Evaluation of calcium carbonate in eggshells using thermal analysis

2019 ◽  
Vol 138 (4) ◽  
pp. 2751-2758 ◽  
Author(s):  
Matjaž Kristl ◽  
Sabina Jurak ◽  
Maksimilijan Brus ◽  
Vilma Sem ◽  
Janja Kristl
Keyword(s):  
Thermal Analysis ◽  
Calcium Carbonate

The Carbonation of Calcium-Silicate-Hydrate C-S-H in Cement Mortar Studied Using Thermal Analysis and Gas Pycnometer: Determination of the Quantity of Calcium Carbonate Produced and the Increase in Molar Volume

2014 ◽  
Vol 931-932 ◽  
pp. 411-415 ◽  
Author(s):  
Son Tung Pham ◽  
William Prince
Keyword(s):  
Thermal Analysis ◽  
Calcium Carbonate ◽  
Relative Humidity ◽  
Molar Volume ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Cement Mortar ◽  
Accelerated Carbonation ◽  
Carbonation Of Portlandite

The objective of this work was to examine the microstructural changes caused by the carbonation of normalised cement mortar. Samples were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO2 concentration. The main contributions of this study were: 1) a new way to determine separately the amount of calcium carbonate CaCO3 produced by the carbonation of portlandite Ca (OH)2 and that associated with the carbonation of calcium-silicate-hydrate C-S-H using only thermal analysis; 2) determination of the increase in the molar volume of the calcium-silicate-hydrate C-S-H due to carbonation using gas pycnometer, which indicated an increase of about 39 cm3 for 1 mole of C3S2H3 carbonated. The results indicated that the amount of CaCO3 produced by the carbonation of C-S-H is higher than that produced by the carbonation of portlandite.

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

2021 ◽  
Vol 406 ◽  
pp. 481-491
Author(s):  
K. Abdellaoui ◽  
A. Boumaza ◽  
N. Kamoun
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Calcium Carbonate ◽  
Physical Characterization ◽  
Physical Chemical ◽  
Geological Conditions ◽  
Chemical Techniques ◽  
Eastern Algeria ◽  
Extrinsic Defects

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.

Thermal synthesis of sodium calcium carbonate—A potential thermal analysis standard

1971 ◽  
Vol 2 (4) ◽  
pp. 305-312 ◽  
Author(s):  
John Ward Smith ◽  
Donald R. Johnson ◽  
William A. Robb
Keyword(s):  
Thermal Analysis ◽  
Calcium Carbonate ◽  
Thermal Synthesis ◽  
Sodium Calcium

A TEM study of the microstructure of avian eggshells

1992 ◽  
Vol 50 (2) ◽  
pp. 1102-1103
Author(s):  
S. Q. Xiao ◽  
S. Baden ◽  
A. H. Heuer
Keyword(s):  
Electron Microscope ◽  
Calcium Carbonate ◽  
Nucleation And Growth ◽  
Growth Mechanisms ◽  
Shell Surface ◽  
Thin Sections ◽  
Polycrystalline Metals ◽  
Transmission Electron ◽  
Nucleation And Growth Mechanisms

The avian eggshell is one of the most rapidly mineralizing biological systems known. In situ, 5g of calcium carbonate are crystallized in less than 20 hrs to fabricate the shell. Although there have been much work about the formation of eggshells, controversy about the nucleation and growth mechanisms of the calcite crystals, and their texture in the eggshell, still remain unclear. In this report the microstructure and microchemistry of avian eggshells have been analyzed using transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS).Fresh white and dry brown eggshells were broken and fixed in Karnosky's fixative (kaltitanden) for 2 hrs, then rinsed in distilled H2O. Small speckles of the eggshells were embedded in Spurr medium and thin sections were made ultramicrotome.The crystalline part of eggshells are composed of many small plate-like calcite grains, whose plate normals are approximately parallel to the shell surface. The sizes of the grains are about 0.3×0.3×1 μm3 (Fig.l). These grains are not as closely packed as man-made polycrystalline metals and ceramics, and small gaps between adjacent grains are visible indicating the absence of conventional grain boundaries.

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