................................................................................... 146

VIa.2.1 Procedure ......................................................................................... 146

VIa.2.2 Optimization of parameters of precipitation ...................................... 146

VIa.2.3 Study of interference of anions and cations using excess of reagent ... 146

VIa.2.4 Evaluation of stoichiometry of metal to reagent ................................ 147

VIa.2.5 Study of interference of cations at substoichiometric level ................ 147

VIa.2.6 Metal analysis in the complex ........................................................... 147

VIa.3 Results and discussion ....................................................................................... 148

INDEX


CHAPTER - VIb: Application of the developed method for the estimation of zinc(II)

with 2-mercaptobenzothiazole in ethyl alcohol in spiked and actual samples

VIb.1 Introduction ....................................................................................................... 172

VIb.2 Experimental ..................................................................................................... 172

VIb.2.1 Estimation of Zn(II) in spiked samples .............................................. 172

VIb.2.2 Estimation of Zn(II) in actual samples............................................... 174

VIb.3 Results and discussion ....................................................................................... 178

VIb.4 Summary and conclusions .................................................................................. 181

VIb.5 Works cited ....................................................................................................... 183

CHAPTER - VII: Sequential separation of Zinc(II), Cobalt(II) and Nickel(II) employing


VII.1 Introduction ....................................................................................................... 186

VII.2 Experimental ..................................................................................................... 187

VII.2.1 Procedure ......................................................................................... 187

VII.2.2 Study of interference of cations ......................................................... 188

VII.2.3 Sequential separation and estimation of Zn(II), Co(II) and Ni(II) in actual samples of ores ...................................................................... 189

VII.3 Results and discussion ....................................................................................... 190

VII.4 Summary and conclusions .................................................................................. 197

VII.5 Works cited ....................................................................................................... 199

ANNEXURES

Bibliography ........................................................................................................................ I

Paper presentation and publications .................................................................................. XII

Synopsis ......................................................................................................................... XIII

ABBREVIATIONS

LIST OF FIGURES

LIST OF TABLES

ABBREVIATIONS

School of Science, SVKM’s NMIMS University Page i

ABBREVIATIONS

AgCl Silver chloride

AR Analytical reagent

BARC Bhabha Atomic Research Centre

BiOCl Bismuth oxychloride

cm Centimetre

Conc. Concentrated

Dil. Dilute

DMG Dimethylglyoxime

g Gram

G3 sintered crucible Crucible with sintered disc of grade 3 having pore size

15-40 microns

GR Guaranteed reagent

H2S Hydrogen sulfide

H2SO4 Sulfuric acid

HCl Hydrogen chloride

HEV’s Hybrid electric vehicles

Hg2Cl2 Mercurous chloride

ABBREVIATIONS

School of Science, SVKM’s NMIMS University Page ii

HNO3 Nitric acid

hr Hour

K Kelvin

ITALAB Industrial Testing and Analytical Laboratory

KSCN Potassium thiocyanate

lbs Pounds

M Molarity

2-MBT or C7H5NS2 2-Mercaptobenzothiazole

mg Milligram

min Minutes

mL Millilitre

Mol Mole

N Normality

NH3 Ammonia

NH4Cl Ammonium chloride

(NH4)2HPO4 Diammonium hydrogen phosphate

NH4OH Ammonium hydroxide

NH4SCN Ammonium thiocyanate

ABBREVIATIONS

School of Science, SVKM’s NMIMS University Page iii

pH Negative base-10 logarithmic value of the hydrogen ion

concentration

pKa Negative base-10 logarithm of the acid dissociation

constant of a solution

s seconds

SO2 Sulfur dioxide

USP United States Pharmacopeia

WC Tungsten carbide

w.r.t With respect to

oC Degree Celsius

LIST OF FIGURES

School of Science, SVKM’s NMIMS University Page iv

LIST OF FIGURES

Figure No. Title Pg. No.

Figure I-I Position of nickel, cobalt and zinc in periodic table 4

Figure I-II Crystal structure of nickel 6

Figure I-III End uses of nickel 7

Figure I-IV Crystal structure of cobalt 10

Figure I-V End uses of cobalt 13

Figure I-VI Crystal structure of zinc 15

Figure I-VII End uses of zinc 18

Figure II-I Interconversion of thione to thiol 38

Figure II-II Structural representation of thiol ion 38

Figure IVa-I Effect of pH on the precipitation of Ni(II) with

2-MBT in ethyl alcohol

72

Figure IVa-II Effect of variation of time of digestion on the

precipitation of Ni(II) with 2-MBT in ethyl alcohol

74

Figure IVa-III Effect of amount of reagent (2-MBT in ethyl alcohol)

on the precipitation of Ni(II)

77

LIST OF FIGURES

School of Science, SVKM’s NMIMS University Page v

Figure No. Title Pg. No.

