If you are going to ever put any kind of floor covering over your slab, run away from Sodium Silicate. The stuff does seal fairly well, working as a densifier, but only to the top 1/8", or so. It also works to close all the pores in the slabs surface, inhibiting any capillary bond your floor covering adhesives, or cementitious patches, might need to adhere to the slab. In our area locally, there have been a lot of problems with Sodium Silicate products. As a matter of fact, one 180,000 sf project we had, had SS applied to half the concrete, before we stopped them. It was being used as a Moisture Mitigation System, but not one flooring, adhesive, or patch, manufacturer would warranty over it. The second half was done in Lithium Silicate, which wasn't a problem. Dealing with that first half, including grinding some of it, priming all of it, plus all the extra prep work, led to over a half million dollars in Change Orders.
I saw it work, in that the high Relative Humidity in the slab was held at bay, leaving low results with Calcium Chloride Tests on the surface, but the cure rate difference between the denser concrete and the less dense concrete led to a lot of surface cracking, which just directed any moisture vapor to those cracks. Combine that with the lack of adhesion, due to the lack of capillary bond, and you can see why a lot of flooring and tile professionals feel that Sodium Silicate is of the Devil.
Other ideas?