According to Watchtower rules, the only valid grounds for divorce is adultery. Any spouse, husband or wife, can file for divorce if the other spouse commits adultery.
Neglect, physical abuse and spiritual endangerment are not valid grounds for divorce. They are only valid grounds for separation.
If a JW divorces without adultery occurring then that JW loses his privileges. He or she would be disfellowshipped if they unrepentantly started and are continuing a romantic/dating relationship with someone else and/or got married.