Analytical Chemistry of Niobium and Tantalum (eBook)

Front Cover 1
Analytical Chemistry of Niobium and Tantalum 4
Copyright Page 5
Table of Contents 6
CHAPTER I. INTRODUCTION 8
HISTORY OF NIOBIUM AND TANTALUM 10
MINERALS OF NIOBIUM AND TANTALUM 10
CONCENTRATION OF EARTH ACID MINERALS 11
SAMPLING 11
METALLURGY 11
USES OF NIOBIUM 14
USES OF TANTALUM 15
REFERENCES 16
CHAPTER II. PROPERTIES OF NIOBIUM AND ITS COMPOUNDS 18
PHYSICAL PROPERTIES OF NIOBIUM 18
CHEMICAL PROPERTIES OF NIOBIUM 19
REFERENCES 20
CHAPTER III. PROPERTIES OF TANTALUM AND ITS COMPOUNDS 21
PHYSICAL PROPERTIES OF TANTALUM 21
CHEMICAL PROPERTIES OF TANTALUM 22
REFERENCES 23
CHAPTER IV. COMPOUNDS OF NIOBIUM AND TANTALUM OF ANALYTICAL INTEREST 24
REFERENCES 26
CHAPTER V. DETECTION AND IDENTIFICATION 27
MARIGNAC TEST FOR TANTALUM IN MIXED ACIDS< D
REFERENCES 33
CHAPTER VI. DISSOLUTION OF THE SAMPLE, PRECIPITATION SEPARATIONS AND GRAVIMETRIC DETERMINATIONS 34
POTASSIUM BISULFATE-TARTARIC ACID METHOD OF SCHOELLER 34
TARTRATE HYDROLYSIS FOR PRECIPITATION OF THE MAJOR FRACTION OF THE TANTALIC, NIOBIC AND TUNGSTIC ACIDS 35
RECOVERY OF UNPRECIPITATED EARTH ACIDS FROM THE TARTARIC ACID HYDROLYSIS FILTRATE BY THE TANNIN PRECIPITATION METHOD OF SCHOELLER 35
PURIFICATION OF THE EARTH ACIDS PRECIPITATE 36
SEPARATION OF TANTALUM, NIOBIUM AND TITANIUM BY THE OXALIC ACID-TANNIN METHOD, FROM ZIRCONIUM, HAFNIUM, THORIUM, ALUMINUM, BERYLLIUM AND URANIUM, SMALL QUANTITIES OF IRON, MANGANESE AND CHROMIUM, AND PARTIAL REMOVAL OF TUNGSTEN 37
THE SEPARATION OF TANTALUM FROM NIOBIUM BY TANNIN PRECIPITATION 40
TANNIN GRAVIMETRIC METHOD FOR THE DETERMINATION OF TANTALUM AND NIOBIUM IN THEIR MIXTURES—MODIFICATION BY BHATTACHARYA 41
TANTALUM, NIOBIUM AND TITANIUM GRAVIMETRIC DETERMINATION BY TANNIN, SEPARATION OF TANTALUM FROM NIOBIUM AND COLORIMETRIC DETERMINATION OF TITANIUM IN EACH— BHATTACHARYAÜ9) 42
HYDROFLUORIC-HYDROCHLORIC-PHOSPHORIC-TARTARIC ACIDS METHOD FOR SOLUTION OF SAMPLES—FAYE 42
SEPARATION OF NIOBIUM PENTOXIDE FROM LOW-GRADE ORES—SILICIC ACID AS CARRIER—MILNER AND SMALES 43
GRAVIMETRIC DETERMINATION OF TANTALUM USING SELENOUS ACID—GRIMALDI AND SCHNEPFE 44
GRAVIMETRIC COMBINED TANTALUM AND NIOBIUM DETERMINATION BY PRECIPITATION WITH SELENOUS ACID, SEPARATION FROM OTHER ELEMENTS— GRIMALDI AND SCHNEPFE 45
SOLUTION AND SEPARATION IN SAMPLES (SOILS FROM SUKULU, UGANDA, AND GRANITE FROM NIGERIA) CONTAINING ^g AMOUNTS OF NIOBIUM (0.2 PER CENT) AND TANTALUM (0.02 PER CENT)—TANNIC ACID-SILICA CARRIER METHOD—MILNER AND SMALES 46
MANGANESE DIOXIDE AS A COLLECTOR FOR SMALL AMOUNTS OF NIOBIUM—APPLICATION TO LOW-GRADE ORES CONTAINING TITANIUM, TUNGSTEN, MOLYBDENUM AND CHROMIUM, AND THE THIOCYANATE PHOTOMETRIC METHOD—DOROSH 48
GRAVIMETRIC DETERMINATION OF NIOBIUM IN THE PRESENCE OF TUNGSTEN BY PRECIPITATION WITH CUPFERRON—PONOMAYEV AND SHESKOV'SKAYA 48
SEPARATION OF NIOBIUM AND TANTALUM FROM ZIRCONIUM WITH SALICYLHYDROXAMIC ACID— MAJUMDAR AND MUKHERJEE 50
SEPARATION OF NIOBIUM, TANTALUM, TITANIUM AND ZIRCONIUM, APPLICATION OF THE REAGENTS, PYROGALLOL, N-BENZOYL-N-PHENYLHYDROXYLAMINE, SALICYLHYDROXAMIC ACID AND CUPFERRON TO THE QUANTITATIVE RECOVERY OF EACH METAL— MAJUMDAR AND MUKHERJEE 50
SEPARATION AND GRAVIMETRIC DETERMINATION OF NIOBIUM, TANTALUM OR THEIR MIXTURES FROM OTHER IONS WITH HYDROXAMIC ACIDS 52
SEPARATION OF NIOBIUM, TANTALUM, TITANIUM AND ZIRCONIUM FROM IRON BY PRECIPITATION WITH HEXAMETHYLENETETRAMINE—TRAUBE) 53
GRAVIMETRIC DETERMINATION OF NIOBIUM IN THE PRESENCE OF LARGE AMOUNTS OF TITANIUM— PONOMAREV AND SHESKOV'SKAYA 54
PYROGALLOL PRECIPITATION SEPARATION OF NIOBIUM AND TANTALUM FROM TITANIUM AND ZIRCONIUM, BENZENEARSONIC ACID PRECIPITATION AND DETERMINATION OF THE MIXED ACIDS IN MINERALS AND ORES—ALIMARIN AND FRID 55
SEPARATION OF NIOBIUM AND TANTALUM WITH BENZENEARSONIC ACID—MAJUMDAR AND MUKHERJEE 56
GRAVIMETRIC DETERMINATION OF NIOBIUM IN A MIXTURE OF NIOBIUM, TANTALUM, TITANIUM, TIN AND ANTIMONY WITH 8-HYDROXYQUINOLINE AS PRECIPITANT—BELEKAR AND ATHAVALE 57
SEPARATION AND GRAVIMETRIC DETERMINATION OF NIOBIUM AND TANTALUM FROM TITANIUM. REDUCTION OF THE TITANIUM BEFORE HYDROLYTIC PRECIPITATION OF THE EARTH ACIDS—OSHMAN 58
GRAVIMETRIC DETERMINATION OF TANTALUM WITH n-PROPYLARSONIC ACID IN THE PRESENCE OF NIOBIUM, TITANIUM AND TUNGSTEN—DUPRAW 60
SEPARATION OF NIOBIUM FROM TANTALUM BY SODIUM PYROSULFATE FUSION AND SELECTIVE SOLUTION OF NIOBIUM IN SULFURIC ACID—McCUISTION, SCHULZ AND JENSEN 60
SEPARATION AND DETERMINATION OF MIXED EARTH ACIDS BY THE SODIUM PEROXIDE FUSION-HYDROCHLORIC ACID DIGESTION METHOD APPLIED TO COLUMBITE-TANTALITE ORES—McCUISTION, SCHULZ AND JENSEN 61
