Rust in concrete

[snowman682]

I have a concrete side walk I am doing. It has rust on it, not hard water, not metal in the concrete, but rust/metal from years of snow removal. It is pretty bad in spots. Just tried a mix of 24oz of oxiolic acid to 2 gallons of water and it didnt touch it. Any suggestions?

[Certified MD Roof Cleaner]

I'd try mixing a lil stronger. Try another 8-12oz per gallon. If that doesnt work u can try Super Iron Out or RustAid. I usually have to mix my oxalic really strong to get it to remove rust. Spray it on, let dwell, re apply, let dwell. Its a hurry up and wait process.

[snowman682]

this is what i have. it is shiney cuz it is wet. going to try muriatic acid next

[snowman682]

it is metal that rubbed off of cutting edges for snow removal for years. having my doubts on getting it off with chems. might be taking grinder with me next time. i know that will work!!!!