Techniques in Underground Mining Selections from Underground Mining Methods Handbook Edited by Richard E. Gertsch and Richard L. Bullock Published by the Society for Mining, Metallurgy, and Exploration Copyright 0 1998 Society for Mining, Metallurgy, and Exploration, Inc. All Rights Reserved Printed in the United States of America No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Society for Mining, Metallurgy, and Exploration, Inc. PO Box 625002 Littleton, CO, USA 80162-5002 303-973-9550 ISBN 978-0-87335-163-8 Library of Congress Cataloging-in-PublicationD ata Techniques in underground mining : selections from Underground mining methods handbook / edited by Richard E. Gertsch and Richard L. Bullock. 836 p. 21.6 x 27.9 cm. Includes bibliographical references and index. ISBN 978-0-87335-163-8 (he) 1. Mining engineering. I. Gertsch, Richard E. 11. Bullock, . Richard Lee, 1929- 111. Society for Mining, Metallurgy, and Exploration (U.S.) Iv. Underground mining methods handbook. TN275T33 1998 622.2--dc21 98-28643 CIP . . . . . . . . Foreword m . . . . . In 1982, SME published the Underground Mining Methods Handbook-a 1,754-page comprehensive review of underground mining. It contained one of the best collections of information on underground mining of any book published since the Mining Engineers Handbook by Robert Peele. However, the original is out of print, and there is a lack of printed information currently available on this topic. Thus, a condensed version of the Underground Mining Methods Handbook was produced to aid in the training of mining engineers and practicing professionals. In producing the original handbook, Dr. William Hustrulid, an editorial advi- sory board, and the SME-AIME Book Publishing Committee recruited 165 authors and section editors from academia and the mining industry. Their goal was to put together a collection of knowledge that was comprehensive and unique. They succeeded, and the Underground Mining Methods Handbook served the industry well. And although it was published over 15 years ago, most of the information is still meaningful and applicable in the education of new mining engineers today. Therefore, this new version, Techniques in Underground Mining-Selections from the Underground Mining Methods Handbook, is published by SME as a teaching tool and source book. Richard Bullock ix .............. Preface Considered a shrinking industry in the late 1980s and early 1990s, under- ground mining is now experiencing a revival. Unfortunately, there is a void of material that adequately addresses the important mining methods and opera- tional techniques needed by both mining engineering students and industry professionals. As a temporary solution, the original Underground Mining Methods Handbook (published in 1982 and now out of print) has been con- densed in this new version, Techniques in Underground Mining-Selections From the Underground Mining Methods Handbook. The discriminating reader will question why the editors included or excluded certain sections from the original. To assist the editors, guidelines were estab- lished to produce an inexpensive volume that would include descriptions of underground methods for mining students. The guidelines followed by the editors were: include only those sections that address and describe underground mining methods; limit the mining methods to noncoal mining methods; reduce the text to one-third of the original text; and make no revisions to sections or chapters (although deletions within a chapter were allowed if it improved the chapter). The editors excluded sections and chapters that covered equipment, coal min- ing, rock fragmentation, rock mechanics and ground control methods, venti- lation, economic evaluation, financial consideration, and exploration. These subjects are covered in other available texts. One mining method-the use of timber support- extensively covered in the original book had to be deleted in order to meet the page limit guideline. Although timbering is mines is still important, particularly in drifting, there is a definite trend away from mining methods requiring timber as the main sup- port. Thus, this method is not included in this version. vii Although many chapters on mining equipment in the original handbook are still applicable, many others are obsolete. The change from pneumatic to hydraulic drills is a good example. Since updated information is available from other sources, mining equipment is not included. Chapters on economics and cost considerations were a compromise. The sections that originally stood alone were eliminated. However, the cost analysis that accompany the mining methods are included, even though the costs are 15 years out of date. The methods used to calculate costs are worth preserving and the actual updated costs could easily be substituted into that methodology. The introductory section was also a compromise. The editors decided to leave in enough material to introduce the subject and to provide adequate discussions of engineering matters unique to underground mining, although somewhat shared with surface mining, including sampling, reserve analysis, and planning. Reprinting a condensed version of the Underground Mining Methods Hand- book is only a temporary solution to the problem of providing an updated text on underground mining methods. A completely new version must soon be written. This version should include updates to all the mining method changes, particularly those changed in vertical crater retreat, undercut and fill with high-density cemented or paste backfill, in-situ or solution mining, and hardrock longwall mining methods. It seems unlikely that any