Process for producing a hot blended material of amorphous silicon dioxide – crystalline silicon dioxide, process for producing artificial stone from the material by press-vibration method in vacuum environment and the artificial stone product obtained from this process

A process for producing artificial stone, wherein the process comprises the following steps:

• i) heating a mixture of sand, crushed glass and solid waste from quartz stone production in amount of 60 to 90% by weight together with Na2CO3 in amount of 1 to 13% by weight, Al2O3 in amount of 1 to 13% by weight, (CaCO3/MgCO3 in amount of 5 to 13% by weight and processing aid at a temperature between 1000° C. and 1600° C. to obtain common molten frit with amorphous silicon dioxide in range of from 40 to 80% by weight;
• ii) preparing crystalline silicon dioxide from the sand, quartz, and cristobalite with a size ≤500 μm, with or without a heating process from 25° C. to 1600° C. before mixing with the common molten frit with amorphous silicon dioxide;
• iii) injecting, mixing and hot press-rolling the crystalline silicon dioxide into the common molten frit with amorphous silicon dioxide, together with adjusting an injection pressure of the crystalline silicon dioxide and a flow rate of the common molten frit with amorphous silicon dioxide so that a proportion of the common molten frit with amorphous silicon dioxide is in range from 60 to 95% by weight and a proportion of the crystalline silicon dioxide is in range of 2 to 40% by weight, wherein a total silicon dioxide content of an obtained product ranges from about 80% to 95% by weight;
• wherein a mixture of the common molten frit with amorphous silicon dioxide and the crystalline silicon dioxide is mixed and homogenized through stages:
• stage 1:
• injecting the crystalline silicon dioxide directly into a molten frit stream of the common molten frit with amorphous silicon dioxide, through a hot press-rolling mixing roller system which is configured to adjust a rotating speed, moving speed in and out of a roller and distance between two rollers to perform a hot rolling-mix for a first time to yield a molten mixture, at this stage a mixture temperature ranges from 1000 to 1600° C., and
• stage 2:
• passing the molten mixture through a cool rolling and mixing roller system which is primarily cooled by water or air and which is configured to adjust the rotating speed, the moving speed in and out of the roller and the distance between the two rollers to perform a rolling mixing for a second time, at this stage the mixture temperature ranges from 500 to 1000° C.;
• iv) passing the molten mixture, after the stage 2, through a mold or flat heat-resistant conveyor system that has vertical movement perpendicular to the roller and mixing and rolling rollers in which a speed and distance between the roller and a conveyor belt is configured to be adjusted in order to adjust a particle size as specified to yield particles, wherein the roller is secondarily cooled by water or air, at this stage the mixture temperature ranges from 100 to 500° C.;
• v) grinding the particles from the step (iv) by a mill system to obtain the hot blended material of amorphous silicon dioxide-crystalline silicon dioxide with specified sizes;
• and
• (vi) producing artificial stone products by using blended material of the amorphous silicon dioxide-crystalline silicon dioxide obtained in the step (v) and base resins by press-vibration method in a vacuum environment, in which a ratio of the base resin used is in range from 6 to 20% by weight and a ratio of the blended material of the amorphous silicon dioxide-crystalline silicon dioxide obtained in the step (v) is in range from 80 to 94% by weight.