1、BRITISH STANDARD BS EN 12904:2005 Products used for treatment of water intended for human consumption Silica sand and silica gravel The European Standard EN 12904:2005 has the status of a British Standard ICS 71.100.80 BS EN 12904:2005 This British Standard was published under the authority of the S
2、tandards Policy and Strategy Committee on 31 March 2005 BSI 31 March 2005 ISBN 0 580 45785 0 National foreword This British Standard is the official English language version of EN 12904:2005. It supersedes BS EN 12904:1999 which is withdrawn. The UK participation in its preparation was entrusted to
3、Technical Committee CII/59, Chemicals for drinking water treatment, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referr
4、ed to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisi
5、ons of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, o
6、r proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 13 and a back cover. The BSI copyright notic
7、e displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12904 March 2005 ICS 71.100.80 Supersedes EN 12904:1999 English version Products used for treatment of water inten
8、ded for human consumption - Silica sand and silica gravel Produits utiliss pour le traitement de leau destine la consommation humaine - Sable et gravier de quartz Produkte zur Aufbereitung von Wasser fr den menschlichen Gebrauch - Quarzsand und Quarzkies This European Standard was approved by CEN on
9、 3 February 2005. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards ma
10、y 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 under the responsibility of a CEN member into its own language and notified to the Cen
11、tral Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, P
12、oland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any m
13、eans reserved worldwide for CEN national Members. Ref. No. EN 12904:2005: EEN 12904:2005 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms, definitions and symbols.5 4 Description .5 5 Physical properties5 6 Chemical properties 6 7 Test methods7 8 Labelling- Tr
14、ansportation -Storage8 Annex A (informative) General information on silica sand and silica gravel9 Bibliography 13 EN 12904:2005 (E) 3 Foreword This document (EN 12904:2005) has been prepared by Technical Committee CEN/TC 164 “Water supply”, the secretariat of which is held by AFNOR. This European S
15、tandard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2005, and conflicting national standards shall be withdrawn at the latest by September 2005. This document supersedes EN 12904:1999. Significant technica
16、l differences between this edition and EN 12904:1999 are as follows: a) correction of the data on chemical composition in table A.1; b) use of the more appropriate terms “silica sand” and “silica gravel” throughout the standard; c) deletion of the reference to EU Directive 80/778/EEC of 15 July 1980
17、 in order to take account of the last Directive in force (see1). 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, Fran
18、ce, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 12904:2005 (E) 4 Introduction In respect of potential adverse effects on the quality of water inte
19、nded 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 of the EU or EFTA; b) It should be noted that, while awaiting the adoption of verifiable European
20、 criteria, existing national regulations concerning the use and/or the characteristics of this product remain in force. NOTE Conformity with the 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 th
21、is document is subject to regulation or control by National Authorities. EN 12904:2005 (E) 5 1 Scope This document is applicable to silica sand and silica gravel used for treatment of water intended for human consumption. It describes the characteristics of silica sand and silica gravel and specifie
22、s the requirements and the corresponding test methods for silica sand and silica gravel. It gives information on their use in water treatment. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cite
23、d applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12901:1999, Products used for treatment of water intended for human consumption - Inorganic supporting and filtering materials Definitions. EN 12902, Products used for treatment of
24、 water intended for human consumption - Inorganic supporting and filtering materials - Methods of test. 3 Terms, definitions and symbols For the purpose of this document, the terms, definitions and symbols given in EN 12901:1999 apply. 4 Description 4.1 Identification 4.1.1 Chemical name(s) Silica,
25、silicon dioxide (SiO 2 ). 4.1.2 Synonym or common names Silica sand and silica gravel. 4.2 Commercial forms Silica sand and silica gravel according to this standard are available in different particle size ranges. 5 Physical properties 5.1 Appearance The product is a grey/white, yellow or multicolou
26、red granular material. The structure is crystalline, with a smooth to rough texture. The particle shape is spherical or angular depending mainly on the origin and manufacturing procedure (quarrying or dredging, or crushing). The shape influences filtration performance, see A.3. The product shall be
27、generally homogeneous and shall be visibly free of extraneous matter. EN 12904:2005 (E) 6 5.2 Particle size distribution The particle size distribution shall be described by either: a) effective size: (d 10 ) , with a maximum deviation of 5 %; uniformity coefficient: (U), shall be less than 1,5; min
28、imum size : (d 1) , with a maximum deviation of 5 %; or: b) particle size range and mass fraction of oversize and undersize particles according to application. The maximum contents of oversize and undersize shall be a mass fraction of 5 % for the application of the product in multi media filters and
29、 a mass fraction of 10 % for use in single media filters. For use as a support layer, maximum contents of oversize and undersize of mass fraction of 15 % are acceptable. See A.2.3 for examples of available particle sizes that are used. NOTE 1 The particle size can decrease during transportation and
