1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-19153-5 SANS 11724:2007Edition 1 ISO 11724:2004Edition 1SOUTH AFRICAN NATIONAL STANDARD Solid mineral fuels Determination of total fluorin
4、e in coal, coke and fly ash This national standard is the identical implementation of ISO 11724:2004 and is adopted with the permission of the International Organization for Standardization. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428
5、7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 11724:2007 Edition 1 ISO 11724:2004 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee StanSA SC 5140.20D, South African commi
6、ttee for solid mineral fuels - Coke, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This standard was published in May 2007. Reference numberISO 11724:2004(E)ISO 2004INTERNATIONAL STANDARD ISO11724First edition2004-11-01Solid mineral fue
7、ls Determination of total fluorine in coal, coke and fly ash Combustibles minraux solides Dtermination de la teneur totale en fluor dans le charbon, le coke et les cendres SANS 11724:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 117
8、24:2004(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading
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11、low. ISO 2004 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body
12、 in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2004 All rights reservedSANS 11724:2007This s tandard may only be used and printed by approved
13、 subscription and freemailing clients of the SABS .ISO 11724:2004(E) ISO 2004 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references . 1 3 Principle . 1 4 Reagents 1 5 Apparatus. 2 6 Sample 4 6.1 Coal and coke 4 6.2 Fly ash 5 7 Procedure. 5 7.1 Number of determinations . 5
14、 7.2 Preparation of test sample. 5 7.3 Blank tests . 5 7.4 Pyrohydrolysis procedure 5 7.5 Solution measurement . 6 8 Calculations. 7 8.1 General. 7 8.2 Direct-comparison ISE method . 8 8.3 Analyte-addition ISE method . 8 8.4 IC method. 9 9 Expression of result 9 10 Precision 9 10.1 Repeatability lim
15、it . 9 10.2 Reproducibility critical difference . 10 11 Test report 10 Bibliography . 11 SANS 11724:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11724:2004(E) iv ISO 2004 All rights reservedForeword ISO (the International Organizat
16、ion for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established h
17、as the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Int
18、ernational Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Public
19、ation as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent ri
20、ghts. ISO 11724 was prepared by Technical Committee ISO/TC 27, Solid mineral fuels, Subcommittee SC 5, Methods of analysis. SANS 11724:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .INTERNATIONAL STANDARD ISO 11724:2004(E) ISO 2004 All r
21、ights reserved 1Solid mineral fuels Determination of total fluorine in coal, coke and fly ash 1 Scope This International Standard specifies a method for the determination of total fluorine in coal, coke and fly ash. From measurement of the total fluorine alone, it is not possible to estimate the amo
22、unt of fluorine released to the environment by utilization of the coal and subsequent disposal of the ash residue. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated refer
23、ences, the latest edition of the referenced document (including any amendments) applies. ISO 589:2003, Hard coal Determination of total moisture ISO 687:1974, Coke Determination of moisture in the analysis sample ISO 5068:1983, Brown coals and lignites Determination of moisture content Indirect grav
24、imetric method ISO 5069-2:1983, Brown coals and lignites Principles of sampling Part 2: Sample preparation for determination of moisture content and for general analysis ISO 11722:1999, Solid mineral fuels Hard coal Determination of moisture in the general analysis test sample by drying in nitrogen
25、ISO 13909-4:2001, Hard coal and coke Mechanical sampling Part 4: Coal Preparation of test samples ISO 13909-6:2001, Hard coal and coke Mechanical sampling Part 6: Coke Preparation of test samples 3 Principle Mixing of the sample of coal, coke or fly ash with silica, and pyrohydrolysis in a tube furn
26、ace at approximately 1 200 C in an atmosphere of oxygen and water vapour. Absorption of the volatilized fluorine compounds in a suitable solution and processing for determination by ion-selective electrode (ISE) or ion chromatographic (IC) techniques. 4 Reagents CAUTION Care must be exercised when h
27、andling reagents, some of which are toxic and corrosive. During the analysis, use only reagents of recognized analytical grade and only distilled water, or water of equivalent purity. SANS 11724:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the S
28、ABS .ISO 11724:2004(E) 2 ISO 2004 All rights reserved4.1 Silica of top size 75 m, ignited at 1 000 C for 1 h. CAUTION Fine silica is dangerous to health if inhaled. 4.2 Solutions for ISE measurement 4.2.1 Standard fluorine solution (1 g contains 200 g of F). a) For direct-comparison method Dissolve
29、0,221 0 0,000 2 g of dry (110 C for 1 h) sodium fluoride in approximately 400 ml of water contained in a tared plastic bottle, dilute to 500 g 0,5 g net with water, and mix. b) For analyte-addition method Dissolve 0,221 0 0,000 2 g of dry (110 C for 1 h) sodium fluoride in a tared plastic bottle con
30、taining 150 ml of water and 100 g of buffer (4.2.3). Dilute to 500 g 0,5 g net with water, and mix. 4.2.2 Absorption solution (0,025 mol/l NaOH). Dissolve 2,0 g of sodium hydroxide in about 500 ml of water. Transfer to a tared 2,5 litre plastic bottle, dilute to 2 000 g net with water, and mix. 4.2.
