SMELTING SILVER rocks4brains（冶炼银rocks4brains）.pdfVIP

SMELTING SILVER Creative Commons License Smelting Silver by Dr. C. M. Helm-Clark Ph.D. is licensed under a Creative Commons Attribution 4.0 International License. SMELTING SILVER Catherine M. Helm-Clark, Ph.D. Summary This project attempted to reproduce the lead reduction method of smelting silver, as is described in classical, medieval and renaissance sources on pyrometalurgy. The lead reduction smelting process involves two-steps: a fusion of the ore material with lead in a carbon-rich environment, followed by the separation of silver from the lead in an oxygen-rich environment. Period metallurgists used a variety of fluxes, elevated temperatures, and the principle of separation by density to achieve a final product of relatively pure silver. The silver produced for this project was made by following the medieval smelting instructions, albeit using smaller quantities than a full-scale period smelting facility. A few modern substitutions were necessary in order to accommodate the furnaces available for this project, namely flour as a substitute for charcoal as a source of carbon, and natural gas or electricity as substitutes for charcoal as a fuel. All the furnaces used in this project were modern, since landlords take a dim view of building smelting furnaces in the middle of the apartment living room. Approximately a half pound of rock was smelted for a total yield of 4 milligrams of silver. The Sources There are four primary sources used for this study, Pliny the Elders Natural History, Theophiluss De Diversis Artibus, Biringuccios Pirotechnia, and most importantly, Agricolas De Re Metallica. Agricola, Bir