SEPARATION OF NIOBIUM AND TANTALUM WITH CUPFERRON—MAJUMDAR AND CHOWDHURY 62
GRAVIMETRIC DETERMINATION OF TANTALUM BY PRECIPITATION WITH N-BENZOYL-N-PHENYLHYDROXYLAMINE FROM A FLUORIDE SOLUTION WITH NO INTERFERENCE FROM NIOBIUM, TITANIUM AND OTHER IONS—MOSHIER AND SCHWARBERG 63
SEPARATION OF TANTALUM FROM NIOBIUM BY PRECIPITATION WITH SODIUM HYPOPHOSPHITE FROM OXALATE SOLUTION—ALIMARIN AND FRID,< 48) STOCKHAUSEN AND ZAIL,(49) AND ALIMARIN AND BUROVA
GRAVIMETRIC DETERMINATION OF NIOBIUM IN RUSTLESS AND HEAT-RESISTANT STEELS— BAGSHAWE AND ELWELL 66
GRAVIMETRIC ANALYSIS OF TUNGSTEN-TANTALUM-RHENIUM ALLOYS—REEDED 68
PURIFICATION OF EARTH ACIDS FROM IRON AND MOLYBDENUM 69
DETERMINATION OF NIOBIUM AND TANTALUM BY PRECIPITATION FROM HOMOGENEOUS SOLUTION —TOMICEK 70
REFERENCES 71
CHAPTER VII. SEPARATIONS BY SOLVENT EXTRACTION 74
SEPARATION OF NIOBIUM BY EXTRACTION OF ITS CUPFERRATE 75
DETERMINATION OF NIOBIUM OR TANTALUM IN URANIUM- AND ZIRCONIUM-BASE ALLOYS. APPLICATION OF SOLVENT EXTRACTION^) 77
SOLVENT EXTRACTION SEPARATION OF PURE TANTALUM AND PURE NIOBIUM FROM FISSION PRODUCTS—STEVENSON AND HICKS 78
SOLVENT EXTRACTION OF NIOBIUM FROM FISSION PRODUCTS—HICKS AND GILBERT 80
EXTRACTION SEPARATION OF NIOBIUM, TANTALUM AND ZIRCONIUM BY ACETONE AND MORIN— RAO, SARMA AND RAO 81
SEPARATION OF TANTALUM FROM TITANIUM AND NIOBIUM BY EXTRACTION 81
SEPARATION OF NIOBIUM AND TANTALUM BY HYDROCHLORIC ACID EXTRACTION OF A KETONE SOLUTION OF THEIR ANHYDROUS MIXED PENTACHLORIDES 82
SEPARATION OF TANTALUM AND NIOBIUM BY COUNTERCURRENT LIQUID-LIQUID EXTRACTION. PRODUCTION METHOD OF WERNING, HIGBIE, GRACE, SPEECE AND GILBERT 83
EXTRACTION AND PHOTOMETRIC DETERMINATION OF TANTALUM WITH PHENYLFLUORONE 85
PHOTOMETRIC DETERMINATION OF NIOBIUM IN MIXED ACIDS BY PHENYLFLUORONE AFTER SOLVENT EXTRACTION WITH METHYL ISOBUTYL KETONE— SENISE AND SANT' AGOSTINO 87
DETERMINATION OF TANTALUM IN URANIUM AND PLUTONIUM METALS BY SOLVENT EXTRACTION AND HYDROQUINONE COLORIMETRIC METHOD— WATERBURY AND BRICKER 88
PHOTOMETRIC DETERMINATION OF NIOBIUM AND MOLYBDENUM WITH 8-QUINOLINOL IN URANIUM-BASE ALLOYS—MOTOJIMA AND HASHITANI 91
SOLVENT EXTRACTION OF THE 5,7-DICHLORO-8-QUINOLINOL COMPLEX OF NIOBIUM AND TANTALUM—BRUNINX AND IRVINE 93
