BS-EN-ISO-10058-1996.pdf
BRITISH STANDARD BS EN ISO 10058:1996 Magnesites and dolomites Chemical analysis The European Standard EN ISO 10058:1996 has the status of a British Standard ICS 73.080; 81.080 UDC 666.762.3 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 10058:1996 This British Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 May 1996 © BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference RPI/14 Draft for comment 90/43441 DC ISBN 0 580 25723 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee RPI/14, Chemical analysis of refractories and technical ceramics, upon which the following bodies were represented: British Ceramic Research Ltd. British Gas plc British Industrial Ceramic Manufacturers Association British Iron and Steel Producers Association Bureau of Analysed Samples Limited China Clay Association Ministry of Defence Refractories Association of Great Britain Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 10058:1996 © BSI 12-1999i Contents Page Committees responsibleInside front cover National forewordii Foreword2 1Scope3 2Dissolution and determination of silica3 3Determination of alumina6 4Determination of total iron calculated as iron(III) oxide8 5Determination of titanium(IV) oxide8 6Determination of manganese(IV) oxide10 7Determination of chromium(III) oxide11 8Determination of calcium oxide13 9Determination of magnesium oxide15 10Determination of potassium, sodium and lithium oxides16 11Determination of the loss on ignition17 12Test report18 Annex A (normative) Determination of boron content of magnesites19 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 10058:1996 ii © BSI 12-1999 National foreword This British Standard has been prepared by Technical Committee RPI/14 and is the English language version of EN ISO 10058:1996 Magnesites and dolomites Chemical analysis published by the European Committee for Standardization (CEN). It is identical with ISO 10058:1992 Magnesites and dolomites Chemical analysis published by the International Organization for Standardization (ISO). It supersedes BS 1902-2.3:1970 which is withdrawn. EN ISO 10058:1996 was produced as a result of international discussions in which the United Kingdom took an active part. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, pages 2 to 21 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 10058 January 1996 ICS 73.080 Descriptors: Refractory materials, raw materials, dolomite (mineral), chemical analysis, determination of content, losses on ignition English version Magnesites and dolomites Chemical analysis (ISO 10058:1992) Produits de magnésie et de dolomie Analyse chimique (ISO 10058:1992) Magnesit und Dolomit Chemische Analyse (ISO 10058:1992) This European Standard was approved by CEN on 1995-12-08. 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 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 translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1996 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members. Ref. No. EN ISO 10058:1996 E Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 10058:1996 © BSI 12-1999 2 Foreword The text of the International Standard from ISO/TC 33, Refractories, of the International Organization for Standardization (ISO) has been taken over as a European Standard by the Technical Committee CEN/TC 187, Refractory products and materials. 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 July 1996, and conflicting national standards shall be withdrawn at the latest by July 1996. According to CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 10058:1996 © BSI 12-19993 1 Scope This International Standard specifies methods for the determination of silica, alumina, titania, iron oxide and oxides of manganese, chromium, calcium, magnesium, sodium, potassium and lithium. It also specifies methods for determining the loss on ignition of magnesite and dolomite, and of refractories based on these raw materials. Annex A describes a method for the determination of the boron content of magnesites only. NOTE 1Physical methods are used increasingly for chemical analysis. At present, it is not possible to describe a standardized test method, because the type of apparatus used is important. 