Disk and process for producing base material for disk, and disk roll

A process for producing a disk roll comprising:

• preparing disks,
• the disks comprising mullite fibers, an inorganic filler having an aspect ratio of from 1 to 25, and an inorganic binder,
• the inorganic filler being wollastonite,
• the mullite fibers containing Al2O3 and SiO3 in a ratio of from 70:30 to 80:20,
• the inorganic binder being Kibushi clay and bentonite,
• the disks comprising from 30 to 50% by mass of the mullite fibers, from 20 to 50% by mass of the inorganic filler and from 20 to 40% by mass of the inorganic binder, the disks not comprising mica;
• and
• fitting the disks on a rotatable shaft by insertion whereby the outer peripheral surface of the disks serves as a conveying surface.