1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 12906:2012Products used for treatmentof water intended for humanconsumption PumiceBS EN 12906:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implemen
2、tation of EN 12906:2012. Itsupersedes BS EN 12906:2005 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/59, Chemicals for drinking water treatment.A list of organizations represented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 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 77571 0ICS 71.100.80Compliance with a British Standard cannot confer immuni
4、ty fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 December 2012.Amendments issued since publicationDate Text affectedBS EN 12906:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12906 October 2012 ICS 71.100.8
5、0 Supersedes EN 12906:2005English Version Products used for treatment of water intended for human consumption - Pumice Produits utiliss pour le traitement de leau destine la consommation humaine - Pierre ponce Produkte zur Aufbereitung von Wasser fr den menschlichen Gebrauch - Bims This European Sta
6、ndard 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 references concerni
7、ng 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 member into i
8、ts 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, France, Germ
9、any, 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 KOMITEE FR
10、 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 12906:2012: EBS EN 12906:2012EN 12906:2012 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative referen
11、ces 53 Terms, definitions and symbols .54 Description .55 Physical properties 56 Chemical properties 67 Test methods 78 Labelling, transportation and storage .7Annex A (informative) General information on pumice .9Bibliography . 12BS EN 12906:2012EN 12906:2012 (E) 3 Foreword This document (EN 12906:
12、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 latest by April 2013, and conflicting nat
13、ional standards shall be withdrawn at the latest by April 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 patent rights. This document supersed
14、es EN 12906:2005. The significant technical difference between this edition and EN 12906:2005 is as follows: Updating of 8.2 in line with current legislation. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement thi
15、s 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, Poland, Portugal, Romania, Slovaki
16、a, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 12906:2012EN 12906:2012 (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 Standard: a) this European Standard p
17、rovides 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/or the characteristics of this
18、 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 control by National Authorities. BS
19、 EN 12906:2012EN 12906:2012 (E) 5 1 Scope This European Standard is applicable to pumice used for treatment of water intended for human consumption. It describes the characteristics of pumice and specifies the requirements and the corresponding test methods for pumice. It gives information on its us
20、e 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 edition of the referenced documen
21、t (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 supporting and filtering materials
22、 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 Aluminosilicate (AlxSiyOz). 4.1.2 Synonym or common names None. 4.2 Commercial forms Pumice accor
23、ding to this European Standard is a natural product and is available in different particle size ranges. 5 Physical properties 5.1 Appearance The product is a white to grey coloured granular material. The product has a granular shape, porous structure, smooth texture. The product shall be generally h
24、omogeneous and shall be visibly free of extraneous matter. BS EN 12906:2012EN 12906:2012 (E) 6 5.2 Particle size distribution The particle size distribution shall be determined on samples taken at the point of manufacture using the method of test given in EN 12902. NOTE 1 The particle size can decre
25、ase during transportation and handling. The particle size distribution shall be described by either: a) effective size: (d10) with a maximum deviation of 5 %; uniformity coefficient: (U) which shall be less than 1,5; minimum size: (d1) with a maximum deviation of 5 %; or b) by particle size range an
26、d 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 of the product as a filtration layer in multi media filters and a mass fraction of 10 % for use in single media filters. For
27、 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 values can be necessary for certain applications. 5.3 Density 5.3.1 Bulk density loose The bulk density loose shall be in t
28、he range of 300 kg/m3to 650 kg/m3. 5.3.2 Bulk density packed The bulk density packed shall be in the range of 320 kg/m3to 750 kg/m3. 6 Chemical properties This European Standard specifies the minimum purity requirements for pumice used for the treatment of water intended for human consumption. Limit
29、s 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 so, this shall be notified to the user and when necessary to relevant authorities. Users of this product should check the national regulatio
