METHOD FOR PRODUCTION OF GRANULAR BUILDING MATERIAL FROM WASTE OF PROCESSING OF APATITE-NEPHELINE ORES Russian patent published in 2022 - IPC C04B20/04 C04B20/06 C04B28/26 C04B38/00 

FIELD: building materials.

SUBSTANCE: invention relates to the field of production of building materials, in particular to the production of artificial porous fillers for concretes and granular heat-insulating materials for filling heat insulation, as well as to the production of a semi-finished product for the production of granular building material. A method for the production of granular building material from a raw material mixture consisting of a siliceous component and an alkaline binding solution includes drying and grinding of the siliceous component, preparation of the binding solution by joint wet grinding of vitreous sodium silicate, sodium carbonate, and water at a temperature of 80-110°C for 10-180 min. Mixing of components and granulation of the mixture are carried out in the same device – a granulator. After granulation, raw granules are subjected to thermal processing: drying to a moisture content of 1-15% at a temperature of 200°C and calcination for 5 to 60 min. As the siliceous component, waste of processing of apatite-nepheline ores – dried ground powder of apatite flotation tails – AFT with a physical moisture content of 0.3% is used. Joint wet grinding is carried out at the following ratio of components of the binding solution, wt.%: vitreous sodium silicate 5-20, sodium carbonate 5-20, water 60-90. Mixing and granulation are carried out at the ratio of the binding solution and the specified siliceous component from 1:15 to 1:5. Calcination is carried out at a temperature of 750-930°C. while the total content of alkaline oxides in the final material is from 15 to 25 wt.%.

EFFECT: reduction in bulk density and water absorption, increase in compressive strength of granular building material, reduction in a calcination temperature, disposal of waste of processing of apatite-nepheline ores.

2 cl, 13 tbl, 7 ex