Cleaning dried mud compound sanded "powder"?

There is dried mud compound sanded "powder" all over my white tiled living room floor from a sloppy repair drywall project. The maintenance people left this. All they did after installed new drywall - include sanding the new mud -- is sweep the old stuff up. My vacuum cleaner will not get it all off.... show more There is dried mud compound sanded "powder" all over my white tiled living room floor from a sloppy repair drywall project. The maintenance people left this. All they did after installed new drywall - include sanding the new mud -- is sweep the old stuff up. My vacuum cleaner will not get it all off. Can I mop this up or will it cake up? How do I completely get rid of the very fine powder all over my living room? Is there some sort of cleaner that makes this process easier? Are drywall installers expected to vacuum up after themselves?
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