1、BRITISH STANDARD BS ISO 2597-1:2006 Iron ores Determination of total iron content Part 1: Titrimetric method after tin(II) chloride reduction ICS 73.060.10 BS ISO 2597-1:2006 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2006 BSI 200
2、6 ISBN 0 580 48387 8 National foreword This British Standard reproduces verbatim ISO 2597-1:2006 and implements it as the UK national standard. It supersedes BS ISO 2597-1:1994 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee ISE/58, Iron ores, which h
3、as the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the
4、 UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards
5、 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 provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard doe
6、s not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 13 and a back cover. The BSI copyright notice displayed in this document indicates when the document was
7、last issued. Amendments issued since publication Amd. No. Date Comments Reference number ISO 2597-1:2006(E)INTERNATIONAL STANDARD ISO 2597-1 Second edition 2006-05-01 Iron ores Determination of total iron content Part 1: Titrimetric method after tin(II) chloride reduction Minerais de fer Dosage du f
8、er total Partie 1: Mthode titrimtrique aprs rduction au chlorure dtain(II) BS ISO 2597-1:2006ii BS ISO 2597-1:2006 iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Principle. 2 4 Reagents 2 5 Apparatus 3 6 Sampling and samples . 4 6.1 Laboratory sample 4 6.2 Prep
9、aration of test samples. 4 6.2.1 Ores having significant contents of combined water or oxidizable compounds 4 6.2.2 Ores outside the scope of 6.2.1. 4 7 Procedure 4 7.1 Number of determinations . 4 7.2 Test portion . 5 7.3 Determination of hygroscopic moisture content 5 7.4 Blank test and check test
10、. 5 7.5 Determination 5 7.5.1 Decomposition of the test portion 5 7.5.2 Reduction 6 7.5.3 Titration 7 7.5.4 Blank test. 7 8 Expression of results . 7 8.1 Calculation of total iron content 7 8.2 General treatment of results 8 8.2.1 Repeatability and permissible tolerance 8 8.2.2 Determination of anal
11、ytical result . 8 8.2.3 Between-laboratories precision 8 8.2.4 Check for trueness . 9 8.2.5 Calculation of final result . 10 8.3 Oxide factors in percent. 10 9 Test report . 10 Annex A (normative) Flowsheet for the procedure for the acceptance of analytical values for test samples 11 Annex B (inform
12、ative) Derivation of precision statements 12 Annex C (informative) Decontamination of the waste solutions from the analysis 13 BS ISO 2597-1:2006 iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work
13、of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-government
14、al, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The mai
15、n task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Att
16、ention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 2597-1 was prepared by Technical Committee ISO/TC 102, Iron ore and direct reduced iron, Subcommitte
17、e SC 2, Chemical analysis. This second edition cancels and replaces the first edition (ISO 2597-1:1994), which has been editorially revised. ISO 2597 consists of the following parts, under the general title Iron ores Determination of total iron content: Part 1: Titrimetric method after tin(II) chlor
18、ide reduction Part 2: Titrimetric method after titanium(III) chloride reduction Part 3: Calculation method v Introduction This part of ISO 2597 has been updated to correct errors in the presentation of statistical information in the previous edition. This is considered to be an editorial revision. B
19、S ISO 2597-1:2006blank1 Iron ores Determination of total iron content Part 1: Titrimetric method after tin(II) chloride reduction WARNING This part of ISO 2597 may involve hazardous materials, operations and equipment. This part of ISO 2597 does not purport to address all of the safety issues associ
20、ated with its use. It is the responsibility of the user to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use. 1 Scope This part of ISO 2597 specifies a titrimetric method for the determination of the total iron content of iron or
