Determination of clinker, cement and additives introduced in the grinding
The first "unified norms delivery and verification of Portland cement" appeared in Germany in 1878. It was the first German standard, which normalized the quality of the material, while the mass of the product. In 1909. Portland cement and ferrous were standardized in 1917. - Shlakoportlandtsement.Portlandtsement made from clinker with the addition of sulfate (gypsum rock or rock anhydrite in a quantity of 5-10%) and ferrous slag Portland cement further comprises granulated blast furnace slag, Open Path - additionally contains traces. In addition to these species in some countries it is also produced alumina cement and sulphate slag. These two types of cement in the Federal Republic of Germany are not made and are not standartizovany.Teper in Germany and many other European countries, there is a norm (standard) EN 197-1, gives a definition of cement as follows: "The cement - hydraulic binder, obtained by pulverizing inorganic material that, when mixed with water forms a cementitious paste, which hydrates, becomes stable and hardens under water and indoors "[As to standard EN 197-1 cement exists with the introduction of secondary components in an amount of 0-5%. The following possible basic components:
● Portland cement clinker (K)
● The granulated blast furnace slag (S)
● pozzolan
- Natural pozzolan (P)
- Natural volcanic pozzolan (Q)
● Fly ash
- Rich in silica fly ash (V)
- Lime rich fly ash (W)
● Burnt shale (T)
● Limestone (L, LL)
● Silikashtaub (D)
Additionally, the cement also contains calcium sulfate, cement and some technological additives.
The composition of the raw meal. Equations 1-4
In practice, the composition is characterized by raw materials (also part of PZ clinker) in most cases by the ratio of oxide (so-called modules). They set out certain chemical analyzes oxides. Lime standard (KSt or as it is accepted in Kazakhstan KN saturation ratio) in the majority of cases, is used to calculate the optimum lime component. The high lime component (CaO) allows the formation of rich lime silicate clinker phases during its firing. They are used for quality assurance with regard to the development of high strength cement. CaO content must be agreed with the content of other oxides - SiO2, A12O3, Fe2O3. If there is an excess of CaO (lime CaOsvob free), it can lead to later reaction with water, formation of Ca (OH) 2, and the increase in volume of the cement stone destruction. The optimum proportion of lime should be high, but not be too high. Lime Standard (KN) is used to accurately establish the optimal proportion of lime. It is expressed in the feed (or clinker) shows the available CaO proportion in percent that can bind in the firing process with the existing oxides SiO2, A12O3, Fe2O3 phase in the clinker; those. It expresses actually contained in the raw material or a mixture of CaO in the clinker,% of CaO to the amount that can be caused in the process of clinker burning and cooling.
Уравнение
1
A more precise definition of lime possible with KStII. Today, it is almost exclusively used:
equation 2
In a later account of MgO, which can replace up to 2% CaO, introduced KStIII
equation 3
It should be constantly taken into account fluctuations in MgO. Lime standard technical clinker is between 90 and 104 [24], especially with high-quality clinker> 97.
It means:
KSt I = standard for lime Cul
KStII = standard for lime and Leah Parker
KStIII = on lime Shpana standard Vёrmanna and Knёfelya
w (oxide) oxide = wt.%, and both are taken into account oxides CaO, MgO, SiO2, Al2O3 or Fe2O3.
Example:
Chemical analysis gave the raw meal eventually CaO = 65,7%, SiO2 - 21.1%, Al2O3 = 6.6%, Fe2O3 = 3.1%, MgO = 2.0%, balance - 1.5%.
equation 4
Silicate modulus (n) - the ratio SiO2 - (silicic acid) to the amount of A12O3 - (alumina) and Fe2O3.