Geochemical assessment of Naopurdan limestone for cement making - Chwarta area, Kurdistan Region, NE Iraq

Volume 1 , Issue 1 , January 2016 , Pages 257-267

Authors

¹ University of Sulaimani, School of Science, Department of Geology

The Naopurdan limestone klippe is covering about 19.28 Km2

of Chwarta area-Sulaimani City. Fifteen samples were collected from this limestone body and analyzed

by X-ray fluorescence technique. The analysis was carried out in Mass Cement

Company. The Petrographical study revealed the presence of different fossil content

such as Nummulitesspp ( N. perforates; N.milliucaput; N.globulosa; N.atacicus;

N.bahyranses)., Alvelinaspp( A. eleptica; A. aragoensis; A. oblonga; A. fusiformis).,

Miliolina ; Algae (Lithothaminum sp.; Cympolina sp. ); echinoid bioclasts; corals; and

Orbitolites; Coskinolinasp; Somalina sp. Index fossils indicate the Middle Eocene age

for this limestone body. The formaniferal wackestone and packstone microfacies are the

most common facies in the studied samples, as well as recrystallized limestone observed

in two samples. The depositional environment as deduced from lithology and fossil

content is shoal marine environment.

Petrological study indicated that the limestone samples are crystalline and dominantly

composed of calcite with CaCO3 content more than 95 %. Geochemical analysis results

of fifteen handpicked samples indicated that the limestone from the Naopurdan

Formation shows LOI range between (38.50% to 43.29%), Si02 (0.11% to 7.92%),

CaO (55.19% to 45.82%), A12O3(0.01% to 0.97%), Fe2O3(0.02 % to .46%) and MgO

0.37 % to 4.29 %,K2O,Na2O, and SO3 are present in traces. The lime saturation

factors (LSF) of studied samples have widely differing values ranging from 188.64 to

7543.52, but most have values above the limits required for high quality cement. Thus a

claystone rocks from Red Bed Series have been added to reach the best point of LSF of

clinker. All materials after mixing proved that they meet the specification required for

clinker production.

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