The Mechanical Strength of Granular Sulphur and its Relation to Size Distribution and Storage Silo Clogging


Article Preview

The purpose of this study was to investigate the effect of particle size distribution on the mechanical properties of granular sulphur and its relation to silo blockage at South Pars Gas Complex Phases 2 & 3. Solid elemental sulphur is a relatively hard, friable crystalline material that tends to break up into smaller particles when subjected to force or stress of any magnitude. Conglomeration of the dust so produced clogs storage silos, making truck loading difficult. Grain size selection is based on the “friability value” and “maximum entropy” for granules in a static state. The model of the behavior of confined granular sulphur is based on the principle of continuum mechanics. Granules were formed by feeding liquid sulphur and water to a rotating granulation drum. Sample granules were classified into different size fractions (300 μm – 4.75 mm) by sieve analysis, and friability tests were done by the Fines 28-inch tumbler S5-77 test. Friability and granule size data collected over four years were studied. The implication of field analysis and laboratory tests is that the granule size should be controlled during sulphur solidification while ensuring that only granular material with the correct mechanical characteristics is stored in the silo and shipped.



Edited by:

Wu Fan




R. Moradifar et al., "The Mechanical Strength of Granular Sulphur and its Relation to Size Distribution and Storage Silo Clogging", Applied Mechanics and Materials, Vols. 110-116, pp. 83-90, 2012

Online since:

October 2011




[1] Operation Manual, Document Number: VP-2017-144-U101-0077.

[2] Operating Manual, Utilities and Off-sites Section 3. 17, Unit 144 Sulphur Storage and Solidification, misc. 99012 999 9100 0129, South Pars Gas Complex.

[3] Schulze, D.: Silo Design, Silo Size and Variations.

[4] Yakovlev, P. V.: Investigation of heat exchange in the water granulation of sulfur,. Astrakhan State Technical University. (Translated from Khimicheskoe i Neftegazovoe Mashinostroenie (4), 13–14 (Apr. 2005).

[5] Goddard, J. D.: Entropy and Material Instability in the Quasi-Static Mechanics of Granular Media, Aerospace and Mechanical Department, University of California, San Diego.

[6] Hyne, J. B.: Alberta sulphur terminal, NRCB Application #0702, Calgary (Mar 2009).

[7] Jahanbazi, N.: Sieve Analysis of Sulphur Forms,. SP-LAB-AM-606, South Pars, Phases 2&3 Laboratory.

[8] Khodakarami, H.: Determination of Friability of Sulphur Forms Using 28-Inch (70 mm) Diameter Tumbler Test Apparatus,. SP-LAB-AM-602, South Pars, Phases 2&3 Laboratory Technical Manual.