237 238 rhenium resources in Arizona, there appear to be a few hundred tons Schwartz, G. M., 1953, Geology of the San Manuel copper deposit, Arizona: U.S. Geo!. Survey Prof. Paper 2;)0, 6u p. of this metal that are associated with the molybdenum resources. The Thurmond, R. E., Olk, J. F., Komadina, G. A., Journay, J. A., Spaulding, E. D., production of rhenium may be expected to increase considerably. and Hernlund, R. 'V., 1958, Pima, three-part story, geoiogy, openpit, milling: Mining Eng., v. 10, no. 4, p. 4u3-4G2. SELECTED REFERENCES U.S. Hureau of Mines, 1!J67, I1Iolybuenum, in Minerals Yenrbook, 1!JG6, Volume I-II: U.S. Bur. Mines, p. 331. Anderson, C. A., Scholz, E. A., and Strob£'ll, J. D., Jr., 1955, G£'ology and ore --- 1068, Rhenium, in Commodity Data Summaries: U.S. Bur. Mines, p. d('posits of the Bagdad area, Yavapai County, Arizona: U.S. Geol. Shrvey Prof. 124-125. PaJlpr 278, 103 p. Cooper, J. R., 191'iO, Johnson Camp area, Cochise County, Arizona, in Arizona zinc and lead deposits, Part I: Arizona Bur. Mines Bull. 156, p.3().-39. NIOBIUM AND TANTALUM Creasey, S. e., 10;)0, Geology of the St. Anthony (Mammoth) area, Pinal County, Arizona, in Arizona zinc and lead deposits, Part I: Arizona Bur. Mines Bull. (By R. L. Parker, U.S. Geological Survey, Denver, Colo.) 156, p. (;3-84. Creasey, S. C., Rnd Quick, G. L., 19f.ifl, Copper deposits of part of Helvetia mining INTRODUorION district, Pima County, Arizona: U.S. Geol. Survey Bull. 1027-Jt~, p. 301-323. Dings, :\1. G., 1951, The Wallapai mining district, Cerbat Mountains, Mohave Niobium (columbium) and tantalum are rare metals that have be­ County, Arizona: U.S. Geo!. Survey Hull. 97B-E., p.123-162. Engineering and Mining Journal, 1968, Markets: Eng. Mining Jour. v. 169, no. come increasingly important in modern technology; they are useu in 2, p. 21-25. certain elect.ronic, nuclear, chemical, and high temperature metallurgi­ Granger, H. C., and Raup, R. H., 1002, Reconnaissance stUdy of uranium deposits cn,} applications. Both metals are used for vacuum tube elements, super­ in Arizona: U.S. Geol. Survey Hull. 1147-A, 54p. Hamilton, Peggy-Kay, and Kerr, P. F., 1959, Umohoite from Cameron, Arizona: conductors, and corrosion-resistant equipment and laboratory ware, Am. Mineralogist, v. 44, p. 124B-1260. and as constituents in high temperature nonferrous alloys. These IIpikes, V. C., 1921, Gold, silver, ropper, lead, and zinc in Arizona, in Mineral metals, in the form of ferrocolumbium or ferrotantulum-columbium, Resourcps of the United States, 1018: U.S. Gool. Survey, pt. I, p. 329-368. are used in the manufacture of special types of steel. Niobium and Hess, F. L., 1HZ1, Molyb<lenum, in Mineral nesources of the United States, 1018: tantalum carbides are used in hot-forging dies, cutting tools, and jet U.S. Geo!. Survey, pt. I, p. 795-805. ---1924, Molybdenum deposits, short review: U.S. Geol. Survey Bull. 761, engine turbine blades. Niobium especially is used for cladding and al­ 35p. loying' lluclear fuels, whereas t.:\Iltlllum is used fol' capacitors, recti­ Johnson, W. P., and Lowell, J. D., 1961, Geology and origin of mineralized fiers, and surgical implants (Miller, 1959 j Barton, 1962; Stevens, breccia pipes in Copper Basin, Arizona: Eron. Geology, v. 56, no. 5, p. 916-940. 1965a, b). Kinnison, J. E., 1966, The Mission eOII/l('r (]PllOsit, Arizona itL Titley, S. R.. and Hicks, C. L., Eds., Geology of the porphyry copper deposits, southwestern North Various substitutes for columbium are vanadium in stainless st.eel; . Amt'rIt"8: Arizona Univ. (Tucson), p. 281-287. molybdenum, vanadium, tungsten, and ceramic coatings in high tem­ Kirkemo, Harold, Anderson, C. A., and Crpasey, S. C., 1965, Invelltigations of perature applications; and alloys of technetium, vanadium, tin, and molybdenum deposits in the conterminolL'l United States, 1042-00: U.S. Geol. Survey Bull. 1182--E, 00 p. gadolinium in certain applications in the control of nuclear fusion re­ Kuhn, T. H., 1941, Pipe deposits of the Copper Creek area, Arizona: Econ. actions. Substitutes for tantalum include aluminum, silicon, germa­ GeoloAY, v. 36, no. 5, p. 512-538. nium, selenium, zirconium, titanium, and misch metal in various Olson, II. J., 1966, Oxidation of a sulfide body, Glove mine, Santa Cruz County, electronic applications; and platinum, niobium, and zirconium in Arizona: Econ. Gpology, v. 61, no. 4, p. 731-743. Ppierson, N. P., 1962, Geology and ore deposits of the Globe-Miami district, Ari­ corrosion-resistant materials. zona: U.S. Gool. Survey Prof. Paper :!42, 151 p. The United States is the world's largest consumer of niobium and Petprron, N. P., and Swanson, R. W., 1nG6, Gpology of the Christmas copper mine, tantalum, relying almost entirely on foreign sources, principally Ni­ Gila County, Arizona: