1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 5072:2013Brown coals and lignites Determination of true relativedensity and apparent relativedensityBS ISO 5072:2013 BRITISH STANDARDNational forewordThis British Standard
2、 is the UK implementation of ISO 5072:2013.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/16, Solid mineral fuels.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the nec
3、essaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 81216 3ICS 73.040Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was pu
4、blished under the authority of theStandards Policy and Strategy Committee on 31 May 2013.Amendments issued since publicationDate Text affectedBS ISO 5072:2013 ISO 2013Brown coals and lignites Determination of true relative density and apparent relative densityCharbons bruns et lignites Dtermination
5、de la densit relative vraie et de la densit relative apparenteINTERNATIONAL STANDARDISO5072Second edition2013-05-01Reference numberISO 5072:2013(E)BS ISO 5072:2013ISO 5072:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no p
6、art of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member
7、body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 5072:2013ISO 5072:2013(E) ISO 2013 All rights reserved iiiContents PageForeword iv1 Scope . 12 Nor
8、mative references 13 Terms and definitions . 14 Determination of the true relative density by the water method . 14.1 Principle 14.2 Reagents 14.3 Apparatus 24.4 Sample 24.5 Procedure 24.6 Calculation of results . 34.7 Precision of the method 34.8 Test report . 45 Determination of the apparent relat
9、ive density 45.1 Principle 45.2 Reagents 45.3 Apparatus 45.4 Sample 45.5 Procedure 55.6 Calculation of results . 65.7 Precision of the method 65.8 Test report . 6BS ISO 5072:2013ISO 5072:2013(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national sta
10、ndards 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 or
11、ganizations, 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.International Standards are drafted in accordance with the rules given
12、 in the ISO/IEC Directives, Part 2.The main 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
13、% of the member bodies casting a vote.Attention 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 5072 was prepared by Technical Committee ISO/TC 27, Solid mi
14、neral fuels, Subcommittee SC 5, Methods of analysis.This second edition cancels and replaces the first edition (ISO 5072:1997), of which this constitutes a minor revision.iv ISO 2013 All rights reservedBS ISO 5072:2013INTERNATIONAL STANDARD ISO 5072:2013(E)Brown coals and lignites Determination of t
15、rue relative density and apparent relative density1 ScopeThis International Standard describes methods for the determination of true relative density and the apparent relative density of brown coals and lignites.2 Normative referencesThe following referenced documents are indispensable for the appli
16、cation 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 5068-2, Brown coals and lignites Determination of moisture Part 2: Indirect gravimetric method for moisture in t
17、he analysis sampleISO 5069-2, Brown coals and lignites Principles of sampling Part 2: Sample preparation for determination of moisture content and for general analysis3 Terms and definitions3.1true relative densityratio of the mass of a sample of dry coal ground to pass through a 212 m sieve to the
18、mass of an equal volume of water at a specified temperature3.2apparent relative densityratio of the mass of a dry coal to the mass of a volume of water equal to the apparent volume of the coal at a specified temperature4 Determination of the true relative density by the water method4.1 PrincipleThe
19、true relative density is determined pycnometrically by water displacement, with the inclusion of a wetting agent to ensure dispersion of the solid in the displacement medium.NOTE The use of other displacement media such as methanol is not recommended because of possible swelling of some brown coals
20、and lignites in such liquids.4.2 Reagents4.2.1 Distilled or deionized water, freshly boiled.4.2.2 Wetting agent, 5 % (volume fraction) solution of detergent (such as sodium dodecyl sulfate) is suitable.4.2.3 Potassium dichromate-sulfuric acid mixture, for cleaning pycnometers. ISO 2013 All rights re
