Need a safe way to remove mortar

[ciscokid]

The guys doing the fireplace in my new house addition did a great job on the stone work, but left mortar all over the slate hearth. I didn't notice it until the carpet was laid. What can I use to remove the mortar stains without damaging the carpet. I'm afraid to use muriatic acid. I've heard it's pretty potent stuff.

[Tools]

I'd get them back to fix it.

Tools

[Dirty Doogie]

Try rubbing the mortar stains with an offcut of the slate. It looks like the slate is very porous and it may be that the slate has absorbed lime or calcium type salts which could be impossible to remove. If the mortar stain is just on the surface then careful rubbing will remove it.

[Make it work]

I'd get them back to fix it.

Tools

+1, unless they forgot to send you the bill, then I'd have a go.

[Planned LScape]

A weak hydrochloric acid:water solution could work, or try a garden supply for a masonry cleaner, that removes mortar deposits

I would be ringing the contractor first though