ISO INTERNATIONAL STANDARD 11258 Third edition 2015-08-15 Iron ores for shaft direct-reduction feedstocks Determination of the reducibility index, final degree of reduction and degree of metallization Minerais de fer pour charges utilisées dans les procedés par reduction directe - Détermination de I'indice de reéductibilité, du degré final de réduction et du degré de métallisation Reference number ISO 11258:2015(E) SO International Organization for Standardization @ IS0 2015 dardization 5956617 IS0 11258:2015(E) COPYRIGHTPROTECTEDDOCUMENT Is0 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISOcopyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel.+41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org Internatinair PrganizationforStandardization Not for Resale, 2015/11/11 08:32:12 etworking permitted without license from IHS IS0 11258:2015(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. .1 2 Normative references ..1 3 Terms and definitions ..1 4 Principle .1 5 Sampling, sample preparation, and preparation of test portions 2 5.1 Sampling and sample preparation. 12 5.2 Preparation of test portions. .2 6 Apparatus :2 6.1 General. .2 7 Test conditions .3 7.1 General. .3 7.2 Reducing gas. 3 7.2.1 Composition 3 7.2.2 Purity .3 7.2.3 Flow rate .3 7.3 Heating and cooling gas 3 7.4 Temperature of the test portion .4 8 Procedure .4 8.1 Number of determinations for the test 4 8.2 Chemical analysis. ..4 8.3 Reduction. 4 8.4 Chemical analysis after reduction .4 9 Expression ofresults .5 9.1 Calculation of the final degree of reduction (Rgo) 5 9.2 Calculation of the reducibility indices dR/dt(R=40) and dR/dt(R=90) 5 9.2.1 Reductioncurve .5 9.2.2 Reducibility index for 40 % reduction .5 9.2.3 Reducibility index for 90 % reduction .6 9.3 Calculation of the degree of metallization (M) 6 9.3.1 Determination of the degree of metallization from chemical analysis (M) 9.3.2 Determination of the degree of metallization from Rgo (MR) .6 9.4 Repeatability for Rgo and acceptance of test results .7 10 Test report. .7 11 Verification Annex A (normative) Flowsheet of the procedure for the acceptance of test results ..1 Annex B (informative) Derivation of formula for reducibility ..12 Annex C (informative) Derivation of formula for degree of metallization from Rgo ..14 Bibliography ..16 iii Institute of Standardization 5956617 withoutlicense from IHS