DOCSLIB.ORG

Development of Two-Component Gassing System to Sensitize Explosive Emulsions

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Development of Two-Component Gassing System to Sensitize Explosive Emulsions DEVELOPMENT OF TWO-COMPONENT GASSING SYSTEM TO SENSITIZE EXPLOSIVE EMULSIONS. by KABAMBA KATENDE JONATHAN BTech: Chemical Engineering (Cape Peninsula University of Technology) Dissertation submitted in fulfilment of the requirements for the degree Master of Engineering: Chemical Engineering in the Faculty of Engineering and the Built Environment at the Cape Peninsula University of Technology Supervisor: Prof I. Masalova Co-supervisor: Dr. N.N. Tshilumbu Cape Town, South Africa CPUT copyright information The dissertation/thesis may not be published either in part (in scholarly, scientific or technical journals), or as a whole (as a monograph), unless permission has been obtained from the University and AEL Mining Services. Preamble ABSTRACT This study investigated explosive emulsions used in civilian mining for breaking rocks. These emulsions were highly concentrated (mass fraction greater than 90 %) and consisted of a dispersion of an aqueous solution of industrial grade ammonium nitrate in a fuel phase containing surface active agents. For such emulsions to detonate, they must be sensitized. This is usually done by generation of gas bubbles (voids) in-situ via a gassing reaction, whereby a gassing component is added to the emulsion to react with ammonium nitrate (present in large quantity), which is a one-component method. In this method, any excess of gassing agent gives rise to an undesired extent of gassing reaction, resulting in poor blasting performance. This study reports an alternative approach to sensitizing explosive emulsions, by using a two-component gassing system, one (KI) that was added to the fuel phase or to ammonium nitrate solution in a pre-determined amount prior to emulsification, and the other (H2O2) added to the explosive emulsion after manufacture, when sensitization was required. Thus, the primary goal of this research was to carry out a phenomenological study of the dependence of H2O2 and KI concentrations, as well as the effect of pH on the emulsion density over time, with a view to shedding light on the factors controlling the final gassed emulsion density, and on optimizing the process. Blasting experiments were also conducted to compare the performance of the new method to the one currently being used. Three industrial fuel phases were selected for this study: F800, Bullfinch and R602/45. The H2O2 solution (30 wt%) and KI concentrations were varied from 0.09 to 7.80 wt% and 0.004 to 0.1 wt% respectively. The pH values ranged from 4.4 to 6.5. The research showed that the stoichiometric reaction between KI and H2O2 was dominant rather than the catalytic decomposition of H2O2. It was also found that when KI was added to the fuel phase, the rate of density change increased and the final gassed emulsion density decreased with increasing H2O2 concentration. As with the effect of H2O2, an increase in rate of density change and a decrease in final emulsion density with increasing KI concentration were observed. For KI concentrations of 0.008 wt% (F800) and 0.004 wt% (Bullfinch and R602/45), the reference density was reached and the excess of H2O2 did not affect the extent of gassing reaction or the final gassed emulsion density. Unexpectedly, emulsions in which KI was added to the ammonium nitrate solution yielded exactly the same results. Interestingly, it was demonstrated that regardless of the phase in which KI is initially added prior to emulsification, the gassing reaction neither occurred in the fuel nor the aqueous phase but at the interface formed by the fuel and aqueous phases. i Blasting experiments showed that emulsions sensitized by the new method (two-component system) yielded velocities of detonation 7 to 11% lower than the current method (one- component system). This was probably due to the differences in porosity of emulsions sensitized by different methods. The studies conducted have shown that the use of the two-component (H2O2 and KI) gassing system is suitable to regulate the extent of the gassing reaction in explosive emulsions for pH < 6.0. The two-component gassing system could be used in the explosives industry where consistent blasting performance is required. ii Preamble DECLARATION I, Kabamba Katende Jonathan, hereby declare that, to the best of my knowledge, this thesis represents my own work and has not been submitted previously for examination toward any degree or diploma qualification at any other University. Furthermore, it represents my own opinions and not necessarily those of the Cape Peninsula University of Technology. ……………………………………….. Kabamba Katende Jonathan February 2018 iii Preamble DEDICATION The following have played a vital role in my life and I dedicate