SOLVENT EXTRACTION SEPARATION AND DETERMINATION OF NIOBIUM AND TANTALUM IN ORES WITH PYROCATECHOL-n-BUTANOL— ZAIKOVSKII 94
SEPARATION OF NIOBIUM AND TANTALUM BY EXTRACTION—ALIMARIN, PETRUKHIN AND CHIEH 95
SOLVENT EXTRACTION SEPARATION OF NIOBIUM AND TANTALUM BY A XYLENE SOLUTION OF METHYLDIOCTYLAMINE 96
SOLVENT EXTRACTION OF NIOBIUM AND TANTALUM WITH TRIBUTYL PHOSPHATE 97
SOLVENT EXTRACTION SEPARATION OF PALLADIUM FROM NIOBIUM AND ZIRCONIUM—DUKE AND STAWPERT.(33) APPLICATION TO BINARY ALLOYS 98
REFERENCES 98
CHAPTER VIII. ION EXCHANGE AND CHROMATOGRAPHY, SEPARATIONS AND DETERMINATIONS 100
ANION EXCHANGE SEPARATION OF MACRO-QUANTITIES OF TITANIUM, TUNGSTEN, MOLYBDENUM AND NIOBIUM AND ITS APPLICATION TO STEELS AND TITANIUM ALLOYS 102
SEPARATION BY ANION-EXCHANGE. DETERMINATION OF TITANIUM, ZIRCONIUM, NIOBIUM AND TANTALUM IN STEELS—HAGUE AND MACHLANdD 103
ION EXCHANGE SEPARATION OF TITANIUM, NIOBIUM, AND TANTALUM. SHORT COLUMN METHOD WITH AMBERLITE IRA-400 RESIN—WETLESEN 105
ION EXCHANGE SEPARATION OF TITANIUM, ZIRCONIUM, VANADIUM, NIOBIUM, TANTALUM, MOLYBDENUM, AND TUNGSTEN. DETERMINATION IN STEELS—BANDI, BUYOK, LEWIS, AND MELNICK 106
CHROMATOGRAPHY ON PAPER 107
NIOBIUM AND TANTALUM DETERMINATION IN LOW-GRADE PHOSPHATE ORES, APPLICATION OF PAPER-COLUMN CHROMATOGRAPHY TO THEIR SEPARATION—BURSTALL AND WILLIAMS 108
DETERMINATION OF NIOBIUM AND TANTALUM IN MEDIUM- AND HIGH-GRADE ORES—WILLIAMS 109
PREPARATION OF SAMPLE SOLUTIONS FOR PAPER STRIP CHROMATOGRAPHY 114
DETERMINATION OF NIOBIUM AND TANTALUM IN STEEL BY PAPER CHROMATOGRAPHY AND PHOTOMETRIC MEASUREMENT OF THEIR OXINATES —SCOTT AND MAGEE 115
ASCENDING CHROMATOGRAPHY ON PAPER STRIPS WAS APPLIED BY MOROSHKINA AND YÜ< 25>
ELECTROPHORETIC METHOD OF SEPARATION OF NIOBIUM AND TANTALUM 117
ION EXCHANGE SEPARATION OF NIOBIUM AND TANTALUM IN OXALIC ACID SOLUTION—GILLIS, EECKHOUT, CORNAND, AND SPEECKE 118
ELUTION OF NIOBIUM AND TANTALUM WITH CHLORIDE-FLUORIDE MIXTURES 118
REFERENCES 120
CHAPTER IX. COLORIMETRIC DETERMINATIONS WITH HYDROGEN PEROXIDE 121
SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF NIOBIUM AND TANTALUM WITH HYDROGEN PEROXIDE—PALILLA, ADLER AND HISKEY 123
PERNIOBIC ACID-SULFURIC ACID-ORTHOPHOSPHORIC ACID SPECTROPHOTOMETRIC METHOD— TELEP AND BOLTZ 124
ASSAY OF HIGH PURITY NIOBIUM METAL BY DIFFERENTIAL SPECTROPHOTOMETRY USING A MODIFIED PERNIOBIC ACID-SULFURIC ACID-ORTHOPHOSPHORIC ACID METHODÜ6)-BACKER, WIEDERKEHR AND GOWARD 125
REFERENCES 126
CHAPTER X. COLORIMETRIC DETERMINATIONS WITH POLYPHENOLS 128
COLORIMETRIC DETERMINATION OF TANTALUM AND NIOBIUM WITH POLYPHENOLS 128
PYROGALLOL AS A COLORIMETRIC REAGENT FOR NIOBIUM AND TANTALUM 128
PHOTOMETRIC DETERMINATION OF TANTALUM IN TITANIUM ALLOYS BY MEANS OF PYROGALLOL— NORWITZ, CODELL AND MIKULA 129
PHOTOMETRIC DETERMINATION OF NIOBIUM AND TANTALUM IN STEELS—EDER 131
DETERMINATION OF TANTALUM IN NIOBIUM METAL. SOLVENT EXTRACTION AND PYROGALLOL SPECTROPHOTOMETRIC METHOD—THEODORE 132
PHOTOMETRIC DETERMINATION OF NIOBIUM AND TANTALUM IN BINARY ALLOYS AND ZIRCONIUM ALLOYS BY PYROGALLOL—WOOD AND SCHOLES 134
PHOTOMETRIC DETERMINATION OF NIOBIUM, TUNGSTEN AND TANTALUM IN STAINLESS STEELS—IKENBERRY, BOYER AND MARTIN 137
SIMULTANEOUS COLORIMETRIC DETERMINATION OF NIOBIUM AND TANTALUM IN HIGH- AND LOW-GRADE ORES BY THE COMBINED NIOBIUM-THIOCYANATE AND TANTALUM-PYROGALLOL PROCEDURES—MARZYS 140
PHOTOMETRIC DETERMINATION OF TANTALUM WITH PYROGALLOL IN HYDROCHLORIC ACID MEDIUM. APPLICATION TO TANTALUM-BEARING ROCKS METHOD OF DINNING) 142
IMPROVED PYROGALLOL DETERMINATIONS OF NIOBIUM AND TANTALUM 143
SPECTROPHOTOMETRIC DETERMINATION OF TANTALUM IN THE PRESENCE OF NIOBIUM WITH PYROCATECHOL IN THE ABSENCE OF TITANIUM SARMA AND GUPTAS) 145
TANTALUM BY PYROCATECHOL— PETROVSKY 147
COLORIMETRIC DETERMINATION OF NIOBIUM WITH PYROCATECHOL—PETROVSKY 147
REFERENCES 148
CHAPTER XI. COLORIMETRIC DETERMINATIONS WITH THIOCYANATE 149
THE NIOBIUM THIOCYANATE COLORIMETRIC AND QUANTITATIVE SPECTROPHOTOMETRIC METHOD 149
COLORIMETRIC DETERMINATION OF NIOBIUM WITH THIOCYANATE. ETHER EXTRACTION METHOD— LAUW-ZECHA, LORD AND HUME 151
SOLVENT EXTRACTION STUDIES OF THE NIOBIUM THIOCYANATE COMPLEX—TROITSKII 152
COLORIMETRIC DETERMINATION OF NIOBIUM WITH THIOCYANATE—FREUND AND LEVITT 152
ACETONE-INTENSIFIED THIOCYANATE METHOD FOR NIOBIUM IN TITANIUM PRODUCTS—MUNDY 154
APPLICATION OF THE NIOBIUM THIOCYANATE METHOD TO THE DETERMINATION OF NIOBIUM IN LOW-GRADE ORES, WITH SPECIAL MODIFICATIONS TO ELIMINATE ERRORS FROM INTERFERING ELEMENTS— MARZYS 156
APPLICATION OF THE THIOCYANATE METHOD TO THE COLORIMETRIC DETERMINATION OF NIOBIUM IN TITANIUM ALLOYS—NORWITZ, CODELL AND VERDERAME 159
