METALLURGICAL PROBLEMS MY ALLISON BUTTS, A. B., B. S. Professor of Electrometallurgy, Lehigh U Co-author of Engineering Metallurgy SECOND EDITION THIRD IMPRESSION McGRAW-HILL BOOK COMPANY, INC. NEW YOKK AND LONDON 1043 METALLURGICAL PROBLEMS COPYRIGHT, 1932, 1943, BY THE McGRAW-HiLL BOOK COMPANY, INC. PRINTED IN THE UNITED STATES OF AMERICA All rights reserved. This book, or parts thereof, may not be reproduced in any form wthout permission of the publishers. DEDICATED TO THE MEMORY OF JOSEPH WILLIAM RICHARDS PIONEER IN METALLURGICAL CALCULATIONS AN INSPIRING TEACHER AND A MAN OF RARE QUALITIES PREFACE The purposes in view in preparing the second edition of this book may be included largely in three categories 1 the desirability of bringing the work up to date both with respect to changes in the fundamental data used in metallurgical calculations and with respect to changes in metal lurgical practice 2 changes dictated by the experience of the author and of others in eleven years use of the book, particularly with regard to textual clarification, arrangement, and better balance of the problem material and 3 the desirability of making available new problem material in place of some of that which has been used repeatedly in class instruction over a long period. The first edition of A Textbook of Metallurgical Problems was an outgrowth of Professor Joseph W. Richardss book Metallurgical Calculations which was regarded by many as one of the most useful books available to the metallurgical industry. Since Richardss volume was not in a form most suitable for use as a college text, it was then the object of the present author not only to produce a more recent work in the same field asMetallurgical Calculations, but also to make available a book more adaptable to student use. In this second edition the same objects remain the title has been shortened to Metallurgical Problems both for the sake of brevity and to avoid emphasizing its function as a textbook to the exclusion of a hoped-for usefulness to industry. The first edition of this book attempted to follow the methods and forms used by Richards to such an extent as to make it relatively easy to use by those accustomed to his book, while at the same time using more recent data, new material in accordance with later practice, and some innovations in harmony with instructional changes made in college depart ments of chemistry and physics. The same plan is followed in the second edition, but the changes have been carried further, following progress in technical education. For example, free energy and other thermo dynamic concepts did not appear in Richardss book, nor was any use made of methods of calculus. These were introduced in the first edition of this book and have been extended in the second edition. Nevertheless, knowledge of higher mathematics is still relatively unimportant in the use of the book also, the substitution of the more familiar heats of reaction for free-energy change has not been abandoned for approximate calcula tions when these may be properly used. With regard to heats of reaction, vii Viu . PREFACE a change has been made in this edition to the A concept and notation now so widely adopted in physical chemistry and therefore made familiar to present-day students. In revising the physical and chemical data in this book, the author has drawn from recently published compilations acknowledged atthe appropriate places rather than from original sources. These - compila-tions for the most part present data in the forms most often desired in scientific work. In some instances these are not the forms most useful in industry, and much time has been spent by the author in conversion to what seemed to be a more readily usable basis...