I have a building that is 60' x 104', the top soil was removed and appx 160 tons of bank sand was installed and graded to prep for a 6" concrete floor. After tamping there were several wet areas and the base was not firm, now that it has rained, the whole area is wet and will have to be pumped. My question is this: Is there a product that is readily available that will "dry up" the sand ? Or how can I get the base to be firm again prior to pouring the concrete?

The only way you can dryit out is Make drain holes around prem and hope for no rain for a few days . Instead of bank sand you should have used (RED SAND) IT compacts good ,drys fast if it rains. This is the kind of sand always used. Call your local lumber yard they will help you get some scoop the other up and save it for some other prodject ( TEEL THEM YOU WANT SOME FILL RED SAND).::

Not sure where you are but gravel is the preferred base. It drains very quickly and will not puddle. You can pour concrete on gravel that is wet.

Go to the center of the site and remove a 3 ft. square section of sand. Use plywood scraps to hold sand back then dig down another 12" below bottom of sand level. Place a sump pump covered with silt fabric in the hole. Cover the entire site with 6 mil plastic sheeting. When your set to pour be sure to leave the sheeting in place. Good luck