21、served 1BS ISO 5072:2013ISO 5072:2013(E)4.3 Apparatus4.3.1 Analytical balance, sensitive to 0,1 mg.4.3.2 Camel hair brush, of such a diameter that bristles can pass completely through the stem of the funnel (4.3.4).4.3.3 Filter paper, for drying the necks of the pycnometers.4.3.4 Funnel, with a stem
22、 of sufficient length to reach the middle of the pycnometer flask.4.3.5 Glass cloth, fibre free for polishing the pycnometers prior to weighing.4.3.6 Glass syringe, with a needle to bring the pycnometer liquid to the mark of the pycnometer.4.3.7 Earthing point, to remove static charge from pycnomete
23、rs.4.3.8 Mercury thermometer, capable of measuring the temperature in the range of 20 C to 30 C with a minimum scale spacing of 0,1 C.4.3.9 Pycnometers, of capacity 50 ml, with capillary-bored ground stoppers, internal diameter of the neck no greater than 5 mm.4.3.10 Vacuum desiccator, with protecti
24、ve cage.NOTE The use of a vacuum desiccator is preferable for the purpose of degassing samples.4.3.11 Vacuum pump, capable of attaining a vacuum of residual pressure from 0 kPa to 5 kPa.4.3.12 Water bath, thermostatically controlled, the temperature of which shall be maintained at 25 C 0,1 C as meas
25、ured by a thermometer (4.3.8) permanently placed in the water bath.4.3.13 Weighing boat, with a capacity of not less than 2 g.4.4 SampleThe sample for the determination of true relative density shall be the general analysis sample (ground to pass through a 212 m sieve) prepared in accordance with IS
26、O 5069-2.4.5 Procedure4.5.1 Calibration of the mass of the pycnometer(s)Pipette 10 ml of wetting agent (4.2.2) into the pycnometer(s) (4.3.9). Pipette 10 ml of water (4.2.1) into the pycnometer(s). Swirl to mix the solution. Place the pycnometer(s) in the vacuum desiccator (4.3.10) and evacuate to 0
27、 Pa to 500 Pa for 15 min. Release the vacuum and fill the pycnometer(s) with water (4.2.1) using a glass syringe (4.3.6) to 3 mm from the top of the neck.Place the pycnometer(s) in a water bath (4.3.12) thermostatically controlled at 25 C 0,1 C. Allow to equilibrate for at least 1 h 45 min. Top up t
28、he pycnometer(s) to the meniscus using a glass syringe without removing them from the water bath. Leave the pycnometer(s) in the water bath for a further 5 min.Remove the pycnometer(s) from the water bath and insert the capillary-bored stopper(s) such that no air is trapped in the pycnometer(s). Wip
29、e the outside of the pycnometer(s) gently using filter paper (4.3.3) to 2 ISO 2013 All rights reservedBS ISO 5072:2013ISO 5072:2013(E)remove excess water. Polish the pycnometer(s) using fibre-free glass cloth (4.3.5) to remove any visible film. Touch the pycnometer(s) to the earthing point (4.3.7).
30、Weigh the pycnometer(s) and record the mass(es) to the nearest 0,1 mg.The mean of three replicate determinations of the mass of each pycnometer which fall within the range of 1 mg is taken as the calibration mass of the pycnometer.4.5.2 Determination of true relative densityWeigh 2 g 0,1 g of sample
31、, to the nearest 0,1 mg, into a weighing boat (4.3.13). Transfer the sample to a pycnometer using a funnel (4.3.4) and a camel hair brush (4.3.2). Ensure that no material is lost during the transfer.Pipette 10 ml of wetting agent (4.2.2) into the pycnometer allowing the wetting agent to run down the
32、 inner surface of the pycnometer. Pipette 10 ml of water (4.2.1) into the pycnometer, allowing the water to run down the inner surface of the pycnometer. Swirl gently to wet the sample with the minimum production of bubbles. Place the pycnometer in the vacuum desiccator and evacuate to 0 Pa to 500 P
33、a for 15 min. To ensure that no sample containing froth is expelled from the pycnometer, regulate the vacuum supply to remove any froth produced below the neck of the pycnometer. Release the vacuum and fill the pycnometer with water (4.2.1) to 3 mm from the top of the neck using a glass syringe.Plac
34、e the pycnometer in a water bath thermostatically controlled at 25 C 0,1 C. Allow to equilibrate for at least 1 h 45 min. Top up the pycnometer to the meniscus using a glass syringe, without removing from the water bath. Leave the pycnometer in the water bath for a further 5 min.Remove the pycnomete
35、r from the water bath and insert the capillary bored stopper such that no air is trapped in the pycnometer. Wipe the outside of the pycnometer gently using filter paper to remove excess water. Polish the pycnometer using fibre-free glass cloth to remove any visible film. Touch the pycnometer to the
