Author: M. V. Regnault

Publisher: Forgotten Books

Published: 2015-06-24

Total Pages: 810

ISBN-13: 9781330297681

Excerpt from Elements of Chemistry, Vol. 2 of 2: For the Use of Colleges, Academies, and Schools § 732. Although the metals described in the second part of this work are never technically employed in the metallic state, they still find very extensive application in the state of various compounds, all of which are manufactured in chemical works by processes similar to those employed for obtaining them in the laboratory on a smaller scale. Among the metals yet remaining for our examination, however, a considerable number are employed in the metallic state, and are extracted from their ores by processes of a particular kind, called metallurgical processes. In every case when they are to be used in the metallic state they must fulfil all the conditions enumerated (§ 276); which, however, many do not, as some are of rare occurrence, while the extracting of others presents too great practical difficulties, and still others have as yet found no technical application, being, therefore, of purely scientific interest. Nevertheless, on account of the great analogy existing between them in a chemical point of view, the study of those which find a technical application cannot be separated from that of those which are not so applied. The latter will, therefore, occupy our attention as well as the former, but to a much more limited extent. Mechanical Preparation of Ores. § 733. Under the general name of ores are comprised such combinations of metals, occurring in nature, as contain a sufficient proportion of metal to be worked with profit. The proportion varies with the marketable value of the metal, and according to the greater or less facility with which it can be obtained from its combination in the ore: iron ores, for instance, the commercial price of which metal is very low, must therefore be very rich if they are to be profitably worked. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.