Molybdenum - Man''s 21st Century MetalHistory
It wasn't until the late eighteenth century that Molybdenum was first identified. In 1778 the Swedish scientist Carl Wilhelm Scheele discovered, that molybdenite was the sulfide of a previously unknown metal that he named molybdenum after the Greek word molybos ("lead-like").
Molybdenum remained mainly a laboratory curiosity throughout most of the 19th century until the technology for the extraction of commercial quantities became practical. Schneider & Co., a French company, developed an alloy that used molybdenum for armour plate in 1891.
Tungsten demand soared during World War I as it was traditionally used to harden steel for armour plating. As the supply of tungsten became severely strained, molybdenum was substituted for the production of many hard and impact resistant steels. The resulting increased demand initiated an intensive search for new sources of molybdenum supply, culminating with the development of the massive Climax deposit in Colorado and its initial operation in 1918.
The world's greatest concentration of molybdenum occurs in the Western Cordillera – the mountains along the eastern half of the geological Pacific Rim of Fire, from the tip of North America to South America.
Estimates by the U.S. Geological Survey place China as having 39 percent of the world's molybdenum as low-grade porphyry deposits. Countries with significant molybdenum deposits are: United States, Chile, Canada, and Russia.
Fig 1: Country molybdenum deposits using estimates form the United States Geological Survey.
General Uses of Molybdenum
Molybdenum when alloyed with steel forms high-strength metal able to withstand both low and high temperatures. This application is useful in steam turbines for central power stations, gas turbines in jet planes, nuclear energy applications, oil drill rigs and oil/natural gas pipelines especially for those under arctic conditions.
Corrosion resistance of stainless steel can be increased by molybdenum additions. Molybdenum-containing stainless steel is now specified in automotive trim for long life even along the seacoast and in contact with de-icing salts.
Chemical applications of molybdenum include: hydrocarbon desulfurization catalysts, coal liquefaction, and as MoS2 lubricants.
Catalytic applications are the most important chemical end-use for molybdenum, accounting for about 8% of molybdenum consumption. Demand is expected to grow at about 5% up to 2010. Spent catalysts are both regenerated for reuse and recycled for recovery of secondary molybdenum.
Catalyst regeneration is expected to increase through to 2008, but the need for fresh catalysts will not decline because tighter emission standards and fuel economies are stimulating greater need for use of catalysts.
Production
The primary producers of molybdenum are the United States, Chile, and China. Canada, Peru and Russia are also significant molybdenum producing countries. Mine production of molybdenum increased from about 280 million pounds in 2002 to over 400 million pounds in 2005, with output increasing by almost 16% in 2004 alone.
Fig 2: Molybdenum production by region between 1994 and 2005. Courtesy of the International Molybdenum Association.
Molybdenum is primarily obtained as a by-product from copper mining. In 2005, only 34% of the world's molybdenum originated from primary mines.
Ten companies account for about two thirds of world molybdenum mine production. Codelco produces about 19% from its four copper mining divisions in Chile.
Phelps Dodge from their primary molybdenum mine located in Fort Madison, Iowa and two copper-moly mines in the USA produces 13% of the world's molybdenum. Phelps Dodge is planning on reopening their Climax mine in Colorado at the end of 2009. Reasons for the long start-up are: time required to rebuild the Climax mill, finding skilled mine workers, refitting engines to reduce emissions and obtaining new tires for mine equipment. The mine is forecasted to be able to produce 20-30 million pounds of molybdenum annually.
Rio Tinto more than doubled molybdenum output from the Bingham Canyon mine in 2005 to become the third largest producer with almost 9% of world production.
Both Grupo Mexico and Thompson Creek (now Blue Pearl Mining) produced 8% of the world's molybdenum in 2005.
The Chilean company, Molymet, produces about 46 million pounds of molybdenum concentrates and plans increase roasting capacity in 2007 to produce another 12 to 15 million pounds per year to accommodate the growing demand.
