1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 12910:2012Products used for treatmentof water intended for humanconsumption GarnetBS EN 12910:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implemen
2、tation of EN 12910:2012. Itsupersedes BS EN 12910:2005 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/59, Chemicals for drinking water treatment.A list of organizations represented on this committee can beobtained on request to its secretary.This p
3、ublication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 77572 7ICS 13.060.20; 71.100.80Compliance with a British Standard cannot co
4、nfer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 January 2013.Amendments issued since publicationDate Text affectedBS EN 12910:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12910 November 2012 I
5、CS 71.100.80 Supersedes EN 12910:2005English Version Products used for treatment of water intended for human consumption - Garnet Produits utiliss pour le traitement de leau destine la consommation humaine - Grenat Produkte zur Aufbereitung von Wasser fr den menschlichen Gebrauch - Granatsand This E
6、uropean Standard was approved by CEN on 9 September 2012. 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 referenc
7、es concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre 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 me
8、mber into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, F
9、rance, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES
10、 KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12910:2012: EBS EN 12910:2012EN 12910:2012 (E) 2 Contents Page Foreword 3Introduction . 41 Scope 52 Norma
11、tive references 53 Terms, definitions and symbols . 54 Description . 55 Physical properties 56 Chemical properties 67 Specific properties. 78 Test methods 79 Labelling, transportation and storage . 7Annex A (informative) General information on garnet . 9Bibliography 12BS EN 12910:2012EN 12910:2012 (
12、E) 3 Foreword This document (EN 12910:2012) 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 or by endorsement, at the lat
13、est by May 2013, and conflicting national standards shall be withdrawn at the latest by May 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such pat
14、ent rights. This document supersedes EN 12910:2005. The significant technical difference between this edition and EN 12910:2005 is as follows: Updating 9.2 in line with current legislation. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following count
15、ries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Pol
16、and, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 12910:2012EN 12910:2012 (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 European Standa
17、rd: a) this European Standard 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 and
18、/or the characteristics of this product remain in force. NOTE Conformity with this European Standard 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 European Standard is subject to regulation or cont
19、rol by National Authorities. BS EN 12910:2012EN 12910:2012 (E) 5 1 Scope This European Standard is applicable to garnet used for treatment of water intended for human consumption. It describes the characteristics of garnet and specifies the requirements and the corresponding test methods for garnet.
20、 It gives information on its use in water treatment. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest ed
21、ition 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 water intended for human consumption Inorganic sup
22、porting and filtering materials Methods of test 3 Terms, definitions and symbols For the purposes 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) Almandite Fe3Al2(SiO4)3.Andradite Ca3Fe2(SiO4)3. NOTE Both form
23、s can have other metals in partial substitution for the major constituents. 4.2 Commercial form Each of the two main types of garnet is available in different particle size grades. 5 Physical properties 5.1 Appearance The product is a pink, red or brown to black coloured granular material. Cubic cry
24、stals; the particle shape can be angular to sub-angular to rounded depending on origin. The product shall be generally homogeneous and shall be visibly free of extraneous matter. BS EN 12910:2012EN 12910:2012 (E) 6 5.2 Particle size distribution The particle size distribution shall be determined on
25、samples taken at the point of manufacture using the method of test given in EN 12902. NOTE 1 The particle size can decrease during transportation and handling. The particle size distribution shall be described by either: a) effective size : (d10) with a maximum deviation of 5 %; uniformity coefficie
26、nt : (U) which shall be less than 1,5; minimum size : (d1) with a maximum deviation of 5 %; or b) by particle size range and by 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 application o
27、f the product as a filtration layer in multi media filters and a mass fraction of 10 % for use in single media filters. For use as a support layer, maximum mass fractions of oversize and undersize of 15 % are acceptable. See A.2.3 for examples of available particle sizes that are used. NOTE 2 Other
28、values can be necessary for certain applications. 5.3 Density 5.3.1 General The density of garnet varies with the mineralogical form. Garnet with absolute density lower than 3,8 g/cm3should not be used in multi media sand - garnet filters to prevent intermixing of media. 5.3.2 Bulk density loose Alm
29、andite: The bulk density loose shall be in the range of 2 150 kg/m3to 2 250 kg/m3. Andradite: The bulk density loose shall be in the range of 1 850 kg/m3to 2 000 kg/m3. 5.3.3 Bulk density packed Almandite: The bulk density packed shall be in the range of 2 350 kg/m3to 2 400 kg/m3. Andradite: The bul