2 Dissolution and determination of silica 2.1 Principle Decompose the sample with hydrochloric acid and separate the silica by coagulation with a polyethylene oxide solution. Filter, wash the residue, heat and weigh it, and submit it to a treatment with hydrofluoric and sulfuric acids. After this treatment, weigh the remaining residue again and fuse it in sodium carbonate and boric acid. It is then dissolved in the filtrate from the silica, and the solution is diluted to a standard volume to obtain the stock solution (A) of the sample. In an aliquot, the small quantity of silica not separated by coagulation is subsequently determined by a spectrophotometric method based on the formation of molybdenum blue, using alternatively iron(II) sulfate or tin(II) chloride as a reducing agent. The absorbance maximum of the reduced silicomolybdate complex lies at a wavelength of 810 nm. 2.2 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 2.2.1 Sodium carbonate, anhydrous. 2.2.2 Boric acid, powdered. 2.2.3 Polyethylene oxide solution, 2,5 g/l. Add 0,5 g of polyethylene oxide to 200 ml of water while stirring slowly, preferably with a mechanical stirrer, until dissolved. Discard after 2 weeks. 2.2.4 Accelerator granules, ashless, of mass about 1 g. 2.2.5 Hydrochloric acid, concentrated, Ô = 1,19 g/ml. 2.2.6 Hydrochloric acid, diluted 1 + 19. Add 1 volume of hydrochloric acid (2.2.5) to 19 volumes of water. 2.2.7 Sulfuric acid, concentrated, Ô = 1,84 g/ml. 2.2.8 Hydrofluoric acid, 40 % (m/m). 2.3 Apparatus Usual laboratory apparatus and the following. 2.3.1 Sand bath or hot plate. 2.3.2 Muffle furnace, capable of being controlled at 1 180 °C to 1 200 °C. 2.3.3 Platinum crucible 2.4 Procedure Weigh into a 250 ml beaker, 5,000 g1) of finely ground analytical sample dried at 110 °C. Add 25 ml of water and 40 ml of concentrated hydrochloric acid (2.2.5) and cover with a watch-glass. Transfer to a sand bath or a hot-plate (2.3.1) and boil for 30 min. Allow the beaker and contents to cool, rinse the watch-glass with water, add the accelerator granules (2.2.4) and stir to break up the pulp. Then add, stirring all the time, 5 ml of polyethylene oxide solution (2.2.3) and allow to stand for 5 min. Filter the solution through a closed-pore paper filter suitable for separating very fine precipitates. Transfer the residue (containing the precipitate of silica) quantitatively with hot diluted hydrochloric acid (2.2.6) to the filter paper. Wash the precipitate six times with hot diluted hydrochloric acid (2.2.6) and then with hot water until free from chlorides (up to a volume of about 400 ml). Store the filtrate. Transfer the filter paper and precipitate to a heated and weighed platinum crucible (2.2.3). Heat at a low temperature until the precipitate is free from carbonaceous matter, then heat it in the muffle furnace (2.3.2) controlled at 1 180 °C to 1 200 °C to constant mass (m1), a time of 15 min normally being sufficient. Moisten the residue in the cold crucible with water, add 5 drops of concentrated sulfuric acid (2.2.7) and 10 ml of hydrofluoric acid (2.2.8). Evaporate to dryness in the sand bath or on the hot-plate in a fume cupboard. 1) In the case of natural iron and silica-rich magnesite, the sample mass may optionally be reduced to 2,000 g. The aliquots to be taken for the determination are to be changed accordingly. