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International Journal of Agricultural Policy and Research
Vol.3 (1),pp 53-59, January 2015
Available online at
Article 14/ID/JPR194/07/ pages
Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License.

Original Research Article

Mechanical and chemical properties of selected mullusc  shells in Nigeria

Etim U. U. Ituen

Department of Agricultural and Food Engineering,Faculty of Engineering,University of Uyo, Nigeria.

Author’s Email: dreuuituen(at)
Tel.: +2348034333660

date Received:     date Accepted: January 2, 2015     date Published:


Important mollusc shells in Nigeria include those of  land  and  water snails, the periwinkle and the clam.  Some farmers burn them to reduce crushing strengths before grinding for  livestock feeds as a source of calcium and other mineral elements. They are also said to be a good liming material for acid soils. It is believed that burning may destroy some of these elements. This work was to investigate their mechanical and chemical properties which may help in the development of affordable equipment to crush the shells without burning. The shells were selected according to size range and subjected to size measurements in terms of equivalent diameter, De, sphericity  and aspect ratio. The sphericity and aspect ratio of the  shells of water snail, the clam and the periwinkle were almost constant, the size notwithstanding. The crushing strengths for all the size range of the shells were determined. Other physical properties such as true density, bulk density, porosity, angle of repose, coefficient of static friction on different surfaces,  for the ground materials, were investigated.  Chemical analysis showed that clam shell was the richest in calcium, sodium, potassium and phosphorus.

Key words: Mollusk shells, size range, size measurement , aspect ratio, crushing strengths, density, coefficient of static friction, micronutrient elements