How to remove white marks from Minton floor

[meganq1234]

Hi,

We recently discovered some red Minton Hollins tiles in our hallway and we’d love to restore them. Some of the tiles have white cloudy marks on them, we have tried wiping these away with water and a very gentle cleanser but with no luck! Is there anything we can do to treat these?
Thank you!

 

[ltppebbs]

Firstly how old is the property, i suspect there is no damp course, what was covering the tiles, and are the joints soft?.
looking at the picture it looks like a lime mortar joint so any cleaning would have to be done very carefully
avoiding the use of to much water.
Also how big an area have you to clean?