Iron Bear Resources' (ASX:IBR) updated mineral resource estimate for its Iron Bear iron ore project in Canada stood at 13.6 billion tonnes containing 30% total iron and 20.7% magnetic iron at a cut-off grade of 12.5% magnetic iron, according to a Tuesday Australian bourse filing.

The company said the total mineral resource has decreased by 18% from the previous estimate dated April 11, 2024, primarily due to revised geological interpretation, updated pit optimization parameters, and application of updated modifying factors.

The indicated mineral resource has increased 114% to 4.5 billion tonnes containing 29.5% total iron and 20.6% magnetic iron, up from 2.1 billion tonnes in the previous estimate, the filing added.

Metallurgical test work confirmed direct reduction grade concentrate grading 71% iron with an overall magnetic iron yield of 88.8%, and blast furnace grade concentrate grading 69.1% iron with a magnetic iron yield of 97.5%, it added.

The company's shares rose 5% in recent Tuesday trade.