NioCorp Developments Ltd. (TSX:NB, OTCQX:NIOBF) has said that metallurgical testing being conducted now by the company is intended to quantify its ability to extract rare earth elements (REEs) from ore at its Elk Creek project in Nebraska.
The company said it is also aimed at testing a carbonation process that can be used to recycle key reagents used in the removal of calcium and magnesium carbonates from the Elk Creek ore ahead of operations that are expected to extract and recover niobium, scandium, titanium, and rare earths once project financing is secured.
If proven successful at the demonstration plant scale, NioCorp said these process improvements have the potential to reduce projected project operating costs (OPEX) and capital expenditures (CAPEX) when compared to estimates in the project's May 2022 feasibility study, as well as to lower the project's anticipated production of greenhouse gas (GHG) emissions as compared to projections in the May 2022 feasibility study.
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It noted that the process improvements could allow it to produce calcium and magnesium materials at purity levels that may be sold as commercial products. However, further analysis and testing are required to determine whether there are reasonable prospects for economic extraction of calcium and magnesium before they could be included in the Elk Creek Mineral Resource, the company added.
NioCorp said its metallurgical consultants at L3 Process Innovation are continuing to perform bench and pilot-scale testing of these process improvements at a dedicated facility in Quebec. The testing will advance from the bench and pilot-scale to the demonstration plant scale once the remaining equipment for the demonstration plant arrives and the demonstration plant assembly can be completed and testing begins. The launch of demonstration plant testing is expected to occur in the coming weeks, it added.
Process improvements explained
The company said the Elk Creek project's existing process flowsheet envisions using hydrochloric acid to remove calcium and magnesium carbonates, and other impurities from mined ore, requiring a significant amount of capital and operating expense to recover and recycle the hydrochloric acid.
Given its emphasis on recycling and recovery operations throughout the Elk Creek project's design, NioCorp said L3's optimized design for the flow sheet utilizes thermal treatment, ammonium chloride, and carbonation to break down the carbonate minerals in the mined ore and remove virtually all of the calcium and magnesium from the ore. Removing these materials early in the process allows for the rest of its processing plant to be smaller and operate more efficiently.
Possible reductions in greenhouse gas emissions
The company said the improved design also regenerates the ammonium chloride consumed during the carbonation stage. Carbonation consumes carbon dioxide and reduces the GHG footprint of the prospective operation.
The optimized design and carbonation process all utilize proven technologies and are not expected to introduce additional technology risk to the project if they are implemented in the final design, it said.
Recently, L3 was able to demonstrate that this carbonation step can produce a calcium and magnesium product that is 96%-97% pure, NioCorp noted. It said it intends to further evaluate the use of this product for underground mine backfill as well as to investigate its potential as a saleable byproduct. The L3 demonstration plant, when constructed and operational, is expected to produce tens of kilograms of this material that can be used for evaluation purposes.
"I have been very pleased with the progress that the L3 team has been making toward proving the technical feasibility of this innovative approach to the Elk Creek Project's flowsheet," NioCorp's COO Scott Honan said in a statement. "This work illustrates how strongly NioCorp is committed to reducing our net greenhouse gas emissions when and where we can. Niobium, scandium, titanium, and the rare earths all play critical roles in reducing greenhouse gas emissions in the products in which they are used. We would also like to produce these critical minerals with as low a GHG profile as possible.”
NioCorp is focused on developing a superalloy materials project in southeast Nebraska that will produce niobium, scandium, and titanium.
Contact the author at stephen.gunnion@proactiveinvestors.com