Travel to china with Iranian Passport

Dear Madam, Dear Sir,
I’m working for a Belgium company and I have a Belgian unlimited residence card. I’m Iranian and have an Iranian nationality and passport (no Belgian nationality). Through my job duties I need to travel to china (maximum once a year) to visit our suppliers and our Chinese facility which is based in Nanjing. Could you please advise me for which visa should I apply and if the procedure is different as I have an Iranian nationality?

Many thanks for your reply,