36、earthing point. Weigh the pycnometer and record the mass to the nearest 0,1 mg.Determine the moisture content, M, on a separate test portion of the sample (4.4) in accordance with ISO 5068-2.4.6 Calculation of resultsCalculate the true relative density of the dry coal, TRDd, according to the formula
37、:TRDmMmM mmdadad= +()()()100100 10012wherem is the mass, in grams, of the analysis sample;m1is the mass, in grams, of the pycnometer and water;m2is the mass, in grams, of the pycnometer, sample and water;Madis the moisture, as a percentage by mass, of the analysis sample.4.7 Precision of the method4
38、.7.1 Repeatability limitThe results of duplicate determinations, carried out in the same laboratory by the same operator using the same apparatus on the same sample within short intervals of time, shall not differ by more than the value given in Table 1. ISO 2013 All rights reserved 3BS ISO 5072:201
39、3ISO 5072:2013(E)4.7.2 Reproducibility limitThe means of the results of duplicate determinations, carried out in each of two laboratories on representative test portions taken from the same sample, shall not differ by more than the value given in Table 1.Table 1 Precision of the methodRepeatability
40、Reproducibility0,02 0,044.8 Test reportThe test report shall contain the following information:a) an identification of the sample;b) a reference to this International Standard including year of publication;c) the result and the method of expression used;d) any unusual features noted during the deter
41、mination.5 Determination of the apparent relative density5.1 PrincipleThe apparent relative density is determined by weighing a sample suspended in water, allowing the sample to drain to remove surface liquid and then reweighing the sample in air.5.2 Reagents5.2.1 Water, distilled or deionized.5.3 A
42、pparatus5.3.1 Beam balance, sensitive to 10 mg, modified as in Figure 1.5.3.2 Evaporating dishes, 160 mm diameter, 60 mm deep.5.3.3 Paper towels or filter papers.5.3.4 Top pan balance, capacity of 1 kg, sensitive to 10 mg.5.3.5 Vacuum pump, capable of attaining 250 Pa pressure.5.3.6 Vacuum desiccato
43、r, 200 mm diameter.5.4 SampleThe determination of apparent relative density shall be carried out on an air-dried sample of particle size 10 mm to 30 mm.4 ISO 2013 All rights reservedBS ISO 5072:2013ISO 5072:2013(E)5.5 ProcedureSet up the beam balance (5.3.1) as shown in Figure 1, with a minimum of 5
44、0 mm of water (5.2.1) covering the gauge basket. Tare the beam balance so that at the balance point approximately 5 g is added to the weight pan. Record the tare mass.NOTE Check the beam balance tare at least once every 5 to 10 determinations.Dimensions in millimetresKey1 tare weight, approximately
45、5 g2 copper wire3 beaker, 800 ml4 gauze basket (phosphor-bronze 12 mm aperture)Figure 1 Modified beam balanceWeigh from 30 g to 35 g of sample (5.4) into an evaporating dish (5.3.2). Add water (5.2.1) to the dish to completely immerse the sample. Place the evaporating dish plus sample in a vacuum de
46、siccator (5.3.6). Evacuate the desiccator to 0 Pa to 250 Pa for 5 min. Release the vacuum and allow to stand for a further 5 min.Transfer the sample to a pad of paper towels (5.3.3), using the paper towels to remove excess water. Immediately place the sample in the gauze basket of the beam balance e
47、nsuring that the sample is totally covered with water. Allow the balance to attain equilibrium and record the mass of the sample in water to the nearest 10 mg. ISO 2013 All rights reserved 5BS ISO 5072:2013ISO 5072:2013(E)Transfer the sample from the gauze basket to a pad of paper towels, using the
48、paper towels to remove any visible surface moisture. Immediately transfer the sample to a top pan balance (5.3.4) and record its mass in air to the nearest 10 mg.NOTE Do not allow excessive drying when transferring the sample.5.6 Calculation of resultsCalculate the apparent relative density of the d
49、ry coal, ARDd, according to the formula:ARDmMmm mdt=+()10010012wherem is the mass, in grams, of the sample in air;m1is the mass, in grams, of the sample suspended in water;m2is the mass, in grams, of the tare weight;Mtis the total moisture, as a percentage by mass, determined on the sample after density determination.5.7 Precision of the method5.7.1 Repeatability limitThe results of duplicate determinations, carried out in the same laboratory by the same operator using the same apparatus on the same sample w
