Can diesel be separated from petrol?

​this is a reply to my last question as for some strange reason I can't reply and leave a comment to the thread. ok thanks to those replies,  I am in oz and the reason I've asked is due to free diesel that has been contaminated with petrol being offered to myself. So, given I have free fuel I am prepared to treat, separate, spend some $ on in trying to produce diesel and petrol separate. I have looked at a continuous separation distill unit but I don't know how it works and the safety factor, don't want to make a bomb! Other ideas are leave the diesel out in sun and evaporate petrol(not so good for environment and water getting in diesel) or add oil to mix. Most of the fuel mix is majority petrol and minority diesel, although exact ratios are unknown. I have run my lawn mower on it quite well so given that it is mostly petrol, can I either;1. Add more petrol pure to further dilute the diesel. 2. Add an octane booster to over come the diesel influence. And specific comments and answers appreciated