A review of the extraction and characteristics of copper-arsenic alloys in the ancient world

Undoubtedly, one of the most important alloying elements in the ancient world is arsenic, which played an important role in the handmade alloys of the early Bronze Age. Arsenic copper alloys and arsenic bronzes undoubtedly have a special place among archaeologists and researchers of ancient metallurgy as a man-made alloy. Arsenic as a contaminating element and impurity is scattered throughout the environment and the ancient metallurgist has used it in the production of arsenic copper alloy for ritual and practical purposes. Arsenic appears as a challenging element in the production of these works as well as the special characteristics that it creates on the surface of these works. One of the most important features of this element in casting is the creation of invers segregation on the surface of these works, which creates the phenomenon of arsenic sweat in these alloys. The primary minerals used in making these alloys are Cu2(AsO4)(OH) olivine or Cu3(AsO4)(OH), iron sulfur arsenide FeAsS and Cu3AsS4 enargite, which are obtained either by direct reduction or by co-smelting. have been placed, or that arsenic was consciously used through Speiss, in the production of arsenical copper alloy in the third millennium. The extraction of arsenic metals is done by two methods direct reduction and Co-Smelting. In the direct reduction smelting method, an alloy of copper and arsenic is created from the oxide ore. But due to the fact that most of the primary ores are sulfide ores, metallurgists have used the other way around, i.e. roasting and direct smelting, which regenerates the metal. In the roasting method, oxide ore is produced and sulfur is removed from the composition in the form of sulfur dioxide, and then copper metal is regenerated by direct smelting. From the extraction of these metals, several other products are created along Co-smelting, which include Matt, Speiss and Slag. The main goal of this article is to provide a comprehensive review of extraction methods, considering the importance of copper-arsenic alloys in the field of archeology and Archaeometallurgy, Providing a comprehensive review on extraction methods, physical characteristics of these alloys and the role of arsenic and its effect as an alloying element in the formation of silver surface as well as other side products as a very important issue in the investigation of early bronze age alloys.