Die Mineralogie, verstanden als Oberbegriff für Kristall-, Mineral-, Gesteins­ und Lagerstättenkunde sowie für Geochemie, wirkt zunehmend über den Kreis der eigentlichen Geowissenschaften hinaus auf viele Bereiche der Technik und der Ingenieurwissenschaften. Dies gilt unter anderem für die Herstellung von keramischen und feuerfesten Stoffen, von Glas, von Zementen und anderen Bindemitteln, von Baustoffen, von Einkristallen und von Kristallen mit bestimmten chemischen und physikalischen Eigenschaften, von Hartstoffen, Schleifmitteln, Farben, Düngemitteln, Isolier­ stoffen, organischen Polymeren und von Brenn- und Baumaterialien für Kern­ reaktoren. Hierher gehören ferner auch die mineralogischen Aspekte der Auf­ bereitung, des Bergbaues, des Hüttenwesens, der Energieerzeugung, der Bau­ technik, der Staubtechnik, der Rückstandsverwertung, der Materialprüfung, der Elektrotechnik, der Korrosion, der Raumfahrt usw. Mineralogische Erkenntnisse an Naturvorgängen helfen weiterhin häufig, technische Prozesse zu verstehen, zu planen und zu steuern. Die steigende Bedeutung der Mineralogie für viele Zweige der Technik, die Vielzahl der in der Literatur weit verstreuten mineralogischen Arbeiten zu diesen Fragen und das notwendigerweise hohe Maß der Spezialisierung lassen nunmehr zusammenfassende Darstellungen aus der Sicht der Mineralogen auf den genannten Gebieten unerläßlich erscheinen. Ziel der neuen Monographienreihe von hohem wissenschaftlichem Niveau ist es, die Anwendung der Methoden und des Wissens­ inhaltes der Mineralogie auf technische Probleme in einer Form darzustellen, die vor allem den Ingenieur, aber auch den technisch orientierten Naturwissenschaft­ ler umfassend informiert.

Although a considerable amount of information concerning the applications for arc plasmas in the materials sciences is available, it is contained in literally thousands of separate manuals, technical notes, textbooks, and government and industrial reports. Each source generally deals with only one specific application or, at best, a narrow range of utilization. This book was developed to provide a comprehensive and up-to-date compilation of information in the technology of arc plasma utilization. The book is divided into two general categories: flame spraying and materials evaluation. In the flame spraying section a comprehensive review of the plasma spraying process is presented. The design and operation of plasma spraying equipment are described. Included are a description of the nature of a plasma, and the design and operation of plasma generators, powder feed systems and accessory control equip­ ment. The general process procedures, and associated process variables are de­ scribed. Particular emphasis is given to the particle heating process and the mechanisms for adherence and cohesion of coatings. Competitive flame spraying equipment is also detailed (combustion process, detonation and electric arc) and compared with the plasma spray process. A discussion and compilation of flame sprayed ceramic and metal materials, their properties and applications are also included.

The preparation of a volume on this topic was undertaken with some hesitancy on my part because the ramifications of the mineralogy of apatite involve both bio­ logical and physical sciences in very elaborate ways. This hesitancy may have arisen in part from the realization that considerable skill would be required in order to extract the meaning from the thousands of papers that have appeared within the past twenty years; the task of attempting to extract and assemble the usable information seemed gigantic. Greatly adding to the difficulty was the fact that a considerable portion of these journal articles contain nothing of value and further confuse a most complex topic. Nevertheless, it was thought that some of my formal education in the bio­ logical sciences, which has been greatly extended and augmented during the past fifteen years, might be integrated with my more extensive education and experience in chemistry, crystallography, mineralogy, geology and physics in order to pro­ duce something that would relate to the mineral apatite and its extremely diverse occurences in nature. At the same time it seemed essential to point out some of the many important aspects in which this knowledge bears on geology, agriculture, chemical engineering, medicine and dentistry.

Structural clay products have had a place in the history of civilization like bread and cloth. Probably because the industry has been so commonplace in the lives of people, 1ittle has been written about it; even the history of its development is sketchy. There is no other book quite like this in publication at present, and it is prompted now because much general scientific knowledge can be, and is, applied to the manufacture of structural clay products. This book is an attempt to bring together in one place the basic sciences that can be useful in all of the processes and experiences of the clayworker. This volume was written primarily as a text to be used in courses for third and fourth year college students; however, there will be a broader interest in it by industrial foremen, engineers, architects, and scientists employed in the manu­ facture, research and use of structural clay products. It will also be a source of general information for those interested in entering the field. The treatment of the basic principles of clay products manufacturing and use is so general that even those interested in refractories, whitewares, and pottery may find many parts useful to them.

