PORTLAND CEMENT PRODUCTION METHOD Russian patent published in 2006 - IPC C04B7/36 

FIELD: building material industry, particularly to produce hydraulic cements.

SUBSTANCE: method involves drying and graining source sludge having saturation factor K_s = 0.85-0.95, alumina modulus p=1.24-1.28 and silica modulus n=1.89-1.92 in concentrator having 4.5 m diameter and festoons of chains; burning the obtained granules at 1400-1450°C temperature in short rotary oven having length of 70 m and transversal dimension of 3.0×3.6 m; cooling the obtained clinker; intergrinding the clinker with gypsum taken in amount of 2.5-3.5% by weight recalculated to SO₃. For above method realization the source sludge has moisture content of 31.0-35.0%, spreadability of 50-70 mm. The concentrator has length of 6 m. the drying operations is carried out at 700-900°C to reach moisture content of 5-6%. The final granules have 10-20 mm dimensions. The intergrinding operation is carried out up to obtaining 8.0-13.0% residue on sieve N008. Mineral additives in amount of 20% by weight may be added during intergrinding operation.

EFFECT: increased intensity of clinkering operation, increased Portland cement clinker quality, reduced power inputs and material consumption.

2 cl, 6 tbl