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 10058:1996 4 © BSI 12-1999 Heat the crucible and the residue, cautiously at first over a Bunsen burner, and finally for 5 min between 1 180 °C and 1 200 °C in the muffle furnace. Allow to cool in a desiccator and weigh (mass m2). If the residue weighs more than 30 mg, repeat the treatment with hydrofluoric and sulfuric acids to ensure that all the silica is removed. The difference between the two masses (m1 m2) represents the “gravimetric” silica. Fuse the residue from the hydrofluoric and sulfuric acid treatment with 2 g of the anhydrous powdered sodium carbonate (2.2.1) and 0,7 g of powdered boric acid (2.2.2). Allow the melt to cool and dissolve in the filtrate from the main silica. Cool, transfer the solution to a 500 ml one-mark volumetric flask, dilute to volume with water and mix. This solution will become stock solution A of the sample for the spectrophotometric determination of the residual silica in accordance with 2.5.1 or 2.5.2 and for the determination of alumina (clause 3), iron(III) oxide (clause 4), titanium(IV) oxide (clause 5), manganese(IV) oxide (clause 6), chromium(III) oxide (clause 7), calcium oxide (clause 8) and magnesium oxide (clause 9). 2.5 Spectrophotometric determination of residual silica in filtrate 2.5.1 Reduction to molybdenum blue complex with iron(II) sulfate 2.5.1.1 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. 2.5.1.1.1 Ammonium hydroxide solution, Ô = 0,9 g/ml. Although the method allows for the presence of silica in the ammonium hydroxide solution, the reagent should contain as little silica as possible. It should be noted that ammonium hydroxide solution stored in glass bottles will dissolve silica from the glass. 2.5.1.1.2 Ammonium iron(III) sulfate solution Dissolve 100 g of ammonium iron(III) sulfate dodecahydrate NH4Fe(SO4)2·12H2O in water, add 300 ml of concentrated hydrochloric acid (2.2.5) and dilute to 1 litre with water. 2.5.1.1.3 Ammonium molybdate solution Dissolve 80 g of hexammonium heptamolybdate tetrahydrate (NH4)6Mo7O24·4H2O in water, filter if necessary, dilute to 1 litre and mix. Store in a polyethylene bottle. Renew the solution after 4 weeks, or earlier if any appreciable deposit is observed. 2.5.1.1.4 Oxalic acid solution Dissolve 100 g of oxalic acid dihydrate (C2H2O4·2H2O) with water and dilute to 1 litre. 2.5.1.1.5 Iron(II) sulfate solution Dissolve 10 g of iron(II) sulfate heptahydrate (FeSO4·7H2O) in water, add 4 drops of diluted sulfuric acid (1 + 1) and dilute to 100 ml with water. Prepare this solution freshly before use. 2.5.1.1.6 Silica stock solution, containing 0,5 g of SiO2 per litre. Ignite a sample of high purity silica to 1 000 °C and cool. Then weigh 0,250 g of this sample in a platinum crucible with 5 g of anhydrous sodium carbonate. Dissolve the melt in a polyethylene vessel in 300 ml of water while adding 20 g of sodium hydroxide. Cool the solution to 20 °C, transfer to a 500 ml one-mark volumetric flask and make up to the mark with water. Stir thoroughly and transfer to a polyethylene flask for storage. This solution will remain stable for 6 months. 1 ml of this standard solution contains 0,5 mg of SiO2. 2.5.1.1.7 Silica standard solution, containing 0,02 g of SiO2 per litre. Dilute 20 ml of the silica stock solution (2.5.1.1.6) to 500 ml with water in a one-mark volumetric flask. Prepare this solution daily if required. 1 ml of this standard solution contains 0,02 mg of SiO2. 2.5.1.1.8 Phenolphthalein solution Dissolve 100 g of phenolphthalein in ethanol and dilute to 100 ml. 2.5.1.2 Apparatus Usual laboratory apparatus and a spectrophotometer, fitted with cells of an appropriate size. 2.5.1.3 Procedure 2.5.1.3.1 Pipette two 5 ml aliquots of the stock solution A, prepared as in 2.4, into two 100 ml one-mark volumetric flasks. Add one drop of phenolphthalein solution (2.5.1.1.8) to each flask, and while continually shaking, add ammonium hydroxide solution (2.5.1.1.1) one drop at a time. As soon as the alkaline reaction produces a red colour, immediately add 5 ml of ammonium iron(III) sulfate solution (2.5.1.1.2). To the first of the two solutions, add 5 ml of ammonium molybdate solution (2.5.1.1.3) and leave to stand for 20 min. NOTE 2Cloudiness may occur but it does not cause any interference and disappears after the addition of oxalic acid. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:33:31 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 10058:1996 © BSI 12-19995 Add 20 ml of oxalic acid solution (2.5.1.1.4) and shake the solution unt
