Avalon Rare Metals, which announced plans to build a $300 million rare earth elements separation plant and refinery in Geismar two years ago, has decided against building the Ascension Parish facility.

Avalon’s plans to build the rare earths refinery in Geismar were abandoned after the company struck a deal with chemical company Solvay, utilizing its separation plant in La Rochelle, France.

Don Bubar, president and CEO of Avalon, said the company considered building a hydrometallurgical plant in Geismar to obtain metals from its ores. But that deal didn’t work financially.

“The cost of transporting the larger volumes of concentrate all the way from northern Canada made this alternative impractical particularly with increasing rail traffic and rising rail freight costs, forcing us to look at sites in western Canada, closer to the mine,” Bubar said in a statement.

Mike Eades, president and CEO of the Ascension Economic Development Corp., said officials with Avalon told him Tuesday it was unlikely that the company would build in the parish.

“We’re disappointed, obviously,” Eades said. “We put a lot of time and effort into this. But there were a lot of moving parts in this deal.”

Avalon, based in Toronto, announced plans for the Louisiana facility in 2012. The plant would have employed 175 people and created nearly 300 indirect jobs.

The facility would have processed heavy rare earths — metals that have a variety of uses, including flat-screen displays, coatings that allow for data storage on DVDs and CDs, magnets used in electric and hybrid cars, microwave filters, and strengthening aluminum and magnesium alloys.

The Geismar plant and refinery would have worked in conjunction with Avalon’s mining and processing operations in the Northwest Territories of Canada, where concentrates of rare earth elements rich in the heavy rare earths would be shipped via rail to Ascension Parish.

But once the deal with Solvay was reached, it reduced how much work would have been done in Louisiana.

One of the good points about the Avalon plant was that it didn’t require access to the Mississippi River, something usually crucial for industrial sites.

“It would have been a really good fit for our industrial community and an opportunity to diversify a little bit,” Eades said.

Follow Timothy Boone on Twitter, @TCB_TheAdvocate.