NioCorp Developments (TSX:NB; OTCQX:NIOBF) reported a rare earth dissolution rate of 86-95% at its demonstration plant in Trois-Rivieres, Que., the company said Wednesday.
That rate was obtained through hydrochloric acid leaching of ore mined at NioCorp's Elk Creek project in southeast Nebraska, the company said in a news release. In further solvent extraction recovery steps, the rare earths loading rate was as high as 99%, indicating potentially strong rates of recovery of separated rare earth oxides.
"These results are in line with our expectations and they show that the ongoing work at the plant is proceeding in a positive direction," said Scott Honan, COO of the Colorado-based company.
"In the coming weeks, we look forward to seeing the final results from the separations extractions testing that is now underway and to reporting those results to the public."
The extraction process also revealed only two significant impurities of iron and a very small amount of nickel.
NioCorp says it is focused on the recovery of high-purity rare earths such as dysprosium oxide and terbium oxide. It is also focused on neodymium-praseodymium oxide, the main component of neodymium-iron-boron permanent rare earth magnets used in the traction motors of electric vehicles.
The Quebec plant is aimed at processing Elk Creek ore in three phases: processing and rare earth extraction, demonstrating an improved process for leaching and niobium and titanium separation, and showing the technical viability of separating high-purity magnetic rare earths from the ore.