To remove rust from wrought iron, use a steel wool pad.
Add a few drops of kerosene or turpentine to the steel wool and rub it on the rusted spots on your fence or patio furniture. You may have to apply pressure as your scrub.
Once you have removed all of the rust, apply a coat of wax to your wrought iron for protection against water and snow.
If you wish to seal your wrought iron fence or furniture, choose a special paint that's intended for use on wrought iron. You will be able to find this type of paint at a local hardware store.