The Chating Cu–Au deposit is a newly discovered porphyry-type deposit within the Nanling–Xuancheng mining district of the Middle–Lower Yangtze River Metallogenic Belt (MLYRMB), China. This study uses numerical simulation to determine the key characteristics of the mineralizing system that formed the Chating deposit that traditional analysis cannot easily identify, including the duration of the mineralizing events that formed the deposit. We also outline the practical value of numerical simulation in determining the processes that operate during mineral deposit formation and how this knowledge can be used in further mineral exploration. Our simulation interlinks heat transfer, pressure, fluid-flow, chemical reaction, and material migration and indicates the presence of a temperature anomaly and modeled zones of mineralization that match the known distribution of mineralization. Our modeling further predicts a potentially mineralized zone at depths below the -1800 m level of the deposit. Combining our numerical modeling with average Cu grades and chemical reaction rates indicates that the Chating deposit formed over a period of 9,600–75,000 years. These data can be used in future prospectivity modeling and mineral exploration as well as to gain insights into the genesis and duration of the system that formed the Chating porphyry Cu-Au deposit as well as porphyry mineralization in general.