This book is intended to be a companion to Kubaschewski’s MetallurgicalThermochemistry, and as such deals primarily with the kinetic and transporttheory of high temperature chemical reactions. I have chosen the title ThermochemicalProcesses rather than High Temperature Materials Chemistry sincemany of the important industrial processes which are described hardly deservethe high temperature connotation, and such a title would have implied a largerstructural and thermodynamic content than is required for the description ofthe industrial processing of materials.
It will be seen that the book has asignificant content from the chemical engineer’s approach, and I feel that thisrapprochement with the materials scientist is overdue.The origins of the material contained in this book are to be found in therapid growth of the scientific description of extractive metallurgical processeswhich began after World War II. This field was dominated by thermodynamicsoriginally, and the development of kinetic and transport descriptionsof these processes followed later. At that time the study of glasses and ceramicswas largely confined to phase diagrams of the multicomponent systems, andprocesses in which gaseous reaction kinetics were rate-controlling were ofmore interest to the chemist than to the materials scientist, a field which,practically, did not exist in that era.The quantitative description of materials processing has now advanced tothe state where most of the processes which are in industrial use can bedescribed within a logical physico-chemical framework. The pace of developmentin this field has largely been determined by the rate of improvementof our experimental capabilities in high temperature chemistry; the ab initiotheoretical contribution to the building of our present knowledge is growingrapidly under the influence of computer capabilities which simplify the fundamentalbasis for a priori calculation. However, the processes and substanceswith which the materials scientist works are usually complex, and the precisionof the information which is required to describe a process accurately isstill too high to be calculated theoretically. The practical situation can nowbe assessed from the substantial results of experimental studies which coveralmost every situation to be found on the present industrial scene.The role of the physico-chemical study of materials processing has beenconsigned to a secondary position of interest by those engaged directly in manufacturing processes. This has probably come about for two reasons. Thefirst and most obvious reason is that economic factors more than physicalchemistry play the important part in industrial decision-making. Those whodirect the production aspects of industry seldom have equally developed skill inthe physico-chemical aspects as well as in economics. As a result, the decisionmakingtends to be under financial direction, and the decision-makers drawtheir scientific advice from research in a digested form. The second reason isthat high temperature chemists have been fully occupied up till now in thebusiness of understanding the processes already in use and their contributionsto industrial progress seem always to be post hoc. At present, it is true to saythat their efforts have been more of value in teaching the student laboratoryworkers than in predicting potentially new processes. To some extent, thisstate of affairs has been brought about by empirical industrial progress whichhas built up a formidable amount of knowledge over decades by the useof works trials. These aspects of industrial development together with thefinancial constraints of process innovation probably account for the fact thatthe physical chemist has had no really outstanding impact on the materialsindustry to date, apart from providing experimental tools for the appraisal ofnew processes, and the ‘tools of thought’ which can be transferred from theanalysis of an established process to prognosis when new methods are beingsought.The treatment in this book is intended for those who have already receivedthe basic courses in classical thermodynamics which nearly all students ofmaterials science and chemical engineering must assimilate nowadays beforepassing on to courses in materials processing. For the interested graduate, abrief refresher in any of the standard textbooks of physical chemistry is recommendedif he/she is not comfortable in thermodynamic analysis. References aregiven at the end of each section to other works and original literature sourceswhich are normally available to the student of materials science. Rather thanpresent the reader with a plethora of original references, I have collected anumber of review articles, and monographs which have seemed to me to bevaluable oversights in this subject. A parallel study of these reference materialswill augment the value of this book very considerably, but it is hopedthat the main ideas which are germane to the analysis of processes are to befound here.In conclusion, any author who has had the experience of seeing a subjectgrow from its early beginnings should acknowledge his debt to the leadingmen in the field who have taught him how to reach a level of competence and‘feel’ for the subject. Among the many colleagues who have played this rolefor me, I would place F.D. Richardson and O. Kubaschewski as the primemovers during the years I spent in the Nuffield Research Group, and others,such as H.J.T. Ellingham, L.S. Darken, and of course, C. Wagner, with whomI ‘sat at the master’s feet’. To all of those who remember having worked with me over the last fifty years, I would extend my thanks for friendshipcoupled with instruction. Finally I must acknowledge the ever-present supportand encouragement which I have received from my wife who has never failedto help me in high times and low with her insight into what forms scientistsoutside of their working persona.
Title : Thermochemical ProcessesPrinciples and Models
Author : C.B. Alcock DSc, FRSC
Kind : Engineering
http://rapidshare.de/files/21046449/ALCOCK__C._B.__2000_._Thermochemical_Processes_-_Principles_and_Models.rar
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Title : Thermochemical ProcessesPrinciples and Models
Author : C.B. Alcock DSc, FRSC
Kind : Engineering
http://rapidshare.de/files/21046449/ALCOCK__C._B.__2000_._Thermochemical_Processes_-_Principles_and_Models.rar