Upon completing his mathematical education in Seville, and because of the continuing conflicts during the reconquista, he set out with his family to Alexandria and then Cairo in 1096.
In Cairo, he entered the service of the Fatimid ruler Abū Tamīm Ma'add al-Mustanṣir bi-llāh and the Vizier Al-Afdal Shahanshah.
His service continued until 1108, when, according to Ibn Abī Uṣaybiʿa, his attempt to retrieve a very large Felucca laden with copper, that had capsized in the Nile, ended in failure.
Abu as-Salt had built a mechanical tool to retrieve the Felucca, and was close to success when the machine's silk ropes fractured.
Abu al-Salt then left Egypt for Mahdia in Tunisia, the capital of the Zirids in Ifriqiya where he entered the service of king Yaḥyā ibn Tamīm as-Ṣanhājī and where his son, ʿAbd al-ʿAzīz was born.