How China's 500kW antenna is giving it a clear lead in the mineral race

China is using its massive 500kW electromagnetic antenna, originally for submarines, to detect hidden lithium, cobalt, gold, and rare earths, boosting its lead in global mineral exploration

In central China, huge antennas stand on rocky land, quietly scanning deep underground. Originally designed for naval communications and submarines, these 500-kilowatt electromagnetic giants now serve a new purpose: locating critical minerals that power green technologies and the global energy transition, South China Morning Post reported. 

Geologists in China are using these ultra-high-power systems to detect hidden lithium, cobalt, rare earths, and uranium deposits far beneath the surface, giving the country an edge in the current global race to acquire critical resources.   

 

Unmatched power and precision

A recent study by the China Geological Survey (CGS), published in Geophysical & Geochemical Exploration, reveals the scope of the country’s electromagnetic capabilities. Every system exceeding 100kW operates within the country, while the strongest US counterpart manages just 30kW, South China Morning Post said. 

Traditional exploration methods, such as direct current resistivity or induced polarisation, are limited to surface or near-surface deposits. As these shallow reserves decrease in number, geologists are pushing into the “second mineral space” between 500 and 2,000 metres underground.   

 

Deep Earth imaging

Detecting signals at such depths is challenging, with natural geological interference and urban noise affecting the process. China’s solution has been to boost transmitter power and combine it with advanced three-dimensional sensor arrays. This approach allows for detailed underground imaging with clarity, the news report said. 

At Tibet’s Jiama Copper Gold Polymetallic Mine, high-power tensor CSAMT (controlled-source audio-magnetotellurics) surveys mapped ore zones more accurately than previous methods. Nationwide tests of the Wireless Electromagnetic Method (WEM) system in 2023 showed signal detection over distances exceeding 2,000 km, proving the effectiveness of these continent-scale transmitters.

 

Innovative techniques

Chinese researchers are also involving new methods like the Wide Field Electromagnetic Method, which extracts reliable data even close to the source. Time-frequency electromagnetic systems measure resistivity, polarisation, and permeability, which help scientists in distinguishing between ore types with precision.