Book Description

Excerpt from The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, Vol. 36: New and United Series of the Philosophical Magazine, Annals of Philosophy, and Journal of Science; January June, 1850 Attention has of late been directed to the extraction of silver by the wet way from many of its ores, of which large quantities are now imported into this country, especially from South America. Several processes have been projected; and one, the subject of a patent, is now extensively practised. It consists in calcining the ore with chloride of sodium, precisely as in the amalgamation process of Freiberg, and then dissolving out the chloride of silver formed during the calcination by a hot saturated solution of chloride of sodium. From this solution the silver is precipitated by metallic copper, and then cupelled. I have examined many South American silver ores, and have found them very variable in respect to the proportion of silver, and the presence of gold and other metals. In one ore I have found as much as 301/4 per cent, of fine silver. Several smelling establishments have, I know, attempted to work some of these ores in the dry way, but the results have not been favourable. Hence will appear the importance of directing attention to the conomic extraction of the silver by the wet way. The ore which I subjected to experiment was an auriferous silver ore, which contained a large proportion of blende, with galena, iron pyrites and copper pyrites in small quantity; the non-metallic part of it consisted chiefly of silica. The silver was present as sulphuret. By roasting, the ore swelled up much, and sulphurous acid was copiously disengaged. I received it in the stale of coarse brownish-gray powder. 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."