Firework Burns on concrete

[RandyL]

Hey everyone!
I went to a movie theater this morning to clean their side walks, and noticed that some people got a little firework happy on the sidewalks in front of the building. I have not really encountered these before that I needed to try to clean up. Is this something that I will just use oxalic on like I would on a rust stain to get out? Or is there another process someone would suggest.

 

[K Gauthier]

Hey everyone!
I went to a movie theater this morning to clean their side walks, and noticed that some people got a little firework happy on the sidewalks in front of the building. I have not really encountered these before that I needed to try to clean up. Is this something that I will just use oxalic on like I would on a rust stain to get out? Or is there another process someone would suggest.

NOT SURE IVE NEVER HAD TO DEAL WITH FIREWORK BURNS YET. BUT IF YOU FIND OUT WHAT WORKS LET US KNOW.

 

[RandyL]

here are some pictures of the burns that I posted on another forum: