PURPOSE: To produce a glass batch which is anhydrous and is thoroughly preheated without intricate previous stages by adding an aq. soln. of caustic soda in the process of bringing a glass raw material into countercurrent contact with ceramic balls which are heated by waste gas.

CONSTITUTION: Heated ceramic balls are supplied from the left end of a rotating body to an inside cylinder and are moved toward the right by the inclination of the rotating body while making heat exchange with an aq. caustic soda soln. and a glass raw material by contacting therewith. The circulation system wherein such ceramic balls are discharged from the inside cylinder, are transferred to a heat exchanger 10, are heated by the waste gas therein and are supplied again to the rotating body is constituted. On the other hand, the glass raw material wherein soda content is deficient is supplied onto the ceramic balls in the inside cylinder from the right end and are subjected to a heat exchange with the ceramic balls by contacting with said balls, then the raw material falls into the space 6 between the inside cylinder and the outside cylinder. The glass raw material is moved toward the left at every repetition of the above-mentioned cycle, whereby the soda content is replenished when the raw material is discharged through a discharging port, and a thoroughly preheated glass batch is produced.