Has the wife become irrevocably divorced after a bid'i divorce that occurred a year and a half ago, and is it obligatory to return her with a dowry?

A bid'i divorce (innovated divorce) is effective, according to the more preponderant opinion. If it occurs before or after consummation, and the 'iddah (waiting period) expires without a رجعة (revocation/reconciliation), then it is a minor irrevocable divorce (طلاق بائن بينونة صغرى). The husband is not permitted to take his wife back except with a new contract and a new mahr (dowry). However, if this was the third divorce, she has become irrevocably divorced from him with a major irrevocable divorce (بينونة كبرى), and she is not lawful for him until she marries another husband.