Metallurgy of the Ngualla rare earth project - challenges, choices and innovations

ASX listed Peak Resources Limited ("Peak") is developing the Ngualla Rare Earth Project in Tanzania. The project holds a JORC 2012 compliant Mineral Resource of 214.4 million tonnes at 2.15% rare earth oxides (REO) at +1% REO cut-off including a high grade weathered Bastnaesite Zone of 21.3 million tonnes of 4.75% at +1% REO cut-off. A Bankable Feasibility Study was recently completed based on a novel flowsheet which includes multiple stages beneficiation at Ngualla in Tanzania and calcination, selective leaching and separation into rare earth oxide products at Tees Valley in England. This paper discusses how the metallurgical processes have been selected and developed to deal with the challenges of project logistics, processing technical risks and low rare earth prices which are faced by all existing and emerging rare earth producers.