Is possible mine Zcash with antminer S7?
No. Zcash currently can only be mined by cpu or gpu. It’s designed to be Asic resistant and requires a good amount of memory.
Also, the Antminer S7 is a SHA256d miner, and Zcash uses the Equihash PoW algorithm. So regardless of how ASIC-resistant Equihash is, the S7 could never be used.