METHOD OF PREPARING LIGHT FILLER Russian patent published in 2004 - IPC

FIELD: manufacture of building materials.

SUBSTANCE: preparation of filler characterized by low density and high strength comprises mixing industrial carbon-containing wastes with adjusting additives, grinding resulting mix, molding crude granules, drying and firing crude granules, and cooling thus obtained fired swollen granules. More specifically, cinder waste from heat-and-power stations is used and amount of adjusting additives is selected from following condition: summary content of silicon, aluminum, and titanium oxides does not exceed 80%; summary content of modifying iron, calcium, magnesium, sodium and potassium oxides does not exceed 33%; content of iron oxides is no higher than 10%; summary content of sodium and potassium oxides is no higher than 14%; summary content of poorly soluble chromium, sulfur, molybdenum, tungsten, copper, and arsenic oxides is no higher than 3%; weight ratio of summary content of aluminum and titanium oxides to silicon oxide content does not exceed 0.4; and weight ratio of summary content of calcium and magnesium oxides to summary content of sodium and potassium oxides does not exceed 2.5. When cinder waste with content of carbon in ashes above 3% is used, waste is separated in organic and mineral portions using flotation process to provide content of non-burned carbon particles in mineral portions no higher than 2% and, when content of non-burned carbon particles is higher than 6%, flotation is carried out in two or more steps.

EFFECT: achieved balance between low density and high strength.

8 cl, 4 tbl