Under the financing deal, Bluescape has agreed to purchase $60 million aggregate principal amount of senior secured convertible notes due 2027 which will be convertible into shares of the 5E's common stock.  

5E's small-scale boron facility is targeting mechanical completion in the fourth quarter of this year. 

Construction of the plant started in April this year.

The firm says the plant will represent the first domestic supply of boron in more than 50 years.

"We continue to see strong increases in boron prices, with average boric acid prices up more than 50% during the first quarter of this year 2022, as compared to average prices in 2020 and 2021," the firm said. 

The secured notes will bear interest at an annual rate of 4.5% if paid in cash, or at an annual rate of 6% through the issuance of additional notes. The notes will be convertible at an initial conversion price of $17.60, which represents a 10% premium to a reference price of $16.00.

Shares in 5E were 5% down at $18.72, giving the firm a market capitalisation of $1.3 billion.