IC8746 - Safety Recommendations for Ammonium Nitrate-Based Blasting Agents 1 of 36 Information Circular 8746
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, .’ i .‘;,, ‘. .;, _-, Safety Recommendations for Ammonium Nitrate-Based Blasting Agents Revision of Information Circular 8179 UNITED STATES DEPARTMENT OF THE INTERIOR Copyright © 2000 International Society of Explosives Engineers IC8746 - Safety Recommendations for Ammonium Nitrate-Based Blasting Agents 1 of 36 Information Circular 8746 Safety Recommendations for Ammonium Nitrate-Based Blasting Agents -Revision of Information Circular 8179 By G. H. Damon, C. M. Mason, N. E. Hanna, and D. R. Forshey UNITED STATES DEPARTMENT OF THE INTERIOR Cecil D. Andrus, Secretary . BUREAU OF MINES Copyright © 2000 International Society of Explosives Engineers IC8746 - Safety Recommendations for Ammonium Nitrate-Based Blasting Agents 2 of 36 This publication has been cataloged as follows: Damon, Glenn H Safety recommendations for ammonium nitrate-based blast- ing agents / by G. H. Damon . [et al.] [Washington] : U.S. Dept. of the Interior, Bureau of Mines, 1977. 31 P” ; 27 cm. (Information circular - Bureau of Mines ; 8746) Bibliography: p” 23-26.. 1. Ammonium nitrate, 2, Explosives, 3.. Blasting. I. United States. Bureau of Mines. 11. Title. 111. Series: United States. Bureau of Mines. Information circular - Bureau of Mines ; 8746. TN23 .U71 no. 8746 622.06173 U.S. Dept. of the Int, Library Copyright © 2000 International Society of Explosives Engineers IC8746 - Safety Recommendations for Ammonium Nitrate-Based Blasting Agents 3 of 36 CONTENTS Page Abstract ............................................................... 1 Introduction ........................................................... 1 Definitions ............................................................ 3 Ammonium nitrate (AN) ............................................. 3 Blasting agent .................................................... 3 Blasting cap (No. 8) .............................................. 4 Cap-sensitive explosive material .................................. 4 Detonator ......................................................... 4 Explosive ......................................................... 4 Explosive material ................................................ 4 Fuel .............................................................. 5 Highway ........................................................... 5 Inhabited buildings ............................................... 5 Magazine .......................................................... 5 Motor vehicle ..................................................... 5 Nitro-carbo-nitrate ............................................... 5 Oxidizer .......................................................... 5 Propellant ........................................................ 5 Railway ........................................................... 5 Semiconductive hose ............................................... 5 Water gel (slurry) ................................................ 5 Sensitivity changes .................................................... 6 Sensitivity tests ...................................................... 6 Cap-sensitivity test .............................................. 6 Projectile impact test ............................................ 7 Bullet impact test ................................................ 7 Fire hazards ........................................................... 7 Fighting fires ......................................................... 8 Ammonium nitrate ................................................... 8 Blasting agents ................................................... 8 Water gels (slurries) ............................................. 9 Explosives ........................................................ 9 Underground applications ............................................... 9 Recommendation covering ammonium nitrate and ammonium nitrate- based blasting agents ................................................ 9 Storage of ammonium nitrate ....................................... 10 Manufacture of blasting agents .................................... 11 Composition .................................................. 11 Fixed location mixing plants ................................. 12 Storage of blasting agents ........................................ 14 Magazines .................................................... 14 Bulk storage bins ............................................ 15 Transportation .................................................... 16 General ...................................................... 16 Bulk delivery and mixing ..................................... 17 Use of blasting agents ............................................ 