Tantalum and niobium scrap

Tantalum and niobium are almost always found together in nature, and USGS notes that tantalum was confused with niobium until 1864. In a scrap bin they are very different things.

Tantalum is, in the words of USGS, “a dark blue-gray, dense, ductile, very hard and easily fabricated metal.” NIST gives its density as 16.65 g/cm3. Niobium is a lustrous gray, ductile metal with a high melting point and relatively low density: 8.57 g/cm3 in the same NIST table. Size for size, a tantalum part weighs nearly twice what a niobium part does.

Older invoices may say columbium, the earlier name for niobium. Both metals appear on the Final 2025 List of Critical Minerals, published in the Federal Register in November 2025.

Sources: USGS Professional Paper 1802-M, Niobium and tantalum (2017); NIST, X-ray mass attenuation coefficients, Table 1 (element densities); USGS Circular 1196-I, Columbium (niobium) recycling in the United States in 1998 (in 1196-A-M, 2004); Federal Register, Final 2025 List of Critical Minerals (November 7, 2025).

Capacitors are the leading use of tantalum in high-end products, USGS says: cell phones, computer hard drives and implanted devices such as pacemakers. In world consumption figures USGS cites from 2011, capacitor-grade tantalum powder came first at 24 percent, just ahead of mill products at 22 percent.

They are also the hardest tantalum scrap to judge. A 1998 USGS study found that new scrap reclaimed at plants making tantalum electronic components was a major source of supply and went back to tantalum processors, while “the amount of tantalum recovered from obsolete electronic equipment is small.” Smaller capacitors also hold less tantalum each and take more labor to recover.

• Factory rejects and surplus reels of loose tantalum capacitors are the cleanest form; keep them labeled.
• Capacitors pulled from boards carry solder and leads, so bag them apart.
• Whole circuit boards are mostly other material: send photos and ask first.

Not every small capacitor is tantalum. USGS names aluminum, ceramics and niobium as substitutes for tantalum in electronic capacitors, so sort a mixed lot or describe it plainly on the quote form.

Sources: USGS Professional Paper 1802-M, Niobium and tantalum (2017); USGS Open-File Report 01-349, Tantalum recycling in the United States in 1998 (2001); USGS Mineral Commodity Summaries 2026, Tantalum (February 2026).

Weight is a clue, not an answer. Tantalum at 16.65 g/cm3 outweighs tungsten carbide, which NTP lists at 15.6, so a tantalum block and a carbide block feel much the same in the hand. Niobium at 8.57 sits near nickel at 8.902 and iron at 7.874 in the NIST table, so niobium sheet can pass for steel or a nickel alloy.

• Tantalum, niobium, tungsten and carbide go in four separate bags, with steel screws and brackets removed.
• Save labels, mill certs and part numbers, and write the metal on each bag.
• Keep capacitors apart from solid tantalum.
• If a piece is a mystery, note where it came from.

Carbide often carries some tantalum of its own. USGS reported that cemented carbide inserts typically held about 3 percent tantalum in 1998. Sell inserts as carbide: we buy carbide too, in any form; see the carbide inserts page.

Sources: NIST, X-ray mass attenuation coefficients, Table 1 (element densities); NTP Report on Carcinogens, Cobalt-tungsten carbide profile; USGS Open-File Report 01-349, Tantalum recycling in the United States in 1998 (2001).

Tell us on the quote form what you have and roughly what it weighs, and add a few photos; you can also email help@carbidebuyerusa.com or call (877) 838-9920. From anywhere in the US you can ship it to us, and we pay the shipping. In California, Arizona and Nevada we come to you and pick it up, in every city of all three states.

Tantalum makes a small box heavy: USPS refuses any mailpiece over 70 pounds and wants dense items of 20 to 45 pounds in at least 200-pound test board. Packing details are on our shipping page.

We pay cash where state law allows. Arizona's payment rule goes by dollar amount, not by metal: a scrap metal sale of $300 or more cannot be paid on site, and the check or money order is mailed to the address on the seller's ID. Industrial accounts that preregister their authorized sellers each year are exempt from that mailing rule.

Nevada requires a scrap metal processor to pay for any scrap metal purchase of $150 or more only by check or electronic transfer. The statute's definition of scrap metal does not name tantalum or niobium, so plan on a check or transfer for a Nevada sale of that size.

In California the mailed-check-or-third-business-day rule applies only to copper, copper alloys, stainless steel and aluminum; tantalum and niobium are not on that list. The scrap metal rules guide covers the record and ID rules in all three states.

Sources: USPS Domestic Mail Manual 201; USPS Domestic Mail Manual 601; Arizona Revised Statutes 44-1642; Nevada Revised Statutes chapter 647; California AB 1508, Chapter 531, Statutes of 2012 (Bus. & Prof. Code 21608.5).