Removing rust from concrete

[smidsy]

I have rust strains on concrete from where my fire drum (truck brake drums stacked 3 high) has been sitting.

This is something I've never had to do before so I'm assuming a scrubbing brush and chemicals.
Will CLR (I've never used the stuff) do the trick or do I need acid - if I need acid what ratio do I dilute it to?
Is there anything else available other than those two?
Cheers
Paul

[jack620]

This stuff should do the trick.

Just a moment... (https://www.bunnings.com.au/diggers-2kg-rust-and-stain-cleaner_p0960276)

[China]

I have used the above mentioned product to successfully remove rust stains from concrete driveway

[Beardy]

Oxalic Acid it the primary product you are looking for which is the key ingredient in the Diggers product recomended by Jack620