BS-ISO-3087-1998.pdf

BRITISH STANDARD BS ISO 3087:1998 Iron ores Determination of the moisture content of a lot ICS 73.060.10 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 3087:1998 This British Standard, having been prepared under the direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 March 1999 © BSI 05-1999 ISBN 0 580 30979 7 National foreword This British Standard reproduces verbatim ISO 3087:1998 and implements it as the UK national standard. It supersedes BS 5663-1:1987 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee ISE/58, Iron ores, which has 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 the UK interests informed; monitor related international and European developments and promulgate them in the 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 or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. 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 ISO title page, pages ii to iv, pages 1 to 10 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. Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 3087:1998 © BSI 05-1999i Contents Page National forewordInside front cover Forewordiii Text of ISO 30871 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 3087:1998 ii © BSI 05-1999 Contents Page Forewordiii Introduction1 1Scope1 2Normative references1 3Definitions1 4Principle1 5Apparatus1 6Samples1 7Procedure1 8Verification2 9Calculation and expression of results2 10Test report3 Annex A (normative) Determination of moisture content of adhesive or wet iron ores4 Annex B (normative) Corrections for sprinkled water and/or rain-water4 Annex C (informative) Precision of moisture measurement7 Annex D (informative) Examples of test reports7 Table 1 Minimum mass of test portion1 Table 2 Number of test portions2 Table 3 Repeatability limit of moisture determination on the gross sample3 Table C.1 Precision of moisture measurement7 Table D.1 Example of a test report for values of moisture measurement on a test portion7 Table D.2 Example of recording and calculating procedure for determination of moisture content of a lot from partial samples (mass basis sampling)8 Table D.3 Example of recording and calculating procedure for determination of moisture content of a lot from partial samples (time basis sampling)9 Table D.4 Example of test report for determination of moisture content of a lot on four test portions taken from the gross sample10 Descriptors: Minerals and ores, iron ores, tests, determination of content, water, moisture content. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 3087:1998 © BSI 05-1999iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work 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-governmental, 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. 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. International Standard ISO 3087 was prepared by Technical Committee ISO/TC 102, Iron ores, Subcommittee 1, Sampling This third edition cancels and replaces the second edition (ISO 3087:1987) which has been technically revised. Annex A and Annex B form an integral part of this of this International Standard, Annex C and Annex D are for information only. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 3087:1998 © BSI 05-19991 Introduction Currenly, large tonnages of iron ore are traded internationally and a small error in the measured moisture content (percentage by mass) of a lot has a considerable effect on the commercial transaction. The correct determination of moisture content of a lot is, therefore, a matter of importance for both the purchaser and the vendor. This International Standard does not address the determination of the hygroscopic moisture content of a test sample for chemical analysis. If the hygroscopic moisture content is required to be determined, reference should be made to ISO 2596:1994, Iron ores Determination of hygroscopic moisture in analytical samples Gravimetric and Karl Fischer methods. 1 Scope This International Standard specifies a method for the determination of the moisture content of a lot of iron ore. This method is applicable to all iron ores, whether natural or processed. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 3082:, Iron ores Sampling and sample preparation procedures1). ISO 11323:1996, Iron ores Vocabulary. 3 Definitions For the purposes of this International Standard, the definitions given in ISO 11323 apply. 4 Principle Drying of the test portion in air at 105 °C to constant mass and measurement of the loss in mass. Calculation of the moisture content. 5 Apparatus 5.1 Drying pan, having a smooth surface, free from contamination and capable of accommodating the specified quantity of a test portion in a layer of nominal thickness not greater than 31,5 mm. 5.2 Drying oven, equipped with a temperature indicator and control apparatus capable of regulating the temperature at any point in the oven at 105 °C ± 5 °C and so designed as to maintain this temperature with a current of air to ensure efficient drying but without any loss of sample, and fitted with a fan that allows for both the circulation and change of air. 5.3 Weighing device, accurate to at least 0,05 % of the initial mass of a test portion. The capacity of the weighing device shall be enough for the initial mass of the test portion. 6 Samples Test samples which have been taken and prepared in accordance with ISO 3082 shall be used. The mass of a test portion, in relation to its nominal top size, is specified in Table 1, in accordance with ISO 3082. Table 1 Minimum mass of test portion 7 Procedure 7.1 Number of moisture measurements Carry out one moisture measurement per test portion on the number of test portions specified in Table 2, according to the conditions of preparation of the test sample. In order to minimize losses of moisture to the atmosphere, it is necessary to perform all the initial weighings of the test portions as quickly as possible after obtaining those test portions. 