Strategic Metals - Tungsten

From the amount of feedback I got on Columns 10 (Strategic Metals) and 11 (Molybdenum) I guess this has become an area of concern to many and a subject of interest in the Financial Community. I was asked quite pointedly, did I really consider this an issue or is it just a topic that makes "good press". Rather than react emotionally, since my personal opinion of the press is just short of politicians, lawyers and used car salesmen, I will answer this as follows; yes, it is a major strategic concern. It will be very difficult for the US to develop new technologies, where such technologies are dependent on raw materials controlled by other countries. This would be especially true if such countries limit international commercial availability of these materials, thereby forcing associated technological developments to move to their country to gain access to them. It will also be very difficult for the US to project an international presence where the very tools of such presence are dependant on raw materials potentially controlled by political and economic competitors. Materials like Indium, which is critical in the development of flat screen displays, and Rare Earths, which are critical in the development of new battery and hydrogen storage technologies, potentially associated with alternative energy systems fall into the technology "bucket". Tungsten, a key component of military armor plating and armor-piercing projectiles, cutting and machine tools and filaments for lighting is probably a good example of the latter. So let's take a look at Tungsten.

First what is it? Tungsten is number 74 on the Periodic Table of the Elements, making it a "Transition Metal" like Molybdenum, with which it shares some properties. Its name is from the Swedish words "tung" and "sten" which mean heavy stone. The chemical symbol however is from the German term "Wolfram", so named because tungsten interferes with the smelting of tin. Early metallurgists called it "Wolframite" or "the devourer of tin" because "it devoured tin like a wolf devoured sheep". Interestingly enough, one of the first scientists of his day to investigate the metal was Peter Woulfe, in 1779; and some historians associate the name "Wolframite" with his name. In 1781 Scheele, for whom the Tungsten mineral Scheelite was named, found that a new acid, called Wolframic acid, could be made from this material. He proposed that the material could be refined by way of the reduction of this acid. Tungsten, as we understand it, was isolated by the Elhuyar brothers (Juan Jose and Fausto) in 1783 by crushing Wolframite ((Fe,Mn)WO 4 ), cleaning and treating it with alkalis forming Tungsten Trioxide (WO 3 ), and then reducing it with Carbon or Hydrogen gas. This forms Tungsten metal and either CO 2 or H 2 O. Today the same approach is used to recover Tungsten from its two primary commercial minerals, Wolframite and Scheelite (CaWO 4 ). Commercial Tungsten deposits are almost always one or both of these minerals. One of the interesting and useful (in locating it) physical characteristics of Scheelite is that it has fluorescent properties, glowing blue to yellow in a short-wave UV light.

Its isotopes vary in molecular weight from 158 to 190, with those of 180, 182, 183, 184 and 186 being considered stable. Some of the others have a relatively long half-life; such as 181 with 121.2 days, 185 with 75.1 days, 188 with 69.78 days and 178 with 21.6 days.

Why is it important? Tungsten has some physical and chemical properties that make it a very attractive metal. For example it has thee highest melting point and lowest vapor pressure of all metals and, over 1,650 degrees Centigrade it has the highest tensile strength. It melts around 3,422 degrees Centigrade and boils at about 5,555 degrees Centigrade, roughly similar to the Sun's surface. Such characteristics make it the choice for high-temperature applications such as lighting filaments, electrical contact points, heating elements and X-ray targets. As an alloying element to steel it imparts some of these characteristics to the steel, resulting in a product that is stable at high temperatures. Tungsten alloy steel has broad application in cutting tools ("T" Steels) and in specialized applications such as rocket nozzles. In the cutting tools arena Tungsten offers some level of substitution for Molybdenum since either Tungsten-alloyed ("T" Steels) or Molybdenum-alloyed ("M" Steels) may be used in some applications.

Where is Tungsten found today? While Tungsten deposits are plentiful in the US, they have not been economical for some time. The last Tungsten mine production of concentrates, of any real size, from a US mine was in 1996, although by some accounts it was the Andrew Mine, northeast of Los Angeles, which ceased production in 1992. The last big US mine, probably the Pine Creek or Jackrabbit, near Bishop in Inyo County, California, ceased production somewhat earlier, but US Tungsten Corporation continued to produce concentrates from stockpiled ores at the Pine Creek Mine until 1994. By the way, the history of the Jackrabbit Mine's name is interesting. The story goes that a prospector named Jim Powning was out prospecting for gold and got hungry. He shot a jackrabbit for food but it ran into a hole. While he was digging it out he found Scheelite. He went back to looking for Gold. When WWI broke out and Tungsten was needed for armaments, and area boomed. The mine, the first discovery of Tungsten in the area, which later became known as the Tungsten Hills, was named in honor of the jackrabbit.

