Q.): What does the Qur’an say about a man being away from his wife for almost two years with no knowledge of their whereabouts to each other?

A.) The couple are still in nikah (marriage) if the husband has not yet issued the talaq (divorce). Mere separation and being apart from one another does not dissolve the nikah. Similarly not keeping in contact with one another also does not dissolve the nikah.

If the marriage is irreconcilable and the husband does not want to issue a talaq then the wife should contact her local Ulama body and ask them to investigate the matter and if needed get the husband to issue the talaq failing which they may annul the nikah if they find valid Shariah grounds to do so.

And Allah Ta’ala Knows Best