Are there asteroids made of ice?

No. At most some will have small amounts. They were formed in conditions where lighter elements required for water were already blown away by the “solar wind” of the sun forming. read more

There are also D type, known as the Trojan asteroids of Jupiter and are dark and carbonaceous in nature, and V type that are distant asteroids between the orbits of Jupiter and Uranus, and they may have originated in the Kuiper Belt. read more

Asteroids are differentiated from comets and meteoroids. In the case of comets, the difference is one of composition: while asteroids are mainly composed of mineral and rock, comets are composed of dust and ice. In addition, asteroids formed closer to the sun, preventing the development of the aforementioned cometary ice. read more

Manned flights to and from the asteroids could potentially reap the same benefits from ice mining as Moon missions and bases would: and do so more easily, as there is no lunar gravity field to lift the resulting propellants out of. read more