All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Firstly, we advice that the word of divorce be not hastily uttered. Uttering the word of divorce is not the solution to marital problems. In many cases, doing so leads to regrettable consequences. Deliberateness is from Allah while hastiness is from Satan. As for the three times in which the word of divorce was uttered, we must say that anger does not prevent the divorce from being effective as long as the anger had not reached a point where the divorcing husband did not know what he was saying. If the husband who is asking this question, had uttered the word of divorce three times, while he was in full knowledge of what he was saying and actually meant it, then he has irrevocably divorced his wife and he must immediately separate from her because she has now become a non-Mahram woman to him. He should not marry her again until after she has married another man and the marriage has been practically consummated. If the second husband divorces her, he can then remarry her if he likes. We are also telling the questioner that it is unlawful for him to let the woman live with him in the same house.
For more benefit on divorce given in anger, please refer to Fataawa 220696, 243088, 245707, 322960, 388225, 395773, 121374, 126164, and 245707.
Allah knows best.