IT'S ELEMENTAL!
NICKEL AT A GLANCE
NICKEL DAVID J. HANSON, C&EN WASHINGTON
I
F THERE EVER WAS A UTILITARIAN
metal, it's nickel. This well-known transition element may have more varied applications than any other metal. It is used in everything from our coins to our automobiles and from jewelry to paper clips, and new uses are found all the time. Basically nickel is a hard, malleable, ductile, lustrous, silver-white metal that takes a high polish. It conducts heat and electricity and is slightly magnetic. It forms numerous compounds, many of them blue
coins are made. The U.S. nickel is 25% nickel and 75% copper. Other useful alloys include nickelchromium and nickel-molybdenum combinations that are the basis for materials that can withstand extremely corrosive chemical plant environments, such as hot sulfuric and phosphoric acids, hydrogen chloride gas, and other oxidative conditions. Electroplating is the second largest use for this versatile metal. The process is used to produce corrosion-resistant and decorative finishes, as well as substrates for chromium coatings. Nickel can be plated on many surfaces, including plastics. Automobile trim, bathroom fittings, and electronic connectors are just a few of the many applications.
Name: From the German kupfernickel, loosely meaning false copper. Atomic mass: 58.69. History: Discovered in 1751 by Swedish chemist Axel F. Cronstedt in niccolite. Occurrence: Rare in Earth's crust, but many experts believe it is far more common in its molten core. Appearance: Silvery white metal. Behavior: Resistant to oxidation. Many forms of nickel are harmful to humans. Uses: Widely used to make stainless steel and many other corrosion-resistant alloys. Also used in rechargeable batteries and heating elements. The coin contains about 25% nickel.
about 57% of total consumption, according to the U.S. Geological Survey Unfortunately nickel comes with an evil side. Several nickel compounds are known human carcinogens. Nickel refiners had a number ofhealth problems in the past, but current exposures to nickel in the workThere is also a process for platplace are much lower. Still, caution is taking nickel without an electric curen with nickel refinery dust and especialrent. This "electroless" process ly nickel sub sulfide (Ni 3 S 2 ). Another makes very uniform plating. Othcompound of concern is nickel carbonyl, er materials can be added to imFIREBALL A 3-mm droplet of nickela highly toxic, volatile liquid used to puriprove the finish, such as Teflon to zirconium, heated to incandescence, hovers fy nickel or to produce fine nickel partiincrease lubricity or silicon carbetween electrically charged plates inside the cles. U.S. and international health agencies bide for wear resistance. This Electrostatic Levitator at NASA's Marshall have set exposure standards for these and process is used on computer hard Space Flight Center in Huntsville, Ala. other nickel compounds. drives for a smooth, nonmagnetic base for the magnetic recording layer. or green, and finely divided nickel can adAnother health issue is contact dermatisorb hydrogen. tis from exposure to nickel. Reactions to Nickel also happens to be an excellent But it is as an alloy with other metals nickel alloys in earrings used for pierced ears catalyst for many chemical reactions. By that nickel really shines. The first report- itself or combined with other are the most frequent, but itchy ed use of nickel was in a nickel-copper-zinc rashes can occur on any body part metals, nickel is used for a myralloy produced in China in the Middle that comes into prolonged coniad of industrial and research apAges. It is believed that some alloys were tact with nickel. The European plications. T h e most famous produced in prehistoric times. Today an Union has banned earrings with nickel catalyst is called Raney estimated 85% of nickel ends up as alloys. more than 0.05% nickel and nickel. Developed by Murray some nickel-plated jewelry The Raney in the 1920s, it is 9 0 % The largest use is in making stainless American Academy of Dermanickel and 10% aluminum. steel. As much as 70% of nickel goes to tology says that nickel allergies make stainless or other steel alloys. With THIS ELEMENT All of these uses demand a lot BROUGHT are the most common chemical concentrations of up to 45%, nickel adds of nickel. T h e U.S. consumes TO YOU BY allergy causing skin problems. strength and corrosion resistance. Surprismore than 195,000 metric tons BAYER ingly 16% of stainless steel goes into the ofnickel yearly But the last nickNickel use continues to grow chemical process industry Electronics conel mine in the U.S. closed in 1987 as new applications are found. sume 18%; auto manufacturing, 15%; and Most new nickel comes from Canada and Nanotechnology electronics, and catalysis the food and beverage industry 13%. Australia. The two most common ores are are areas of exciting nickel research. Use of In addition to its use in steel alloys, nicknickel-iron-sulfide pentlandite, (Ni,Fe)9S16, the metal is rising each year, and the inel forms useful alloys with other metals. and a nickel silicate contained in hydrated dustry is confident about its future. This is Copper-nickel alloys offer a good commagnesium, usually garnierite, (Ni,Mg) 6 one element where you don't have to exagpromise between strength and ductility Si 4 O 10 (OH) 8 . gerate when you say that you're gettingyour and resist corrosion in saltwater, nonoxiBut at a cost of $8,000 per ton, nickel nickel's worth. dizing acids, and alkalies. These alloys are is not cheap. So there is an efficient recyused in industrial plumbing and petroDavid J. Hanson is assistant managing editor cling system to recover and reuse nickel. chemical equipment. More than 110,000 tons of nickel were re- for government andpolicy at C&EN. He has Nickel-copper is also the alloy of which worked for the magazine since 1977. covered from scrap in the U.S. last year, 82
C & E N / S E P T E M B E R 8. 2003
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