30、k density packed shall be in the range of 1 950 kg/m3to 2 250 kg/m3. 6 Chemical properties This European Standard specifies the minimum purity requirements for garnet used for the treatment of water intended for human consumption. Limits are given for impurities commonly present in the product. Depe
31、nding 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. BS EN 12910:2012EN 12910:2012 (E) 7 Users of this product should check the national regulations in order to clarify wheth
32、er it is of appropriate purity for treatment of water intended for human consumption, taking into account raw water quality, contents of other impurities and additives used in the products not stated in this product standard. Limits have been given for impurities and chemical parameters where these
33、are likely to be present 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. The chemical composition vari
34、es with the mineralogical form. Typical data are given in Table A.1. NOTE 1 Because of the nature of the occurrence and production of garnet, a small proportion of other minerals, in particular silica sand and ilmenite, can be present in the commercial product. After filling, washing and commissioni
35、ng of a filter system producing drinking water, garnet should not increase the concentrations of chemical parameters (see 1). NOTE 2 Water extractable substances, determined in accordance with the method for granular materials given in EN 12902, can be used to estimate the leaching of the chemicals
36、specified in EN 12902. 7 Specific properties Garnet is a non-reactive high density filtration and support medium. It is used specifically because of its high density. 8 Test methods 8.1 Sampling Prepare the laboratory sample(s) required by the relevant procedures described in EN 12902. 8.2 Analysis
37、8.2.1 Particle size distribution The particle size distribution shall be determined in accordance with EN 12902. 8.2.2 Bulk density loose The bulk density loose shall be determined in accordance with EN 12902. 8.2.3 Bulk density packed The bulk density packed shall be determined in accordance with E
38、N 12902. 9 Labelling, transportation and storage 9.1 Means of delivery Garnet 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
39、specially cleaned and prepared before use. BS EN 12910:2012EN 12910:2012 (E) 8 9.2 Labelling in accordance with the EU legislation 1)Garnet is not listed within Annex VI of Regulation (EC) No 1272/2008 at the date of publication of this European Standard. The legislation 2, and its amendments for th
40、e purposes of its adaptation to technical and scientific progress contains a list of substances classified by the EU. Substances not listed in this regulation should be classified on the basis of their intrinsic properties according to the criteria in the regulation by the person responsible for the
41、 marketing of the substance. NOTE Additional national regulations may apply to the labelling of this product. 9.3 Transportation regulations and labelling Garnet is not classified as dangerous product for road, rail, sea and air transportation. Garnet is not listed under a UN Number 2). 9.4 Marking
42、The marking shall include the following: name “Garnet“, trade name and grade; net mass; name and the address of supplier and/or manufacturer; statement “This product conforms to EN 12910“. 9.5 Storage (long term stability) Garnet can be stored for an unlimited period of time. 1) See 2. 2) United Nat
43、ions Number. BS EN 12910:2012EN 12910:2012 (E) 9 Annex A (informative) General information on garnet A.1 Origin A.1.1 Raw material Garnet exists in nature in six main varieties of which only two forms are generally used as filtration and supporting materials: almandite garnet and andradite garnet. B
44、oth these varieties occur as massive rock deposits and also as alluvial sands in both geological and modern beach deposits. Garnet rarely occurs as a single pure variety: the different forms often grade into each other with some replacement of the main metallic elements by minor ones. For this reaso
45、n, the analyses of the same type of garnet from different deposits will vary. A.1.2 Manufacturing process Garnet is produced by mining and crushing rock deposits, by quarrying geological alluvial deposits or by collecting alluvial material deposited on modern beaches. The garnet is separated from ot
46、her constituents such as silica and heavy minerals, and sieved to produce specific particle size ranges. A.2 Typical properties A.2.1 Chemical composition Table A.1 shows the range of composition of the two main types of garnet used as filtering and supporting materials. Almandite and andradite garn
47、ets can usually be distinguished by their calcium and aluminium contents and by their densities. Table A.1 Typical chemical composition Parameter Typical value in mass fraction % Almandite Andradite SiO232 to 42 32 to 42 Al2O315 to 25 0 to 15 FeO 20 to 40 0 to 15 Fe2O30 to 15 20 to 35 TiO20 to 5 0 t
48、o 5 CaO 0 to 5 20 to 38 MgO 0 to 15 0 to 5 MnO 0 to 5 0 to 5 The above analyses are typical of the two types of garnet but analyses can vary depending on the deposit. Mineralogical and petrological analyses can give additional information. BS EN 12910:2012EN 12910:2012 (E) 10 A.2.2 Mechanical streng
49、th The mechanical strength of garnet is high. Abrasion products 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 operation. They can be used only for comparison of different filter media. A.2.3 Examples of particle size distribution Examples of particle size distr
