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 978-0-626-19880-0 SANS 12174:2007Edition 2 EN 12174:2006Edition 2SOUTH AFRICAN NATIONAL STANDARD Chemicals used for treatment of water intended for
4、human consumption Sodium hexafluorosilicate This national standard is the identical implementation of EN 12174:2006 and is adopted with the permission of CEN, rue de Stassart 36, B-1050 Brussels. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012
5、 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 12174:2007 Edition 2 EN 12174:2006 Edition 2 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee StanSA TC 5140.19, Water, in accord
6、ance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in June 2007. This SANS document supersedes SABS EN 12174:2001 (edition 1). EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 12174July 2006ICS 13.060.20; 71.060.50;
7、71.100.80 Supersedes EN 12174:2001 English VersionChemicals used for treatment of water intended for humanconsumption - Sodium hexafluorosilicateProduits chimiques utiliss pour le traitement de leaudestine la consommation humaine - Hexafluorosilicatede sodiumProdukte zur Aufbereitung von Wasser fr d
8、enmenschlichen Gebrauch - NatriumhexafluorsilikatThis European Standard was approved by CEN on 23 June 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alterati
9、on. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
10、under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Ic
11、eland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de St
12、assart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12174:2006: ESANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12174:2006 (E) 2
13、 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Description .5 3.1 Identification.5 3.2 Commercial form .6 3.3 Physical properties6 3.4 Chemical properties 7 4 Purity criteria7 4.1 General7 4.2 Composition of commercial product.7 4.3 Impurities and main by-products.7 4.
14、4 Chemical parameters 8 5 Test methods8 5.1 Sampling.8 5.2 Analyses .8 6 Labelling - Transportation - Storage14 6.1 Means of delivery.14 6.2 Risk and safety labelling according to the EU Directives 14 6.3 Transportation regulations and labelling14 6.4 Marking .15 6.5 Storage15 Annex A (informative)
15、General information on sodium hexafluorosilicate.16 A.1 Origin 16 A.2 Use 16 Annex B (normative) General rules relating to safety.17 B.1 Rules for safe handling and use 17 B.2 Emergency procedures.17 Bibliography 18 SANS 12174:2007This s tandard may only be used and printed by approved subscription
16、and freemailing clients of the SABS .EN 12174:2006 (E) 3 Foreword This document (EN 12174:2006) has been prepared by Technical Committee CEN/TC 164 “Water supply”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publicatio
17、n of an identical text or by endorsement, at the latest by January 2007, and conflicting national standards shall be withdrawn at the latest by January 2007. This document supersedes EN 12174:2001. A new requirement in subclause 4.2 specifies a tolerance on the manufacturers declared value of the so
18、dium hexafluorosilicate content. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ic
19、eland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. SANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN
20、12174:2006 (E) 4 Introduction In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by this document: a) this document provides no information as to whether the product may be used without restriction in any of the Member States
21、 of the EU or EFTA; b) it should be noted that, while awaiting the adoption of verifiable European criteria, existing national regulations concerning the use and/or the characteristics of this product remain in force. NOTE Conformity with this document does not confer or imply acceptance or approval
22、 of the product in any of the Member States of the EU or EFTA. The use of the product covered by this document is subject to regulation or control by National Authorities. SANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 1217
23、4:2006 (E) 5 1 Scope This document is applicable to sodium hexafluorosilicate used for treatment of water intended for human consumption. It describes the characteristics of sodium hexafluorosilicate and specifies the requirements and the corresponding test methods for sodium hexafluorosilicate. It
24、gives information on its use in water treatment. It also determines the rules relating to safe handling and use of sodium hexafluorosilicate (see Annex B). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the
25、 edition cited applies. For undated references the latest edition of the referenced document (including any amendments) applies. EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987) ISO 3165, Sampling of chemical products for industrial use - Safety in sa
26、mpling ISO 4281, Sodium hexafluorosilicate for industrial use - Determination of free acidity and total hexafluorosilicate content - Titrimetric method ISO 4793, Laboratory sintered (fritted) filters - Porosity grading, classification and designation ISO 5444, Sodium fluorosilicate for industrial us
27、e - Determination of loss in mass at 105 degrees C ISO 5993, Sodium hydroxide for industrial use - Determination of mercury content - Flameless atomic absorption spectrometric method ISO 6206, Chemical products for industrial use - Sampling Vocabulary ISO 6353-1, Reagents for chemical analysis - Par
28、t 1:General test methods ISO 8213, Chemical products for industrial use - Sampling techniques - Solid chemical products in the form of particles varying from powders to coarse lumps 3 Description 3.1 Identification 3.1.1 Chemical name Disodium hexafluorosilicate 3.1.2 Synonym or common name Sodium s
29、ilicofluoride, sodium hexafluorosilicate 3.1.3 Relative molecular mass 188,055 3.1.4 Empirical formula Na2SiF6SANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12174:2006 (E) 6 3.1.5 Chemical formula Na2SiF6. 3.1.6 CAS-Registr
