Upvote:1
You should get confirmation from immigration, but I'm quite sure that whether you had a student visa for Brazil does not affect your obtaining a tourist visa afterwards.
As a British citizen you can obtain a visa/stamp at the border. Upon entry, you might be asked to show proof of future departure.
My point above is related to the fact that on a tourist visa, you're only allowed to stay in Brazil for a total of 180 days within a 12 month period. But, as said, I don't think that having stayed in Brazil on a student visa adds up to that.
Here's a host of info on visas for Brazil: