When Vietnam scoured forests, mountains for rare earths

By Gia Chinh   December 2, 2022 | 03:26 pm PT
Nearly 100 Vietnamese and Japanese geologists and engineers spent the whole of 2010 surveying the mountains and forests of the northern Yen Bai, Lai Chau and Lao Cai provinces.

They were looking for rare earths, the indispensable materials used in the production of most high-tech equipment.

Rare earths are a group of 17 elements, the majority of which are irreplaceable in the production of batteries, permanent magnets for electric vehicles, wind turbines, aircraft, mobile phones, and defense equipment.

With 44 million tons, China has the largest reserves of rare earths in the world followed by Vietnam (22 million tons), Brazil and Russia (21 million tons each).

For three decades China has been the largest producer and exporter, accounting for a full 80% of production.

Since 2010, when it started restricting mining and exports, the hunt for rare earths began to spread around the world, and countries at the forefront of technological advancements came to Vietnam in the hope of finding alternative sources.

In early 2010 the Japan Oil, Gas and Metals National Corporation and Vietnam's Ministry of Natural Resources and Environment began surveying and exploring the northwestern region for ion adsorption-type rare earth element deposits.

It cost around VND14 billion (US$574,600), which was provided by the Japanese side.

Researchers

A survey team dig for rare earth in Lao Cai Province in 2010. Photo by VnExpress/Dinh Huan

The task was assigned to the General Department of Geology and Minerals and carried out by its geological division for radioactive and rare elements.

Trinh Dinh Huan, head of the division now but then still a technical officer, recalled that Japan chose Vietnam since, in the 1960s, Soviet experts had made initial reports on the discovery of rare earths in the mountainous northwest.

This region is contiguous to southern China, where rare earths are mined, and has a similar geology, geography and climate, meaning they could also possibly be found here at ground level and on a large scale, he said.

But the idea is to locate rare earths of the ion adsorption type since they exist freely, lie on exposed surface, are soluble and easy to extract and process.

Besides, they are the current global favorites.

On being assigned the task, geologists like Huan were worried because at that time their knowledge of rare earths was meager and mostly bookish. They virtually had no information about ion adsorption-type rare earths.

However, due to the urgent nature of the work, a week later Japanese experts and a team of officials from the geological division for radioactive and rare elements began to fan out across mountains and forests of the north.

The advance team sampled most of the identified rare earth mines and prospective ones based on research documents from the 1960s.

Huan recalled: "Back then travel was still difficult, there were no roads. To reach the survey points, we had to cross forests and wade through streams, and went to many places over bamboo bridges.

"But by the time we were ready to leave, the bridges would have been swept away by floods. The survey team would then camp in the forest and wait for the water to recede."

The team discovered that in areas with rare earth deposits the vegetation was often more lush than elsewhere.

In September 2010 hundreds of soil samples from prospected sites were brought back to Hanoi for analysis.

Samples from Ben Den in Gia Phu Commune, Bao Thang District, Lao Cai Province, were found to have the potential to contain ion adsorption-type rare earths.

Rare earths in northwestern Vietnam. Photo by VnExpress/Gia Chinh

Rare earths in northwestern Vietnam. Photo by VnExpress/Gia Chinh

While the location of a rare earth deposit was pinpointed, the next problem was to determine the extent of the reserve. After multiple meetings, the advance team and the Japanese experts agreed that the only way was to test drill at the site.

Those who had just gone to collect the samples then had to once again trek through the mountains and forests of Lao Cai for the drilling.

The contingent this time grew to include 70 Vietnamese and nearly 20 Japanese experts, and they carried 13 drills from the geological division for radioactive and rare elements.

In order not to risk missing the mineral, the team decided to explore an area of 26 square kilometers, including several mountain ranges.

Huan was promoted as project leader with direct charge of the field team. They were divided into two teams. One was a technical team comprising around 20 people that rented a number of locals' houses to live in.

Their job was to come up with plans, locate drilling sites and collect and synthesize data for analysis at the end of the project.

The other team carried out the actual drilling for samples. Since the drilling sites were far from residential areas and the equipment was bulky, the members had to set up camp and live in the forest.

For convenience, the team was divided into several smaller groups, each taking turns to stay behind in the camp to do the cooking. At the end of each day, one person from the drilling team would make a diary, submit it together with the day's soil samples to the technical team and receive instructions for the next day's work.

According to the plan, the field team had to drill 110 holes to depths ranging from seven to 50 meters.

Since each would take two or three days, almost the entire team was focused on the drilling so that the work could be completed in the shortest possible time.

Huan said for geologists working in the middle of a forest amid malaria was not a big problem but the difficult part was having to move the one-ton drilling rigs to the sites through the mountainous and forest terrain without roads.

Many of the sites were a few kilometers apart, meaning it took the drilling team more than a day just to move the rig to a new site.

In addition to hiring on-site labor, every time the team needed to pull a drill uphill, they would ask locals to help tow it using buffaloes.

In the more than four months of working in the forest, the most memorable incident for the field team was the time they went to a garden belonging to an ethnic minority family for drilling.

Though they had worked with the commune authorities to persuade the household and received their permission, while the drilling was going on the family suddenly dismantled the machine and threw parts of it into a pond.

Though it was cold and the temperature was just over 10 degrees Celsius, the team members had to take off their shirts and dive into the water and look for half a day to retrieve the equipment.

At the end of the drilling more than 1,400 soil samples were collected and sent to Germany for analysis.

The quantity and quality of the ion adsorption-type rare earths were to depend entirely on the results of the international partners' analyses.

During the two months they had to wait to get the results, Huan was constantly nervous, and often could not even eat or sleep.

But when the Japanese partner announced that Ben Den had large reserves of rare earths of high quality, far exceeding the initial expectation, he was bursting with joy.

The results showed that the field team had managed to locate three promising rare earth mines, including two in Gia Phu Commune measuring 3.37 square kilometers and 2.93 square kilometers, and a third measuring 2.14 square kilometers in Son Hai Commune, Bao Thang District.

The layer of rare earth deposits was determined to be between 1.4 meters and 24.3 meters thick, with an average of 13.1 meters.

Huan said: "I immediately reported to everyone in the team and the leaders of the General Department of Geology and Minerals.

"Everyone was full of hope that these rare earth mines would be put to use to serve the development of the country."

Nguyen Van Nguyen, deputy director general of the General Department of Geology and Minerals, said the cooperation with Japan resulted in the discovery of a new type of mine that had not ever been found before.

Based on this, Vietnamese geologists came up with experiences to find rare earth mines that are valuable, easy to mine and have little impact on the environment, he said.

The General Department of Geology and Minerals is still investigating and evaluating the rare earth resources (mainly ion adsorption-type) in the northwestern and central regions.

Preliminary results have showed that potentially large quantities of rare earth elements have been discovered in the provinces of Lao Cai, Yen Bai, Ha Giang, Cao Bang, Lang Son, Nghe An, Kon Tum, and Lam Dong.

However, to obtain accurate data for each area, it is necessary to collate the results of the studies once both projects are completed in the two regions, he said.

"These results will definitely confirm that Vietnam's total reserves of rare earths are greater than the figure released by the U.S. in 2022."

 
 
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