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 978-0-626-19879-4 SANS 12175:2007Edition 2 EN 12175:2006Edition 2 SOUTH AFRICAN NATIONAL STANDARD Chemicals used for treatment of water intended for
4、 human consumption Hexafluorosilicic acid This national standard is the identical implementation of EN 12175:2006 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 4
5、28 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 12175:2007 Edition 2 EN 12175:2006 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 accordan
6、ce 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 12175:2001 (edition 1). EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 12175July 2006ICS 71.100.80 Supersedes EN
7、12175:2001 English VersionChemicals used for treatment of water intended for humanconsumption - Hexafluorosilicic acidProduits chimiques utiliss pour le traitement de leaudestine la consommation humaine - AcidhexafluorosiliciqueProdukte zur Aufbereitung von Wasser fr denmenschlichen Gebrauch - Hexaf
8、luorkieselsureThis 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 alteration. Up-to-date lists and bibliograp
9、hical 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 translationunder the responsibility of a CEN m
10、ember 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, Iceland, Ireland, Italy, Latvia, Lith
11、uania, 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 Stassart, 36 B-1050 Brussels 2006 CEN
12、 All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12175:2006: ESANS 12175:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12175:2006 (E) 2 Contents Page Foreword3 Introducti
13、on .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 4.4 Chemical parameters 8 5 Test meth
14、ods8 5.1 General8 5.2 Sampling.8 5.3 Analyses .10 6 Labelling - Transportation - Storage16 6.1 Means of delivery.16 6.2 Risk and safety labelling according to the EU Directives .17 6.3 Transportation regulations and labelling17 6.4 Marking .17 6.5 Storage18 Annex A (informative) General information
15、on hexafluorosilicic acid.19 A.1 Origin 19 A.2 Use 19 Annex B (normative) General rules relating to safety.20 B.1 Rules for safe handling and use 20 B.2 Emergency procedures.20 Bibliography 21 SANS 12175:2007This s tandard may only be used and printed by approved subscription and freemailing clients
16、 of the SABS .EN 12175:2006 (E) 3 Foreword This document (EN 12175:2006) 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 publication of an identical text
17、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 12175:2001. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound
18、to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland an
19、d United Kingdom. SANS 12175:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12175:2006 (E) 4 Introduction In respect of potential adverse effects on the quality of water intended for human consumption, caused by the product covered by
20、 this document: a) this document provides no information as to whether the product may be used without restriction in any of the Member States 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
21、 and/or the characteristics of this product remain in force. NOTE Conformity with this document does not confer or imply acceptance or approval 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 Nationa
22、l Authorities. SANS 12175:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12175:2006 (E) 5 1 Scope This document is applicable to hexafluorosilicic acid used for treatment of water intended for human consumption. It describes the chara
23、cteristics of hexafluorosilicic acid and specifies the requirements and the corresponding test methods for hexafluorosilicic acid. It gives information on its use in water treatment. It also determines the rules relating to safe handling and use of hexafluorosilicic acid (see Annex B). 2 Normative r
24、eferences The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references the latest edition of the referenced document (including any amendments) applies. EN ISO 3696, Water for analytical labora
25、tory use - Specification and test methods (ISO 3696:1987) ISO 3165, Sampling of chemical products for industrial use - Safety in sampling ISO 5440, Sodium hexafluorosilicate for industrial use - Determination of phosphate content - Molybdovanadate spectrophotometric method ISO 5993, Sodium hydroxide
26、 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. Part 1: General test methods 3 Description 3.1 Identification 3.1.1 Chemical name
27、 Hexafluorosilicic acid 3.1.2 Synonym or commons names Hydrofluosilicic acid Silicate -hexafluoro dihydrogen Fluorosilicic acid HFSA 3.1.3 Relative molecular mass 144,09 3.1.4 Empirical formula H2SiF6. SANS 12175:2007This s tandard may only be used and printed by approved subscription and freemailin
28、g clients of the SABS .EN 12175:2006 (E) 6 3.1.5 Chemical formula H2SiF6.3.1.6 CAS-Registry Number1)16961-83-4 3.1.7 EINECS reference2)241-034-8 3.2 Commercial form The product is an aqueous solution. 3.3 Physical properties 3.3.1 Appearance and odour The product is a clear, colourless liquid with a
29、 pungent odour. 3.3.2 Density The density of a mass fraction 35 % solution at 25 C is 1,35 g/ml. The density of a mass fraction 20 % solution at 25 C is 1,18 g/ml. 3.3.3 Solubility (in water) The product is miscible in any proportion. 3.3.4 Vapour pressure The vapour pressure at 20 C is approximatel
