Tungsten could be held ransom unless domestic mines open

Tungsten, or wolfram, is the 74th element on the periodic table of elements and, like many other metals that have found their way onto critical mineral lists in Canada, Europe, and the United States, this sturdy metal is vulnerable to supply disruption.

Tungsten has been known since prehistoric times, and as far back as 350 years ago, Chinese porcelain makers were using this element as a pigment to incorporate a unique peach color into their designs.

Its provenance as one of the toughest elements on Earth began in 1779 when an Irish mineralogist and chemist named Peter Woulfe discovered a new metal while examining ore from Sweden.

Ironically, the name wolfram does not originate from Woulfe but from one of its principal ores, wolframite, which was named some 30 years earlier.

Two years after Woulfe's findings, a Swedish-German pharmaceutical chemist named Carl Wilhelm Scheele discovered that a new acid, tungstic acid, could be made from scheelite – which at the time was called tungsten. From this, he deduced that a new metal could be obtained by reducing this acid.

Despite both scientists getting close, the discovery of tungsten is attributed to brothers José and Fausto Elhuyar, Spanish chemists who found an acid made from wolframite that was identical to tungstic acid. Thus, at the Royal Basque Society in the town of Bergara, Spain, the brothers succeeded in isolating tungsten by reduction of this acid with charcoal and are forever credited with the discovery of the heavy metal.

Strategic metal

The strategic value of tungsten came to notice in the early 20th century when British authorities acted to free the Carrock mine from German control. However, tungsten would play a more significant role during World War II when political tensions in Europe were at their highest.

Portugal, as the main European source of the element, was put under pressure from both sides because of its deposits of wolframite ore at Panasqueira.

Due to tungsten's desirable properties, such as resistance to high temperatures, its hardness and density and its strengthening of alloys, this made it an important raw material for the arms race, both as a constituent of weapons and equipment but also in the production of tungsten carbide cutting tools for machining steel.

Nearly 60% of the tungsten consumed in the U.S. during 2020 was used to make cemented tungsten carbide, a compound of roughly equal parts tungsten and carbon.

Nearly twice as strong as steel, tungsten carbide is often found on the working end of drill bits, saw blades, wear plates, and other items that require this compound's toughness to meet some of the most demanding conditions in the mining, oil and gas, construction, and metal-working industries.

Tungsten carbide's hardness and density also make this metallic compound ideal for making armor-piercing ammunition for the military.

Of all metals in pure form, tungsten has the highest melting point (6,192 degrees Fahrenheit). Because it retains its strength at these high temperatures, elemental tungsten is used in many high-temperature applications.

Heating elements, lightbulb filaments, rocket engine nozzles, and TIG (tungsten inert gas) welding are among the many applications that take advantage of tungsten's ability to hold up to heat.

US criticality

According to the United States Geological Survey Mineral Commodity Summaries 2022, world mine production and reserves for 2021 include:

• China – 66,000 metric tons produced and 1.9 million metric tons of reserves.

• Vietnam – 4,500 metric tons produced and 100,000 metric tons of reserves.

• Russia – 2,400 metric tons produced and 400,000 metric tons of reserves.

• Bolivia – 1,400 metric tons produced with reserve amount not available.

• Rwanda – 950 metric tons produced and reserve amount not available.

• Austria – 900 metric tons produced and 10,000 metric tons of reserves.

• Spain – 900 metric tons produced and 52,000 metric tons of reserves.

• North Korea – 400 metric tons produced and 29,000 metric tons of reserves.

• Portugal – 620 metric tons produced and 5,100 metric tons of reserves.

And finally,

• United States – zero metric tons produced and reserve amount not available.

"World tungsten supply was dominated by production in China and exports from China," the USGS wrote in its report.

Last year, China's government regulated its tungsten industry by limiting the number of mining and export licenses, imposing quotas on concentrate product, and placing constraints on mining and processing.

Reduced production during or after purported environmental and safety inspections at Chinese mining operations contributed to periods when supplies of tungsten concentrates were down from China.

While production of tungsten concentrate outside of China was expected to increase in 2021, it remained less than 20% of the world's production.

As a stopgap, the U.S. government has been supplementing its own supply out of its stockpiles, and according to USGS data, the available amount in the stockpile was down nearly 1,000 metric tons from the previous year leaving only 6,850 metric tons.

