1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 12912:2012Products used for treatmentof water intended for humanconsumption BariteBS EN 12912:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implemen
2、tation of EN 12912:2012. Itsupersedes BS EN 12912:2005 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/59, Chemicals for drinking water treatment.A list of organizations represented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 77573 4ICS 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 12912:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12912 November 2012 I
5、CS 71.100.80 Supersedes EN 12912:2005English Version Products used for treatment of water intended for human consumption - Barite Produits utiliss pour le traitement de leau destine la consommation humaine - Baryte Produkte zur Aufbereitung von Wasser fr den menschlichen Gebrauch - Baryt This Europe
6、an 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 references co
7、ncerning 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
8、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, France
9、, 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 KOMI
10、TEE 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 12912:2012: EBS EN 12912:2012EN 12912:2012 (E) 2 Contents Page Foreword 3Introduction . 41 Scope 52 Normative
11、references 53 Terms, definitions and symbols . 54 Description . 55 Physical properties 66 Chemical properties 77 Test methods 78 Labelling, transportation and storage . 9Annex A (informative) General information on barite 11Bibliography 15BS EN 12912:2012EN 12912:2012 (E) 3 Foreword This document (E
12、N 12912:2012) 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 May 2013, and conflicti
13、ng 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 patent rights. This document supe
14、rsedes EN 12912:2005. The significant technical difference between this edition and EN 12912:2005 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
15、 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, Poland, Portugal, Romania, Slo
16、vakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 12912:2012EN 12912:2012 (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 Standa
17、rd 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/or the characteristics of
18、 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 control by National Authoritie
19、s. BS EN 12912:2012EN 12912:2012 (E) 5 1 Scope This European Standard is applicable to barite used for treatment of water intended for human consumption. It describes the characteristics of barite and specifies the requirements and the corresponding test methods for barite and gives information on i
20、ts 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 edition of the referenced do
21、cument (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 mate
22、rials Methods of test EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696) 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 B
23、arium sulfate. 4.1.2 Synonym and common names Barite, baryte, heavy spar, tiff, cawk. 4.1.3 Chemical formula BaSO4. 4.1.4 CAS Registry number 1)13462-86-7. 1) Chemical Abstracts Service Registry Number. BS EN 12912:2012EN 12912:2012 (E) 6 4.1.5 EINECS reference 2) 236-664-5. 4.2 Commercial form Bari
24、te according to this European Standard is available in different particle size ranges. 5 Physical properties 5.1 Appearance The product has various light shades, including white to yellow, with a vitreous lustre. The product has an angular shape and a crystalline structure. The product shall be gene
25、rally homogeneous and shall be visibly free of extraneous matter. 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 decrease during transportation and
26、 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 and by mass fraction of oversize
27、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 use as a support layer, maximu
28、m 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 the range of 2 200 kg/m3to 2 400
29、 kg/m3. 2) European Inventory of Existing Commercial Chemical Substances. BS EN 12912:2012EN 12912:2012 (E) 7 5.3.2 Bulk density packed The bulk density packed shall be in the range of 2 500 kg/m3to 2 600 kg/m3. 6 Chemical properties This European Standard specifies the minimum purity requirements f
30、or barite 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 so, this shall be notified to the user and when necessary to
31、relevant authorities. 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, contents of other impurities and additives used in the products not
32、stated in this product standard. Limits have been given for impurities and chemical 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
