American Resources Policy Network
Promoting the development of American mineral resources.
  • Through the Gateway: Rhenium – Rare and Sexy?

    It has helped make airline travel affordable. It helps keep us safe. And it may just be sexier than Salma Hayek – at least in the eyes of one observer. 

    We’re talking about Rhenium, yet another metal brought to us largely courtesy of Copper refinement.  A silvery white, metallic element, Rhenium, according to USGS, has “an extremely high melting point (3,180 degrees Celsius), and a heat-stable crystalline structure, making it exceptionally resistant to heat and wear.”  Thanks to these properties, it has been an indispensible component for superalloys used in turbine blades for jet aircraft engines.  As the BBC put it[t]he ability of superalloys to operate at such extreme temperatures is what makes your holiday to the Algarve or Florida affordable.”

    At an average abundance of less than one part per billion in the continental crust, Rhenium, like its fellow Copper Co-Product is also an extremely rare metal.  Global production is pegged at a total  of a mere 46 metric tons, with more than 80 percent of that amount going into superalloys.

    Its rare metal status is one of the key reasons why recycling rates for Rhenium are increasing.  While in the past, scrapped blades used to be sold and recycled in the stainless steel industry, today most of the rare metals contained in the superalloys used in turbine blades are recovered for reuse in manufacturing.

    End users have also worked hard on substitution. As the Economist reported a few years ago,

    “General Electric, one of the world’s biggest makers of jet engines, has spent years developing nickel-based superalloys to replace rhenium. But the best GE’s boffins could manage was to reduce the amount of metal required, not eliminate it altogether. Moreover, few manufacturers possess the resources to achieve even such limited progress.”

    The United States currently imports 79 percent of the Rhenium we use. Because the recovery process is complicated and requires special facilities, we are unlikely to fully meet our demand with domestic resources.

    However, a strong demand for Rhenium is likely here to stay. That, coupled with the fact that we have proven Rhenium reserves in the U.S. (the development of one of which has been projected to generate more than 20 tons of Rhenium per year as a Copper Co-Product, thus significantly reducing our reliance on foreign imports), should suffice to get policy makers’ attention — regardless of their stance on Salma Hayek.

  • Through the Gateway: Selenium – More Than Just a Dietary Supplement

    Chances are, you’ve heard of Selenium.  As a trace element, it is an essential mineral found in small amounts in the body, with antioxidant properties. It is also a much-used suite of tools to automate web browsers across many platforms — which is why weeding out our news alerts for stories relevant to ARPN followers can be time-consuming.

    However, more relevant from our vantage point are this rare mineral’s other uses.  According to USGS, Selenium, which is known to have semiconducting properties, is used in glass manufacturing to decolorize the green tint caused by iron impurities, and — increasingly important to new applications — to reduce solar heat transmission.  In catalysts, it enhances selective oxidation, in plating solutions, it improves appearance and durability, and in gun bluing, it improves appearance and provides corrosion resistance.  It is further used in rubber-compounding chemicals, in the electrolytic production of manganese, and in copper, lead, and steel alloys to improve machinability.

    Perhaps its most important use today is its application in solar technology.  Like Tellurium, Selenium plays a critical role in the performance of thin-film photovoltaic cells.  While Tellurium is used in combination with Cadmium for CdTe technology, Selenium is alloyed with Copper, Indium and Gallium, creating a material commonly referred to as CIGS.

    Both CdTe and CIGS technologies were the new kids on the block during the first solar boom, though Selenium’s  photoconductive properties were already discovered by British scientist Willoughby Smith in 1873. Companies engaged in both technologies have since vied for front-runner status  in the solar world by attempting to improve the respective material’s efficiencies.  While CIGS seemed to have a leg up up until recently, new test results for CdTe are promising. The bottom line, however: both materials, and with that Tellurium and Selenium, are in high demand.

    What holds true for most tech metals and minerals, applies here too: substitution may occur, but technological advances in materials sciences will likely continue to fuel demand. Selenium may have been replaced by organic photoreceptors in some plain paper copiers, but new nano-technological applications, for example in electronics, are already being tested by researchers.

    As is the case with Tellurium, most Selenium used in the United States is derived from residues produced during the refining process of Copper, so the supply of Selenium is of course directly affected by the supply of Copper.

    If you’ve read our last post about Tellurium, you probably have Bob Marley’s “No Woman, No Cry” stuck in your head now. You’re welcome.

  • Through the Gateway: Tellurium – A Rare Metal With Abundant Demand

    It may not have felt like it, but spring is here, and love is in the air (not just according to us, but also according to science). We’re here to help – and thought we’d share this gem of a pick-up line (available on T-shirts online): “You must be made of Copper and Tellurium, because you [...]
  • Through the Gateway: Copper – Far More Than Your “Old School” Industrial Metal

    We’re kicking off our online informational campaign on Gateway Metals and their Co-products by taking a closer look at one of the most well-known industrial mainstay metals – Copper. Lately, “old school” Copper – long acknowledged as an indispensable building block of the industrial age — has been undergoing turbulent times on the global commodity [...]
  • If Orange Is the New Black, Then “Co-product” is the New “By-Product”

    As we set out to take an in-depth look “Through the Gateway” over the course of the next few months, we will be zeroing in on the five gateway metals we examined as part of our 2012 report – Aluminum, Copper, Nickel, Tin and Zinc, as well as the tech metals they“unlock.” These materials have increasingly found [...]
  • Pizza, the Age of Rare Metals and Co-Products

    “If you don’t have yeast, you don’t have pizza.” What may seem like a random – albeit logical – conclusion has more to do with critical minerals than you may think.  David Abraham, director of the Technology, Rare and Electronic Materials Center, recently used the yeast/pizza analogy to exemplify the importance of rare metals, which [...]