30、handling. NOTE 2 Other values can be necessary for certain applications. 5.3 Density 5.3.1 Bulk density loose The bulk density loose shall be in the range of 1 400 kg/m 3 to 1 700 kg/m 3 .5.3.2 Bulk density packed The bulk density packed shall be in the range of 1 500 kg/m 3to 1 900 kg/m 3 .6 Chemic
31、al properties This document specifies the minimum purity requirements for silica sand and silica gravel used for the treatment of water intended for human consumption. Limits are given for impurities commonly present in the products. Depending on the raw material and the manufacturing process other
32、impurities may be present and, if so, this shall be notified to the user and when necessary to relevant authorities. NOTE Users of these products should check the national regulations in order to clarify whether it is of appropriate purity for treatment of water intended for human consumption, takin
33、g 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 chemical parameters where these are likely to be present in significant quantities from the current production pro
34、cess 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. Silica sand and silica gravel shall conform to table 1. EN 12904:2005 (E) 7 Table 1 - Composition of silica san
35、d and silica gravel Limit in mass fraction in % of the product Type 1 Type 2 Type 3 d 10 2 mm d 10 2 mm SiO 2min. 96 80 80 80 Acid-soluble material max. 2 2 5 10 NOTE 1 The contents of SiO 2and acid-soluble material give information about the source of silica sand and silica gravel. NOTE 2 Other pot
36、ential components are given in A.2.1. NOTE 3 After filling, washing and commissioning of a filter system producing drinking water the silica sand or silica gravel should not increase the concentrations of chemical parameters (see 1). NOTE 4 Water-extractable substances, determined in accordance with
37、 the method for granular materials given in EN 12902, can be used to estimate the leaching of the chemicals specified in EN 12902. 7 Test methods 7.1 Sampling Prepare the laboratory sample(s) required by the relevant procedures described in EN 12902. 7.2 Analysis 7.2.1 Particle size distribution The
38、 particle size distribution shall be determined on samples taken at the point of manufacture using the method of test given in EN 12902. 7.2.2 Bulk density loose The bulk density loose shall be determined in accordance with EN 12902. 7.2.3 Bulk density packed The bulk density packed shall be determi
39、ned in accordance with EN 12902. 7.2.4 Content of silica The content of silica shall be determined in accordance with EN 12902. 7.2.5 Acid-soluble material The content of acid-soluble material shall be determined in accordance with EN 12902. EN 12904:2005 (E) 8 8 Labelling- Transportation -Storage 8
40、.1 Means of delivery Silica sand and silica gravel shall be delivered in bags, semi-bulk containers, or bulk. In order that the purity of the product is not affected, the means of delivery shall not have been used previously for any different product or it shall have been specially cleaned and prepa
41、red before use. 8.2 Risk and safety labelling according to the EU Directives 1)Silica sand and silica gravel are not subject to labelling regulations at the date of publication of this document. NOTE 1 Annex I of the Directive 67/548/EEC on Classification, packaging and labelling of dangerous substa
42、nces and its amendments and adaptations in the European Union contains a list of substances classified by the EU. Substances not in this Annex I should be classified on the basis of their intrinsic properties according to the criteria in the Directive by the person responsible for the marketing of t
43、he substance. NOTE 2 Additional national regulations could apply to the labelling of this product. 8.3 Transportation regulations and labelling Silica sand and silica gravel are not classified as dangerous goods. 8.4 Marking The marking shall include the following: - name “silica sand” or “silica gr
44、avel“, trade name, grade and type; - net mass; - name and the address of the supplier and/or manufacturer; - statement “This product conforms to EN 12904“. 8.5 Storage 8.5.1 Long term chemical stability Silica sand and silica gravel can be stored for an unlimited period of time and shall be adequate
45、ly protected from outside contamination. 1)See 2 EN 12904:2005 (E) 9 Annex A (informative) General information on silica sand and silica gravel A.1 Origin A.1.1 Raw material Natural silica sand, silica gravel. A.1.2 Manufacturing process Silica sand and silica gravel are produced by quarrying, dredg
46、ing or crushing, cleaning, drying, and sieving. A.2 Typical properties A.2.1 Chemical composition The composition depends on the origin. Typical values (mass fraction) are given as an example in table A.1 (the main components are given in clause 6). Table A.1 - Chemical composition Mass fraction in
47、%Parameter Type 1 Type 2 Type 3 Al 2 O 3 3 13 13 Fe 2 O 3 2 10 2 CaO 1,5 1 5 K 2 O 2 4 1 Na 2 O 1,5 2 1 Mineralogical and petrological analyses give additional information. A.2.2 Mechanical strength The mechanical strength of silica sand and silica gravel is high. EN 12904:2005 (E) 10 Abrasion produ
48、cts consist of dust and small particles of material. They are formed during transportation, filling, and washing. Abrasion products are not completely removed by washing. The existing methods for determination of abrasion do not lead to exact results regarding behaviour of filter media during operat
49、ion. They can be used only for comparison of different filter media. A.2.3 Examples of particle size distribution Examples of particle size distribution described by different particle size ranges and a permissible mass fraction of oversize and undersized product are given in table A.2. Table A.2 - Examples of particle size range Permissible mass fraction, % a)Particle size range mm Undersize Oversize Silica sand 0,4 0,5 0,6 0,63 0,71 to to to to to 0,8 1,0 1,18 1,0 1,25 5 5 0,85 1,0 1,0