this work to them. o My parents Matthieu Katende Kabamba and Therese Cibangu. I would have never made it this far without their spiritual, moral and financial support. o My brothers Glory and Daniel Katende, and sisters Patricia and Gracia Katende. When supported by such champions, one is continuously motivated to succeed. o My uncle Philip Mpiana and his wife Fidelie Mpiana for the love and care they have shown me. o My father in the faith, Ajacent Mwembo, who did not only offer me advice on spiritual matters but also introduced me to the world of books. o My best friend and companion in this journey Arsene Mulindwa for his continuous spiritual and moral support. o My spiritual leaders Rev. Kiluba wa Kiluba, Ebenezer Kiluba and Emmanuel Kongolo; and JTL South Africa. I am grateful for their prayers and support. o Jesus Christ, my Lord and Saviour in whom are hidden all the treasures of wisdom and knowledge. He is the source of inspiration. iv Preamble ACKNOWLEDGMENTS I would like to acknowledge: o AEL Mining Services South Africa for the financial support towards this research, for availing their facilities to conduct my experiments, for permission to publish the results of this study for my dissertation. Opinions expressed in this dissertation are those of the author and not of AEL Mining Services SA. o The Cape Peninsula University of Technology (CPUT) and the Flow Process and Research Unit (FPRC) for availing their facilities to conduct some of my experiments. o Prof. Veruscha Fester for introducing me to my supervisor. o My supervisor Prof. Irina Masalova who has given me a taste for science and research. o My co-supervisor Dr. Nsenda N. Tshilumbu for his patience in teaching me the ABCs of research. Thanks for the lengthy hours invested in equipping me with research skills. o Mr. Naziem George the lab manager for teaching me safe laboratory practices o My amazing teammate and brother Fabrice; and my FPRC friends (Whitney, Willy, Buyisile, Zintle, Jorika, Banielle, Flash and Maverick). v Preamble NOMENCLATURE Symbol Description Unit d Diameter m L Length m M Mass kg M1 Mass of density cup g M2 Mass cup + sensitised emulsion g t Time µs V Volume of density cup cm3 ρ Sensitised emulsion density g/cm3 Abbreviations AN Ammonium nitrate ANS Ammonium nitrate solution TNT Trinitrotoluene VOD Velocity of detonation vi Preamble GLOSSARY Terms Definition Emulsion: Two immiscible liquids (usually oil and water) with one of the liquids dispersed as small spherical droplets in the other. Explosive Emulsions: Emulsion that consists of small droplets of oxidiser solution tightly packed in a fuel. Gassed emulsion: Explosive emulsion in which voids have been introduced using a chemical reaction Gassing: Use of chemical reaction to produce voids within emulsion explosive Over-gassing: Phenomenon in which final sensitized emulsion density drops below desired value leading to poor blast performance Sensitization: Introduction of small, low density voids into emulsion providing hot spots at which an explosion may nucleate Sensitized emulsion: Explosive emulsion in which voids have been introduced Apparent equilibrium density: Gassed explosive emulsion density recorded at the end of the first hours of observation (2 to 3 hours) True equilibrium density Gassed explosive emulsion density recorded after overnight observation Emulsification Process of dispersing one liquid into a second immiscible liquid vii Preamble TABLE OF CONTENTS ABSTRACT ............................................................................................................................ i DECLARATION ..................................................................................................................... iii DEDICATION........................................................................................................................ iv ACKNOWLEDGMENTS ........................................................................................................ v NOMENCLATURE ................................................................................................................ vi GLOSSARY .......................................................................................................................... vii TABLE OF CONTENTS ....................................................................................................... viii TABLE OF FIGURES ............................................................................................................. x LIST OF TABLES ................................................................................................................ xiii CHAPTER 1 .......................................................................................................................... 1 INTRODUCTION ..................................................................................................................
Load more

Recommended publications
  • Transport of Dangerous Goods
    ST/SG/AC.10/1/Rev.16 (Vol.I) Recommendations on the TRANSPORT OF DANGEROUS GOODS Model Regulations Volume I Sixteenth revised edition UNITED NATIONS New York and Geneva, 2009 NOTE The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. ST/SG/AC.10/1/Rev.16 (Vol.I) Copyright © United Nations, 2009 All rights reserved. No part of this publication may, for sales purposes, be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, magnetic tape, mechanical, photocopying or otherwise, without prior permission in writing from the United Nations. UNITED NATIONS Sales No. E.09.VIII.2 ISBN 978-92-1-139136-7 (complete set of two volumes) ISSN 1014-5753 Volumes I and II not to be sold separately FOREWORD The Recommendations on the Transport of Dangerous Goods are addressed to governments and to the international organizations concerned with safety in the transport of dangerous goods. The first version, prepared by the United Nations Economic and Social Council's Committee of Experts on the Transport of Dangerous Goods, was published in 1956 (ST/ECA/43-E/CN.2/170). In response to developments in technology and the changing needs of users, they have been regularly amended and updated at succeeding sessions of the Committee of Experts pursuant to Resolution 645 G (XXIII) of 26 April 1957 of the Economic and Social Council and subsequent resolutions.
    [Show full text]
  • Common Military List of the European Union
    6.4.2016 EN Official Journal of the European Union C 122/1 IV (Notices) NOTICES FROM EUROPEAN UNION INSTITUTIONS, BODIES, OFFICES AND AGENCIES COUNCIL COMMON MILITARY LIST OF THE EUROPEAN UNION adopted by the Council on 14 March 2016 (equipment covered by Council Common Position 2008/944/CFSP defining common rules governing the control of exports of military technology and equipment) (updating and replacing the Common Military List of the European Union adopted by the Council on 9 February 2015 (1)) (CFSP) (2016/C 122/01) Note 1 Terms in ‘quotations’ are defined terms. Refer to ‘Definitions of Terms used in this List’ annexed to this List. Note 2 In some instances chemicals are listed by name and CAS number. The list applies to chemicals of the same structural formula (including hydrates) regardless of name or CAS number. CAS numbers are shown to assist in identifying a particular chemical or mixture, irrespective of nomenclature. CAS numbers cannot be used as unique identifiers because some forms of the listed chemical have different CAS numbers, and mixtures containing a listed chemical may also have different CAS numbers. ML1 Smooth-bore weapons with a calibre of less than 20 mm, other arms and automatic weapons with a calibre of 12,7 mm (calibre 0,50 inches) or less and accessories, as follows, and specially designed components therefor: Note ML1. does not apply to: a. Firearms specially designed for dummy ammunition and which are incapable of discharging a projectile; b. Firearms specially designed to launch tethered projectiles having no high explosive charge or communi­ cations link, to a range of less than or equal to 500 m; c.
    [Show full text]
  • Wettability of Aluminium with Sic and Graphite in Aluminium Filtration
    Light Metals 2011 Edited by: Stephen J. Lindsay TMS (The Minerals, Metals & Materials Society), 2011 WETTABILITY OF ALUMINIUM WITH SIC AND GRAPHITE IN ALUMINIUM FILTRATION Sarina Bao1, Anne Kvithyld2, Thorvald Abel Engh1, Merete Tangstad1 Norwegian University of Science and Technology, Trondheim, NO-7491, Norway 2SINTEF Materials and Chemistry, Trondheim, N-7465, Norway Keywords: Wettability, Contact angle, Aluminium, Graphite, SiC, Time dependent property Abstract éõõ The aim of aluminium filtration is to remove inclusions such as ] ■ SCSiC,Laurent,1996 . .nJ ! I · OxidizedSCSiC.Laurent ,1991 AI3C4. For inclusions to be removed they have to come in close '40j-■---;-- £-J.Ì A SSiC,Shimbo,1989 ] T ! : V SSiC,Han,1993 contact with the filter walls composed of A1203 or SiC. It is p I2O1 J.-Ä-..J. : + RBSiC,Han,1993 therefore important that the molten aluminium has close contact ^3 \ ! ! 6 SSiC,Candan,2002 OfHQfll ; ]..►. j I] • SCSiC,Laurent,1987 | with the filter wall. In addition to wetting properties between G J i inclusions (AI4C3) and molten aluminium, the wettability of the s eoi -i i *i i filter (SiC) by aluminium is determined in sessile drop studies in w the temperature range 1000-1300°C. Wettability changes with g 60I-- ! $ 4- time in three successive steps and improves with time. To 40 4 j -.<;- describe wettability at filtration temperatures employed in the Ö I ! industry of around 700°C, the results will be extrapolated to this 2èº ■—.—■—1—-—1—-—i ■—.—■—1—.—I temperature in future work. 600 700 800 900 1000 1100 1200 1300 Introduction Temperature/°C Figure 1 The equilibrium contact angle vs.
