Assessment of limestone of Jeribe formation for ordinary Portland cement industry in Bekhair anticline, Duhok governorate, Iraqi Kurdistan Region

الملخص EN

The limestone of Jeribe Formation in Bekhair anticline, Duhok Governorate, was assessed as raw materials for the Ordinary Portland Cement (OPC) industry.

Four sections were selected; the formation consists of fossiliferous limestone and thin layers of dolomitic limestone which are less than one-meter-thick and did not affect the average percentage of MgO in the mixture.

The petrographic study showed that the main mineral of limestone rocks is fine calcite with a size of less than 0.25 mm.

The physical and mechanical tests of samples indicate low porosity, and the compressive strength range between (168-1291 kg /cm³), which are acceptable for the cement industry and make the rocks easy to crush and grind during the preparation of the mixture.

The chemical analysis revealed that the mean concentration of Cao is 51.77% which dominates over other oxides, including MgO (2.06 %), SiO: (1.95%), Al₂O, (0.60%), and, Fe: 0; (0.22%), While the remaining oxides (K: O, Na2O, TiO2, MnO, PO, and SO;) are considered trace oxides.

The lime saturation factors (LSF) of the studied sections range from (1101.74 to 2334.89), which are over the limits necessary for high-quality cement; thus, claystone from Fatha Formation was added to achieve the best point of clinker LSF.

The clinker phases C3S, C2S, C3A, and C4AF in the studied sections (Z1, Q.

K, and T) range between (49.19-56.70), (17.88-23.11).

(10.87-11.30), and (9.20-9.42) % respectively, and they are within the standard acceptable range.

According to the results of the analyses, we conclude that the best mixture of limestone ranges between (65.9-69.3) % and claystone ranges between (30.7-34.1) % in the study area are of good quality and meet the requirements of international standards for ordinary Portland cement.