When compared to the 15mln tons of copper from which it is sourced, rhenium’s approx 45mt supply and 54mt demand is by any standards small. But this small market has big applications – an un-substitutable 3% addition in nickel-base super alloys and 0.3% with platinum in bi-metallic reforming catalysts.
A newcomer to this market will not be surprised, therefore, that the world’s largest copper producing country,Chile, is also the world’s largest rhenium producer. The figures below are taken from official records published by Banco Central de Chile and show the development of exports over the last 16 years. The main producer responsible for these exports is Molymet who produces rhenium as a by-product of roasting molybdenum sulphide concentrates. Most of the rhenium exported is in the form of rhenium metal pellets Re 99.9% and 90% or more of the exports are toUSA.
Pie chart 2 below shows how super-alloy demand for the aerospace and industrial gas turbine industry dominate rhenium demand. Not shown in the figures is the approximately 15mt of rhenium recycled each year from spent reforming catalysts, as they do not affect the supply-demand balance. The figure of 5mt catalyst demand represents top-up quantities for the manufacture of new catalyst and demand for other rhenium-bearing catalysts. The remaining 4mt approx is consumed variously in anodes for medical equipment, thin filaments for spectrographs and lighting and the Re content in alloy spray powders.
Missing from these figures, because they may not be statistically followed, is the amount of rhenium that finds its way back into the super-alloy production loop from nickel-base alloy scrap such as end-of-life turbine blades, casting scrap, grindings. It is these units that presently make up the deficit of this market.