21、es, using potassium dichromate after reduction of the trivalent iron by tin(II) chloride. The method is applicable to total iron contents between 30 % (mass fraction) and 72 % (mass fraction) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. NOTE An equivalent
22、International Standard that does not use mercury(II) chloride is ISO 9507:1990, Iron ores Determination of total iron content Titanium(III) chloride reduction methods. A suggested procedure for removal of mercury from the waste solutions before discharge to effluent drains is given in Annex C. 2 Nor
23、mative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 385, Laboratory glassware B
24、urettes ISO 648, Laboratory glassware One-mark pipettes ISO 1042, Laboratory glassware One-mark volumetric flasks ISO 2596, Iron ores Determination of hygroscopic moisture in analytical samples Gravimetric, Karl Fischer and mass-loss methods ISO 3082, Iron ores Sampling and sample preparation proced
25、ures ISO 3696, Water for analytical laboratory use Specification and test methods ISO 7764, Iron ores Preparation of predried test samples for chemical analysis BS ISO 2597-1:20062 3 Principle The test portion is decomposed by one of the following methods: a) For samples containing not more than 0,0
26、5 % (mass fraction) vanadium, 0,1 % (mass fraction) molybdenum or 0,1 % (mass fraction) copper: treatment with hydrochloric acid, the residue being filtered off and ignited, treatment with hydrofluoric and sulfuric acids to remove silica, and fusion with potassium pyrosulfate. The melt is dissolved
27、in hydrochloric acid, iron is precipitated with ammonia solution, the precipitate is re-dissolved in hydrochloric acid and this solution is added to the main solution. b) For samples containing more than 0,05 % (mass fraction) vanadium: fusion with alkali, the melt being leached with water and filte
28、red, the filtrate being discarded. The residue is dissolved in hydrochloric acid. Trivalent iron in the solution is reduced using tin(II) chloride. Excess reductant is oxidized with mercury(II) chloride. The reduced iron is titrated with potassium dichromate solution, using sodium diphenylaminesulfo
29、nate as the indicator. 4 Reagents During the analysis, use only reagents of recognized analytical grade, and only water that complies with grade 2 of ISO 3696. 4.1 Hydrochloric acid, = 1,16 g/ml to 1,19 g/ml. 4.2 Hydrochloric acid, = 1,16 g/ml to 1,19 g/ml, diluted 1 + 1. 4.3 Hydrochloric acid, = 1,
30、16 g/ml to 1,19 g/ml, diluted 1 + 2. 4.4 Hydrochloric acid, = 1,16 g/ml to 1,19 g/ml, diluted 1 + 10. 4.5 Hydrochloric acid, = 1,16 g/ml to 1,19 g/ml, diluted 1 + 50. 4.6 Sulfuric acid, = 1,84 g/ml. 4.7 Sulfuric acid, = 1,84 g/ml, diluted 1 + 1. 4.8 Hydrofluoric acid, = 1,13 g/ml, 40 % (mass fractio
31、n), or = 1,19 g/ml, 48 % (mass fraction). 4.9 Orthophosphoric acid, = 1,7 g/ml. 4.10 Ammonia solution, = 0,90 g/ml. 4.11 Sodium carbonate (Na 2 CO 3 ), anhydrous powder. Heat for 30 min at 500 C, or confirm that the water content is not more than 1 % (mass fraction) (by heating a test portion for 30
32、 min at 500 C and measuring the loss in mass). 4.12 Sodium peroxide (Na 2 O 2 ), dry powder. Store this reagent in a dry environment and do not use after it has begun to agglomerate. 4.13 Potassium pyrosulfate (K 2 S 2 O 7 ), fine powder. BS ISO 2597-1:20063 4.14 Sulfuric acid-orthophosphoric acid m
33、ixture. Cautiously pour 150 ml of sulfuric acid (4.6) into about 300 ml of water while stirring, cool in a water bath or running water, add 150 ml of orthophosphoric acid (4.9) and dilute to 1 litre with water. 4.15 Sodium hydroxide, 20 g/l solution. 4.16 Tin(II) chloride, 100 g/l solution. Dissolve
34、 100 g of crystalline tin(II) chloride dihydrate (SnCl 2 2H 2 O) in 200 ml of hydrochloric acid (4.1) by heating the solution in a water bath. Cool the solution and dilute to 1 litre with water. Store this solution in a brown glass bottle with the addition of a small quantity of granular or mossy ti
35、n metal. NOTE The tin(II) chloride solution may be prepared in 250 ml lots. 4.17 Mercury(II) chloride (HgCl 2 ), 50 g/l solution. 4.18 Potassium permanganate (KMnO 4 ), 30 g/l solution. 4.19 Iron standard solution, 0,1 mol/l. Weigh, to the nearest 0,002 g, 5,58 g of pure iron minimum purity 99,9 % (