Die Mineralogie, verstanden als Oberbegriff für Kristall-, Mineral-, Gesteins­ und Lagerstättenkunde sowie für Geochemie, wirkt zunehmend über den Kreis der eigentlichen Geowissenschaften hinaus auf viele Bereiche der Technik und der Ingenieurwissenschaften. Dies gilt unter anderem für die Herstellung von keramischen und feuerfesten Stoffen, von Glas, von Zementen und anderen Bindemitteln, von Baustoffen, von Einkristallen und von Kristallen mit bestimmten chemischen und physikalischen Eigenschaften, von Hartstoffen, Schleifmitteln, Farben, Düngemitteln, Isolier­ stoffen, organischen Polymeren und von Brenn- und Baumaterialien für Kern­ reaktoren. Hierher gehören ferner auch die mineralogischen Aspekte der Auf­ bereitung, des Bergbaues, des Hüttenwesens, der Energieerzeugung, der Bau­ technik, der Staubtechnik, der Rückstandsverwertung, der Materialprüfung, der Elektrotechnik, der Korrosion, der Raumfahrt usw. Mineralogische Erkenntnisse an Naturvorgängen helfen weiterhin häufig, technische Prozesse zu verstehen, zu planen und zu steuern. Die steigende Bedeutung der Mineralogie für viele Zweige der Technik, die Vielzahl der in der Literatur weit verstreuten mineralogischen Arbeiten zu diesen Fragen und das notwendigerweise hohe Maß der Spezialisierung lassen nunmehr zusammenfassende Darstellungen aus der Sicht der Mineralogen auf den genannten Gebieten unerläßlich erscheinen. Ziel der neuen Monographienreihe von hohem wissenschaftlichem Niveau ist es, die Anwendung der Methoden und des Wissens­ inhaltes der Mineralogie auf technische Probleme in einer Form darzustellen, die vor allem den Ingenieur, aber auch den technisch orientierten Naturwissenschaft­ ler umfassend informiert.

Although a considerable amount of information concerning the applications for arc plasmas in the materials sciences is available, it is contained in literally thousands of separate manuals, technical notes, textbooks, and government and industrial reports. Each source generally deals with only one specific application or, at best, a narrow range of utilization. This book was developed to provide a comprehensive and up-to-date compilation of information in the technology of arc plasma utilization. The book is divided into two general categories: flame spraying and materials evaluation. In the flame spraying section a comprehensive review of the plasma spraying process is presented. The design and operation of plasma spraying equipment are described. Included are a description of the nature of a plasma, and the design and operation of plasma generators, powder feed systems and accessory control equip­ ment. The general process procedures, and associated process variables are de­ scribed. Particular emphasis is given to the particle heating process and the mechanisms for adherence and cohesion of coatings. Competitive flame spraying equipment is also detailed (combustion process, detonation and electric arc) and compared with the plasma spray process. A discussion and compilation of flame sprayed ceramic and metal materials, their properties and applications are also included.

The preparation of a volume on this topic was undertaken with some hesitancy on my part because the ramifications of the mineralogy of apatite involve both bio­ logical and physical sciences in very elaborate ways. This hesitancy may have arisen in part from the realization that considerable skill would be required in order to extract the meaning from the thousands of papers that have appeared within the past twenty years; the task of attempting to extract and assemble the usable information seemed gigantic. Greatly adding to the difficulty was the fact that a considerable portion of these journal articles contain nothing of value and further confuse a most complex topic. Nevertheless, it was thought that some of my formal education in the bio­ logical sciences, which has been greatly extended and augmented during the past fifteen years, might be integrated with my more extensive education and experience in chemistry, crystallography, mineralogy, geology and physics in order to pro­ duce something that would relate to the mineral apatite and its extremely diverse occurences in nature. At the same time it seemed essential to point out some of the many important aspects in which this knowledge bears on geology, agriculture, chemical engineering, medicine and dentistry.

Structural clay products have had a place in the history of civilization like bread and cloth. Probably because the industry has been so commonplace in the lives of people, 1ittle has been written about it; even the history of its development is sketchy. There is no other book quite like this in publication at present, and it is prompted now because much general scientific knowledge can be, and is, applied to the manufacture of structural clay products. This book is an attempt to bring together in one place the basic sciences that can be useful in all of the processes and experiences of the clayworker. This volume was written primarily as a text to be used in courses for third and fourth year college students; however, there will be a broader interest in it by industrial foremen, engineers, architects, and scientists employed in the manu­ facture, research and use of structural clay products. It will also be a source of general information for those interested in entering the field. The treatment of the basic principles of clay products manufacturing and use is so general that even those interested in refractories, whitewares, and pottery may find many parts useful to them.