Roasting of Gold and Silver Ores, and the Extraction of Their Respective Metals Without Quicksilver

Roasting Of Gold And Silver Ores, And The Extraction Of Their Respective Metals Without Quicksilver by G. Küstel. This treatise, originally published in 1870 and expanded in 1880, is a comprehensive manual for mining engineers detailing methods to extract gold and silver from ores without the use of mercury. The work covers the theory and practice of desulphurization, reduction, and chloridizing roasting, explaining how chlorides form and how chlorine gas or cold chlorination enables subsequent separation of metals. It includes in-depth discussion of roasting furnaces—reverberatory, long furnaces, Stetefeldt mechanical furnaces, and revolving designs—plus the chemistry of desulphurization, sulphuric acid, lime and salt usage, and the role of steam. It surveys various leaching and precipitation approaches (lixiviation, hyposulphite processes, Patera, Kiss, Ziervogel, Hofmann, Augustin), with local case studies such as Freiberg and San Marcial. The book aims to equip practitioners with practical, scalable techniques to maximize chloride formation, silver chloride extraction, and final bullion quality without quicksilver.