The Colorado-based company said that the added technology is expected to allow it to apply for a state construction air permit from the Nebraska Department of Environmental Quality (NDEQ), which is designed for maintenance of air quality standards at lower emissions projects. This is versus a federal air permit through the US Environmental Protection Agency (EPA) through the Prevention of Significant Deterioration (PSD) programme, which it called "cumbersome" and more costly.

"NioCorp's efforts to reduce its air emissions, and associated environmental impacts, is expected to allow the project to navigate a more efficient permitting process than is typically encountered under the US EPA's PSD process," it said, adding that federal air permits for higher-emitting facilities require a more extensive application process, as well as longer timelines for approvals.

"The often-complex and costly Best Available Control Technology (BACT) assessment required under the US EPA's PSD programme may no longer be necessary for the project," it added. "While still very rigorous, air-emissions modelling protocols for lower-emitting facilities are less complex than for higher-emitting facilities."

Elk Creek may also still be eligible for a state law variance that would permit it to commence construction at the site before the final state permit is even issued.

NioCorp is planning to submit its State Construction Air Permit programme application next month.

It has been making strides at the proposed mine and niobium/scandium/titanium advanced materials manufacturing facility, including recycling of process reagents in the early phases of the project that will minimise the emissions profile of the plant. It will also be utilising components such as baghouses, scrubbers, low nitrogen oxide (NOx) combustion systems, state-of-the-art acid regeneration and other technologies to meet its mission.

"Our goal from day one of this project was to produce environmentally friendly superalloy materials in an environmentally friendly manner," CEO and executive chairman Mark Smith said.

"By making the early investment necessary to reduce our environmental impacts, we strive to do what is right by the environment, while also reaping the benefits of navigating a more efficient environmental permitting process."