(Safely) Removing rust from concrete: How?

Hydrochloric Acid is about the most potent you can use. Vinegar may work also, same for citric acid.
i used the pressure washer and it did a pretty good job.....now i use a push broom and sweep it all away.....right after grinding
Check with Lowes Depot....they got it in the paint depts.....I forget the chemical name, damnit....

it's cheeep, or WAS....ain't nuttin cheeeep these daze....