Recently, the Dangba lithium mine in Maerkang City, Sichuan Province, passed the mineral resource reserve review and filing by the Ministry of Natural Resources, adding 440,000 mt of lithium oxide resources. The cumulative measured lithium oxide resources have reached 1.1207 million mt, making it the first granite pegmatite-type lithium deposit in Sichuan with over 1 million mt of lithium oxide resources. It is also the largest granite pegmatite-type lithium deposit with measured resources in Asia to date.
On the global lithium mine map,
Sichuan shines brightly.
From Jiajika and Maigitang in Yajiang County
to Ke'eryin and Lijiagou,
each deposit discovery has its unique story.
What journey has the exploration of the Dangba lithium mine in Maerkang gone through?
From Less Than 10,000 mt to Over 1 Million mt
The Dangba mining area
is located in the Ke'eryin region of Aba Prefecture. Less than 10,000 mt was the measured lithium oxide resource in the Dangba mining area in 2007. Today, it is a well-known rare metal mining field in China, primarily focused on lithium.
The Lijiagou spodumene deposit,
not far from the Dangba deposit, is also located in the Ke'eryin region. At that time, its exploration also faced significant challenges and fell far short of expectations. However, the prospectors did not give up. A few years later, the Sichuan Institute of Comprehensive Geological Survey, a subsidiary of the Sichuan Geological Survey Institute, opened the "door" to lithium resources, achieving a major breakthrough in Lijiagou by identifying a super-large-scale deposit. This significant breakthrough also boosted confidence in finding lithium on a larger scale.
In 2011,
the Sichuan Institute of Comprehensive Geological Survey
incorporated the mining and exploration rights of the Dangba mining area
into an integrated exploration effort.
These two deposits in the Ke'eryin region share similarities ➤ both face challenges such as thick surface soil cover, limited exposure of ore bodies, and difficulty in understanding their distribution patterns. Therefore, during the exploration of the Dangba mining area, the exploration techniques and scientific theories used in Lijiagou were applied and practiced. However, this does not mean that the successful experience of Lijiagou could be directly replicated like an assembly line.
"Each deposit is unique and has its complexities. For example, the lithium ore in Lijiagou is clustered in a 'parallel' pattern, while the ore bodies in Dangba are clustered like a 'wild goose formation,'"
explained Tang Wenchun, Chief Scientist of the Sichuan Geological Survey Institute.
Since 2011,
the exploration of the Dangba lithium mine has accumulated an investment of over 170 million yuan, with more than 40,000 meters of drilling work completed.
After more than a decade of exploration,
marked by challenges and discoveries,
a "progressive breakthrough" trilogy has been written.
↓↓↓
In 2014, the Dangba mining area achieved its first phase of exploration breakthrough, submitting over 660,000 mt of lithium oxide resources.
Three years later, the second phase of exploration breakthrough was achieved, adding nearly 250,000 mt of lithium oxide resource reserves.
Subsequently, through continuous deep exploration and blind target identification, over 1.12 million mt of lithium oxide resource reserves were identified, marking the third phase of exploration breakthrough.
"We spend six to seven months a year in the field. Each increase in reserves is a process of deepening understanding,"
said Senior Geological Engineer Jian Li, who has been involved in the exploration of the Dangba mining area from the beginning.
Exploration: Bold Assumptions, Careful Verification
200 Million Years Ago,
magma activity deep within the Earth formed pegmatite.
This type of rock, hidden deep within the strata,
is relatively small in scale, varies in shape, and is highly scattered.
Moreover, most of it does not contain lithium ore.
"This requires a certain level of imagination and thinking to discover the mineralization patterns, then deploy appropriate methods and technologies for verification—essentially bold assumptions and careful verification," said Tang Wenchun.
Through the comprehensive application and collaboration of
geophysical, geochemical, and remote sensing methods,
combined with mineral deposit geochemistry
and mineralogy research methods,
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the exploration team conducted in-depth studies on the mineralization conditions and enrichment patterns in the mining area.
After pinpointing the concealed locations of thick and large ore bodies, they used geological engineering methods such as drilling to verify and control the ore bodies.
"Simply put, we needed to determine what factors controlled the pegmatite and pegmatite ore bodies in the Dangba mining area, what their distribution patterns were, and how to predict the shapes of deep ore bodies,"
explained Tang Wenchun. This is a multidisciplinary collaborative process involving over 10 subjects in comprehensive research, ultimately leading to new insights into the deposits here. The shapes and spatial positions of the concealed ore bodies gradually became clear.
From the cross-sectional view of the mining area, the ore veins being sought resemble a "thin ribbon," irregularly extending from the surface to the deep crust, akin to "finding a needle in a haystack."
After discovering traces of the ore veins,
the next step was to
set up drill holes
to observe the "ore" through a narrow scope.
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The entire work area has an elevation difference of 2,200 meters. Technical personnel climbed within this area, setting up over 140 drill holes. Over more than a decade, they drilled a cumulative depth of over 40,000 meters. At peak times, more than 100 professional technical personnel and drilling technicians were working on-site.
To meet the planned schedule, the technical personnel worked as late as December, when the plateau had already turned into a silver-white world. Water supply pipes outside the camp had frozen into ice columns, and roads were sealed by black ice. To replenish living supplies, staff had to hike tens of kilometers through the mountains.
"Ultimately, 11 lithium ore bodies were delineated, with one main ore body accounting for over 80% of the resources,"
said Senior Geological Engineer Yunhua Cai, who was responsible for field operations. During the third phase of exploration, the exploration team continuously innovated exploration approaches, applying advanced hydraulic portable drilling technology to implement green exploration techniques such as multi-hole drilling from a single base and multi-branch drilling from a single hole. These innovations solved technical challenges such as significant deformation and deviation of deep drill holes from the ore bodies, greatly improving exploration efficiency.
