Recycling of Rhenium from W–Re-Alloyed Scraps by a Pyrometallurgical Method

Rhenium (Re) was recycled from W–Re-alloyed scraps by a pyrometallurgical method, in which the scraps were first oxidized in air at 675 °C to volatize into Re 2 O 7 vapor. The Re 2 O 7 vapor was condensed and leached in ammonia solution, forming NH 4 ReO 4 powder with a regular polyhedral shape and purity over 99.99%. Re powder with average particle size of about 14.17 μm and purity over 99.9% was finally obtained by reducing the NH 4 ReO 4 powder in H 2 atmosphere. A recycling device with a high volatilization and collection rate of Re 2 O 7 was designed. The present work provides an effective and simple method to recycle above 96% of Re from the W–Re-alloyed scraps. Graphical Abstract Re was recycled from W–Re-alloyed scraps by a pyrometallurgical method, which mainly consists of four processes namely oxidation, leaching, crystallization, and hydrogen reduction. The Re powder has high purity with more than 99.9%, and recovery rate above 96%, which can be further used in the production of various Re alloys. W powder prepared by hydrogen reduction of WO 3 powder can also be used in various W alloys.