PERTH (miningweekly.com) – A detailed project update into the Ngualla rare earths project, in Tanzania, has delivered a capital cost reduction of 10% and operating cost reductions of some 18%, owner Peak Resources reported.
A 2014 prefeasibility study (PFS) estimated that the project would require a capital investment of $367-million to produce 10 000 t/y of rare earths over a mine life of around 50 years.
At the time, the project was estimated to have a net present value of $1.31-billion and an internal rate of return of 39%.
Peak reported on Wednesday that capital costs for the Ngualla project had now reduced to $330-million, while operating costs had declined by some $21-million a year to $97-million a year.
The operating cost reduction was achieved through the optimisation of the flow sheet, which Peak said confirmed its selection of the alkali roast process, allowing for the early injection of the majority of low value cerium and deleterious iron, leading to significant reduction in reagent costs.
Peak MD Darren Townsend told shareholders that the further reductions in capital and operating costs helped to position Ngualla as one of the world’s lowest-cost rare-earth projects.
As part of a bankable feasibility study, Peak would review a number of capital cost items included in the revised cost estimate, in the hopes of removing further costs.
Meanwhile, the project mine life had now been estimated at 31 years, instead of the more than 50 years considered in the PFS, with the new mine life based on the high-grade weathered Bastnaesite zone, which comprised only 22% of the total mineral resource in terms of contained rare earths.