    [Show full text]
  • Chemical Compatibility Between Aluminium Base Matrices and Light Refractory Carbide Reinforcements
    CHEMICAL COMPATIBILITY BETWEEN ALUMINIUM BASE MATRICES AND LIGHT REFRACTORY CARBIDE REINFORCEMENTS J.C. Viala, M. Peronnet, F. Bosselet and J. Bouix Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, Université Lyon 1, F 69622 Villeurbanne Cedex, France SUMMARY: The main features of the interface chemistry of Al/B4C, Al/TiC and Al/SiC couples at temperatures up to 1000 °C are presented and discussed in terms of thermodynamics, kinetics and reaction mechanism. The Al/B4C couple appears reactive whatever the temperature whereas a reactive-non reactive transition occurs at 812 °C on heating for the Al/TiC couple and at 650 °C on cooling for the Al/SiC couple. The reaction products are Al3BC and AlB2 or β-AlB12 for the Al/B4C couple, Al4C3 and Al3Ti for Al/TiC and finally Al4C3 and dissolved silicon for Al/SiC. Whatever the couple, interaction always proceeds via a dissolution-precipitation mechanism which ends in certain instances with the passivation of the base carbide surface by a continuous Al3BC or Al4C3 layer. Some examples are given illustrating how advantage can be taken of these features for interface tailoring. KEYWORDS: metal matrix, aluminium, boron carbide, titanium carbide, silicon carbide, interface, chemical reactions. INTRODUCTION The physical and mechanical characteristics of the light refractory carbides SiC, TiC and B4C make them suitable for being used as reinforcement in aluminium base metal matrix composites. Discontinuously reinforced composites or cermets have thus been produced by incorporating particles, small crystals or whiskers of these carbides in the metal matrix by various pyrometallurgic techniques [1-3]. Attempts have also been made to elaborate such products by in-situ reaction of carbon particles with appropriate alloy melts [4, 5].
    [Show full text]
  • Aluminium Carbide
    safety data sheet according to Regulation (EC) No. 1907/2006 (REACH), amended by 2015/830/EU Aluminium carbide pure article number: 3094 date of compilation: 2017-01-17 Version: 1.0 en SECTION 1: Identification of the substance/mixture and of the company/undertaking 1.1 Product identifier Identification of the substance Aluminium carbide Article number 3094 Registration number (REACH) This information is not available. EC number 215-076-2 CAS number 1299-86-1 1.2 Relevant identified uses of the substance or mixture and uses advised against Identified uses: laboratory chemical 1.3 Details of the supplier of the safety data sheet Carl Roth GmbH + Co KG Schoemperlenstr. 3-5 D-76185 Karlsruhe Germany Telephone: +49 (0) 721 - 56 06 0 Telefax: +49 (0) 721 - 56 06 149 e-mail: [email protected] Website: www.carlroth.de Competent person responsible for the safety data : Department Health, Safety and Environment sheet e-mail (competent person) : [email protected] 1.4 Emergency telephone number Emergency information service Poison Centre Munich: +49/(0)89 19240 SECTION 2: Hazards identification 2.1 Classification of the substance or mixture Classification according to Regulation (EC) No 1272/2008 (CLP) Classification acc. to GHS Section Hazard class Hazard class and cat- Hazard egory state- ment 2.12 substance and mixture which, in contact with water, emits flam- (Water-react. 2) H261 mable gas 3.2 skin corrosion/irritation (Skin Irrit. 2) H315 3.3 serious eye damage/eye irritation (Eye Irrit. 2) H319 3.8R specific target organ toxicity - single exposure (respiratory tract ir- (STOT SE 3) H335 ritation) Ireland (en) Page 1 / 12 safety data sheet according to Regulation (EC) No.