33、, by-products or additives being present, this shall be notified to the user. The composition of the commercial product shall conform to the requirements specified in Table 1. Table 1 Composition of commercial product Parameter Limit in mass fraction % Barium sulfate min 92 Acid-soluble material max
34、 3 NOTE The contents of BaSO4and acid-soluble material do not influence filtration properties but give information about the source of barite After filling, washing and commissioning of a filter system producing drinking water, barite should not increase the concentrations of chemical parameters (se
35、e 1). NOTE 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 Prepare the laboratory sample(s) required by the relevant procedures de
36、scribed 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 EN 12902. BS EN 12912:2012EN 12912:2012 (E) 8 7.2.3 Bulk density p
37、acked The bulk density packed shall be determined in accordance with EN 12902. 7.2.4 Main product - barium sulfate 7.2.4.1 Principle Melting of mineral with sodium carbonate followed by disintegration in water and filtration to recover water insoluble carbonates. The solid is treated with hydrochlor
38、ic acid solution and the acid insoluble fraction is filtered off. Barium sulfate is precipitated by addition of ammonium sulfate solution and gravimetrically determined. 7.2.4.2 Reagents All reagents shall be of recognised analytical grade and the water used shall conform to grade 3 in accordance wi
39、th EN ISO 3696. 7.2.4.2.1 Ammonium hydroxide solution, NH4OH = 0,9 g/ml. 7.2.4.2.2 Ammonium sulfate solution, (NH4)2SO4100 g/l solution. 7.2.4.2.3 Hydrochloric acid, HCl = 1,18 g/ml. 7.2.4.2.4 Sodium carbonate, Na2CO3.7.2.4.2.5 Sodium carbonate solution, (Na2CO3) 30 g/l solution. 7.2.4.2.6 Methyl re
40、d, 0,5 g/l solution. 7.2.4.3 Apparatus Ordinary laboratory apparatus and glassware together with the following. 7.2.4.3.1 Platinum crucible. 7.2.4.3.2 Electric furnace, capable of being controlled at (850 25) C. 7.2.4.3.3 Porcelain crucible. 7.2.4.3.4 Oven, capable of being controlled at (105 2) C.
41、7.2.4.4 Procedure Weigh in the platinum crucible (7.2.4.3.1), to the nearest 0,1 mg, about 0,5 g of barite previously finely powdered and dried at 105 C (m1). Add about 3 g of sodium carbonate (7.2.4.2.4), mix and heat until the melt is clear. Cool and carefully disintegrate the solid with hot water
42、. Filter and wash thoroughly the crucible and solid with hot sodium carbonate solution (7.2.4.2.5). Transfer the filter paper and the filtered solid to a 250 ml beaker and acidify with hydrochloric acid (7.2.4.2.3). Wash the crucible with few millilitres of hydrochloric acid and add the liquid to th
43、e solution. Boil the solution for 5 min and filter into a 600 ml beaker. Carefully wash the filter and the 250 ml beaker with water. BS EN 12912:2012EN 12912:2012 (E) 9 Add to the filtrate a few drops of methyl red indicator solution (7.2.4.2.6) and ammonium hydroxide solution (7.2.4.2.1) until the
44、colour turns to yellow. Acidify the solution with 3 ml of hydrochloric acid (7.2.4.2.3) and dilute to approximately 300 ml. Heat the solution to boiling and add slowly 50 ml of ammonium sulfate solution (7.2.4.2.2) stirring with a glass rod. Cover the beaker with a watch glass and allow to stand for
45、 at least 4 h at a temperature of about 80 C. Then filter on a close-texture ashless filter paper. Wash the precipitate with boiling water until the chlorides disappear from the filtrate (test with silver nitrate solution). Ignite the porcelain crucible (7.2.4.3.3) in the electric furnace at (850 25
46、) C (7.2.4.3.2) for 1 h. Place the crucible in a desiccator, cool to room temperature and weigh to the nearest 0,1 mg and note the mass m0. Place the filter paper with the precipitate in the ignited and weighed porcelain crucible and dry in an oven. Ignite the paper in air, then ignite for 2 h in th
47、e furnace at (850 25) C. Allow to cool in a desiccator and weigh to the nearest 0,1 mg (m2). 7.2.4.5 Expression of results The barium sulfate content, expressed as a percentage mass fraction, is calculated from the following formula: 100102=mmmX (1) where m0is the mass in grams of the empty ignited
48、porcelain crucible; m2is the mass, in grams of the ignited porcelain crucible plus barium sulfate; m1is the mass, in grams of the test portion. 7.2.5 Acid-soluble material The content of acid-soluble material shall be determined in accordance with EN 12902. 8 Labelling, transportation and storage 8.
49、1 Means of delivery Barite shall be delivered in bags (paper or plastics materials), 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 legislation 3)Barite is not listed within Annex VI of Regulation (EC) No 1272/2008 at the date of publication of this European Standard. 3)
