All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
A marriage contract not concluded by the bride’s Wali (legal guardian) is invalid according to the majority of Muslim scholars as clarified in Fatwa 195979. However, the divorce takes effect in this case because of the scholarly difference of opinion on the validity of such a marriage. Divorce in this case is irrevocable and the husband does not have the right to revoke the divorce and take his wife back in marriage (except with a new marriage contract fulfilling all the conditions of a valid marriage).
Based on that, the wife in question is irrevocably divorced. If the husband has divorced her three times in one session, some scholars believed that only one divorce takes effect; thus the wife has become irrevocably divorced (with the first divorce) and the other two divorces do not take effect.
According to this scholarly opinion, this man is entitled to remarry this woman with a new marriage contract concluded by her Wali in the presence of two witnesses. If the bride’s Wali refuses to marry her off to that man without a legitimate reason, they may refer the case to an Islamic court whose judge can marry her off or order her Wali to do so.
Allaah Knows best.