This book treats magnetic separation from the point of view of both the engineer in the field who operates magnetic separators and the research scientist in the laboratory. It emphasizes those aspects of magnetic separation where lack of support in fundamental research is most evident. The intention is to bring the engineer and the scientist closer together, to promote the application of basic physical phenomena in engineering practice, and to gain the acceptance of the industry. The book presents a fairly broad survey of magnetic separation as applied to and practised primarily by the mineral-processing industries, although its use in other industries is reviewed briefly. It includes information on the physical principles of magnetic separation, magnetic properties of minerals and their measurement, the generation of magnetic field, theoretical and practical problems of magnetic separation, and experience gained in the design and operation of magnetic-separation systems. In detail, the book consists of six chapters dealing with the following topics: The Physical Properties of Magnetic Separation, Review of Magnetic Separation Techniques, Theory of High-gradient Magnetic Separation, Practical Aspects of Magnetic Separation, Industrial Applications of High-gradient Magnetic Separation, and The Economics of Magnetic Separation. The six appendices deal with symbols, abbreviations, values of physical constants, conversions from one unit to another, definitions of derived units, and a list of selected equipment manufacturers. There is a comprehensive bibliography (almost 600 items) and a subject index. The book should be of value to engineers and consulting metallurgists, as well as to students who want to learn more about this branch of technology. It attempts to meet the needs of the growing number of engineers, technologists, and applied physicists who are engaged in the practical exploitation of magnetic separation.

This book reflects changes that have occurred during the last two decades in theoretical understanding and practical implementation of magnetic techniques in materials treatment. Research and development needs, based on the current strategic thinking and on principles of sustainable development are outlined. Development of magnetic separators based on powerful permanent magnetic materials, construction of reliable superconducting separators, design of efficient eddy-current separators and industrial implementation of magnetic carriers and magnetic fluids are examples of innovative changes that have taken place during the last twenty years. The book reflects the current technological trends and re-positions the research, development and practice of magnetic methods of material treatment in such areas as minerals beneficiation, recycling, waste treatment and biomedical and clinical applications.

During the last 30 years the study of the magnetic properties of rocks and minerals has substantially contributed to several fields of science. Perhaps the best known and most significant advances have resulted from the study of palaeomagnetism, which led to quantitative confirmation of continental drift and polar wandering through interpretation of the direction of remanent magnetism observed in rocks of different ages from different continents. Palaeomagnetism has also, through observations of reversals of magnetiz ation, ancient secular variation and ancient field intensities provided data relevant to the origin of the geomagnetic field, and other investigations have contributed significantly to large-scale and local geological studies, the dating of archaeological events and artefacts and more recently to lunar and meteoritic studies. Rock and mineral magnetism has proved to be an interesting study in its own right through the complex magnetic properties and interactions observed in the iron-titanium oxide and iron sulphide minerals, as well as contributing to our understanding of remanent magnetism and magnetization processes in rocks. Simultaneous with the development of these studies has been the develop ment of instruments and techniques for the wide range of investigations involved.