30、y Number1)16893-85-9 3.1.7 EINECS reference2)240-934-8 3.2 Commercial form The product is a crystalline powder. 3.3 Physical properties 3.3.1 Appearance and odour The product is a colourless, odourless fine crystalline powder. 3.3.2 Density The particle density of the crystals is 2,8 g/cm3at 20 C. T
31、he bulk density of the product is approximately 1,5 g/cm3at 20 C. 3.3.3 Solubility The solubility of the product in water is 7 g/l at 20 C. 3.3.4 Vapour pressure Not applicable. 3.3.5 Boiling point at 100 kPa3)Not applicable. 3.3.6 Crystallisation point The product melts above 500 C. 3.3.7 Specific
32、heat Not known. 1) Chemical Abstracts Service Registry Number. 2) European Inventory of Existing Commercial Chemical Substances. 3)100 kPa = 1 bar. SANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12174:2006 (E) 7 3.3.8 Visco
33、sity, dynamic Not applicable. 3.3.9 Critical temperature Not applicable. 3.3.10 Critical pressure Not applicable. 3.3.11 Physical hardness Not applicable. 3.4 Chemical properties The pH value of a saturated aqueous solution (7 g/l) of sodium hexafluorosilicate is approximately 10. Sodium hexafluoros
34、ilicate reacts with acids to form hydrofluoric acid. 4 Purity criteria 4.1 General This document specifies the minimum purity requirements for sodium hexafluorosilicate used for the treatment of water intended for human consumption. Limits are given for impurities commonly present in the product. De
35、pending on the raw material and the manufacturing process other impurities may be present and, if so, this shall be notified to the user and when necessary to relevant authorities. NOTE Users of this product should check the national regulations in order to clarify whether it is of appropriate purit
36、y for treatment of water intended for human consumption, taking into account raw water quality, required dosage, contents of other impurities and additives used in the products not stated in this document. Limits have been given for impurities and chemicals parameters where these are likely to be pr
37、esent in significant quantities from the current production process and raw materials. If the production process or raw materials lead to significant quantities of impurities, by-products or additives being present, this shall be notified to the user. 4.2 Composition of commercial product The conten
38、t of sodium hexafluorosilicate shall not be less than a mass fraction of 98 % (Na2SiF6). The concentration of sodium hexafluorosilicate shall be within 5 % of the manufacturers declared value. 4.3 Impurities and main by-products The product shall conform to the requirements specified in Table 1. Tab
39、le 1 Impurities Impurity Limit in mass fraction in % of commercial product Water- insoluble mattermax.0,5 Moisture max. 0,3 SANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12174:2006 (E) 8 4.4 Chemical parameters The product
40、 shall conform to the requirements specified in Table 2. Table 2 Chemical parameters Parameter Limit mg/kg of commercial product Antimony (Sb) max. 80 Arsenic (As) max. 400 Cadmium (Cd) max. 40 Chromium (Cr) max. 400 Lead (Pb) max. 400 Mercury (Hg) max. 10 Nickel (Ni) max. 400 Selenium (Se) max. 80
41、NOTE Other chemical parameters and indicator parameters are not relevant in sodium hexafluorosilicate because the raw materials used in the manufacturing process are free of them. For parametric values of sodium hexafluorosilicate on trace metal content in drinking water, see 1. 5 Test methods 5.1 S
42、ampling Observe the general recommendations of ISO 3165 and take account of ISO 6206. Prepare the laboratory sample(s) required by the relevant procedure described in ISO 8213. NOTE Sodium hexafluorosilicate presents a toxic hazard through inhalation of dust (see B.1). 5.2 Analyses 5.2.1 Main produc
43、t The sodium hexafluorosilicate content shall be determined in accordance with ISO 4281. This standard includes the determination of free acid. 5.2.2 Impurities 5.2.2.1 Insoluble matters 5.2.2.1.1 Procedure Weigh and transfer to a beaker 2 g of the sample which previously has been dried at 105 C to
44、constant mass. Dissolve in 500 ml of hot water. Generally 15 min to 30 min is sufficient time. SANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12174:2006 (E) 9 Filter through a tared Gooch crucible or a tared fritted-glass f
45、ilter of medium porosity (porosity P 16 according to ISO 4793). Wash with at least six separate 25 ml portions of boiling water, allowing the crucible to drain between washings. Dry the crucible or filter at 105 C to constant mass. 5.2.2.1.2 Expression of results The content of insoluble matters, C1
46、, expressed as mass fraction in % is given by the following equation: 100211xmmC = (1) where m1is the mass, in grams, of the filter residue; m2is the mass, in grams, of the test portion. 5.2.2.2 Moisture content The content of moisture shall be determined in accordance with ISO 5444. 5.2.3 Chemical
47、parameters 5.2.3.1 General The content of chemical parameters shall be determined using the procedures specified in Table 3. Table 3 Procedures for the determination of chemical parameters Element Reference Method Wavelength nm Flame As see 5.2.3.3 Hydride AAS 193,7 n.a Sb see 5.2.3.3 Hydride AAS 21
48、7,6 n.a Cd ISO 6353-1, MG 29 see 5.2.3.2 AAS 228,8 air-acetylene Cr ISO 6353-1, MG 29 see 5.2.3.2 AAS 357,8 air-acetylene Pb ISO 6353-1, MG 29 see 5.2.3.2 AAS 217,0 or 283,3 air-acetylene Ni ISO 6353-1, MG 29 see 5.2.3.2 AAS 232,0 Oxidizing Air-acetylene Se see 5.2.3.3 Hydride AAS 196,0 n.a Hg In ac
49、cordance with ISO 5993 flameless AAS 253,6 n.a n.a. not applicable. AAS Atomic absorption spectrometry. SANS 12174:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12174:2006 (E) 10 5.2.3.2 Determination of cadmium (Cd), chromium (Cr), lead (Pb) and nickel (Ni) 5.2.3.2.1 Principle The elements cadmium (Cd), chromium (Cr), lead (Pb) and nickel (Ni) are determined using atomic absorption spectrometry with standard additions method in taking account of ISO 6353-1. 5.2.3.2.2 Reagents All re
