Antminers come in different types. Each is specialized in a certain proof of work algorithm and not just a certain coin.
For your s9, you can mine any coin that you want that has the sha-256 algorithm ONLY.
This gives you a few options but you'd be mainly mining Bitcoin or BCH.
Hello,
Is it possible to mine bytecoins (bcn) with antminer s9??
Pls help.
Which other coins can i mine with antminer s9, pls advise...
I want to mine solo altcoins.
So no you can't mine BCN with your s9.
Why do you want to solomine altcoins
Right now the profitability of BTC and BCH mining is amazing. Why not exploit that and make the most out of it. You're basically leaving the easy way and looking for the difficult way of making money.
Anyway, you can check the most profitable coin for your miner on whattomine through this link.
https://goo.gl/W7iEuiAccording to them you'd be making no less than $37 per day with BTC and you have other options of course. Don't waste your electricity on crappy coins (that popup in the altcoins section) as you'll probably get nothing out of them other than wasting your time.