SPECIAL PROCEDURE FOR NIOBIUM IN PURE TANTALUM METAL AND TANTALUM PENTOXIDE—HASTINGS AND McCLARITY 160
THIOCYANATE METHOD FOR NIOBIUM IN THE PRESENCE OF TANTALUM—BUKHSH AND HUME 162
FIELD DETERMINATION OF NIOBIUM IN ROCKSWARD AND MARRANZINO 162
SIMULTANEOUS DETERMINATION OF NIOBIUM AND TUNGSTEN BY THE ACETONE HOMOGENOUS THIOCYANATE METHOD—McDUFFIE, BANDI AND MELNICK 164
DETERMINATION OF NIOBIUM IN THE PARTS-PER-MILLION RANGE IN ROCKS. A MODIFIED THIOCYANATE METHOD—GRIMALDI 165
REFERENCES 167
CHAPTER XII. COLORIMETRIC DETERMINATIONS WITH OTHER REAGENTS 169
HYDROQUINONE PHOTOMETRIC METHOD FOR THE SIMULTANEOUS DETERMINATION OF NIOBIUM AND TITANIUM, OR NIOBIUM AND TUNGSTEN IN ALLOYS—McKAVENEY 169
DETERMINATION OF NIOBIUM IN STEEL BY PHOTOMETRIC MEASUREMENT OF THE NIOBIUM OXINATE EXTRACT IN CHLOROFORM—KASSNER, GARCIA-PORRATA AND GROVE 171
METHYL VIOLET SPECTROPHOTOMETRIC METHOD FOR TANTALUM IN STEEL—GREENBERG AND SMART 172
METHYL VIOLET SPECTROPHOTOMETRIC METHOD FOR TANTALUM IN NIOBIUM METAL—GREENBERG AND SMARTS 173
METHYL VIOLET SPECTROPHOTOMETRIC METHOD FOR TANTALUM IN ORES—POLUETKOV, KONONENKO AND LAUERE) 173
PHOTOMETRIC DETERMINATION OF TANTALUM OR NIOBIUM OR TANTALUM PLUS NIOBIUM, IN TITANIUM AND ITS ALLOYS USING ARSENAZO REAGENT— NIKITINA 174
PHOTOMETRIC DETERMINATION OF TANTALUM WITH GALLIC ACID—FREUND, HAMMILL AND BISSONNETTE 175
SPECTROPHOTOMETRIC DETERMINATION OF NIOBIUM IN HYDROCHLORIC ACID—KANZELMEYER AND FREUND 176
REFERENCES 177
CHAPTER XIII. TITRIMETRIC METHODS 178
REDOX METHOD FOR NIOBIUM—KNOWLES AND LUNDELL 178
GRAVIMETRIC DETERMINATION OF TANTALUM IN TANTALUM-NIOBIUM-CONTAINING SPECIAL STEELS APPLICATION OF THE VOLUMETRIC DETERMINATION OF THE NIOBIUM FOR PURITY—CUNNINGHAM
TITRIMETRIC DETERMINATION OF NIOBIUM IN SPECIAL STEELS—CUNNINGHAM 181

REFERENCES 183
CHAPTER XIV. CHLORINATION AND VOLATILIZATION IN DETERMINATIONS 185
CHLORINATION SEPARATIONS OF EARTH ACID ORES USING OCTACHLOROPROPANE 185
THE SCHÄFER AND PIETRUCK CHLORINATION AND QUANTITATIVE DETERMINATION OF NIOBIUM AND TANTALUM IN OXIDE SAMPLES^) 187
SEPARATION OF THE METALS, NIOBIUM AND TANTALUM BY HALOGENATION WITH ALUMINUM HALIDE, AND SUBSEQUENT FRACTIONAL DISTILLATION 189
REFERENCES 190
CHAPTER XV. POLAROGRAPHY OF NIOBIUM AND TANTALUM 191
POLAROGRAPHY OF NIOBIUM 191
POLAROGRAPHIC DETERMINATION OF NIOBIUM IN ZIRCONIUM-BASE ALLOYS—STRICOS 193
