Yeah. Even if you could somehow manage an average of 2 minutes a scan, which seems highly optimistic, that's over 48 hours non-stop.

Maybe if you had multiple trays so you could load one while the other was scanning, the scanning was automated so that a whole tray could be scanned without interaction, and nothing went wrong.

Also remember that if you're automating this, you aren't going to be doing interactive touchups, so you need to hang onto all of the data and not lossily compress the images. Assuming a 2700dpi slide scanner, 35mm slides, and 24bpp, that's basically 28MB of uncompressed image data per slide. If your scanner supports it, you'll want to record more than 24bpp of data, especially if it does a scratch-and-dust scan, but there will probably be some lossless compression involved, too. Still, though, that's a total size of about 40GB for your whole library. (Which, now that I do the math, isn't so big these days.)