METHOD FOR PRODUCING COLORED PORTLAND CEMENT Russian patent published in 1997 - IPC

FIELD: construction material industry. SUBSTANCE: this relates to producing COLORED cast portland cement with plasticizing additive. According to method, primary portland cement or portland cement clinker or gypsum is milled by stages with coloring agent and then with plasticizer. Used in this case is ready-made grey portland cement or cream-colored portland cement produced from whitened standard portland cement clinker or white portland cement. Production of aforesaid grades of portland cement from portland cement clinkers of grey, cream and white color can be included in process of producing colored portland cement by milling at acceleration of particles of milled materials equal to 10-20 g with their subsequent milling together with plasticizer at same rate of acceleration. Usable as coloring agent are any organic or non-organic pigments or their mixes which do not hamper technical characteristics of portland cement recorded prior to introduction of coloring agents. Milling fineness at first stage should correspond to 4% residue on screen with openings of 0.08, and at second stage - 2% residue on screen with same size of openings. Colored portland cement produced by aforesaid method has distinctive color tones, is of high strength, quick-hardening, and stable at thermal-moisture treatment and ultraviolet irradiation. It can be used in construction, architecture and sculpture activities and also in producing artificial stones. EFFECT: high efficiency. 7 cl, 1 tbl