Chemical composition, thermodynamics, and recycling : the beginnings of predictive behavioral modeling for ancient copper-based systems
In their attempts to understand the unwritten past of human technology and progression, archaeologists have borrowed aspects of the natural sciences to answer big questions. In one such pursuit, fundamental aspects of the sciences have been employed towards the chemical compositional analysis of copper-based artifacts, often to simply classify which is bronze, brass, or pure copper, and to explain why they are significant in limited space and time. This thesis takes the variety of identified metal types and compositions from these analyses and builds the beginnings of an ambitious thermodynamic model based on the accepted premise of consistent and widespread recycling of ancient metals over time. Following the laws of thermodynamics, in systems at equilibrium, the model predicts the outcome of metal losses over the course of ancient pyrometallurgical processes from molten systems through both volatilization and oxidation using rigorous and established mathematics and theory. Elemental loss likelihoods are modeled for all binary copper-based metals, using activity coefficients, and ternary copper and zinc-based systems, with the excess Gibbs free energy, respectively. The calculations are performed using custom-written
Sabatini, Benjamin J.
Archaeology ; Metallurgy ; Archaeology science ; Materials science ; Thermodynamics ; Thermodynamic Modeling ; Equilibrium ; Activity ; Oxidation ; Volatility
Chemical composition, thermodynamics, and recycling : the beginnings of predictive behavioral modeling for ancient copper-based systems. In their attempts to understand the unwritten past of human technology and progression, archaeologists have borrowed aspects of the natural sciences to answer big questions. In one such pursuit, fundamental aspects of the sciences have been employed towards the chemical compositional analysis of copper-based artifacts, often to simply classify which is bronze, brass, or pure copper, and to explain why they are significant in limited space and time. This thesis takes the variety of identified metal types and compositions from these analyses and builds the beginnings of an ambitious thermodynamic model based on the accepted premise of consistent and widespread recycling of ancient metals over time. Following the laws of thermodynamics, in systems at equilibrium, the model predicts the outcome of metal losses over the course of ancient pyrometallurgical processes from molten systems through both volatilization and oxidation using rigorous and established mathematics and theory. Elemental loss likelihoods are modeled for all binary copper-based metals, using activity coefficients, and ternary copper and zinc-based systems, with the excess Gibbs free energy, respectively. The calculations are performed using custom-written
chemical_composition recycle beginning predictive behavioral model ancient copper_based system attempt past_human technology progression archaeologists borrow aspect natural_science answer big question pursuit fundamental_aspect science employ towards chemical compositional_analysis copper_based artifact often simply classify bronze brass pure copper explain significant limited space_time take variety identify metal type composition analysis build beginning ambitious model_base accepted premise consistent widespread recycle ancient metal time following law system equilibrium model predict outcome metal loss course ancient process melt system oxidation use rigorous establish mathematics theory elemental loss likelihood model binary copper_based metal use activity coefficient copper based_system excess free energy respectively calculation perform use custom written