Applications of Argon
Argon is used for a variety of applications ranging from light bulbs to the manufacture of silicon crystals for the semiconductor industry, and as a filler in multi-pane glass windows. But it’s most important application is in the metals industry.
Argon is widely used in metals production, processing and fabrication. It plays an important role in welding where, as a shielding gas, it is used to exclude atmospheric air from contact with metals such as chromium, vanadium, titanium, aluminum and magnesium that can react with oxygen and nitrogen. Argon, combined with small amounts of oxygen or carbon dioxide to help to broaden and stabilise the arc and improve bead profile, is the shielding gas of choice for welding alloys such as carbon and stainless steels, where small amounts of dissolved nitrogen can reduce ductility.
Integral throughout a number of metals production processes, argon is also used to prevent oxidation during die-casting of hot light metal alloys, such as aluminum and magnesium alloys for products such as car wheels.
Aside from shielding, argon’s most important metals processing applications are in steel making. Steel producers would find it difficult to carry on without argon as, the molten alloy needs to be stirred during production to ensure the temperature and composition is homogenous throughout the melt. Due to its inert nature, argon is ideal for this purpose.
Argon is produced, most commonly, in conjunction with the manufacture of high purity oxygen using cryogenic distillation of air. Since the boiling point of argon is very close to that of oxygen, separating pure argon from oxygen requires many stages of distillation.
For many decades, the most common argon recovery and purification process used several steps. Taking a ‘side-draw’ stream from the primary air separation distillation system at a point in the low-pressure column where the concentration of argon is highest than processing the feed in a crude argon column, which returns the nitrogen to the low pressure column and produces a crude argon product.
Warming the crude argon and reacting the oxygen impurity in the stream with a controlled amount of hydrogen to form water, removing the water vapour by condensation and adsorption, re-cooling the gas to cryogenic temperature and finally, removing the remaining non-argon components through further distillation in a pure argon distillation column.
Health and safety
Argon is colourless, tasteless, odourless and inert. Although nontoxic, argon can act as a simple asphyxiant by displacing air or liquefying oxygen. In addition, exposure to liquid argon may cause severe frostbite to the skin and eyes. To avoid these harmful effects, producers and customers should follow strict safety guidelines for storage and handling.
Due to tight supply and an increase in input costs, all the suppliers have announced price hikes in 2007 in the range of 10-20% for argon. From April to December, the major producers of industrial gases announced that they would increase prices for Argon by 10% to 20%.
On 1st April 2007, Airgas increased pricing on packaged and bulk gases as well as other products, with increases of 10%-15% for argon. In addition to price increases for gases, Airgas also jacked up rental rates for cylinders and bulk tanks and even service charges by 8%-15%. This was followed by another announcement for additional price increases effective 1st January 2008, in the range of 10%-15% for argon.
On 1st June 2007, Scott Specialty Gases announced an across-the-board increase for all specialty pure gases and gaseous mixtures, while pure argon as well as helium and argon mixtures were raised 10%. Not to be left out, Air Products increased prices effective as of 1st October 2007 on certain high-purity process chemicals in North America.
In making these announcements, each company cited a variety of factors, “higher electricity and energy prices have led to substantial increases in product costs” relates Airgas in its announcement. Scott succinctly stated, “Escalating costs of energy and quality raw materials are cited as the drivers behind the increase.” Rising energy prices and material costs appear to be the most common fundamental factors accredited to the increases.
Demand and supply-Demand for argon remained pretty strong throughout 2007, with the demand/supply mismatch most severe in the US (all three largest US producers of argon: Praxair (34%), Air Liquide (25%) and Air Products & Chemicals (18%) reported tight supply of argon), followed by Europe and to some extent Asia.
Outlook of future growth
World production of steel has increased by more than 7% each year over the last few years, reaching 1.2 billion tonnes of raw steel in 2006. As a result of this trend, based on a demand which should continue to grow by more than 5% each year in the next few years, demand for argon is likely to be healthy and we expect to see a 6% growth in argon production.