ISO INTERNATIONAL STANDARD 11760 Secondedition 2018-11-27 Classification of coals Classification des charbons Reference number IS0 11760:2018(E) ISO @IS02018 IS0 11760:2018(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2018, 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 ii @ IS0 2018 - All rights reserved IS0 11760:2018 Contents Page Foreword ..iv Introduction. .. 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions 4 Classification .3 4.1 General. .3 4.2 Rank-Primary categories. .3 4.3 Rank Sub-categories 4 4.4 Petrographic (maceral group) composition 4.5 Ash yield .6 5 Nature of the coal sample. ..6 6 Descriptive classification terminology ..7 7 Analytical tolerances. ..7 8 Graphic representation .8 Bibliography 9 @ IS0 2018 - All rights reserved iii