I did give honest thought to recycling some of the characters from the last attempt at the novel. Some of you may have projects of your own that don't last long, but you like certain characters so much that you want to salvage them. I felt that way myself when I began this new project. However, I don't think it's something you can or should do.
Those characters that you fall in love with are, whether consciously or subconsciously, tailored to particular stories and situations. I'll give you an example. In my last novel attempt, I had a character who was in the Israeli army. She was pint-sized and took crap from no one. I liked her, and wanted to keep her around, but her upbringing in Israel results in a different character than if she were raised in the United States where this second shot at the novel is entirely focused.
Could I have saved certain parts of her character? Possibly, but not without difficulty. When you detail characters to a certain degree, all of their traits and personality quirks become glued together as a whole, and pulling them apart results in fracturing. So my advice to you is that if you want to rescue your characters from a failed project from the paper shredder, don't. It's like chasing a woman who doesn't love you. You can't put the pieces back together.
Also, I would suggest that you don't even hold on to the names of the characters. I didn't think this would be a big deal, but then I began to catch myself trying to resurrect old characters into new ones.
Just start from scratch, folks. That's really the best advice I can give sometimes. Take what you've learned about making characters and apply those lessons towards the goal of making new ones.