    [Show full text]
  • Safety Data Sheet
    SAFETY DATA SHEET Revision Date 18-Feb-2020 Revision Number 2 1. Identification Product Name Aluminum carbide Cat No. : 14038 CAS-No 1299-86-1 Synonyms No information available Recommended Use Laboratory chemicals. Uses advised against Food, drug, pesticide or biocidal product use. Details of the supplier of the safety data sheet Company Alfa Aesar Thermo Fisher Scientific Chemicals, Inc. 30 Bond Street Ward Hill, MA 01835-8099 Tel: 800-343-0660 Fax: 800-322-4757 Email: [email protected] www.alfa.com Emergency Telephone Number During normal business hours (Monday-Friday, 8am-7pm EST), call (800) 343-0660. After normal business hours, call Carechem 24 at (866) 928-0789. 2. Hazard(s) identification Classification This chemical is considered hazardous by the 2012 OSHA Hazard Communication Standard (29 CFR 1910.1200) Flammable solids Category 1 Substances/mixtures which, in contact with water, emit Category 2 flammable gases Skin Corrosion/Irritation Category 2 Serious Eye Damage/Eye Irritation Category 2 Specific target organ toxicity (single exposure) Category 3 Target Organs - Respiratory system. Label Elements Signal Word Danger Hazard Statements Flammable solid In contact with water releases flammable gas ______________________________________________________________________________________________ Page 1 / 7 Aluminum carbide Revision Date 18-Feb-2020 ______________________________________________________________________________________________ Causes skin irritation Causes serious eye irritation May cause respiratory irritation Precautionary
    [Show full text]
  • Annex XV Dossier PROPOSAL for IDENTIFICATION of a SUBSTANCE AS a CATEGORY 1A OR 1B CMR, PBT, Vpvb OR a SUBSTANCE of an EQUIVALEN
    ANNEX XV – IDENTIFICATION OF HYDRAZINE AS SVHC Annex XV dossier PROPOSAL FOR IDENTIFICATION OF A SUBSTANCE AS A CATEGORY 1A OR 1B CMR, PBT, vPvB OR A SUBSTANCE OF AN EQUIVALENT LEVEL OF CONCERN Substance Name(s): Hydrazine EC Number(s): 206-114-9 CAS Number(s): 302-01-2 Submitted by: European Chemical Agency on request of the European Commission Version: February 2011 PUBLIC VERSION: This report does not include the Confidential Annexes referred to in Part II. 1 ANNEX XV – IDENTIFICATION OF HYDRAZINE AS SVHC CONTENTS PROPOSAL FOR IDENTIFICATION OF A SUBSTANCE AS A CATEGORY 1A OR 1B CMR, PBT, VPVB OR A SUBSTANCE OF AN EQUIVALENT LEVEL OF CONCERN ................................................................................7 PART I..........................................................................................................................................................................8 JUSTIFICATION .........................................................................................................................................................8 1 IDENTITY OF THE SUBSTANCE AND PHYSICAL AND CHEMICAL PROPERTIES .................................8 1.1 Name and other identifiers of the substance...................................................................................................8 1.2 Composition of the substance.........................................................................................................................9 1.3 Physico-chemical properties...........................................................................................................................9
    [Show full text]
  • Export Control Handbook for Chemicals
    Export Control Handbook for Chemicals -Dual-use control list -Common Military List -Explosives precursors -Syria restrictive list -Psychotropics and narcotics precursors ARNES-NOVAU, X 2019 EUR 29879 This publication is a Technical report by the Joint Research Centre (JRC), the European Commission’s science and knowledge service. It aims to provide evidence-based scientific support to the European policymaking process. The scientific output expressed does not imply a policy position of the European Commission. Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use that might be made of this publication. Contact information Xavier Arnés-Novau Joint Research Centre, Via Enrico Fermi 2749, 21027 Ispra (VA), Italy [email protected] Tel.: +39 0332-785421 Filippo Sevini Joint Research Centre, Via Enrico Fermi 2749, 21027 Ispra (VA), Italy [email protected] Tel.: +39 0332-786793 EU Science Hub https://ec.europa.eu/jrc JRC 117839 EUR 29879 Print ISBN 978-92-76-11971-5 ISSN 1018-5593 doi:10.2760/844026 PDF ISBN 978-92-76-11970-8 ISSN 1831-9424 doi:10.2760/339232 Luxembourg: Publications Office of the European Union, 2019 © European Atomic Energy Community, 2019 The reuse policy of the European Commission is implemented by Commission Decision 2011/833/EU of 12 December 2011 on the reuse of Commission documents (OJ L 330, 14.12.2011, p. 39). Reuse is authorised, provided the source of the document is acknowledged and its original meaning or message is not distorted. The European Commission shall not be liable for any consequence stemming from the reuse.
    [Show full text]
  • Vol. 77 Wednesday, No. 85 May 2, 2012 Pages 25859–26148
    Vol. 77 Wednesday, No. 85 May 2, 2012 Pages 25859–26148 OFFICE OF THE FEDERAL REGISTER VerDate Mar 15 2010 18:33 May 01, 2012 Jkt 226001 PO 00000 Frm 00001 Fmt 4710 Sfmt 4710 E:\FR\FM\02MYWS.LOC 02MYWS sroberts on DSK5SPTVN1PROD with RULES II Federal Register / Vol. 77, No. 85 / Wednesday, May 2, 2012 The FEDERAL REGISTER (ISSN 0097–6326) is published daily, SUBSCRIPTIONS AND COPIES Monday through Friday, except official holidays, by the Office PUBLIC of the Federal Register, National Archives and Records Administration, Washington, DC 20408, under the Federal Register Subscriptions: Act (44 U.S.C. Ch. 15) and the regulations of the Administrative Paper or fiche 202–512–1800 Committee of the Federal Register (1 CFR Ch. I). The Assistance with public subscriptions 202–512–1806 Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402 is the exclusive distributor of the official General online information 202–512–1530; 1–888–293–6498 edition. Periodicals postage is paid at Washington, DC. Single copies/back copies: The FEDERAL REGISTER provides a uniform system for making Paper or fiche 202–512–1800 available to the public regulations and legal notices issued by Assistance with public single copies 1–866–512–1800 Federal agencies. These include Presidential proclamations and (Toll-Free) Executive Orders, Federal agency documents having general FEDERAL AGENCIES applicability and legal effect, documents required to be published Subscriptions: by act of Congress, and other Federal agency documents of public interest. Paper or fiche 202–741–6005 Documents are on file for public inspection in the Office of the Assistance with Federal agency subscriptions 202–741–6005 Federal Register the day before they are published, unless the issuing agency requests earlier filing.
    [Show full text]
  • Characterisation of Aluminium Black Dross Before and After Stepwise Salt-Phase Dissolution in Non-Aqueous Solvents
    This is a repository copy of Characterisation of aluminium black dross before and after stepwise salt-phase dissolution in non-aqueous solvents. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/164459/ Version: Accepted Version Article: Hu, K., Reed, D., Robshaw, T.J. orcid.org/0000-0002-9816-8236 et al. (2 more authors) (2021) Characterisation of aluminium black dross before and after stepwise salt-phase dissolution in non-aqueous solvents. Journal of Hazardous Materials, 401. 123351. ISSN 0304-3894 https://doi.org/10.1016/j.jhazmat.2020.123351 Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/). Reuse This article is distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) licence. This licence only allows you to download this work and share it with others as long as you credit the authors, but you can’t change the article in any way or use it commercially. More information and the full terms of the licence here: https://creativecommons.org/licenses/ Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ 1 Characterisation of aluminium black dross before and after stepwise salt-phase 2 dissolution in non-aqueous solvents 3 4 Keting Hu1, Dan Reed2, Thomas J. Robshaw1 Rachel M.
