1、BRITISH STANDARD BS ISO 13318-1:2001 Determination of particle size distribution by centrifugal liquid sedimentation methods Part 1: General principles and guidelines ICS 19.120 BS ISO 13318-1:2001 This British Standard, having been prepared under the direction of the Materials and Chemicals Sector
2、Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 19 August 2002 BSI 19 August 2002 ISBN 0 580 40288 6 National foreword This British Standard reproduces verbatim ISO 13318-1:2001 and implements it as the UK national standard. Together
3、 with BS ISO 13318-2 and BS ISO 13318-3 (to be published), it supersedes BS 3406-6:1985, which will be withdrawn on publication of BS ISO 13318-3. The UK participation in its preparation was entrusted by Technical Committee LBI/37, Sieves, screens and particle sizing, to Subcommittee LBI/37/4, Sizin
4、g by methods other than sieving, which has the responsibility to: A list of organizations represented on this subcommittee 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 B
5、SI Catalogue under the section entitled “International Standards 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
6、 their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. 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 in
7、terests informed; monitor related international and European developments and promulgate them in the UK. 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 16, an inside back cover and a back cover. The BSI copyr
8、ight date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsReference number ISO 13318-1:2001(E) INTERNATIONAL STANDARD ISO 13318-1 First edition 2001-03-01 Determination of particle size distribution by centrifugal liqu
9、id sedimentation methods Part 1: General principles and guidelines Dtermination de la distribution granulomtrique par les mthodes de sdimentation centrifuge dans un liquide Partie 1: Principes gnraux et lignes directrices BSISO133181:2001BSISO133181:2001iiISO -813311:(1002E) ISO 1002 All rights rsed
10、evre iii Contents Page Foreword.iv Introduction.v 1 Scope 1 2 Normative references 1 3 Terms definitions and symbols2 4 Principles4 5 Particle size, shape and porosity limitations9 6 Test conditions 10 7 Sampling.11 8 Preparation for a sedimentation analysis .11 9 Tests in duplicate and validation .
11、12 10 Reporting of results.12 Annex A (informative) The effect of measurement zone depth 14 Annex B (informative) Accuracy of Stokes law as a function of Reynolds number 15 Bibliography16 BSISO133181:2001iiiISO -813311:(1002E) vi ISO 1002 All rights rsedevre Foreword ISO (the International Organizat
12、ion 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 h
13、as 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. Int
14、ernational Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. 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
15、member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 13318 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 13318-1 was prepared by Technical C
16、ommittee ISO/TC 24, Sieves, sieving and other sizing methods, Subcommittee SC 4, Sizing by methods other than sieving. ISO 13318 consists of the following parts, under the general title Determination of particle size distribution by centrifugal liquid sedimentation methods: Part 1: General principle
17、s and guidelines Part 2: Centrifugal photosedimentation method Part 3: Centrifugal X-ray method Annexes A and B of this part of ISO 13318 are for information only. BSISO133181:2001ivISO -813311:(1002E) ISO 1002 All rights rsedevre v Introduction Centrifugal sedimentation particle size analysis metho
18、ds are among those in current use for determining size distribution of many powders. Typically, centrifugal methods apply to samples in the 0,1 m to 5 m size range and where the sedimentation condition for a Reynolds number 0,25 is satisfied. No single method of size analysis can be specified to cov
19、er the many different types of material encountered, but it is possible to recommend procedures that may be applied to the majority of cases. The purpose of this part of ISO 13318 is to obtain uniformity in procedure of centrifugal methods in order to facilitate comparisons of size analysis made in
20、different laboratories. Centrifugal sedimentation methods may be undertaken: as part of a research project involving an investigation of the particle size distribution of a material; as part of a control procedure for the production of a material where the particle size distribution is important; as
21、 the basis of a contract for the supply of material specified to be within stated specification limits. Gravitational sedimentation methods are discussed in ISO 13317-1, ISO 13317-2 and ISO 13317-3. BSISO133181:2001vINTENRATIONAL TSANDADR ISO -813311:(1002E) ISO 1002 All rights rsedevre 1 Determinat