18 Blasting operations--general ................................. 18 Blasting operations --underground mines (additional recommendations) ........................................... 20 Copyright © 2000 International Society of Explosives Engineers IC8746 - Safety Recommendations for Ammonium Nitrate-Based Blasting Agents 4 of 36 k ii CONTENTS--Continued Page Water gels (slurries) ............................................. 21 Recommendation covering cap-sensitive compositions ..................... 22 References ............................................................. 23 Appendix A. --American table of distances for storage of explosives ..... 27 Appendix B. -=-Table of recommended separation distances of ammonium nitrate and blasting agents from explosives or blasting agents ....... 29 Appendix C. --Types of magazines ........................................ 31 Copyright © 2000 International Society of Explosives Engineers IC8746 - Safety Recommendations for Ammonium Nitrate-Based Blasting Agents 5 of 36 SAFETY RECOMMENDATIONS FOR AMMONHJM NITRATE-BASED BLASTING AGENTS Revision of Information Circular 8179 bY G. H. Damon, ’ C. M. Mason,2 N. E. Hanna, 3 and D. R, Forshey4 ABSTRACT Since 1963, Bureau of Mines Information Circular 8179 has served the min- ing industry as a fundamental safety guide in the field of blasting agents. In the intervening 14 years, many changes have occurred, and this report pre- sents revised and new recommendations which recognize these changes. For example, AN-F0 is now supplied mostly premixed, whereas in 1963 much of it was mixed by the blaster; aluminum metal (Al) and other fuels are now often added to AN-F0 to increase strength, and flake aluminum powder is used as a sensi- tizer in water gels; and water gels or slurries that are now extensively used were just coming into' practical use in 1963. To provide the widest possible margin of safety, some of the Bureau's recommendations are more stringent than existing regulations. INTRODUCTION The use of ammonium nitrate (AN) as an ingredient in blasting composi- tions is not new. In 1867, Ohlsson and Norrbin patented Ammoniakkrut (5, z),5 consisting of ammonium nitrate, either alone or in mixtures with charcoal, saw- dust, naphthalene, picric acid, nitroglycerin, or nitrobenzene. Since that time ammonium nitrate has been used continuously as an ingredient in dynamite and blasting agent formulations. Although it is an important ingredient of commercial explosives, ammonium nitrate is not classed for transportation pur- poses as an explosive (10), but as an oxidizing material. 1Physical scientist. 'Supervisory research chemist. 3Physical science administrator. 4Staff coordinator--safety research. The first and last authors are with the Office of the Assistant Director--Min- ing, Bureau of Mines, Washington, D.C. The second and third authors are with the Pittsburgh Mining and Safety Research Center, Bureau of Mines, Pittsburgh, Pa. 'Underlined numbers in parentheses refer to references preceding the appen- dixes at the end of this report. Copyright © 2000 International Society of Explosives Engineers IC8746 - Safety Recommendations for Ammonium Nitrate-Based Blasting Agents 6 of 36 . 2 The industrial development of ammonia dynamite, in which ammonium nitrate admixed with various fuels was sensitized by varying percentages of a high explosive such as nitroglycerin, represented a phase in obtaining explosive power from ammonium nitrate. In 1935, a new product, Nitramon,' represented another step in the development of a blasting agent based on the explosive decomposition of ammonium nitrate. The development of Akremite (20) ( a mixture of prilled AN and carbon black) in 1955 brought to the attention of the mining industry and others the basic principles and advantages of using fuel-sensitized ammonium nitrate mix- tures, prepared at or near the site of use, as low-cost blasting agents. Industry responded with enthusiasm, p romptly adopting the concept and adapting it to a wide variety of uses. The Bureau of Mines has followed these developments as time progressed and has done extensive research in certain areas (3, 2, 21, -23-24 -9 33, 39-48).-m Excellent reviews of the field have been prepared by Cook (&), Robinson (z), and Dick e-5). More general information on blasting agents and blasting may be found in references 2, 7, 11, 18, and 19. The Bureau's interest is two- fold: Safety in preparation, storage, transportation, and use of explosive materials; and the potential for continued reductions in the cost of blasting operations in all types of mining and other uses of explosives. Because of this interest, the Bureau, from the inception of the new developments in blast- ing agents, advised the industry on safe practices in the use of these mate- rials. The first publication was IC 7988, which appeared in 1960 (36), concurrent with Manual