MIT Uncovers Ancient Metalworking Techniques Using Advanced CT Scans

Researchers at the Massachusetts Institute of Technology (MIT) have uncovered significant insights into ancient metalworking processes, specifically copper smelting, through the use of advanced CT scanning technology. This innovative approach allowed them to study ancient slag waste from a site in Iran known as Tepe Hissar, shedding light on the techniques employed by some of the earliest metallurgists around 5,000 years ago.

Revolutionizing Archaeometallurgy

Metallurgy has played a pivotal role in human development, marking a shift in how societies utilized and processed metals. Despite its importance, much about the early methods of metal production remains unclear. According to MIT researchers, the primary goal of their study was to comprehensively understand how ancient civilizations created metal products, from raw material extraction to finished goods. “The goal is to understand, from start to finish, how they accomplished making these shiny metal products,” they stated to MIT News.

Previous analyses of ancient slag have yielded limited information, but the MIT team has pioneered a new application of CT scanning technology, enhancing traditional methods of studying artifacts. This novel approach has opened new avenues for research, allowing a deeper exploration of metallurgy’s origins.

Insights from Ancient Slag

The slag sample investigated by the researchers originated from Tepe Hissar, which is recognized as one of the earliest sites for copper processing. The date of the slag has been established to range between 3100 and 2900 BCE. This region is vital for understanding the development of metallurgy, as it is believed to be where the first metallurgists began extracting copper from ore.

For their analysis, the MIT team utilized an industrial CT scanner, supplemented by a standard CT scanner available on campus. This combination allowed them to achieve a detailed understanding of the internal structure of the slag, including the distribution of pores and traces of other materials. As explained by the researchers, “Slag waste is chemically complex to interpret because in our modern metallurgical practices it contains everything not desired in the final product.” This complexity makes it challenging to draw conclusions about ancient metal production methods.

Traditional methods such as X-ray fluorescence, X-ray diffraction, and optical and scanning electron microscopy were also employed in the study. However, the CT scans proved particularly valuable in providing a comprehensive overview of the slag’s internal composition and structural features.

As a result of this research, discussions have emerged within the archaeological community regarding the historical processing of metal. Notably, debates have arisen over the role of arsenic, which was present in the slag and may have influenced early metal production techniques. The researchers noted that this inquiry could lead to a better understanding of ancient metallurgical practices.

“Moving forward, CT scanning could be a powerful tool in archaeology to unravel complex ancient materials and processes,” MIT concluded. Their work indicates that this technology could significantly enhance systematic studies on copper smelting and the long-term stability of artifacts, providing a crucial foundation for future investigations.

Through this pioneering study, MIT researchers are contributing to a deeper understanding of the technological capabilities of early civilizations, offering a glimpse into how ancient societies navigated the complex world of metallurgy.