Figure IVa-IV Substoichiometric precipitation of Ni(II) with 2-MBT

in ethyl alcohol

86

Figure Va-I Effect of pH on the precipitation of Co(II) with


111

Figure Va-II Effect of variation of time of digestion on the

precipitation of Co(II) with 2-MBT in ethyl alcohol

113

Figure Va-III Effect of amount of reagent (2-MBT in ethyl alcohol)

on the precipitation of Co(II)

115

Figure Va-IV Substoichiometric precipitation of Co(II) with 2-MBT

in ethyl alcohol

124

Figure VIa-I Effect of pH on the precipitation of Zn(II) with


152

Figure VIa-II Effect of variation of time of digestion on the

precipitation of Zn(II) with 2-MBT in ethyl alcohol

154

Figure VIa-III Effect of amount of reagent (2-MBT in ethyl alcohol)

on the precipitation of Zn(II)

156

Figure VIa-IV Substoichiometric precipitation of Zn(II) with 2-MBT

in ethyl alcohol

165

LIST OF TABLES

School of Science, SVKM’s NMIMS University Page vi

LIST OF TABLES

Table No. Title Pg. No.

Table IVa-1 Standardization of Ni(II) solution with

dimethylglyoxime

69

Table IVa-2 Effect of pH on the precipitation of Ni(II) with 2-MBT

in ethyl alcohol

70

Table IVa-3 Effect of variation of time of digestion on the


73

Table IVa-4 Effect of amount of reagent (2-MBT in ethyl alcohol)

on the precipitation of Ni(II)

76

Table IVa-5 Interference of salt of different anions on the


78

Table IVa-6 Interference of different cations on the precipitation of

Ni(II) with excess of 2-MBT in ethyl alcohol

80

Table IVa-7 Substoichiometric precipitation of Ni(II) with 2-MBT

in ethyl alcohol

85

Table IVa-8 Interference of different cations on the

substoichiometric precipitation of Ni(II) with 2-MBT

in ethyl alcohol

87

Table IVa-9 Estimation of the amount of Ni(II) in nickel

2-mercaptobenzothiazole complex by

dimethylglyoxime method

91

LIST OF TABLES

School of Science, SVKM’s NMIMS University Page vii


Table IVb-1 Recovery of Ni(II) in complex materials spiked with

Ni(II)

97

Table IVb-2 Determination of the amount of Ni(II) in actual

samples

98

Table Va-1 Standardization of Co(II) solution as tripotassium

hexanitrocobaltate

108

Table Va-2 Effect of pH on the precipitation of Co(II) with


109

Table Va-3 Effect of variation of time of digestion on the


112

Table Va-4 Effect of amount of reagent (2-MBT in ethyl alcohol)

on the precipitation of Co(II)

114

Table Va-5 Interference of salt of different anions on the


117

Table Va -6 Interference of different cations on the precipitation of

Co(II) with excess of 2-MBT in ethyl alcohol

119

Table Va -7 Substoichiometric precipitation of Co(II) with 2-MBT

in ethyl alcohol

123

Table Va-8 Interference of different cations on the

substoichiometric precipitation of Co(II) with 2-MBT

in ethyl alcohol

126

LIST OF TABLES

School of Science, SVKM’s NMIMS University Page viii


Table Va-9 Estimation of the amount of Co(II) in cobalt

2-mercaptobenzothiazole complex by tripotassium

hexanitrocobaltate method

130

Table Vb-1 Recovery of Co(II) in complex materials spiked with

Co(II)

138

Table Vb-2 Determination of the amount of Co(II) in actual

samples

139

Table VIa-1 Standardization of Zn(II) solution as zinc

pyrophosphate

149

Table VIa-2 Effect of pH on the precipitation of Zn(II) with 2-MBT

in ethyl alcohol

150

Table VIa-3 Effect of variation of time of digestion on the


153

Table VIa-4 Effect of amount of reagent (2-MBT in ethyl alcohol)

on the precipitation of Zn(II)

155

Table VIa-5 Interference of salt of different anions on the


158

Table VIa -6 Interference of different cations on the precipitation of

Zn(II) with excess of 2-MBT in ethyl alcohol

160

Table VIa -7 Substoichiometric precipitation of Zn(II) with 2-MBT

in ethyl alcohol

164

LIST OF TABLES

School of Science, SVKM’s NMIMS University Page ix


Table VIa-8 Interference of different cations on the

substoichiometric precipitation of Zn(II) with 2-MBT

in ethyl alcohol

167

Table VIa-9 Estimation of the amount of Zn(II) in zinc

2-mercaptobenzothiazole complex by zinc

pyrophosphate method

171

Table VIb-1 Recovery of Zn(II) in complex materials spiked with

Zn(II)

179

Table VIb-2 Determination of the amount of Zn(II) in actual

samples

180

Table VII-1 Recovery of Zn(II) in a mixture of Zn(II), Ni(II) and

Co(II) employing 2-MBT in ethyl alcohol

191

Table VII-2 Recovery of Ni(II) in a mixture of Zn(II), Ni(II) and


192

Table VII-3 Recovery of Co(II) in a mixture of Zn(II), Ni(II) and


193

Table VII-4 Recovery of Zn(II) in ore ‘Z’ and ore ‘R’ 194

Table VII-5 Recovery of Ni(II) in ore ‘Z’, ore ‘S’ and ore ‘R’ 195

Table VII-6 Recovery of Co(II) in ore ‘Z’ and ore ‘S’ 196

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