Study of Chemical and Physical Characterization of the Natural Dolomite of Ain Mlila-Algeria

Abstract

Dolomite is one of the commonest minerals that abound in the formation of a number of geological conditions. And it is found in abundance in eastern Algeria, especially Ain Mlila-Wilaya of Oum El Bouaghi-Algeria. The analyzed sample of raw dolomite has been by various physical-chemical techniques. The constituents of these carbonates are Ca, Mg, C, O, Al, Si, Fe, Ba, F, and Sr, analysis by XRD, and Raman, show that in addition to CaMg(CO3)2, we may have calcium carbonate. The Photoluminescence analysis characterizes the intrinsic and extrinsic defects of this carbonate. Differential thermal analysis reveals the different transformations of this mineral during heating. Indeed several stages including the elimination of water, the departure of CO2, the formation of MgO, and finally the formation of CaO.

The Regeneration of Dolomite as a Heterogeneous Catalyst for Biodiesel Production

“…Absorption peaks characteristic of natural dolomite (1438 cm −1 , 879 cm −1 ) associated with a carbonate bond (CO 3 2-) disappeared after calcination, indicating that dolomite decomposed to oxides of calcium and magnesium [30,31]. The characteristic peak situated around 3650 cm −1 indicates the presence of the OH present in Ca(OH) 2 and also Mg(OH) 2 compounds [32]. In the spectrum, the absorption peaks characteristic of the deformational vibrations of the products formed during the heating of dolomite appears, i.e., Mg-O (1417-1520 cm -1 ) and Ca-OH (3642 cm -1 ) (Figure 2a, curve 1) [30][31][32].…”

“…The characteristic peak situated around 3650 cm −1 indicates the presence of the OH present in Ca(OH) 2 and also Mg(OH) 2 compounds [32]. In the spectrum, the absorption peaks characteristic of the deformational vibrations of the products formed during the heating of dolomite appears, i.e., Mg-O (1417-1520 cm -1 ) and Ca-OH (3642 cm -1 ) (Figure 2a, curve 1) [30][31][32]. Some absorption peaks characteristic of the CO 3 2− group (~950-1000 cm −1 , 1120-1150 cm −1 , 1670 cm −1 , and 2926 cm −1 ) are slightly shifted to the higher energy region.…”

“…Analyzing the FTIR spectra of the used dolomite, which was regenerated via calcination (Figure 2b, curves 2-4), an increase in the intensity of the absorption peak characteristic of deformational vibrations of OH groups (3642 cm −1 ) can be observed. The vibrational band detected at around 1450 cm −1 corresponds to the formation of oxide Me (Me = Mg, Ca) [32], and as the number of calcination cycles increases, the intensity and position of this absorption band change. The intensity of the band increases and shifts towards higher wavenumbers.…”