new work will encompass the sweeping range of topics covered in the 1982 original. Thus, any new handbook will likely cover several volumes. Richard Gertsch Richard Bullock viii . . . . . . . . . . . . . . Contents FOREWORD xi PREFACE xiii SECTION 1 OVERVIEW 1 Ore Reserve Calculation Leigh A. Readdx David S. Bolin, and Graham A. Mathieson 3 Choosing an Underground Mining Method HamHamrin 45 General Mine Planning Richard L. Bullock 87 Sampling, Dilution, and Recovery C. Alan Tapp 129 SECTION 2 METHODS REQUIRING MINIMUM SUPPORT 157 Room-and-Pillar Method of Open-Stope Mining Richard L. Bullock 159 Production Methods of Noncoal Room-and-Pillar Mining Richard L. Bullock 171 Open Stope Mining at the Magmont Mine, Bixby, Missouri G.D. Bates 215 Sublevel Stoping C. David Mann 223 Considerations for Sublevel Stoping Brian W. Lawrence 227 iii Excavation Design and Mining Methods in the 1100 Orebody, Mount Isa Mine, Australia B. Hornsby and B.J.K. Sullivan 249 Strissa Mine K.-A. Bjorkstedt 275 Sublevel Stoping at the EB Massive Reefs at Loraine Gold Mines, Ltd. RD.H. Bebb 311 Large Blasthole Stoping at Rodsand Gruber, Norway Tore M. Larsen 321 Vertical Crater Retreat: An Important Mining Method L.C. Lang 329 Crater Blasting Method Applied to Pillar Recovery at Falconbridge Nickel Mines Ltd. C.J. Monahan 343 Cost Calculations for Sublevel Longhole Stoping Gordon M. Pugh and David G. Rasmussen 353 Cost Estimation for Sublevel Stoping-A Case Study A.J. Richardson 361 SECTION 3 STOPES REQUIRING ADDITIONAL SUPPORT OTHER THAN PILLARS 373 Shrinkage Stoping: An Introduction William Lyman 375 Shrinkage Stoping at the Crean Hill Mine K.J. Henderson 385 Shrinkage Stoping at the Idarado Mine Compiled by WilliamA . Hustrulid 393 Cost Calculations for Mechanized Shrinkage Stoping Gordon M. Pugh and David G. Rasmussen 421 Cut-and-Fill Stoping: An Introduction Joel K. Waterland 439 Principles of Stope Planning and Layout for Ground Control PA. MacMillian and B.A. Ferguson 445 Cut-and-Fill at Mount Isa Mines Ltd. B. Hornsby and Stafjs Mount Isa Mines 455 The Zinc Corporation, Ltd., and New Broken Hill Consolidated, Ltd. R.E. Le Messurier 469 Cut-and-FillS toping at Star Mine Gordon Miner 485 Cut-and-Fill Stoping at Lucky Friday Mine Stafi Lucky Friday Mine 495 iv Cut-and-Fill at the Bruce Mine Ronald T. Johnson, Keith E. mas, and John Nelson 503 Cut-and-Fill at Homestake Mining Co. Joel K. Waterland and StaB Homestake Mining Co. 515 Cost Calculations for Highly Mechanized Cut-and-Fill Stoping Gordon M. Pugh and David G. Rasmussen 525 Undercut-and-Fill Mining: An Introduction J. W. Murray 557 Undercut-and-Fill Mining as Practiced by Homestake Mining Co. AS. Winters 573 Undercut-and-Fill Mining at Falconbridge Mine of Falconbridge Nickel Mines Ltd. S.A. Tims 579 Cost Calculations for Underhand Cut-and-Fill Mining Gordon M. Pugh and David G. Rasmussen 595 SECTION 4 SUBLEVEL CAVING 603 Sublevel Caving: An Introduction E.W. Cokayne 605 The Mechanics and Design of Sublevel Caving Systems Rudolf Kvapil 621 Sublevel Caving at Craigmont Mines Ltd. R.A. Baase, W.D. Diment, andA.J. Petrina 655 Sublevel Caving at the Stobie Mine, Inco Metals Co. G. W. Johnston 687 Sublevel Caving at LKAEJ’s Kiirunavaara Mine H. Heden, K. Lidin, and R. Malmstrom 697 Planning Economics of Sublevel Caving Dan Nilsson 725 SECTION 5 BLOCK AND PANEL CAVING 741 Block Caving: General Description Ray L. Tobie and Douglas E. Julin 743 Climax Panel Caving and Extraction System John C. Gould 755 San Manuel Mine R.L. Tobie, LA. Thomas, and H.H. Richards 771 The Henderson Mine William G. Doepken 783 INDEX 801 V SECTION 1 Overview 1 . . . . . . . . . . . . . . Ore Reserve Calculation CHAPTER 1 Leigh A. Readdy, David S. Bolin, and Graham A. Mathieson INTRODUCTION The estimation of ore reserves is a process that begins with the earliest explo- ration stages on a property and continues throughout any subsequent evalua- tion and exploitation of the deposit. During exploration and preliminary evaluation, the results of these reserve estimates constitute the basic data for prefeasibility studies and economic analysis. The decision to continue explo- ration and development or to abandon a prospect is often based upon these studies. During the active life of a mine, reserve computations are continuously revised to assist in development planning, cost and efficiency analyses, qual- ity control, and improvement of extraction and processing methods. Accurate reserve estimates are also required when financing a project, purchasing or selling a property, and for accounting purposes such as depletion and tax calculation. It is important to remember that the reliability of ore reserve estimates vanes progressively through time as more and more information becomes available. The lowest order of reliability of estimation of reserves exists at the time of discovery. The maximum level of certainty concerning the ore reserves within a deposit is reached when the deposit is completely mined out. Between these two extremes are variable levels of certainty as to the tonnage and grade of the resource. This is particularly true of that portion of the mineral resource that constitutes the “minable reserve,” as this portion is dependent upon eco- nomic as well as geological and technological factors. In the following discussion, several of the factors affecting ore reserve compu- tation and some of the commonly used methods of calculation are presented. The first part of the discussion is confined to classical methods of hand calcu- lation utilizing level maps and sections. The second part of the discussion pre- sents an overview of somewhat more sophisticated methods of geostatistics