    [Show full text]
  • Hydrazine Chemical Abstracts Service Registry Number 302-01-2
    Screening Assessment for the Challenge Hydrazine Chemical Abstracts Service Registry Number 302-01-2 Environment Canada Health Canada January 2011 Screening Assessment CAS RN 302-01-2 Synopsis The Ministers of the Environment and of Health have conducted a screening assessment of hydrazine, Chemical Abstracts Service Registry Number 302-01-2. The substance hydrazine was identified in the categorization of the Domestic Substances List as a high priority for action under the Chemicals Management Plan Challenge initiative. Hydrazine was identified as a high priority as it was considered to pose an intermediate potential for exposure of individuals in Canada and is classified by other agencies on the basis of carcinogenicity. The substance did not meet the ecological categorization criteria for persistence or bioaccumulation potential, but it did meet the criteria for inherent toxicity to aquatic organisms. Most hydrazine is imported into Canada in aqueous solutions, the form of the product commonly found on the market. In aqueous solution, all the hydrazine is invariably present as the hydrate. This chemical species has a molecule of water loosely attached to an electronegative nitrogen atom by a weak hydrogen bond. The hydrated form is not considered to be chemically different from the anhydrous substance, and can be considered to represent a mixture of the substance with water. Therefore, this assessment considers that hydrazine and hydrazine hydrate are effectively the same substance. Only minor differences in physical-chemical properties are observed between these two forms due to the association of hydrazine with water in the hydrated form. According to information submitted under section 71 of CEPA 1999, hydrazine was not manufactured by any company in Canada in the calendar year 2006 above the 100 kg reporting threshold.
    [Show full text]
  • Thick Adherent Diamond Films on Aln with Low Thermal Barrier Resistance
    Thick adherent diamond films on AlN with low thermal barrier resistance Soumen Mandal,∗,† Jerome Cuenca,† Fabien Massabuau,‡ Chao Yuan,¶ Henry Bland,† James W. Pomeroy,¶ David Wallis,§,‡ Tim Batten,k David Morgan,⊥ Rachel Oliver,‡ Martin Kuball,¶ and Oliver A. Williams∗,† †School of Physics and Astronomy, Cardiff University, Cardiff, UK ‡Department of Materials Science & Metallurgy, University of Cambridge, Cambridge, UK ¶Center for Device Thermography and Reliability, Bristol University, Bristol, UK §School of Engineering, Cardiff University, Cardiff, UK kRenishaw plc., Wotton-under-Edge, UK ⊥Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, UK E-mail: mandals2@cardiff.ac.uk,[email protected]; williamso@cardiff.ac.uk Abstract Growth of >100 µm thick diamond layer adherent on aluminium nitride is pre- sented in this work. While thick films failed to adhere on untreated AlN films, hy- arXiv:1907.02481v1 [physics.app-ph] 4 Jul 2019 drogen/nitrogen plasma treated AlN films retained the thick diamond layers. Clear differences in zeta potential measurement confirms the surface modification due to hydrogen/nitrogen plasma treatment. Areal Raman maps showed an increase in non- diamond carbon in the initial layers of diamond grown on pre-treated AlN. The presence of non- diamond carbon has minimal effect on the interface between diamond and AlN. The surfaces studied with x-ray photoelectron spectroscopy (XPS) revealed a clear dis- tinction between pre-treated and untreated samples. The surface aluminium goes from 1 nitrogen rich environment to an oxygen rich environment after pre-treatment. Cross section transmission electron microscopy shows a clean interface between diamond and AlN. Thermal barrier resistance between diamond and AlN was found to be in the range of 16 m2K/GW which is a large improvement on the current state-of-the-art.
    [Show full text]