Originally published in 1920. PREFACE: Electrolytic copper refining was for so many years conducted under conditions of strict commercial secrecy that but little has been published regarding the principles of operation, as distinct from descriptions of individual plants. This littlebook comprises a series of articles, eachdealing with one of the problems of refining, which originally appeared in Chemical and Metallurgical Engineering. Whatever of value it may contain is due to the fact that it is almost entirely a record of personal experience in a field where but little literature is available. NEW YORK, December, 1920. vit LAWRENCE ADDICKS. COntents include: PREFACE vii I. METAL LOSSES 1 II. METALS IN PROCESS 18 III. TANK RESISTANCE 38 IV. CURRENT DENSITY 54 V. CURRENT EFFICIENCY 71 VI. IMPURITIES 80 VII. BY-PRODUCTS 100 VIII. FURNACE REFINING 124 IX. THE REQUIREMENTS OF REFINED COPPER 143 X. COPPER FROM SECONDARY MATERIAL 158 XI. THE POWER PROBLEM 171 XII. ELEMENTS OF DESIGN 183 XIII. APPLICATION TO OTHER FIELDS 194 INDEX. . 203