If you want to add a Trash can to your KDE Desktop follow these steps:
Create a text file on your Desktop by right-clicking on it and select Create New > Text File. Name the file Trash.desktop.
Open this file and paste the following in the file:
[Desktop Entry]
Comment=Contains removed files
EmptyIcon=trashcan_empty
Encoding=UTF-8
Icon=trashcan_full
Name=Trash
Type=Link
URL=trash:/
Save the file and close it.
You’re done!
wasn't that easy?...
Note: You may have to reboot to get the trashcan icon to appear on your desktop. Ben