30、ns in order to clarify whether 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 product not stated in this product standard. Limits have been given for impurities and chemi
31、cal parameters where these 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. Th
32、e content of acid-soluble material shall be less than a mass fraction of 5 %. NOTE 1 The exact composition does not influence filtration properties and is given in A.2.1. BS EN 12906:2012EN 12906:2012 (E) 7 After filling, washing and commissioning of a filter system producing drinking water, pumice
33、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 specified in EN 12902. 7 Test methods 7.1 Sampling Prep
34、are the laboratory sample(s) required by the relevant procedures described in EN 12902. 7.2 Analysis 7.2.1 Particle size distribution The particle size distribution shall be determined in accordance with EN 12902. 7.2.2 Bulk density loose The bulk density loose shall be determined in accordance with
35、 EN 12902. 7.2.3 Bulk density packed The bulk density packed shall be determined in accordance with EN 12902. 7.2.4 Acid-soluble material The content of acid-soluble material shall be determined in accordance with EN 12902. 8 Labelling, transportation and storage 8.1 Means of delivery Pumice shall b
36、e 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 prepared before use. 8.2 Labelling according to the EU legislat
37、ion 1)Pumice 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 the purposes of its adaptation to technical and scientific progress contains a list of substances classified by the EU. Substance
38、s 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 marketing of the substance. 1) See 2. BS EN 12906:2012EN 12906:2012 (E) 8 8.3 Transportation regulations and labelling Pumice
39、is not a dangerous cargo. 8.4 Marking The marking shall include the following: name “pumice“, trade name and particle size range; net mass or the volume; name and the address of supplier and/or manufacturer; statement “this product conforms to EN 12906“. 8.5 Storage (long term chemical stability) Pu
40、mice can be stored for an unlimited period of time. BS EN 12906:2012EN 12906:2012 (E) 9 Annex A (informative) General information on pumice A.1 Origin A.1.1 Raw material Natural pumice. A.1.2 Manufacturing process Pumice is produced by quarrying and crushing, then cleaning, drying and sieving. A.2 T
41、ypical properties A.2.1 Chemical composition The composition depends on the origin of the raw materials. Examples are given in Table A.1. Table A.1 Chemical composition Parameter Mass fraction in % SiO2range 55 to 75 Al2O3range 10 to 25 Fe2O3max 2CaO max 2 K2O max 10 Na2O max 10 Mineralogical and pe
42、trological analyses give additional information. A.2.2 Mechanical strength The mechanical resistance of pumice is relatively low. Abrasion products consist of dust and small particles of material. They are formed during transportation, filling, and washing. Abrasion products are not completely remov
43、ed 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 distribution des
44、cribed by different particle size ranges and a permissible mass fraction of oversize and undersize product are given in Table A.2. BS EN 12906:2012EN 12906:2012 (E) 10 Table A.2 Examples of particle size range Permissible mass fraction % aParticle size range mm Undersize Oversize 0,6 to 1,6 5 5 1,4
45、to 2,5 1,6 to 2,5 2,0 to 3,15 2,0 to 4,0 2,5 to 4,0 10 10 aGenerally the maximum permitted mass fractions of undersize and oversize are 5 % for application of the product as a filtration layer in multi media filters and 10 % for use in single media filters. Other particle size ranges can be specifie
46、d. A.2.4 Density A.2.4.1 Absolute density The absolute density is greater than 2,3 g/cm3. A.2.4.2 Particle density dry The particle density dry is generally in the range of 0,7 g/cm3to 1,2 g/cm3. A.2.4.3 Particle density wet The particle density wet is generally in the range of 1,1 g/cm3to 1,7 g/cm3
47、. NOTE It can require several days for particles to become saturated with water. A.2.5 Porosity of particles The porosity of particles is generally in the range of volume fraction of 50 % to 85 %. A.3 Use A.3.1 Function Pumice is used as a filtering material. A.3.2 Specific amount The amount of pumi
48、ce used depends on the application. Filtration rate and filter media depth vary with the suspended matter content of the water to be filtered. A.3.3 Means of application Pumice is used in open or closed, single or multilayer filters. BS EN 12906:2012EN 12906:2012 (E) 11 A.3.4 Secondary effects The p
49、roduct has no secondary effects. A.4 Hydraulic characteristics A.4.1 Interstitial volume The interstitial volume is approximately 0,4 (V/V). If used for calculations the interstitial volume should be measured. A.4.2 Head loss during filtration Head loss depends on size, shape and roughness of particles, filtration rate, filter bed depth, and water temperature. A.4.3 Expansion during up-flow washing Expansion during washing depends on flow rate, effective size, density, shape and roughness, and water tem
