The MFC-J825DW uses the brscan4 model scanner driver, which you need to configure using a command like
brsaneconfig4 -a name=SCANNER model=MFC-J825DW ip=xx.xx.xx.xx
where xx.xx.xx.xx is the IP address of your scanner.
Personally, with my MFC-J825DW, I do not bother with the scan-key-tool. It just allows you to press the scan button on your device and have the scan automatically open in the GIMP on your computer. I prefer to use xsane, but you need to change the default mode to an appropriate mode. http://www.linuxquestions.org/questi...2/#post5002255