CEMENT

[:ru]Бикбау М. Я.[:en]Bikbau M. Ya[:] [:ru]акад. РАЕН, д. х. н., генеральный директор ОАО «Московский институт материаловедения и эффективных технологий»[:en]Doct. Chemic. Sci., academic of RAEN, general director of Moscow institute of material science and effective technologies[:]

Alitinform №3-4 (04-05) 2008 г. 21-27 p.

Abstract

The prospective development of mechanic-chemically activated low-clinker cements manufacture is shown, which allows cement grinding’s unit costs reducing with simultaneous increase in its quality and cost-price reduction. Analyses of new data on low water-consumption cements (binders) as well as results of pilot-industrial launch of the line with production rate of 50 ton/h are presented. The optimal technological scheme and aggregate arrangement of production, including drying a part of mineral admixtures on clinker coolers, is recommended. The mechanism of the process is described which at cement grinding fulfils the mechanic-chemical activation of clinker grains with simultaneous particles’ micro-capsulation by modified polymer shell at nano-level.

Substantial part of Portland cement in the world is manufactured by adding to cement on the stage of grinding different mineral silica additives which are well combined in cement brick with Portland cement minerals and take part in cement brick structure’s forming.

The new State Standard (SS – GOST) 31108-2003 as well as regulating documents for manufacturing Portland cement with mineral additives in other countries proceed from the existing views regarding decrease hydraulic activity in cement brick in normal hardening terms, which decrease is proportional to mineral additives ratio increase compared to clinker ratio. According to the mentioned SS this supposes cement brand to go down from 62,5 to 52,5, then to 42,5, 32,5 and finally to 22,5.