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The development of a blasthole stemming performance evaluation model using a purpose built testing facility

Dissertation (MEng)--University of Pretoria, 2009.

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Other Authors: Webber-Youngman, R.C.W.
Format: Thesis
Published: University of Pretoria 2013
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access_status_str Open Access
author2 Webber-Youngman, R.C.W.
author_browse Webber-Youngman, R.C.W.
author_facet Webber-Youngman, R.C.W.
collection Thesis
dc_rights_str_mv © 2009, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MEng)--University of Pretoria, 2009.
format Thesis
id oai:repository.up.ac.za:2263/29843
institution University of Pretoria (South Africa)
last_indexed 2026-06-10T12:36:25.392Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2013
publishDateRange 2013
publishDateSort 2013
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/29843 The development of a blasthole stemming performance evaluation model using a purpose built testing facility Webber-Youngman, R.C.W. Thompson, Roger John dboshoff@angloamerican.co.za Boshoff, Dawid Blasthole stemming performance evaluation model UCTD Dissertation (MEng)--University of Pretoria, 2009. The ability of an explosive to break rock is influenced considerably by the extent of confinement in the blasthole and it is believed that confinement is improved by the use of stemming. The aim of this paper is to present the first and second stages of results in developing a stemming performance testing and evaluation facility for small diameter boreholes. The results showed that different stemming products have differences in terms of their functionality, which can have a major impact on the efficiency of rock breaking. Two test procedures were used, one through the exclusive use of compressed air and the second using a purpose built high pressure test rig with small quantities of explosives. Both tests were used to identify and evaluate the ability of various stemming products to resist the escape of explosive gas through the collar of a blasthole. Extensive research was conducted to determine the types of stemming products most commonly used in South African underground hard rock mines, and the differences in design between the various products are discussed. The first stage of tests using compressed air only did not prove adequate to predict with certainty the pressure behaviour in the borehole of a particular product under high pressure conditions. The purpose built high pressure test rig did not prove to be a very effective tool to test stemming products under high pressure conditions. The test rig only incorporated the effect of gas pressure on the stemming product and in doing so omitted to take the effect of the shock wave into account. This study proved that to only take the gas pressure generated in the blasthole into account in not sufficient to effectively test stemming product design. A more comprehensive study should include the effect of gas pressure in the borehole, shock waves generated by the explosive and also the coefficient of friction of both the surface of the stemming product as well as the inside of the blasthole. Mining Engineering unrestricted 2013-09-07T16:53:48Z 2009-12-09 2013-09-07T16:53:48Z 2009-09-02 2009-12-09 2009-11-26 Dissertation Boshoff, D 2009, The development of a blasthole stemming performance evaluation model using a purpose built testing facility, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/29843 > E1471/ag http://hdl.handle.net/2263/29843 http://upetd.up.ac.za/thesis/available/etd-11262009-215859/ © 2009, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle Blasthole stemming performance evaluation model
UCTD
The development of a blasthole stemming performance evaluation model using a purpose built testing facility
title The development of a blasthole stemming performance evaluation model using a purpose built testing facility
title_full The development of a blasthole stemming performance evaluation model using a purpose built testing facility
title_fullStr The development of a blasthole stemming performance evaluation model using a purpose built testing facility
title_full_unstemmed The development of a blasthole stemming performance evaluation model using a purpose built testing facility
title_short The development of a blasthole stemming performance evaluation model using a purpose built testing facility
title_sort development of a blasthole stemming performance evaluation model using a purpose built testing facility
topic Blasthole stemming performance evaluation model
UCTD
url http://hdl.handle.net/2263/29843
http://upetd.up.ac.za/thesis/available/etd-11262009-215859/