FIELD: manufacture of building materials. SUBSTANCE: peculiar feature of invention is that, in a known method of manufacturing facing and ornamental-facing slabs based on silica wastes from various industries including layer-by-layer laying-up of starting components of slab stocks into molds and their subsequent thermal treatment with electric heater wherein stock undergoes heating, caking, face surface melting, and tempering, thermal treatment of stocks is conducted simultaneously for upper and lower, in respect to heater, stock layers forming upper and lower stacks. According to invention, preliminary heating of stocks is performed in the upper stack, whereas tempering of stocks after their surface melting is performed in closed space formed by contacting with each other molds with stocks of the lower stack under self-cooling to a temperature within the range from 150 to 50 C. Peculiar feature of the continuous-operation installation is that, in a known installation containing electric heater, heat insulated molds for slab stocks and mechanism for horizontal charging and discharging molds and their vertical step-by-step displacement, mold with heater is additionally provided with mechanism for horizontal displacement and is constructed in the form of heat insulated framework, whose shape corresponds to that of stock. Installation makes it possible to 1.5-2 times reduce power consumption per unit product, increase productivity, improve quality of face surface owing to complete removal of moisture and volatile substances when preliminarily heating stocks. Practically eliminated are temperature gradients along stock thickness in the course of tempering, which increases yield of valid products. EFFECT: enhanced efficiency of process. 4 cl, 1 dwg