36、mass fraction) into a 500 ml conical flask and place a small filter funnel in the neck. Add 75 ml of hydrochloric acid (4.2) in small increments and heat until the iron has dissolved. Cool and oxidize with 5 ml of hydrogen peroxide 30 % (volume fraction) added in small portions. Heat to boiling and
37、boil to decompose the excess hydrogen peroxide and to remove chlorine. Transfer to a 1 000 ml one-mark volumetric flask, dilute to volume with water and mix. 1,00 ml of this solution is equivalent to 1,00 ml of potassium dichromate standard volumetric solution. 4.20 Potassium dichromate, standard vo
38、lumetric solution, c(K 2 Cr 2 O 7 ) = 0,016 67 mol/l. Pulverize about 6 g of potassium dichromate standard reagent minimum purity 99,9 % (mass fraction) in an agate mortar, dry in an air bath at 140 C to 150 C for 2 h, and cool to room temperature in a desiccator. Dissolve 4,904 g of this dried and
39、pulverized potassium dichromate in water and dilute the solution to exactly 1 000 ml. Record, on the stock bottle, the temperature at which this dilution was made (t 1 ). 4.21 Sodium diphenylaminesulfonate, solution. Dissolve 0,2 g of powdered sodium diphenylaminesulfonate (C 6 H 5 NHC 6 H 4 SO 3 Na
40、) in a small volume of water and dilute to 100 ml. Store this solution in a brown glass bottle. 5 Apparatus Ordinary laboratory apparatus, including burettes, one-mark pipettes and one-mark volumetric flasks complying with the specifications of ISO 385, ISO 648 or ISO 1042, respectively (unless othe
41、rwise indicated), and the following. 5.1 Zirconium, vitreous carbon or alkali-resistant sintered alumina crucibles, of capacity 25 ml to 30 ml. BS ISO 2597-1:20064 5.2 Platinum crucibles, of capacity 25 ml to 30 ml. 5.3 Porcelain crucibles, of capacity 25 ml to 30 ml. 5.4 Weighing spatula, of non-ma
42、gnetic material or demagnetized stainless steel. 5.5 Muffle furnace, capable of being maintained at between 500 C 10 C and 800 C 10 C. 6 Sampling and samples 6.1 Laboratory sample For the analysis, use a laboratory sample of minus 100 m particle size which has been taken and prepared in accordance w
43、ith ISO 3082. In the case of ores having significant contents of combined water or oxidizable compounds, use a particle size of minus 160 m. NOTE A guideline on significant contents of combined water and oxidizable compounds is incorporated in ISO 7764. If the determination of total iron relates to
44、a reducibility test, prepare the laboratory sample by crushing and pulverizing, to less than 100 m particle size, the whole of one of the reducibility test portions which has been reserved for chemical analysis. In the case of ores having significant contents of combined water or oxidizable compound
45、s, use a particle size of minus 160 m. 6.2 Preparation of test samples Depending on the ore type, proceed in accordance with either 6.2.1 or 6.2.2. 6.2.1 Ores having significant contents of combined water or oxidizable compounds Prepare an air-equilibrated test sample, in accordance with ISO 2596, w
46、ith the following types of ores: a) natural or processed ores in which the content of combined water is higher than 2,5 % (mass fraction); b) processed ores containing metallic iron; c) natural or processed ores in which the sulfur content is higher than 0,2 % (mass fraction). 6.2.2 Ores outside the
47、 scope of 6.2.1 Prepare a predried test sample as follows. Thoroughly mix the laboratory sample and, taking multiple increments, extract a test sample in such a way that it is representative of the whole contents of the container. Dry the test sample at 105 C 2 C, as specified in ISO 7764. (This is
48、the predried test sample.) 7 Procedure 7.1 Number of determinations Carry out the analysis at least in duplicate in accordance with Annex A, independently, on one test sample (6.2). NOTE The expression “independently” means that the second and any subsequent result is not affected by the previous re
49、sult(s). For this particular analytical method, this condition implies that the repetition of the procedure is carried out either by the same operator at a different time, or by a different operator, including appropriate recalibration in either case. BS ISO 2597-1:20065 7.2 Test portion Taking several increments, weigh, to the nearest 0,000 2 g, approximately 0,4 g of the test sample (6.2) usi