POLAROGRAPHIC DETERMINATION OF NIOBIUM IN STEELS USING A HYDROCHLORIC ACID MEDIUM—VIVARELLI 194
POLAROGRAPHIC DETERMINATION OF NIOBIUM IN ORES USING A HYDROCHLORIC ACID MEDIUMELVING AND OLSON 195
POLAROGRAPHIC DETERMINATION OF NIOBIUM IN TITANIUM ORES AND PIGMENTS USING CONCENTRATED HYDROCHLORIC ACID BASE ELECTROLYTE—BALCHIN AND WILLIAMS 195
POLAROGRAPHY OF NIOBIUM IN ORTHOPHOSPHORIC ACID—KURBATOV 197
POLAROGRAPHIC DETERMINATION OF TITANIUM AND NIOBIUM IN A PYROPHOSPHORIC ACID MEDIUM—KURBATOV 197
POLAROGRAPHIC DETERMINATION OF NIOBIUM, TITANIUM AND IRON IN A PYROPHOSPHORIC ACID SUPPORTING ELECTROLYTE—KURBATOV 197
POLAROGRAPHY OF NIOBIUM IN ETHYLENEDIAMINETETRAACETIC ACID 198
POLAROGRAPHY OF NIOBIUM IN CITRIC ACIDKENNEDY 199
POLAROGRAPHIC DETERMINATION OF NIOBIUM IN HIGHLY ALLOYED STEELS—BRINDLEY 200
POLAROGRAPHY OF TANTALUM—KIRBY AND FREISER 201
POLAROGRAPHY OF NIOBIUM AND TANTALUM IN FUSED SALT SYSTEMS—GUT 201
REFERENCES 202
CHAPTER XVI. X-RAY DIFFRACTION AND X-RAY FLUORESCENCE 204
THE DETERMINATION OF NIOBIUM AND TANTALUM BY X-RAY TECHNIQUES 204
REFERENCES 219
CHAPTER XVII. RADIOACTIVE TRACERS AND NEUTRON ACTIVATION 221
RADIOACTIVITY IN THE ANALYSIS OF NIOBIUM AND TANTALUM 221
GENERAL PROCEDURE FOR THE USE OF TRACERS 221
DETERMINATION OF TANTALUM BY NEUTRON ACTIVATION ANALYSIS 222
NEUTRON ACTIVATION ANALYSIS OF TANTALUM AND TUNGSTEN IN ROCKS AND METEORITESATKINS AND SMALES 224
SEPARATION OF ZIRCONIUM-95 FROM NIOBIUM-95 BY EXTRACTION OF ZIRCONIUM-95 WITH TRI-n-BUTYL PHOSPHINE OXIDE—UMEZAWA AND HARA 227
EXTRACTIVE SEPARATION OF ZIRCONIUM AND NIOBIUM—MOORED 227

REFERENCES 229
CHAPTER XVIII. DETERMINATION OF IMPURITIES 231
DETERMINATION OF HYDROGEN, NITROGEN AND OXYGEN IN NIOBIUM 231
PHOTOMETRIC DETERMINATION OF IRON, TITANIUM, AND COPPER IN TANTALUM AND TANTALUM O X I D E - HASTINGS, McCLARITY AND BRODERICK 232
THE DETERMINATION OF FREE HYDROFLUORIC ACID IN TANTALUM-NIOBIUM-HYDROFLUORIC ACID SOLUTIONS BY NEAR-INFRARED SPECTROPHOTOMETRY— ALLEN AND GAHLER 235
DETERMINATION OF PHOSPHORUS IMPURITIES 236
DETERMINATION OF TANTALUM IMPURITIES IN THE METALS NIOBIUM AND ZIRCONIUM 237
DETERMINATION OF TRACE AMOUNTS OF THORIUM IN NIOBIUM-TANTALUM BEARING ORES— TILLU AND ATHAVALE 239
POLAROGRAPHIC DETERMINATION OF TIN IN TUNGSTEN AND TANTALUM-NIOBIUM ALLOYS AND IN STEELS— KRAL AND KYSIL 240
