This story leaves out “bog iron” a form of iron produced by bacteria in peat bogs, swamps and other marshy places with a naturally occurring source of iron. You could and can find it in small nodules up to golf ball size. Did not need to be smelted just melted. Secret weapon of the Vikings. Had a high Silica content (glass) content so nails made from it did not corrode so bad once the outer iron layer went away. Bring your longship upon to the beach burn it recover nails cut new timber and build new ship. Worked for them maybe thousand years.
Interesting on bog iron! Just read the wiki on it.