Mineral reactions in calcareous rocks can be modeled in the system CaO-MgO-SiO2-H2O-CO2 (CMS-HC) However, other components (e.g., FeO, Al2O3, Na2O
, K2O and TiO2) are also present, playing a very important role in the stabilization of additional mineral phases such as micas, epidote-group minerals, garnet, feldspar, titanite, rutile.
Among other major components Na2O
, common in source magmas, has been almost completely dissolved and removed.
According to TAS diagrams by  and  which are drawn according to alkaline Na2O
and K2O quantities in SiO2, all the studied samples are placed in quartzmonzonite, granite, diorte, quartzmonzodiorite, monzonite and granodiorite range (figs.
The impure limestone (SLS) reported an average of 52.96% CaCO3 and 7.9% MgCO3 with consistently elevated SiO2, Al2O3, Fe2O3 and Na2O
reflecting contained alumino-silicate minerals.
Concentrations of major elements and total REEs in all lithotypes Sample SiO2 A1203 Fe203 MgO CaO Na2O
Parameters Chemical composition (%) CaO 4.83 Si[O.sub.2] 1.76 [Al.sub.2][O.sub.3] 0.552 Fe2[O.sub.3] 0.317 S[O.sub.3] 0.243 MgO 0.186 Na2O
0.072 [K.sub.]2O 0.068 [P.sub.2][O.sub.5] 0.062 SrO 0.046 Cl 0.030 ZnO 0.019 Ti[O.sub.2] 0.017 CuO 0.011 C 44.6 H 5.33 N 1.47 Physical characteristics ph 7.4 BET surface area ([m.sup.2]/g) 1.532 Particle diameter (cm) 0.5-1 Water holding capacity (g water/g dry GGR) 2.9 Bulk density (kg/[m.sup.3]) 37.62 TABLE 2: Comparison between adsorption capacities of different adsorbents.
Coal ash showed lower amount of Na2O
, [K.sub.2]O and higher content of [Al.sub.2][O.sub.3], Si[O.sub.2] and [Fe.sub.2][O.sub.3] compared to horse manure and the bottom ash.
Chemical assays Tests NBR Unit Results Loss by Fire--LF 5743/89 % 3.21 Magnesium Oxide--MgO 9203/85 % 2.88 Sulfuric anhydride--S[O.sub.3] 5745/89 % 3.60 Insoluble residue 8347/92 % 1.22 Equivalent alkalis in Na2O
(0.658 -- % 0.88 x K2O% + [Na.sub.2]O%) Free Calcium Oxide--CaO 7227/90 % 1.44 Physical and mechanical assays Tests NBR Unit Results Specific Area (Blaine) 7224/96 [m.sup.2] 4.950 [Kg.sup.-1] Specific Gravity 6474/84 g [cm.sup.-3] 3.11 Density -- g [cm.sup.-3] 1.07 Fineness--Residue by 0.075mm 11579/91 % 0.42 sieve (#200) Fineness--Residue by 0.044mm 11579/91 % 2.62 sieve (#325) Water of normal consistency paste 11580/91 min.
The percentages of Na2O
and C[O.sub.2] are below detection limits 0.20 % and 0.03 % (w/w), respectively.
Observa-se, tambem, que a perda ao fogo, inferior a 10%, o teor de MgO, inferior a 3% e o teor de alcalis em Na2O
, inferior a 1,5%, tambem atendem as exigencias da normalizacao (ABNT, 1992c; ASTM, 1992).