Does impurity disappear if it burns and turns to ash?

Scholars have differed regarding the purity of ashes from impure substances after burning them:

1. Abu Hanifa and Muhammad (this is the relied-upon opinion among Hanafis, the chosen opinion of Malikis, and contrary to the apparent opinion among Hanbalis) held that the ashes resulting from the burning of an impure or ritually impure substance are pure, as fire purifies through transformation.

2. The Shafi'is (this is the apparent view in the Hanbali school, the counter-opinion to the relied-upon view among Malikis, and the opinion of Abu Yusuf among Hanafis) held that the ashes of an impure substance are impure because the particles of impurity remain and have not transformed.

Shaykh al-Islam Ibn Taymiyyah chose the opinion of its purity, preferring that transformation is sufficient for purification.