There were about 200 molybdenum mines in China's Huludao Region that accounted for two-thirds of the country's annual output of about 79 million pounds. Mining activity in this area has significantly decreassed since February 2005 primarily due to tax fraud, illegal mining or license expiration. The sharp fall in Chinese production was offset by greatly increased US, Chilean and Peruvian production. In 2005, China's top molybdenum mining company produced 24 million pounds, representing about six percent of the world's total production.
On November 2, 2006 the Chinese government levied a 10% export duty tax on molybdenum oxide and ferromolybdenum. A move that will further reduce China molybdenum exports.
Acquiring molybdenum from recycling is becoming a much more important source of molybdenum as the recent run-up in cost has made it economically viable for scrap dealers to deal in scrap based on molybdenum content.
Demand
The price of molybdenum peaked at just over US$35/pound in 2005 shortly after the Chinese molybdenum mines of Huludao were closed.
The main end-use of molybdenum is in steel. Stainless steel accounted for an estimated 28% of worldwide molybdenum demand in 2005, followed by full alloy steel (15%), tool and high speed steel (10%), high strength low alloy steel (9%) and carbon steel (9%).
The global market for molybdenum is estimated to have grown from about 200 million pounds in 1990 to nearly 400 million pounds in 2005 for an average year-on-year growth rate of 4.3%. The USA, Japan, Germany and China together make up half the market.
Fig 3: Molybdenum consumption by region between 1994 and 2005. Courtesy of the International Molybdenum Association.
Chinese consumption of molybdenum has doubled to nearly 40 million pounds between 2000 and 2005. Sources for this demand are the double-digit annual growth in China's industrial base. China also wishes to increase its use of natural gas, a step that would require the construction of more pipelines, and subsequently more molybdenum.
Near Term Demands for Molybdenum
Exploration for new sources of oil has led to the development of deep drilling. The very deep reservoirs are often contaminated with corrosive sulphides, brines and carbon dioxide. Molybdenum is used in the most sulphide stress-cracking resistant low-alloy steel available for use in sour wells. Oil companies are turning to higher molybdenum stainless steels (13-16% Mo) to manage these unfavourable elements at those depths.
In early February 2006, China Oil News reported that China plans to spend US$15 billion to build coal liquefaction plants in that country. China hopes to draw from its enormous coal deposits for conversion into oil products, using molybdenum-based catalysts.
Construction of larger buildings requires stronger, more resistant types of steel. Malaysia's Petronas Towers, the worlds tallest buildings, are clad in an exterior made from a Type 316 stainless steel, containing 3% Molybdenum. This metal is also used in the construction of the Olympic Stadium in Beijing and in throughout the some 28 city metro systems China is currently constructing.
According to the IMOA, "The most corrosion resistant stainless steels contain 6 to 7.3 percent molybdenum. These grades are used for power plant condensers, offshore piping, and critical components in nuclear power plants such as service water piping."
The proposed Yucca Mountainnuclear waste storage facility located 100 miles northwest of Las Vegas, Nevada could require as much as 33 million pounds of molybdenum. On July 18, 2006 the U.S. Department of Energy agreed upon March 31, 2017 as the date to open the facility and begin accepting waste.
Fig 4: Potential waste package designs for spent nuclear fuel and radioactive waste. Courtesy of DOE.
The primary use of molybdenum will be in the walls of the storage container. The inner wall would be made of Type 316L stainless steel (2-3% Mo) and the nickel-base Alloy 22 (12.5-14.5% Mo) for the outer wall.
And to leave the biggest for last…
Over 100,000 kilometres of pipelines are currently planned around the world over the next two decades. The metal demand for the construction of these projects is staggering.
For a standard pipeline 30 inches wide by 1 inch thick, about 1,100 pounds of molybdenum is used per kilometer. Larger pipelines, such as the proposed 4,000 km long Trans-Siberian and 2,250 km long Trans-Alaskan pipeline, measure 52 inches across and have a thickness of 3 inches.