Atherley, who is based in London, has operational, development, capital markets and media experience across the mining and energy sectors in Africa, Australia, Europe, China and the UK.
The company believes Longonjo has the potential to become a globally significant magnet metal deposit in both size and grade.
Stephen Dobson will step down as chairman and remain on the board as a non-executive director.
Atherley said: “The clean energy revolution has resulted in a dramatic increase in demand for battery metals, notably lithium and cobalt.
“Attention is now turning to a very much larger market – the rapidly growing application of electric motors to virtually all walks of life.
“From hair dryers to electric vehicles to grid-scale wind turbines, electric motors will be at the core of our clean energy future.”
Essential in electric motors
Neodymium Praseodymium (NdPr) metals are essential for the manufacture of electric motors and, following acquisitions in recent years, China now controls more than 90% of the production.
Rift Valley is divesting its interests in Tanzania to focus on its flagship Longonjo NdPr Project, at which 2018 field exploration programs are underway.
Drilling is planned
This program includes drilling that will target extensions to the resource of 11.6 million tonnes at 4.30% rare earth oxide (REO).
It will also aim to upgrade the resource to the indicated category and provide samples for metallurgical test work.
Atherley adds: “With just 14% of the target area drilled to date, the Longonjo NdPr Project has already reported a substantial mineral resource estimate.
“Dave Hammond and the team believe there is potential for considerably more.
“I very much look forward to supporting Dave and his team as they unlock the full potential of this exciting project.”
Atherley has wide-ranging international and capital markets experience.
He served as executive director of the investment banking arm of HSBC Australia where he undertook a range of advisory roles in the resources sector.
Beijing was his base from 2005 to 2015 and he developed strong connections within Chinese business, industry bodies and senior government officials.
He has been a regular business commentator on China and the resources sector.