However, there are ample possible mine sites that could stymie the potential risks of having China lock its supply down completely, albeit if they ever get through permitting or if they become available from being sealed away in conservation areas.

North American Tungsten

Tungsten resources are plentiful for this heavy metal in Canada and the U.S., especially the Rocky Mountain states and provinces, as well as Alaska, Yukon, and Northwest Territories.

Mines along the Yukon-Northwest Territories border are past tungsten producers and are among the most promising projects for restoring a North American supply of this durable critical metal.

According to a 2014 technical report prepared for North American Tungsten, a company that fell into financial difficulties in its attempts to resume tungsten mining in this area, the Cantung project hosts 3.84 million metric tons of indicated resources averaging 0.97% tungsten trioxide, and 1.37 million metric tons of inferred resources grading 0.8% tungsten trioxide.

Mactung, which is about 100 miles northwest of Cantung, hosts 33 million metric tons indicated resource averaging 0.88% tungsten trioxide, making it one of the largest known undeveloped, high-grade tungsten-skarn deposits in the world.

Despite Mactung's world-class size and grade, along with being advanced well into permitting, North American Tungsten had to file for creditor protection before it could develop the mine that would have produced roughly 750,000 metric tons of tungsten per year, which would have been added to the 383,000 metric tons per year being produced at Cantung up until around 2015.

Following North American Tungsten's bankruptcy, a court-appointed monitor oversees site operations, which is funded by the federal government.

Canadian mineral explorer Fireweed Metals Inc., however, recently agreed to buy the Mactung tungsten project from the NWT government for C$15 million.

As it lies adjacent to the company's flagship Macmillan Pass zinc-lead-silver project in the Yukon, the company has decided to add this strategic property to its quickly growing portfolio of critical minerals and metals.

"We now have not only one of the largest undeveloped zinc resources in the world at our Macmillan Pass Project, but also one of the world's largest and highest-grade undeveloped tungsten projects at the advanced stage Mactung Project," said Fireweed Metals CEO Brandon Macdonald. "With both zinc and tungsten being designated as critical minerals by Canada, the US, and the EU, Fireweed is positioned to leverage the transition to a sustainable green economy."

Cantung, however, remains under care and maintenance directed by the court-appointed monitor.

Viable tungsten and copper reserves remain at the Cantung mine, and the territorial government is looking for a company to resume operations at the mine before the site is remediated and eventually closed.

At least six tungsten exploration projects are located just across the border in Canada's Yukon.

Locked away Bear Mountain

While there is not any tungsten produced in the U.S. today, this sturdy, industrial metal was historically mined in several Alaska locales to meet America's needs during both World Wars.

The gold-rich hills around Fairbanks, in the heart of Alaska's interior, are one of the past-producing tungsten regions.

However, the largest deposit of tungsten in Alaska may lie in the Bear Mountain occurrence along the southern slopes of the Brooks Range.

During visits to Bear Mountain in the 1980s, U.S. Bureau of Mines geologists James Barker and R.C. Swainbank identified a 100-acre area of surface mineralization indicative of a large porphyritic molybdenum-tungsten deposit.

Analysis of 20 soil and 36 rock samples collected during 1985 returned abundant tungsten and molybdenum along with lesser amounts of niobium.

Soil samples collected at the time returned tungsten values exceeding 500 parts per million wolframite, with the best samples containing 5,000 ppm of this tungsten mineral.

"I believe Bear Mountain to be likely the most important tungsten deposit in the U.S.," Barker, who spent much of his career doing critical mineral assessments for the former U.S. Bureau of Mines, told Data Mine North.

The potential of this intriguing tungsten-molybdenum discovery, however, may never be realized due to its location.

In addition to being in a remote corner of northeast Alaska, this potentially world-class tungsten-molybdenum deposit is situated within the Arctic National Wildlife Refuge, or ANWR, a 19.3-million-acre region set aside for wilderness and wildlife conservation.

"It's a shame that mineral evaluations aren't done before we place an area off-limits," Barker reflected.

While Bear Mountain tungsten, molybdenum, and niobium may be stored in a restricted reserve, past-producing mines in Alaska and Northwest Territories have answered North America's urgent call for tungsten in the past and have the potential to answer a similar call should a pressing need for the durable industrial metal rise again in the future.