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1、BRITISH STANDARD BS 1902-3.16: 1990 Methods of testing Refractory materials Part 3: General and textural properties Section 3.16 Determination of pore size distribution (method 1902-316) Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 190
2、2-3.16:1990 This British Standard, having been prepared under the direction of the Refractory Products Standards Policy Committee, was published under the authority of the Board of BSI and comes into effect on 30 November 1990 BSI 08-1999 The following BSI references relate to the work on this stand
3、ard: Committee reference RPM/1 Draft for comment 88/44009 DC ISBN 0 580 18364 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Refractory Products Standards Policy Committee (RPM/-) to Technical Committee RPM/1, upon which the following
4、 bodies were represented: British Ceramic Research Ltd. British Steel Industry Electricity Supply Industry in England and Wales Engineering Equipment and Materials Users Association Refractories Association of Great Britain Refractory Contractors Association Society of Glass Technology Amendments is
5、sued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1902-3.16:1990 BSI 08-1999i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Designation1 3Definitions1 4Principle1 5App
6、aratus2 6Test samples2 7Procedure3 8Calculation of results6 9Test report7 Figure 1 General arrangements of coarse and fine pore measuring devices illustrating two methods of detecting the mercury level in the capillary4 Figure 2 Schematic arrangement of sample holder5 Table 1 Examples of ways of pre
7、senting results6 Table 2 Density of mercury7 Publications referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1902-3.16:1990 ii BSI 08-1999 Foreword This Section of BS 1902-3 has been prepared under the direction
8、of the Refractory Products Standards Policy Committee. The method is based on measurement of pore size distribution by mercury intrusion. As very high pressures are used in the determination and small volumes of mercury are measured, it is more convenient to use a commercially available apparatus th
9、an to construct one to comply with this method. The manufacturers operating manuals give details of how their apparatus is to be used. 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.
10、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, pages 1 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and ma
11、y have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1902-3.16:1990 BSI 08-19991 NOTEThis Section is to be used in conjunction with BS
12、 1902-3.0 “Introduction” and BS 1902-3.1 “Guidance on sampling”. Section 3.0 shows the general arrangement of BS 1902 and lists the Sections of Part 3. 1 Scope This Section of BS 1902-3 describes a method for the measurement of pore size distributions of solid and granular refractory material. The m
13、ethod can be used to measure pore diameters in the approximate range 0.006 m to 600 m. NOTE 1The assumed model in this method has all the pores parallel sided and of circular cross section; the results are reported as equivalent pore diameters. A model for pores of different cross section, e.g. elli
14、ptical, can be derived by making appropriate adjustments to the mathematics. NOTE 2This method is unsuitable for materials that: a) contain volatile compounds which give off vapours when placed under vacuum; b) contain metals that amalgamate with mercury. NOTE 3The titles of the publications referre
15、d to in this standard are listed on the inside back cover. 2 Designation The method of determining pore size distribution described in this Section is referred to by the following designation. Method 1902-316. 3 Definitions For the purposes of this Section of BS 1902 the following definitions apply.
