Chemical Analysis Of Silicate Rocks, Volume 6

Preface

Acknowledgements

Chapter 1. Introduction

Preliminary remarks

Chapter 2. Apparatus and Reagents

Balance and weights

Glassware and porcelain

Platinum and substitutes

Platinum ware

Substitutes

Reagents

Filters

Chapter 3. Laboratory Instruments

pH meters

Spectrophotometers

Flame photometers

Chapter 4. Major Factors in Spectrophotometric Methods

Choice of method

pH of solution

Oxidation and reduction of solutions

Presence of interfering elements

Period of reaction

Stability of complexes

Reagents

Photo-sensitive complexes

Temperature

Chapter 5. Common Operations in Silicate Analysis

Decomposition by fluxes

Sodium carbonate fusion

Potassium bisulphate fusion

Sodium peroxide fusion

Fusion of sulphide-containing minerals

Decomposition by acids

Acid-resistant minerals and insoluble residues

Precipitation

Co-precipitation

Post-precipitation

Peptisation

Filtration

Washing of precipitates

Drying and ignition of precipitates

Directions

Chapter 6. Chemical Analysis of Silicate Rocks

The constituents occurring in rocks

The general procedure (The separation of the six groups of elements)

Acid group

Hydrogen sulphide group

Ammonium hydroxide group

Ammonium sulphide group

Ammonium oxalate group

Ammonium phosphate group

Alkali group

Chapter 7. Preparation of the Laboratory Sample

General remarks

Crushing

Grinding

Minerals

Meteorites

Silicates without metal

Silicates with metal

Carbonaceous chondrites

Silicate phase of stony irons

Metal phase of stony irons and iron meteorites

Correcting analytical results to the "dry basis"

Chapter 8. Silicon

Consideration of methods

Gravimetric determination of silicon in silicate rocks and minerals in absence of appreciable chlorine, fluorine or sulphur

Spectrophotometric determination of silicon

Determination of residual silicon in filtrate (12)

Determination of silicon in a suite of rocks of similar composition

Volumetric determination of silicon

Rapid gravimetric determination of silicon in highly siliceous materials

Chapter 9. Total Iron

Consideration of methods

Removal of iron by extraction with ether

Determination of Total iron in silicate rocks and minerals

Volumetric determination

Total iron by the Sulphide-permanganate method without regard to vanadium

Spectrophotometric determination

Total iron as Fe203 by the 2,2'-dipyridyl method

Other methods

Gravimetric determination of Total iron after separation by ion-exchange method

Chapter 10. Titanium

Consideration of methods

Spectrophotometric determinations

Titanium by the hydrogen peroxide method

Titanium by the tiron method

Titanium by the EDTA-tiron method

Other methods

Chapter 11. Aluminium

Consideration of methods

Determination of alumina in silicate rocks

Alumina "difference"

Volumetric determination

Alumina by the EDTA-method

Spectrophotometric determination

Alumina by the 8-hydroxyquinoline method

Chapter 12. Calcium

Consideration of methods

Determination of calcium oxide in silicate rocks in absence of excessive amounts of magnesium and phosphorus

After precipitation as oxalate

After precipitation as phosphate along with magnesium

Chapter 13. Magnesium

Consideration of methods

Determination of magnesia in silicate rocks in absence of excessive amounts of phosphorus, alkali salts, and oxalates

After precipitation as phosphate

After separation of the Ammonium oxalate group

Chapter 14. Ferrous Iron

Consideration of methods

Ferrous iron by the permanganate method

Ferrous iron by the 2,2'-dipyridyl method

Chapter 15. Manganese

Consideration of methods

Volumetric determination

Spectrophotometric determination

Chapter 16. Chromium

Consideration of methods

Chrome minerals

Chromate method

Rocks

Diphenylcarbazide method

Ammonia precipitates

Other methods

Chapter 17. Alkalies

Consideration of methods

Preliminary group separation

Addition of similar concentrations of interfering elements to the standards

Radiation buffers

Internal standards

Standard addition

Ion exchange separation of interfering elements

Scanning of emission peak and deduction of background

Physical factors

Chapter 18. Water and Carbon Dioxide

Consideration of methods

Uncombined water

Combined water

Chapter 19. Phosphorus

Consideration of methods

Decomposition of samples containing phosphorus

Attack by hydrofluoric and nitric acids

Fusion with sodium carbonate

Separation of phosphorus by the ion-exchange method

Principle of method

Spectrophotometric determination of phosphorus pentoxide in silicate rocks and minerals

By the molybdivanadophosphoric acid method

By the molybdenumbluephosphoric acid method

Chapter 20. Total Sulphur

Consideration of methods

Gravimetric determination of Total sulphur in silicate rocks and minerals, containing no more than 2.5 per cent Total S

Chapter 21. Formulas of Minerals

Discussion

Calculations

Possible points for checking a chondrite meteoritic analysis

Chapter 22. Determination of the Specific Gravity

Rocks

Mineral grains

Chapter 23. Notes on the Precision and Accuracy of Results Obtained in Silicate-Rock Analysis and the Limit of Allowable Error

References

Index

Chemical Analysis of Silicate Rocks is the sixth book in the series, “Methods in Geochemistry and Geophysics.” This book provides procedures in chemical analysis of the principal types of silicate rocks and minerals, and it discusses each procedure at length. The book presents different apparatuses and reagents, such as balance and weighs, glassware and porcelain, platinum and substitutes, and filters that are used in the chemical analysis of silicate rocks. Laboratory instruments, such as pH meters, spectrophotometers and flame photometers, are presented in the third chapter. The fourth chapter focuses on the major factors in spectrophotometric methods. The next three chapters cover the common operations in silicate analysis, chemical analysis of silicate rocks, and preparation of the laboratory sample. From chapter eight through 20, each chapter discusses various silicate rocks and minerals, and presents the methods to be used for their chemical analysis. These chemical components are silicon, total iron, titanium, aluminum, calcium, magnesium, ferrous iron, manganese, chromium, alkalies, water and carbon dioxide, phosphorus, and total sulfur. Chapters 21 and 22 offer the formulas of minerals and the determination of specific gravity. The book closes by providing notes on the precision and accuracy of results obtained in silicate rock.