7.2 Measurement Spread the test portion in a layer of nominal thickness not greater than 31,5 mm in the tared drying pan (5.1) and determine the total mass immediately. Record the total mass, the mass of the drying pan, the initial mass of the test portion (m1) and the numerical value of 0,05 % of the initial mass of the test portion. 1) To be published. (Revision of ISO 3081:1986, ISO 3082:1987 and ISO 3083:1986) Nominal top size of test portion (mm) Minimum mass of test portion (kg) 31,510 22,45 10,01 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 3087:1998 2 © BSI 05-1999 Table 2 Number of test portions Place the drying pan with the test portion in the drying oven (5.2) set at 105 °C, and maintain this temperature for not less than 4 h. Remove the drying pan with the test portion from the drying oven and weigh it immediately while still hot in order to minimize any reabsorption of moisture. Alternatively, weigh the test portion after cooling in air in a container having a close-fitting airtight lid. In each case, report the method of weighing. Place once more, the drying pan with the test portion in the drying oven, heat for a further 1 h, and then repeat the weighing. Repeat the procedure in the previous paragraph until the difference in mass between subsequent measurements becomes 0,05 % or less of the initial mass of the test portion. NOTE 1The weighing device should be protected from the influence of heat. NOTE 2Drying times will be dependent on the type of ore under test. For a series of measurements carried out on a particular type of ore, the drying time of the test portion may be specified by check experiments carried out beforehand. NOTE 3For convenience, the test portion of mass 10 kg for ore of particle size less than 31,5 mm may be divided into two portions, each of which is subjected to moisture measurement. In calculating the results, the mean of the two values of initial mass and the mean of the two values of the drying loss in mass should be used. 8 Verification Regular checking of apparatus and procedures is essential to verify the test results. Checks shall be carried out prior to the commencement of a routine test in accordance with this International Standard and at regular intervals thereafter. The frequency of checking is a matter for each laboratory to determine. A detailed record of all verification activities shall be maintained for the following items: a) Sprinkled water measurement volumenometer; b) Rainfall measurement rain gauge; c) Moisture test oven temperature/temperature regulation; circulation and change of air in oven; weighing device. 9 Calculation and expression of results 9.1 Test portion The result of the determination of the moisture content, wi, expressed as a percentage by mass, for each test portion, is given by equation (1) and reported to the second decimal place. where 9.2 Lot The moisture content of a lot is given by one of equations (2) to (5) as the occasion may demand, and reported to the first decimal place. 9.2.1 When moisture determination is conducted on the gross sample from the lot, the moisture of the lot is determined as follows. When the range of the four test results does not exceed 1,3r as shown in Table 3, the arithmetic mean, , of the four results shall be the moisture content, expressed as a percentage by mass, of the lot as given by equation (2). where w1, w2, w3 and w4 are the results of the determinations of the moisture contents, expressed as percentages by mass, on each of the four test portions. When the range of the four test results exceeds 1,3r given in Table 3, the median shall be taken as the moisture content of the lot. The median of four test results is defined as the mean of the two non-extreme test results. Preparation of test sampleNumber of partial samples per lotNumber of test portions to be tested From gross sample4 24 From partial sample3 to 72 minimum $ 81 minimum From increment1 minimum (1) m1is the initial mass, in grams, of the test portion; m2is the mass, in grams, of the test portion after drying. (2) w Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 27 06:04:30 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 3087:1998 © BSI 05-19993 Table 3 Repeatability limit of moisture determination on the gross sample 9.2.2 When mass basis sampling has been performed and moisture determination is conducted on each partial sample, the weighted mean, of the results from all the partial samples, considering the number of increments for each partial sample, shall be the moisture content, expressed as a percentage by mass, of the lot, as given by equation (3), where If it is impracticable to sample the lot as a whole or desirable to sample a lot in separate parts of unequal mass as in the case of time basis sampling, the moisture content of each part shall be determined independently and the weighted mean, of the results, expressed as a percentage by mass, of the lot calculated from the individual results using equation (4). where 9.2.3 When moisture determination is conducted on each increment, the arithmetic mean, of the results for all increments obtained according to 9.1 shall be the moisture content, expressed as a percentage by mass, of the lot as given by equation (5) where 10 Test report The test report shall contain the following information. a) reference to this International Standard, i.e., ISO 3087; b) details necessary for the identification of the sample; c) result of the test; d) reference number of the result; e) any characteristics noticed during the determination, and any operation not specified in this International Standard which may have had an influence on the results. Average of moisture content Repeatability limit r 1,3r %(m/m) (%)(%) # 3 0,200,26 3 # 6 0,250,33 6 0,310,40 (3) kis the number of partial samples; Niis the number of increments in the ith partial sample; wiis the result of the determination of the moisture content, expressed as a percentage by mass, of the ith partial sample, according to Table 2 using as the number of test portions either 4 or 2. (4) kis the number