White cement – modern construction material which is increasingly popular every year as it is used not only in the construction sphere, but also and in creation of architectural products.
Today the most famous producers of white cement is Turkey, Denmark and Egypt. Special color of cement is reached due to specific structure and the specialized production technology. Clinker for the white portlandtsement, differs from usual in the increased maintenance of Si2O (23.5-25.5%) and A12O3 (5.5-7%), insignificant quantity of Fe2O3 (up to 0.25-0.35%) and MnO – 0.05-0.15%. The mineral composition of clinker for white cements fluctuates within (%): C3S – 35-50; 35-45; C3A 14-17; C4AF 0.9-1.4. The maintenance of MgO in it should not exceed 4.5%. For production of the white portlandtsement the cleanest kinds of carbonate and sandy-argillaceous raw materials are used. In particular, the straight limestones or chalk containing no more than 0.15% of the painting oxides are applied. The kaolin, waste of its enrichment and other materials are served as a clay component. The fine-grained white quartz sands, waste of quartz sand received at enrichment of a kaolin, etc. to increase in the silicate module are applied.
The ashless fuel which is not forming soot and ashes that helps to avoid pollution is applied to roasting of clinker. Crushing of raw materials is carried out in special mills, and crushing is carried out by means of silicon or porcelain elements. Such production technology helps to achieve the grinding having higher rates than from traditional cements.
Results of a research of influence of mineral BaSO4 and ZnO additives on synthesis and properties of the low-main clinker of the white portlandtsement are given in work: clinker formation, hydration activity, whiteness of cement.