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The influence of particle shape on parameters of impact crushing / G. Unland in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 220–228 Titre : The influence of particle shape on parameters of impact crushing Type de document : texte imprimé Auteurs : G. Unland, Auteur ; Y. Al-Khasawneh, Auteur Année de publication : 2009 Article en page(s) : pp. 220–228 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Crushing  Impact  Particle  shape Index. décimale : 622 Industrie minière Résumé : The influence of the shape of limestone particles on impact crushing parameters has been investigated by testing single particles in a high-resolution impact analyzer. The measurements conducted included the contact time and force, the transferred energy, the fragment size and shape distribution as well as the energy utilization. The particles tested were classified in seven different shape classes that ranged from spheres and cubes to plate-shaped and acicular bodies. The results show that the measured parameters are significantly influenced by the particle shape. These differences are caused by an additional orientation phase of an irregularly shaped particle prior to the main impact. Usually, the impact bar of the crusher hits one of the corners first, accelerates, rotates the particle and disintegrates a part of it occasionally. For spherical and cubical particles the contact forces and transferred energy are the highest and the contact time is the lowest. These results suggest that the mechanical design of impact crushers could be made on the basis of testing spheres or cubes, which would provide a safety factor in the design. Regarding the size distribution of the fragments, both the upper diameter and size modulus of a truncated Rosin–Rammler–Sperling–Bennet distribution are the lowest for spherical particles while no clear trend was found in respect to the distribution modulus. The comparison of the fragment shape distributions shows, except for the coarser fragments, hardly an influence of the initial particle shape on the smaller fragments. The energy utilization is the lowest with spherical and cubical bodies and rises with increased elongation and flatness of the feed particles. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002094 [article] The influence of particle shape on parameters of impact crushing [texte imprimé] / G. Unland, Auteur ; Y. Al-Khasawneh, Auteur . - 2009 . - pp. 220–228. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 220–228 Mots-clés : Crushing  Impact  Particle  shape Index. décimale : 622 Industrie minière Résumé : The influence of the shape of limestone particles on impact crushing parameters has been investigated by testing single particles in a high-resolution impact analyzer. The measurements conducted included the contact time and force, the transferred energy, the fragment size and shape distribution as well as the energy utilization. The particles tested were classified in seven different shape classes that ranged from spheres and cubes to plate-shaped and acicular bodies. The results show that the measured parameters are significantly influenced by the particle shape. These differences are caused by an additional orientation phase of an irregularly shaped particle prior to the main impact. Usually, the impact bar of the crusher hits one of the corners first, accelerates, rotates the particle and disintegrates a part of it occasionally. For spherical and cubical particles the contact forces and transferred energy are the highest and the contact time is the lowest. These results suggest that the mechanical design of impact crushers could be made on the basis of testing spheres or cubes, which would provide a safety factor in the design. Regarding the size distribution of the fragments, both the upper diameter and size modulus of a truncated Rosin–Rammler–Sperling–Bennet distribution are the lowest for spherical particles while no clear trend was found in respect to the distribution modulus. The comparison of the fragment shape distributions shows, except for the coarser fragments, hardly an influence of the initial particle shape on the smaller fragments. The energy utilization is the lowest with spherical and cubical bodies and rises with increased elongation and flatness of the feed particles. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002094