METHOD OF PRODUCING AND COMPOSITION OF BELITE CLINKER Russian patent published in 2020 - IPC C04B7/02 C04B7/24 C04B7/36 C04B7/38 C04B7/42 C04B7/44 

FIELD: chemistry.

SUBSTANCE: disclosed group of inventions relates to a method of producing belite clinker and a composition of belite clinker. Method involves preparation of crude mixture containing carbonate component in amount of 89.2–90.2 wt% and clay component in amount of 1.1–1.2 wt%, primary combined grinding of carbonate component and clay component in wet self-grinding mill to produce coarse sludge, fine grinding of coarse sludge in tube mills together with ferruginous additives in amount of 2.5–2.6 wt%. Fine grinding is carried out until residue on sieve No. 008 – 7.0±2.0 %, on sieve No. 020 – 3.0±1.0 %. Then, the sludge is mixed and corrected in the sludge basins by adding an alumina component in amount of 1.1–1.2 wt% and a silica component in amount of 4.8–6.0 wt%. Sludge is calcined in a rotary furnace by heating it to 1,350±10 °C with further cooling and obtaining belite clinker. Clinker has the following mineralogical composition, wt%: C3S – 38–48, C2S – 29–39, C3A – 3–5, C4AF – 14–16, periclase, sulphates, CaOfr. – 2–6. Chemical composition of clinker is as follows, in wt%: CaO 62.0–63.6; SiO₂ 23.0–24.0; Al₂O₃ 4.2–5.0; Fe₂O₃ 4.3–5.2; MgO; R₂O(Na₂O; K₂O); SO₃ – balance.

EFFECT: creation of clinker, which enables to obtain cement with slow and more uniform kinetics of set of compression and flexural strength at all stages of hardening, low early strength, which reduces risk of defects in structure of concrete; besides, proposed method provides reduction of slurry burning temperature to 1,350±10 °C, which increases service life of furnace lining and its ability to counteract both high temperatures and chemical action of clinker melt on refractories.

7 cl, 11 tbl, 3 ex, 3 dwg