U.S. Gro!. Survey Bul!. 1027-H., p. 351--373. geria, Congo, Brazil, and Canada for its ore supply. Critical shorl­ Petprl<OIl, R. G., Hamilton, J. C., Ilnd Mrers, A. T., 1959, An oceurrence of rhenium associated with uraninite in Coconino eounty, Arizona: Econ. Geology, v. 54, :iges of these metals, caused by expanded wartime usc, resulted in no. 2, p. 254-267. government allocation controls durmg 1Vorld "'Val' II and the Ko­ Ransome, F. L., 1915, The cOPIX'r deposits of Ray and Miami, Arizona: U.S. rean conflict. During 1952-55 domestic and foreign orcs were pur­ Gpol. Survey Prof. Paper 11G, 1H2 p. chased at bonus prices by the government for stockpiling purposes. Re<b£'r, L. E., Jr., 1916, The mineralization at Clifton-Morenci, Ariz.: Eoon. Geology, v. 11, p. G28-l'i7:l. The program was extended to 1058 for domestic ores. RiC'hard, K. E., and Courtright, J. II., 1054, Structure and mineralization at The U.S. annual imports and production and world al11l11al pro­ Silver Bell, Arizona: Mining EnA'., v. 6, no. 11, p. 10H5-1009; Am. Inst. l\lininA' duction are shown in figmc HG. During the last 14 years, impOl'ts of Mt'tall. P(·troleulll Enginpprs Trans., 1!);1-l, v. l11n. InriG. niobimn-tantalmll COll<~pntl'Htes have ranged from an alltime high of --106<1, Structure and mineralization at Silver Bell, Arizona, in Titley, S. K., nnd IIil'ks, C. L., ('ds., Geolog~' of the porphrry copper dpposits, southwestern . 11,520,262 pounds in 1055 (reflecting government stockpile purchas­ :"orth Anwrica : Arizona Ulliv. ('liwson), I>. 1m-163. ing) to a low of 3,591,530 pounds in 1958. Imports have g'pn'.mtIly in­ Schrad('r, F. C., lllOn. The mi!u'ral deposits of the Cerhat nange, HInck Moun­ creased each year since. 1958 to the 1066 level of 11,421,000 pounds tains, and Grand Wash Cliffs, Mohave County, Arizona: U.S. Geo!. Survey Bull. 397,.226 p. 239 240 27.1 16 ~ (U.S. Bur. Mines, 1956-67) and can be expected to continue to follow this trend in subsequent years because of the increasing domestic con­ sumption of these metals. The U.S. niobium-tantalum production Data from: Minerals Yearbook, 1953-66 I reached a peak qf 428,347 pounds of concentrates in 1958, most of (U.S. Bur. Mines). [Annual volumes ·which came from Idaho placers. Such production, however, amounted for years indicatedJ 14 - to only a tenth of that year's domestic consumption. No domestic pro­ duction has been recorded since 1959 except for a small amount of material stockpiled by two pegmatite mines in South Dakota in 19GG (US. Bur. MUles, 1956-(7). Domestic consumpt,ion of niobium and tantalum is supplied almost entirely by imports from Canada, South 121- America, Africa, and Asia. Arizona, with a total production close to 3,000 pounds of niobium­ I- United Stotes imports tantalum concentrates, ranks sixth among the states as a producer of these elements. Even so Arizona has produced only about 0.2 percent .... of the Nation's toial production, and the State's total production is an :: 10 I- .... exceedingly small fraction of the Nation's annual consumption (Bar­ . :.... ton, 1962, p. 83) . lI) :\.... World production o OCCURRENCE AND U BE z :> a.o _ Niobium and tantalum do not occur in nature as free metals, but are IL found commonly together as constituents of minerals that are com­ o e l­ ll) pounds .of niobium, tantalum, and oxygen with subordinate amounts z of titanium, iron, manganese, rare earths, uranium, thorium, and other o United ..J metals. Important ore minerals are columbite-·tantalite (Fe,Mn) (Nb, ..J Stotes .... .... ::l! production :: Ta) 200; pyrochlore NaCaNb20 oF; yttrotantalite (Fe, Y, U) (Nb, :: Ta)04; microlite (Na,Ca)2Ta200(0,OH,F); euxenite (Y,Ca,Ce,U, .... .... :." .': Th) (Nb,Ta,Ti) 206 ; fergusonite (Y,Ca,U,Th) (Nb,Ta,Ti) 0 ; and :: 4 ::: samarskite (Fe,Y,U) 2(Nb,Ti,Ta) 207, Niobium and tantalum are also .... contained in various amounts in titanium minerals-sphene, rutile .... '.' ::: .... .... ... (ilmenorutile), and ilmenite (Palaehe and others, 1944) . :;:: .... :.- :~:, Contrary to general opinion, niobium is a fairly common element in 4 .,. the earth's crust; it is about as abundant as cobalt and more plentiful .••. ;::: than lead. Tantalum is much scarcer than niobium but more abundant :: m!1n~ :: than antimony, silver, or gold. However, compared with other .••. valuable elements whose crustal abundances are less than mobmm or .... tantalum and which tend to concentrate in discrete ore bodies, concen­ tra,ted deposits of niobium and particularly tantalum are scarce. Niobium and tantalum minerals are found in certain granitic rocks :: and pegmatites, alkalic rock complexes and carbonatites, and placers :: . ! derived from these rocks. Some granite masses contain disseminated columbite-tantalite, euxenite, or other niobium-tantalum-bearing min­ o :::: ..; ...