The kaolin clay deposits in the Western desert of Iraq : an overeview

Other Title(s)

رواسب طين الكاؤولين في الصحراء الغربية العراقية : نظرة شاملة

Joint Authors

Mahdi, Muhammad Abd al-Amir
Ibrahim, Asma Abd al-Aziz
Agha, Mazin Yusuf Tammar

Source

Iraqi Bulletin of Geology and Mining

Issue

Vol. 2019, Issue (s8) (31 Dec. 2019), pp.147-173, 27 p.

Publisher

Ministry of Industry and Minerals Iraqi Geological Survey

Publication Date

2019-12-31

Country of Publication

Iraq

No. of Pages

27

Main Subjects

Earth Sciences, Water and Environment

Topics

Abstract EN

Very large kaolin clay deposits are recorded at the Western Desert of Iraq, in the Ga'ara Formation (Permocarboniferous), Hussainiyat Formation (Lower Jurassic), and Amij Formation (Middle Jurassic) and as flint clay at the base of the Hussainiyat Formation in karsts developed in the Ubaid Formation carbonates.

Other exposed formations, such as Zor Hauran Formation (Upper Triassic) incorporate some thick impure kaolinitic horizons.

The investigated clays are sedimentary (transported) except the flint clay, which is from in situ alteration of kaolin during bauxitization.

The Ga'ara and Hussainiyat kaolin clays are of fluvial origin, Amij kaolin clay of paralic origin and Zor Hauran kaolinitic clay of marine origin.

Kaolinite is the major clay mineral present in these deposits with minor proportions of illite and mixed-layer illite-smectite.

The other main admixtures present are quartz, iron oxyhydroxides (mostly goethite) and anatase.

Particle size of these deposits ranges from very fine to coarse and their plasticity ranges from super-plastic to moderately plastic, except the Hussainiyat flint clay is non-plastic.

Tests on nature of slaking showed that the Ga'ara and Amij kaolin clays disintegrate within 2 – 4 minutes after immersion in water, whereas the Hussainiyat kaolin clays require longer time to disintegrate.

Thermal behavior revealed that clays with little impurities sustain higher temperatures and hence physical properties of the test tiles level off at temperatures as high as 1200 °C.

On the other hand, clays containing high impurities, such as alkalies and iron oxides, level off at temperatures ranging from 1050 to 1100 °C.

Thermal behavior of the silty clay differs from the rest as the linear shrinkage and bulk density show gradual and very slight increase with rise of firing temperature, whereas its open porosity and water absorption decrease in a steeper gradient.

The kaolin clays are classified, for industrial purposes, into two classes: white kaolin clays (Al2O3≥20% and Fe2O3˂3%) and coloured kaolin clays (Al2O3 ≥20% and Fe2O3 ≥3%).

Follow-up investigations were carried out on eighteen localities to estimate, verify and categorize the quantity and quality of the kaolin clay deposits.

The investigations at the Ga'ara locality resulted in estimating about 960 million tons of white and coloured kaolin clay (categories A, C1 and C2), at the Hussainiyat locality about 311 million tons of white and coloured kaolin clays (categories C1 and C2), at Amij locality 32 million tons of coloured kaolin clays (category C2) and at Northeast Hussainiyat locality about 10 million tons of flint kaolin clay.

American Psychological Association (APA)

Agha, Mazin Yusuf Tammar& Mahdi, Muhammad Abd al-Amir& Ibrahim, Asma Abd al-Aziz. 2019. The kaolin clay deposits in the Western desert of Iraq : an overeview. Iraqi Bulletin of Geology and Mining،Vol. 2019, no. (s8), pp.147-173.
https://search.emarefa.net/detail/BIM-894280

Modern Language Association (MLA)

Agha, Mazin Yusuf Tammar…[et al.]. The kaolin clay deposits in the Western desert of Iraq : an overeview. Iraqi Bulletin of Geology and Mining Eighth special issue (2019), pp.147-173.
https://search.emarefa.net/detail/BIM-894280

American Medical Association (AMA)

Agha, Mazin Yusuf Tammar& Mahdi, Muhammad Abd al-Amir& Ibrahim, Asma Abd al-Aziz. The kaolin clay deposits in the Western desert of Iraq : an overeview. Iraqi Bulletin of Geology and Mining. 2019. Vol. 2019, no. (s8), pp.147-173.
https://search.emarefa.net/detail/BIM-894280

Data Type

Journal Articles

Language

English

Notes

Includes bibliographical references : p. 171-173

Record ID

BIM-894280