31、3 Buffer (pH 6,5). Dissolve 10,0 g of potassium nitrate, 5 g of 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA) and 115 g of ammonium acetate in 350 ml of water. Adjust the pH to 6,5 with glacial acetic acid. Dilute to 500 g net with water, and mix. 4.2.4 Solution for conditioning fluoride ISE. We
32、igh 20 g of water, 20 g of absorption solution (4.2.2) and 10 g of buffer (4.2.3) into a polystyrene vial (5.2). Add approximately 200 mg of standard fluorine solution of 4.2.1 a) or 4.2.1 b), and mix. 4.3 Solutions for IC measurement 4.3.1 Standard fluorine solution (1 g contains 200 g of F). Disso
33、lve 0,221 0 0,000 2 g of dry (110 C for 1 h) sodium fluoride in approximately 400 ml of water contained in a tared plastic bottle, dilute to 500 g 0,5 g net with water, and mix. 4.3.2 Absorption solution for IC measurement. Dissolve 0,300 g of sodium hydrogen carbonate and 1,120 g of sodium carbonat
34、e in approximately 500 ml of water and dilute to 2 litres. 4.4 Oxygen, compressed. 5 Apparatus 5.1 Vials, made of glass or polystyrene, of capacity 10 ml to 30 ml with tightly fitting snap-on plastic caps. 5.2 Polypropylene bottles or polystyrene vials, tared, of capacity 125 ml, wide necked with li
35、nerless leakproof screw caps. 5.3 Balances: a balance capable of weighing to the nearest 0,000 1 g; a balance capable of weighing approximately 200 g to the nearest 0,001 g; a balance capable of weighing 600 g to the nearest 0,01 g; and a balance capable of weighing 3 000 g to the nearest 0,1 g. SAN
36、S 11724:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11724:2004(E) ISO 2004 All rights reserved 35.4 Polyethylene dispensing bottles, for the standard fluorine solution (4.2.1), absorption solution (4.2.2) and buffer (4.2.3). 5.5 M
37、icropipette, of variable volume, ranging to at least 1 ml. This is a satisfactory alternative to the 250 ml polyethylene dispensing bottle (5.4) for delivery of small weighed volumes of standard fluorine solution (4.2.1). 5.6 Apparatus for tube-furnace pyrohydrolysis (see Figure 1). 5.6.1 Steam gene
38、rator, consisting of the following: a) round-bottom flask, 2 litre capacity; b) heating mantle, 2 litre capacity; c) Y-piece, glass, 10 mm diameter; d) oxygen distribution tube, porosity 0; e) stopcocks, one three-way and one two-way. 5.6.2 Silica-tube furnace and accessories The apparatus is simila
39、r to that used in ISO 351. a) Silica tube, made of translucent pure silica (25 mm outer diameter, 20 mm inner diameter), of length (typically 700 mm) appropriate to the particular furnace used (generally of an approximate length of 400 mm). Preferably, the gas outlet end should be narrowed to a tubu
40、le of approximately 7 mm diameter. NOTE Combustion tubes of alternative refractory compositions do not have adequate thermal stress characteristics for operation with this method. b) Silicone stoppers, 20 mm diameter, positioned at inlet end (and outlet, if applicable) of the silica tube described i
41、n a). c) Combustion boats, made of high-alumina unglazed porcelain (approximately 97 mm 16 mm 12 mm), preignited at 1 000 C for 1 h. d) Silica pusher and T-tube, comprising a silica push rod (5 mm diameter and 500 mm long) fused at one end to provide a flat disc surface of 10 mm to 12 mm diameter, a
42、nd having a piece of magnetic steel affixed to the other end by epoxy resin. The T-tube (500 mm long) is composed of borosilicate glass and protrudes 10 mm into the silica tube a) through a stopper b). The stem of the T-tube is connected to the steam generator by way of the three-way stopcock 5.6.1
43、e). A magnet is used to move the pusher inside the T-tube. e) Combustion furnace, capable of reaching a temperature of at least 1 200 C. 5.6.3 Absorption vessel: Dreschel gas washing bottle or equivalent, of capacity 125 ml, with gas-distribution tube fitted with a sintered glass disc of 15 m to 40
44、m pore size 5.6.1 d) bent at 90, approximately 60 mm from the top. 5.6.4 Water jacket, suitable for containing the absorption vessel. SANS 11724:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11724:2004(E) 4 ISO 2004 All rights reser
45、vedKey 1 stopcock 8 combustion boat 15 heating mantle 2 Y-piece 9 silica tube 16 oxygen in 3 round-bottom flask 10 cooling water 17 three-way stopcock 4 stopcock 11 absorption vessel 18 steam distribution tube 5 T-piece 12 water jacket 19 to sink 6 silica pusher 13 thermocouple 7 furnace 14 silicone
46、 stopper Figure 1 Schematic diagram of pyrohydrolysis apparatus 5.7 ISE measurement apparatus 5.7.1 Magnetic stirrer, complete with polytetrafluoroethylene stirring bars. 5.7.2 Electrodes: a solid state fluoride ion selective electrode and a reference electrode. The sensing element of the fluoride e
47、lectrode should be polished on each day of use to prolong optimal performance. This may be achieved, for example, by using 0,25 mm diamond dust or alumina sprayed on a polishing cloth, and polishing the electrode for 30 s to 60 s. The electrode, having been stored dry, is conditioned for at least 30
48、 min prior to use, by insertion in a conditioning solution (4.2.4). 5.7.3 Millivoltmeter, having a resolution of 0,1 mV. 5.8 IC measurement apparatus, equipped with a chromatography pump, anion separation columns, conductivity detector and integrator. 6 Sample 6.1 Coal and coke The test sample is th
49、e general analysis sample prepared in accordance with ISO 5069-2, ISO 13909-4 or ISO 13909-6, as appropriate. SANS 11724:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .ISO 11724:2004(E) ISO 2004 All rights reserved 56.2 Fly ash Fly ash normally has a top particle size of less than 75 m and therefore may not require any reduction prior to analysis. However, special care shall be taken in the collection and prep
