Scientists replicate medieval gold purification technique
Scientists at Northwestern University have experimentally replicated a medieval gold purification method employed by West Africans in the 10th and 11th centuries.
The researchers followed a technique initially described in a 2014 paper by archaeologist Sam Nixon, in consultation with Thilo Rehren, a specialist on ancient materials and technologies. Their description of the method was based on a series of clay crucibles and coin molds flecked with gold they found at an excavation in Mali in 2005.
In the scientific article, the experts explain that people from the Malian town of Tadmekka used to heat a mixture of gold, sand and glass at high temperatures to separate out the gold.
Inspired by these findings, Marc Walton, research professor of materials science and engineering at Northwestern’s McCormick School of Engineering, decided to replicate the technique.
With the help of f
ormer postdoctoral fellow Gianluca Pastorelli, Walton used sand from nearby Lake Michigan, gold dust and recycled glass, and conducted a reduced version of the original process. The gold dust was melted and filtered through crushed glass to purify it. Copies of the original clay thumbprint molds were then used to cast replica blank coins in bronze instead of gold, due to the precious metal's high cost.
“We proved this innovative process of purifying gold works,” Walton said in a press release issued by the university. "These medieval Africans, at a confluence of trade routes in the Sahara, were sophisticated in their use of available materials. Their technique of percolating raw materials through molten glass had not been seen before. It is unique to the archaeological record.”
source: MINING.COM
Top News
Glencore in talks to sell Philippine copper smelting unit
Rasul Khalife Soltani, Secretary of the Iranian Steel Producers Association on the sidelines of the 1403 Steel Symposium:
Mobarakeh steel is producing green steel through scrap recycling
Norilsk Nickel plans to sell all it produces in 2025
Volkswagen buys 9.9% of Patriot Battery Metals for $48 million
India’s record gold import said to be due to calculation error
Sibanye raises $500m via metals streaming deal with Franco-Nevada
Norge Mining acquires Europe’s largest natural graphite producer
Aluminum price falls to one-month low in wider commodity slump
Skeena advances Eskay Creek permitting, unlocks Orion funding
Lure of Anglo’s copper mines could test BHP’s spending resolve
Copper giant Peru foresees another production plateau in 2025
Iron ore price weakens as Australia flags return to sub-$100 prices
Nickel price hits 4-year low as gloom offsets potential Indonesia cuts
Mercuria partners with Zambia on metals trading venture
Sibanye raises $500m via metals streaming deal with Franco-Nevada
Triple Flag to acquire royalty on Tres Quebradas lithium project
Volkswagen buys 9.9% of Patriot Battery Metals for $48 million
Aluminum price falls to one-month low in wider commodity slump
India’s record gold import said to be due to calculation error
Lure of Anglo’s copper mines could test BHP’s spending resolve
Iron ore price weakens as Australia flags return to sub-$100 prices
Nickel price hits 4-year low as gloom offsets potential Indonesia cuts
Sibanye raises $500m via metals streaming deal with Franco-Nevada
Triple Flag to acquire royalty on Tres Quebradas lithium project
Volkswagen buys 9.9% of Patriot Battery Metals for $48 million
Aluminum price falls to one-month low in wider commodity slump
India’s record gold import said to be due to calculation error
Glencore in talks to sell Philippine copper smelting unit
