• INDUSTRY & BUSINESS

PRODUCTION BOOST· Fansteel's new tantalum and nio­bium plant in Muskogee, Okia., augments company's output

in North Chicago, ΠΙ. Increased production should take care of all shortages, both current and ixi the near future

More Tantalum and Niobium On W a y N e w Fansteel plant goes on stream this week in Oklahoma,· firm's tantalum output to go up 5 0 % , niobium 1 5 0 %

Ο Ν FRIDAY, FANSTEEL METALLURGI­CAL Corp. officially starts up its new tantalum and niobium plant near Mus­kogee, Okla. The $6.5 million installa­tion ups Fansteel's tantalum production by 50%, niobium by 150%. Beginning with ores, the two metals will be puri­fied, separated, and made into metal powder and ingots, augmenting output of the company's main plant at North Chicago, 111.

The increase in tantalum production should take care of all current shortages as well as any that may arise in the im­mediate future, claims Fansteel, already the world's major producer of the metal. Main reason for increasing tan­talum production is the demand for capacitors. In 1956, when the com­pany decided to build a new plant, its sales of capacitors and tantalum com­ponents supplied to other capacitor makers had risen 68% in one year. Emphasis on missiles in the nation's de­fense program calls for even more tan­talum today. One type of guided mis­

sile, for instance, uses 15,000 capaci­tors.

Tantalum demand for chemical equipment is rising steadily, too. The metal is used in some of the most severely corrosive processes in the chemical and allied process industries. Equipment using tantalum includes heat exchangers, coils, condensers, and the like.

Niobium has only a limited market so far. It's biggest outlets are experi­mental atomic reactors and high tem­perature alloys.

• Decentralization. Early in the planning stage, Fansteel decided to build at a location other than North Chicago. The company and the Gov­ernment thought it best to decentralize as a defense measure. ( But no federal money was used. Financing was done with $3 million in convertible deben­tures, the rest out of earnings). More­over, the company was running out of space in its home town, and cost of ad­ditional land in that heavily populated

area is prohibitive. In the search for land, 150 sites were considered.

The Muskogee decision was clinched by the presence there of a new generat­ing plant built by the Oklahoma Gas & Electric Co. Other reasons for the choice include good manpower supply and water and natural gas resources. Also, the site is near Gulf Coast and other sources of chemical reagents.

Fansteel's Oklahoma property totals 113 acres, and the company has an op­tion on 120 adjoining acres. Structures on the site include twO chemical opera-tions buildings, a sintering building, tank farms, and an administration building. There's plenty of room for expansion, says Fansteel, and the build­ings can be extended in any direction. Outside tanks are used to store hydro­chloric acid and sodhum and potassium hydroxides,

ί Crystallization Process. The tan­talum and niobium extraction and sepa­ration process at Muskogee is the same as the one used in North Chicago

2 4 C & E N M A R C H 10, 1958

MORE EFFICIENT. Extraction and separation process at Muskogee works much like the one at North Chicago; however, increased mechani­zation and instrumentation in the Oklahoma plant result in higher efficiency, Fansteel says. Metals will be made into powder and ingots. Much of the tantalum will go into capacitors. Niobium's biggest outlets, although the market is limited, look like experimental atomic reactors and high-temperature alloys

PUSH BUTTON PROC­ESS. New plants usu­ally bring better per­formance. Fansteel says its new plant has more machinery and instruments than its Illinois plant, so it can cut down on manpower and, at the same time, make the Oklahoma operation more efficient

(I&EC, April 1956, page 686) . Key operation is separating the two metals by fractional crystallization of their fluoride salts. Main improvement at Muskogee is increased mechanization and instrumentation, resulting in higher efficiency and less manpower.

First step in the process is extracting the two metals from tantalite or colum-bite ore (name depends on which metal predominates), which comes from Africa and South America. The ore is fused with sodium hydroxide in a gas-fired furnace. After flaking, the fusion product is leached; first with hot water,

then -with hot hydrochloric acid. Acid leaching gives a mixture of crude tan-talic and niobic acids.

To separate tantalum from niobium, this erude acid mixture is dissolved in hydrofluoric acid. A stoichiometric amount of potassium hydroxide is added to the HF solution. Upon cool­ing the solution, potassium tantalum fluoride (K 2TaF 7 ) crystallizes and is separated. Niobium remains in solu­tion a s potassium niobium oxyfluoride (K2N~bOF5) is recovered as sodium niobate by adding sodium hydroxide.

Electrolysis of K2TaF7 gives pure

tantalum metal powder which is sold as such (in various particle sizes), or is pressed into ingots. Massive metal is obtained by sintering the ingots in a vacuum furnace. Sodium niobate is converted into oxides and carbides. Reacting the two together turns out niobium powder and carbon dioxide.

Sometime in the future, when re­search and pilot plant studies are com­pleted, a liquid-liquid extraction proc­ess to separate the two metals will be used at Muskogee. The plant's produc­tion will go to North Chicago for fabri­cating and for use in capacitors. •

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