Today almost all of our Tungsten is imported; all that is, except what is recovered from scrap, which accounts for about 30% of our total consumption. Of the remainder, the USGS indicates from 2000 to 2003, 47% was from China, 18% from Canada and the balance from a number of other countries led by Russia and Kazakhstan. In 2003 the only Canadian production, the Can Tung Mine in Yukon Territory suspended operations after its two major customers terminated their purchases in favor of Chinese supply. Many of the Russian and Former Soviet Union mines are short of capital to undertake needed modernization of their mines and have reduced production or closed altogether. Like Molybdenum, we have become dependant on China for our needs.

There used to be, and I believe still are, three plants in the US that still process Tungsten concentrates. Osram Sylvania, Inc. in Towanda, Pennsylvania, and Alldyne Powder Technologies in Huntsville, Alabama (a unit of Allegheny Technologies) produce ammonium paratungstate which is used as the base feed for Tungsten-based chemicals and powder. It is also a major form in which Tungsten is traded. Kennemetal of Latrobe, Pennsylvania, uses a thermit process to produce macrocrystalline tungsten carbide directly from concentrates, I believe at their plant in Nevada.

The Western US has an awful lot of Tungsten in it and was historically a major Tungsten producing region. Tungsten is usually found in newer mountains such as the Rockies, in deposits of magmatic (derived from or of magma) or hydrothermal origin. The magmatic deposits are the result of magmatic differentiation where the original lava flows through an area or into cracks and crevices and cools. Since various elements and minerals crystallize out at different temperatures you may get concentrated zones of one of the minerals, like Tungsten. In hydrothermal deposits it is often carried along with other elements and minerals, including Gold and Molybdenum. The Pine Creek Mine, for example, had a Gold by-product.

I am not sure if Tungsten lends itself to mining by small operators, but with the big run-up in price recently (from about $2.45/lb. two years ago to the $15.00/lb. range today), if it ever will be now is probably the time. In May, 2002, ICMJ's Prospecting and Mining Journal ran a great story about a small-scale mining operation for Tungsten done in 1977, in Kern County, California. They claim to have received a 3:1 payback, so it was successful. One big plus they had was they had a relatively nearby outlet for their material; the Union Carbide Tungsten Processing Plant, north of Bishop. It was close enough that they were able to ship ore and not have to concentrate it, which greatly reduced their investment. The problem is today that plant is no longer operational.

If you had Tungsten ore you would probably have to concentrate it to be able to market it, and that would require investment. To do the concentration as inexpensively as possible you would likely employ some type of gravimetric separation. The major ores are pretty heavy; Scheelite having a density of 5.9 to 6.1 and the Wolframite "group" from 7.14 to 7.54, so this should be effective. I am told, by people in the business (major producers) that gravimetric separation is only effective for about a 45% to 55% concentrate. The Kennemetal plant in Nevada used to require a 70%+ concentrate, so you would likely have to ship it to Osram, Alldyne or export it. This would necessitate fairly large volumes, probably rail-car size lots (150,000 pounds) or at least container-size (44,000 pounds) for export. Another option would be to use a trader but you take a price "haircut" with traders, but at least you can access the Market. A second issue, is that Gold is often found with Tungsten and with the gravimetric approach is likely that you would loose any Gold in the material unless you got nugget-sized pieces and could pick them out in some way. If you were panning for Gold however, and didn't contaminate the residue, this could be collected for later processing and recovery of the Tungsten. It also says if you are looking primarily for Tungsten, old Gold tailings piles (like Molybdenum) might be a place to start.

Any way you look at it, this is a lot of material for one person or a few people to come up with by panning, but a large club might undertake its collection as a project. In the early mining days of the Tungsten Hills, Inyo County, California, the miners did pan for Scheelite and appeared to be quite successful, for their day. Today we have another trick to spot Scheelite; it is intensely fluorescent in short-wave ultraviolet light. It glows a pale blue, while the Molybdenum member of this family, often found with it, Powellite, glows yellow. They are both valuable. The heavier member of the "Tungsten Ore Clan", Wolframite is not fluorescent.

By the way, before I get a hundred e-mails telling me Wolframite doesn't exist, let me explain why I use the term. I recognize that some experts deny the existence of Wolframite as a true mineral, but it has been used so extensively and historically for so long that it is a recognized entity. It may be only a transition phase in the solid solution series between Ferberite (FeWO 4 ) and Huberite (MnWO 4 ), but so much information exists on it as Wolframite (Fe,Mn)WO 4 that I feel it would not be prudent to ignore the term; and besides, it is easier than saying Ferberite-Huberite.

Tungsten, in many ways reminds me of Winston Churchill's comment regarding Russia; a riddle wrapped in a mystery inside an enigma. I will dedicate the next column to the identification of some old Gold-Molybdenum-Tungsten mines that might be of interest our readers.

We must all realize what happens when a country allows its own industry to die and has to rely on imports for its needs. Its only choices are to produce our own or to pay and continue to pay higher prices. Unless some of you small miners can find additional domestic supplies, we will all continue to suffer higher prices and the loss of American wealth and technology.

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