TORONTO (miningweekly.com) – US-based Rare Element Resources, which is developing the Bear Lodge critical rare earth project in Northeast Wyoming, this week announced that two independent laboratories had confirmed that the company’s in-house process to liberate rare-earth elements (REEs) from ore was successful, and could potentially be scaled up to a commercial application.

Hazen Research and SGS Lakefield Research have confirmed and expanded on the initial bench-scale test results reported by the Australian Nuclear Science and Technology Organisation.

Rare Element said the tests confirmed the success of the company's proprietary technology to selectively recover REEs from an acid leach solution using oxalic acid, which resulted in a bulk total rare-earth oxide concentrate with a purity level of more than 90%.

The company said it had filed for a provisional US patent on the technology.

SGS Lakefield was currently undertaking further testwork and had been awarded the contract for pilot plant testing.

Equally significant, the studies determined that, with oxalate precipitation, a significant amount of the hydrochloric acid (HCl) left in the REE-depleted barren solution was recoverable by distillation. After adding oxalic acid and the subsequent 90% recovery of the REEs at high temperature, the amount of free acid increased, and the recycled acid was expected to provide nearly 80% of the total HCl requirements for the plant.

"The purity of the end product of this innovative process will make the Bear Lodge concentrate attractive to a number of potential users. While the primary purpose of the large-scale pilot plant tests will be to develop detailed process engineering design criteria for inclusion in the feasibility study, we will use the resulting product generated from this testwork to initiate discussions and provide samples to potential customers.

“We believe this will give them the ability to evaluate the quality of our concentrate and determine its compatibility with their needs, whether that be for advanced technology applications or for use in green technologies,” COO Jaye Pickarts said.

Rare Element also recently released an updated resource estimate for the Bear Lodge project, lifting the total contained rare-earth oxides (REOs) by 65% from the previous estimate to 944-million pounds.

The total National Instrument 43-101-compliant measured and indicated oxide resource is 13.3-million tonnes at an average grade of 3.22% REO, based on a 1.5% cutoff grade.

Meanwhile, Rare Element, in May, said it was notified by the US Forest Service that, after reviewing the company’s plans to mine on Forest Service-owned land, it found the Bear Lodge plan of operations was sufficient for the National Environmental Policy Act process to formally start.

There were currently no significant sources of rare earths outside of China, which accounted for about 95% of the world’s production.