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 is His slave and Messenger.
We have previously stated that divorce takes place if a husband writes it while intending to initiate divorce. For details, refer to Fataawa 89894 and 87034.
However, it appears from your question that you intended divorce when you wrote the divorce of you first wife. If this is true, then divorce has taken effect and the divorce three times in one expression is considered three divorces according to the majority of the jurists .
With regard to your marriage to another woman, if it met the conditions of a valid marriage, the most important of which is the presence of the woman's guardian and the witnesses, then it is a correct marriage. For more benefit about the conditions of the Islamic marriage, refer to Fatwa 83629.
Finally, you should know that your first wife - whether or not she is still your wife – does not affect the validity of your marriage to your second wife.