30、y 3 kPa3). 3.3.5 Boiling point at 100 kPa The product boils and decomposes at 110 C. 3.3.6 Crystallisation point A solution of mass fraction of 35 % crystallizes at -30 C and of a mass fraction of 20 % crystallizes at -11,6 C. 3.3.7 Specific heat Not known. 1)Chemical Abstracts Service Registry Numb
31、er. 2) European Inventory of Existing Commercial Chemical Substances. 3) 100 kPa = 1 bar. SANS 12175:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .EN 12175:2006 (E) 7 3.3.8 Viscosity dynamic A solution of a mass fraction of 20 % has a d
32、ynamic viscosity of 1,4 MPa.s at 25 C. 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 Hexafluorosilicic acid is only stable in an aqueous solution. On evaporation it decomposes to hydrogen fluoride
33、(HF) and silicon tetrafluoride (SiF4). It produces hydrogen on contact with metals, e.g. steel, nickel and aluminium. It is a strong acid and reacts violently with alkalis. It forms hydrogen fluoride (HF) on contact with concentrated acids. It attacks glass. 4 Purity criteria 4.1 General This docume
34、nt specifies the minimum purity requirements for hexafluorosilicic acid used for the treatment of water intended for human consumption. Limits are given for impurities commonly present in the product. Depending on the raw material and the manufacturing process other impurities may be present and, if
35、 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 purity for treatment of water intended for human consumption, taking into account raw water quality, r
36、equired 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 present in significant quantities from the current production process and raw materials. If the pro
37、duction 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 product shall contain between a mass fraction of 20 % and 40 % hexafluorosilicic acid, the remainder be
38、ing water. The concentration of hexafluorosilicic acid 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. SANS 12175:2007This s tandard may only be used and printed by approved subscription
39、and freemailing clients of the SABS .EN 12175:2006 (E) 8 Table 1 Impurities Impurity Limit in mass fraction in % of commercial product Phosphate as P2O5 max.0,75 Free hydrogen fluoride as HF max. 1,5 4.4 Chemical parameters The product shall conform to the requirements specified in Table 2. Table 2
40、Chemical parameters Parameter Limit mg/kg H2SiF6 (100 %) 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 NOTE Other chemical parameters and indicator parameters are not relevant
41、 in hexafluorosilicic acid because the raw materials used in the manufacturing process are free of them. For parametric values of hexafluorosilicic acid on trace metal content in drinking water, see 1. 5 Test methods 5.1 General SAFETY PRECAUTIONS Hexafluorosilicic acid shall be handled with extreme
42、 care, see B.1. All equipment in contact with hexafluorosilicic acid shall be made of plastics (for example polyethylene or polytetrafluoroethylene (PTFE); avoid contact with glass. 5.2 Sampling 5.2.1 General Observe the general recommendations of ISO 3165 and take account of ISO 6206. NOTE The samp
43、ling is carried out at the premises of the manufacturer of the hexafluorosilicic acid unless the customer has adequate facilities to carry out this operation safely at his own premises. SANS 12175:2007This s tandard may only be used and printed by approved subscription and freemailing clients of the
44、 SABS .EN 12175:2006 (E) 9 5.2.2 Sampling from drums and bottles 5.2.2.1 General 5.2.2.1.1 Mix the contents of each container to be sampled by shaking the container, by rolling it or by rocking it from side to side, taking care not to damage the container or spill any of the liquid. 5.2.2.1.2 If the
45、 design of the container is such (for example, a narrow-necked bottle) that it is impracticable to use a sampling implement, take a sample by pouring after the contents have been thoroughly mixed. Otherwise, proceed as described in 5.2.2.1.3. 5.2.2.1.3 Examine the surface of the liquid. If there are
46、 signs of surface contamination, take samples from the surface as described in 5.2.2.2; otherwise, take samples as described in 5.2.2.3. 5.2.2.2 Surface sampling Take a sample using a suitable ladle. Lower the ladle into the liquid until the rim is just below the surface, so that the surface layer r
47、uns into it. Withdraw the ladle before it fills completely and allow any liquid adhering to the ladle to drain off. If necessary, repeat this operation so that, when the other selected containers have been sampled, in a similar manner, the total volume of sample required for subsequent analysis is o
48、btained. 5.2.2.3 Procedure of sampling from a container The samples for testing the hexafluorosilicic acid shall be taken by means of a sampling tube, for example. A tube made of polytetrafluoroethylene (PTFE), approximately 1 500 mm long, with 14,5 mm inside diameter and 1,25 mm wall thickness tape
49、ring to an inside diameter of approximately 5 mm at one end, can be used for this; fit a rubber tube approximately 200 mm long which can be closed by means of a pinch clip, to the other end. When taking the samples, insert the sampling tube as far as possible into the acid to be tested with the clip released. Do this slowly so that the levels of liquid in the sampling tube and in the acid container are the same. Close the clip, withdraw the sampling tube from the acid, allow any liquid adhering at the outside of the tube to drain off, and by