16、 3.1 item the brick, or bag of granular raw material, which is to be tested 3.2 test sample the portion of sample on which pore size measurements are made, in the form of a cut piece of brick or of granular particles 3.3 equivalent pore diameter the diameter of a pore at a given pressure which repre
17、sents the pores of irregular cross section impregnated by mercury at that pressure 3.4 ink bottle pores non-parallel sided pores in the form of an ink bottle with a narrow neck and a wide body, measured as if the whole pore was of the same diameter as the neck 3.5 coarse pores pores with diameters g
18、reater than or equal to 10 m, whose equivalent diameters are measured with the coarse pore measuring device 3.6 fine pores pores with diameters less than 10 m whose equivalent diameters are measured with the fine pore measuring device 3.7 mercury filling device apparatus which is made so that only f
19、ine pores can be measured, employed to evacuate and fill the sample holder with mercury 3.8 coarse pore measuring device an apparatus for measuring the proportion of coarse pores present in a sample, combining the functions of mercury filler and pore measurer 3.9 fine pore measuring device an appara
20、tus for measuring the proportion of fine pores present in a sample 3.10 apparent solid density the ratio of the mass of the material to its apparent solid volume, which is the volume of the solid material plus the volume of the closed pores 4 Principle A test sample is placed in a vessel which is ev
21、acuated and filled with mercury. The pressure on the mercury is increased to force it into progressively finer pores and measurement of the volume of mercury forced into the pores at different pressures enables the pore size distribution to be determined. The data obtained can also be used to calcul
22、ate the apparent porosity, bulk density, and apparent solid density of the test sample (see 8.4). Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:18:38 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 1902-3.16:1990 2 BSI 08-1999 5 Apparatus NOTEThe general arrangements of coarse and fine por
23、e measuring devices illustrating two methods of detecting the mercury level in the capillary are shown in Figure 1. 5.1 Sample holder, as shown in Figure 2, constructed in such a way that the base of the sample holder and the uniform capillary tube forming the neck can be separated from each other,
24、to allow the test sample to be inserted. The volume of the holder shall be sufficient to accommodate a test sample of not less than 1 cm3. The holder shall be designed so that electrical contact can be made with the mercury in the holder, either by an appropriately designed removeable bottom, or by
25、fusing an electrode through the well. 5.2 Mercury filling device, which may be separate from, or an integral part of the coarse pore measuring device (5.5). This filling device shall be capable of evacuating the sample holder to a pressure of 2.67 Pa (20 mHg). After evacuation the device shall enabl
26、e the evacuated sample holder to be filled with mercury by means of a system of valves. 5.3 Mercury, of triple distilled quality. WARNING. It is important that proper precautions for the protection of laboratory personnel are taken when mercury is used. Attention is drawn to the relevant regulations
27、 and guidance documents which include the Department of Employment Technical Data Note No. 21, published by HMSO1). 5.4 Mercury level measuring system, which is fitted to both a coarse pore (5.5) and a fine pore measuring device (5.6) to measure the level of mercury in the capillary tube which drops
28、 as the pressure on the mercury is increased. The system shall be able to measure an intrusion volume to a resolution of greater than 1 mm3. One of the methods described in either 5.4 a) or 5.4 b) shall be used to measure the intrusion volume. a) The intrusion volume may be measured by a mechanical
29、method, in which a fine needle can be raised or lowered down the capillary of the sample holder by means of an electric motor. The motor winds the needle down and stops when the needle touches the mercury. Contact is detected by the completion of an electrical circuit through the needle, mercury and
30、 electrode fitted to the sample holder. The position of the needle is recorded electronically by a micrometer screw mechanism fitted to the motor. b) The intrusion volume may be measured by an electronic method, in which the capacitance between the column of mercury in the capillary and a metal slee
31、ve is measured. The sleeve can either be a surface coating on the sample holder or a separate tube in which the capillary tube fits in the pore measuring device. Electrical contact with the mercury column is achieved by means of the electrode fitted to the sample holder. 5.5 Coarse pore measuring de
32、vice, as illustrated in Figure 1(a), which comprises a mercury level measuring system (5.4), a means of admitting air (in a controlled manner) to the chamber containing the mercury filled sample holder and a means of recording the pressure in the system to a resolution of 0.002 MPa. Where the device
