Roskill forecasts that rising demand for rhenium in aero engines will likely be satisfied by increasing supply of secondary rhenium contained in ‘engine revert’ produced from end-of-life gas turbine parts.
At the 2015 Paris Air Show the big three aero engine manufacturers, GE Aviation, Rolls-Royce and Pratt & Whitney, announced billions of dollars of new sales. This was excellent news to rhenium suppliers since consumption is dominated by the nickel-based superalloys that are used in gas turbine aero engines and also, to a lesser extent, in industrial gas turbines (IGT). Since 2005 total demand from the superalloy sector has grown at a CAGR of 7% and in 2014 accounted for 78% of total demand. However, while a straightforward correlation between gas turbine construction and rhenium demand held true in the past, today the picture is less clear due to a mature recycling industry and the increasing quantity of reprocessed end-of-life gas turbine parts consumed as ‘engine revert’.
In 2014 Chilean refineries produced 40% of primary rhenium from a combination of Chilean and imported molybdenum concentrates. The USA is the second largest producer at just under 20% and other important sources included Poland and China. Kazakhstan’s state-owned rhenium refinery, historically a major producer, produced very little in 2014 due to a lack of raw materials. Secondary supply of rhenium, as pure metal or ammonium perrhenate (APR), increased considerably from 2007 to 2012, in response to high prices and a large investment in new recycling capacity. However, since 2013, against a backdrop of steadily falling spot prices, several recyclers have experienced challenging economic conditions and as a consequence production of secondary rhenium metal and APR has fallen slightly.