How to mount raw disk images

You don't mention under which context you are mounting the disk, but what about going the other way and mounting the disk with the Applescript?

I mention context because when mounting a disk with Applescript is the big caveat that if it is a network volume, and the network is password-protected, then the user name and password would have to be stored as plain text in the script for a seamless execution.

UPDATE: A bit of searching found a similar question elsewhere. Essentially, a script can be made to do this by applying the script as a Folder Action to /Volumes:

on adding folder items to this_folder after receiving these_items
    repeat with aItem in these_items
        tell application "Finder"
            if (local volume of aItem) and (name of aItem is "[Name of Hard Drive]") then
                -- do something with the drive
                -- eject aItem
            end if
        end tell
    end repeat
end adding folder items to

You should parse the output of hdiutil, and mount the filesystems you're interested in - because you can't do what you're trying to do with mount.

The first few lines of the man page show supported syntax:

 mount [-adfruvw] [-t lfs | external_type]
 mount [-dfruvw] special | node
 mount [-dfruvw] [-o options] [-t lfs | external_type] special node

Notice for -a, there are no options to specify a node path, which makes your command invalid syntax.

(Also, I'd suggest testing with a proper image file - one that is an actual CD image. Your image is a hard-disk type, with an Apple Partition Map, and no non-HFS partitions. In Disk Utility, choose New -> Blank Image and note all the selections carefully. You want "CD/DVD"; you can then edit the partition map after you've created it; say, to change to two partitions.)