PHOTOMETRIC DETERMINATION OF VANADIUM IN NIOBIUM—ARTICOLO 241
PHOTOMETRIC DETERMINATION OF MOLYBDENUM IN MOLYBDENUM-NIOBIUM, AND MOLYBDENUM-URANIUM ALLOYS BY MEANS OF TOLUENE-3,4-DITHIOL— GRANGERS 242
TUNGSTEN IN STEEL BY TOLUENE-3,4-DITHIOL— BAGSHAWE AND TRUMAN 243
MOLYBDENUM AND TUNGSTEN IN TANTALUM BY DITHIOL—GREENBERG 245
DETERMINATION OF SMALL AMOUNTS OF TUNGSTEN IN URANIUM-TUNGSTEN-TANTALUM ALLOYS— BRICKER AND WATERBURY 246
ANALYSIS OF A MIXTURE CONTAINING TUNGSTEN, TITANIUM, NIOBIUM, TANTALUM, IRON, COBALT, NICKEL, ALUMINUM, CHROMIUM, VANADIUM, AND CARBON. APPLICATION TO THE ANALYSIS OF CEMENTED CARBIDES—TOUHEY AND REDMOND 247
CARBON IN TANTALUM BY THE LOW PRESSURE COMBUSTION METHOD 250
EMISSION SPECTROMETRIC DETERMINATION OF OXYGEN IN NIOBIUM METAL 252
PHOTOMETRIC DETERMINATION OF COPPER IMPURITY IN EARTH ACID METALS AND OXIDES AS THE COPPER DIETHYLDITHIOCARBAMATE COMPLEX IN CARBON TETRACHLORIDE—HASTINGS, McCLARITY AND BRODERICK 256
PHOTOMETRIC DETERMINATION OF IRON IMPURITY IN TANTALUM OR NIOBIUM OXIDE AS THE FERROUS-OÄTTJOPHENANTHROLINE COMPLEXHASTINGS, McCLARITY AND BRODERICK 257
PHOTOMETRIC DETERMINATION OF TITANIUM IMPURITY IN EARTH ACID METALS AND OXIDES AS THE PEROXYTITANATE COMPLEX—HASTINGS, McCLARITY AND BRODERICK 258
PHOTOMETRIC DETERMINATION OF IRON IMPURITY IN EARTH ACID METALS AND OXIDES AS THE FERROUS-BATHOPHENANTHROLINE COMPLEX— GAHLER, HAMNER AND SHUBERT 259
REFERENCES 260
CHAPTER XIX. SPECTROGRAPHIC DETERMINATION OF NIOBIUM AND TANTALUM AND ASSOCIATED IMPURITIES 262
SPECTROGRAPHIC DETERMINATION OF NIOBIUM AND TANTALUM 262
SPECTROGRAPHIC DETERMINATION OF TANTALUM IN ZIRCONIUM, APPLICATION OF SOLVENT EXTRACTION-CONCENTRATION—ELINSON, PETROV AND REZOVA 263
SPECTROCHEMICAL DETERMINATION OF SMALL AMOUNTS OF ALUMINUM AND SILICON IN NIOBIUM PENTOXIDE—MOROSHKINA AND MALININ^ 264
SPECTROGRAPHIC DETERMINATION OF IMPURITIES IN NIOBIUM METAL—FEATHERINGHAM, LENTZ AND JACOBS 264
SPECTROGRAPHIC DETERMINATION OF ZIRCONIUM AND NIOBIUM IN URANIUM METAL—GOLEB 265
SPECTROGRAPHIC DETERMINATION OF IMPURITIES IN TANTALUM. DETERMINATION OF BISMUTH, CADMIUM, LEAD, TIN AND ANTIMONY— ZAKHAROV, LIPIS AND PETROV 266
DETERMINATION OF TRACE IMPURITIES IN NIOBIUM 267
REFERENCES 271
AUTHOR INDEX 274
SUBJECT INDEX 282