Assessment of Suitability of the Beduh Deposits (Lower Triassic) for Lightweight Aggregates, North Amadyia, Kurdistan Region - Iraq

Volume 1 , Issue 1 , January 2016 , Pages 121-137

Authors

¹ Department of Geology, College of Science, Salahaddin University, Erbil-Iraq

² Department of Geology, College of Science, University of Baghdad, Baghdad-Iraq

This study deals with the assessment of deposits of the Beduh Formation (Lower

Triassic) for lightweight aggregate. It is carried out on channel samples of three

exposures (Beduhe, Sararu and Nazdur) at north of Amadyia. Lithologically, the

formation consists of alternation of reddish purple, reddish brown and greenish grey

shale with subordinate thin sandstone beds and some siltstone streaks.

XRD analysis revealed that the studied samples are composed mainly of clay

minerals such as illite in major proportion with kaolinite, chlorite, smectite and mixed-

layer illite-smectite in minor proportions. The non-clay minerals are quartz and calcite,

in major proportions and minor proportions of feldspar and hematite. Grain size analysis

showed that the raw materials are composed mainly of clay and silt, with subordinate

sand. The plasticity index of these shales is high due to high clay content. Chemical

analyses show that the raw materials are composed essentially of silica, alumina, calcium

oxide and relatively a less proportion of iron oxide, and appreciable amounts of MgO,

K2O, Na2O, TiO2 and MnO.

The raw materials are ground and sieved to two sizes: fine size (less than 0.075

mm) and coarse size (less than 1.00 mm). Water is added (about 12-15 %) to the sieved

samples and thoroughly mixed, pelletized by hand to lumps named here pellets (about

18-20 mm diameter). The pellets are dried and fired at different temperatures with

different soaking times. The evaluation physical tests (bloating, porosity, water

absorption and bulk density) shows that the best results achieved through flash firing at

1120°C with soaking time 30 minutes and rapid cooling, after pre-heating to about 300

to 350°C for 10 to 15 minutes. The coarse raw materials (less than 1.00 mm) show better

results than the finer size (less than 0.075 mm).

Statistics