*2.3. Heat Treatment*

The glass samples were heat-treated from room temperature to the required temperature for a specific soaking time in a muffle furnace, then the furnace was switched off, and the samples were permitted to cool inside it to room temperature. Detection of the crystallization temperatures was guided by the DTA results. Soaking times were measured after the furnace reached the desired temperature. Figure 1 shows Schematic presentation for the production of glass and glass–ceramic materials from industrial wastes.

**Figure 1.** Schematic presentation for the production of glass and glass–ceramic materials from industrial wastes.
