Just found my SD card was corrupted.
Why did you decide it is corrupted? When my phone can't read my SD card I usually do the following. 


Insert the corrupted card in PC and blindly copy its content in some HD directory. I usually specify option ignore errors. It may cause issues with some files, but usually it is recoverable
I format the corrupted card with option check media for errors. If it got formatted with only few or no errors, I usually reuse it. Otherwise I take a new card
I copy all copied content from hard drive back to the new or old recovered card
I return the card back in the phone and usually it continues working as before


Note that SD card usually holds only certain number of rewrites, therefore if you do writing a lot, then a new card will be always a better solution.