33、 is fitted with a facility for introducing nitrogen or air under pressure, either by means of a pump or from a gas cylinder, some pressures above atmospheric pressure, e.g. up to 0.2 MPa, may be obtained. 5.6 Fine pore measuring device, as illustrated in Figure 1(b), which comprises a pressure vesse
34、l, fitted with a mercury level measuring system (5.4) to contain the mercury filled sample holder. The pressure vessel shall be capable of being pressurized up to 210 MPa, by means of a suitable pumping system and hydraulic fluid. The system for measuring the pressure shall have a resolution of 0.00
35、7 MPa. NOTEThe approximate limit for fineness of pores measured is 0.006 m diameter, the size being limited by the pressures developed in the pressure vessel. 6 Test samples 6.1 General Test samples shall comprise particles of maximum size 1 cm3 and shall be washed to remove adhering particles (whic
36、h can affect sample mass and block pores) and dried to constant mass at 110 5 C. NOTE 1With particles larger than 1 cm3, mercury is less likely to reach the centre. NOTE 2Liquids other than water should be used to wash samples susceptible to hydration. Some materials may be affected by heat and an a
37、lternative drying procedure should be adopted. 6.2 Bricks At least three pieces, of a minimum total volume of 2 cm3, shall be taken from the item to form the test sample (brick). For porous materials where the volume of the pores is greater than the volume of the capillary, it will be necessary to r
38、etest with a smaller sample volume (see 7.5) and this shall be reported. 1) Available from HMSO, 49 High Holborn, London WC1 for personal callers, or by post from HMSO, P.O. Box 276, London SW8 5DT. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 24 08:18:38 GMT+00:00 2006, Uncontrolled Copy, (c
39、) BSI BS 1902-3.16:1990 BSI 08-19993 Test samples shall be cut from a brick with a saw or core drill. The pieces shall be sampled to represent different zones of the brick. As there is a possibility that saw marks can be counted as pores, if coarse pores are of particular interest the surfaces of th
40、e test sample shall be polished with a medium of maximum particle size 10 m. If fine pores are of particular interest, the sample shall be tested in the as sawn condition, ignoring pore sizes greater than 125 m. 6.3 Granular material Samples of granular material shall be taken by coning and quarteri
41、ng or using sample splitters. Crushing granular materials to form particles less than 1 cm3 shall be kept to a minimum as crushing may introduce cracks that would be counted as pores. 7 Procedure 7.1 General A liquid that has a high contact angle, , with a solid, will not penetrate capillaries of di
42、ameter, d, in that solid, unless a pressure, p, is applied. These are related as follows where v is the surface tension: The chosen liquid with this method is mercury which has a contact angle of between 130 and 145 for many materials. For oxide refractories an angle of 130 shall be used in calculat
43、ions and for refractories containing carbon, an angle of 140 shall be used. The surface tension of mercury is approximately 0.484 N/m at 25 C and 0.472 N/m at 50 C. During the determination, the temperature of the hydraulic fluid can increase as a result of the work done on it and a value of 0.482 N
44、/m shall be used in the calculations unless otherwise reported. 7.2 Blank determination Carry out blank determination if required (see 8.3.1). 7.3 Evacuation Weigh the cleaned dried test sample to 0.001 g (W1) and place it in a clean dry sample holder. If bulk density, apparent solid density and app
45、arent porosity are required, weigh the sample holder containing the test sample to 0.001 g (W2). Connect the sample holder to the vacuum system of the mercury filling device (5.2) or coarse pore measuring device (5.5) and evacuate until the pressure stabilizes at less than 6.67 Pa ( 50 mHg). If the
46、material does not allow stabilization below 6.67 Pa the material is not suitable for assessment by this procedure and the test shall be abandoned. When the pressure has stabilized at the required level, admit the mercury to the sample holder to fill it. NOTE 1For very accurate work the sample holder
47、 should be evacuated to less than 2.67 Pa (20 mHg) and the final pressure should be reported. NOTE 2If the test sample is in granular form (see 6.3) there may be areas between particles where surface tension prevents complete filling; these may be measured later as large pores. 7.4 Coarse pore measu
48、rement NOTEThis procedure can only be followed if the sample holder has been filled in the coarse pore measuring device (5.5). After filling the sample holder and draining the surplus mercury from the system by means of valves, admit air in a controlled manner. Increase the pressure either: a) almos
49、t continuously; NOTEAs ink bottle pores can lead to error, increase the pressure slowly, or hold it constant from time to time, to allow the mercury volume reading to stabilize; b) in stages, corresponding to pressures for particular pore sizes. At the same time record the volume of mercury forced into the pores by either: 1) plotting the mercury level and pressure readings graphically during the test; 2) recording the pressures and volumes digitally. When the pressure in the system has reached atmospheric pressure, if the system is suitably d