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M.A.W. Gaber / Egyptian Journal of Petroleum xxx (2017) xxx–xxx
4.11. Purity as CaCO3: 95%
The CaCO3 content in studied samples are ranging from 99.30 to 99.65%, which called high purity limestone as per [19].
4.12. Refractive index
Refractive Index is the difference between the speed of light in a vacuum and the speed of light in the gemstone. As light passes through a gemstone, it slows down because a gemstone is denser than air. The angle of refraction in the gemstone determines its RI [20]. The RI is easily measured using a refractometer. Limestone fillers are mainly composed of strongly birefringent calcite mineral with refractive indices ranging from 1.49 to 1.65.
4.13. Specific surface area
Specific surface area is measured by the nitrogen adsorption method (BET: Brunauer, Emmet, Teller). The particle fineness, the particle size distribution, and the particle morphology are, depend- ing on the structure, indirectly reflected in the specific surface area of the filler. Finer, non-structured fillers exhibit a higher specific surface than coarser ones. There is, a direct correlation between the specific surface area of filler and, the internal sizing agent demand. An internal sizing agent is applied to the wet end in order to make the paper more hydrophobic. The specific surface area of regular paper fillers ranges between 2.5 and 14 m 2 /g 1 , while fiber fines show specific surface areas of 6–8 m 2 /g 1 . The surface area
Fig. 6. Brightness of El Minia carbonates.
4.10. Brightness of El Minia calcium carbonate
In paper industry the high dry brightness is preferred to pro- duce the high quality paper. The limestone were crushed to very fine size and tested using Dr. Lange equipment (Fig. 6), and the results achieved the requirements of paper making brightness value ranging from 91 to 93.5% as shown in Table 3.
(a) SEM for El Minia limestone
(b) SEM for el Minia Chalk
Fig. 7. (a) SEM for El Minia limestone (b) SEM for el Minia Chalk.
C o un ts
Dr.M.Abdel-Wahab (12)
1 5 0 0
1 0 0 0
5 0 0
0
1 0
2 0
3 0
4 0
5 0
6 0
Position [°2Theta] (Copper (Cu))
Fig. 8. XRD of Limestone at Samalout area.
Please cite this article in press as: M.A.W. Gaber, Characterizations of El Minia limestone for manufacturing paper filler and coating, Egypt. J. Petrol. (2017), http://dx.doi.org/10.1016/j.ejpe.2017.07.007
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