22、ion of particle size distribution by centrifugal liquid sedimentation methods Part 1: General principles and guidelines 1 Scope This part of ISO 13318 covers methods for determining the particle size distributions of particulate materials, typically in the size range 0,1 m to 5 m, by centrifugal sed
23、imentation in a liquid. NOTE This part of ISO 13318 may involve the use of hazardous materials operations and equipment. This part of ISO 13318 does not purport to address all the safety problems associated with its use. It is the responsibility of the user of this part of ISO 13318 to establish app
24、ropriate safety and health practices and to determine the applicability of the regulatory limitations prior to its use. The methods of determining the particle size distribution described in this part of ISO 13318 are applicable to slurries, particulate materials which can be dispersed in liquids an
25、d some emulsions. A positive density difference between the discrete and continuous phases is necessary, although centrifugal photosedimentation can be used for emulsions where the droplets are less dense than the liquid in which they are dispersed. 2 Normative references The following normative doc
26、uments contain provisions which, through reference in this text, constitute provisions of this part of ISO 13318. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of ISO 13318 are encouraged to
27、investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 758, Liquid
28、 chemical products for industrial use Determination of density at 20 o C. ISO 787-10, General methods of test for pigments and extenders Part 10: Determination of density Pyknometer method. ISO 2591-1, Test sieving Part 1: Methods using test sieves of woven wire cloth and perforated metal plate. ISO
29、 8213, Chemical products for industrial use Sampling techniques Solid chemical products in the form of particles varying from powders to coarse lumps. ISO 9276-1, Representation of results of particle size analysis Part 1: Graphical representation. ISO 14887, Sample preparation Dispersing procedures
30、 for powders in liquids. BSISO133181:20011ISO -813311:(1002E) 2 ISO 1002 All rights rsedevre 3 Terms, definitions and symbols 3.1 Terms and definitions For the purposes of this part of ISO 13318, the following terms and definitions apply. 3.1.1 terminal settling velocity velocity of a particle throu
31、gh a still liquid at which the force due to centrifugation is balanced by the drag exerted by the liquid 3.1.2 Stokes diameter equivalent spherical diameter of the particle that has the same density and terminal settling velocity as the real particle in the same liquid under creeping flow conditions
32、 3.1.3 open pores cavities that are connected to the external surface of the particle either directly or via one another 3.1.4 closed pores cavities that are closed off by surrounding solid and are inaccessible to the external surface 3.1.5 oversize portion of the charge which has not passed through
33、 the apertures of a stated sieve 3.1.6 undersize portion of the charge which has passed through the apertures of a stated sieve 3.1.7 effective particle density particle mass divided by the volume of liquid it displaces 3.1.8 true particle density particle mass divided by the volume it would occupy
34、excluding all pores, closed or open, and surface fissures NOTE True particle density is sometimes referred to as the absolute particle density. 3.2 Symbols For the purposes of this part of ISO 13318, the following symbols apply. BSISO133181:20012ISO -813311:(1002E) ISO 1002 All rights rsedevre 3 Qua
35、ntity Symbol Unit Derivative Unit Density Effective particle density s kg m 3 g cm 3 Liquid density l kg m 3 g cm 3 Liquid viscosity Pasm P a s Acceleration due to gravity g m s 2 Sedimentation distance h mm m Sedimentation time t s Time detector scan passes M minp t limit s Stokes diameter x St m m
36、 Stokes diameter of particles, in measurement zone, commencing from position r i x i m m Upper Stokes diameter x St,U m m Lower Stokes diameter x St,L m m Particle diameter exiting measurement zone x St,p m m Particle diameter entering measurement zone x St,p p m m Terminal settling velocity v m s 1
37、 m s 1 Reynolds number Re dimensionless Combined parameter K 1 m 2 s Combined parameter K 2 m 3 s 1 Hyperbolic scan constant K scan m s Boltzmann constant k J K 1 Absolute temperature T K Fractional uncertainty of particle position due to thermal diffusion f diff dimensionless Extinction coefficient
38、 for particle of size x i E i dimensionless Resolution ratio P dimensionless Zone-height-limited resolution P zone dimensionless Distance of particle from axis of rotation r mm m Distance of particle from axis of rotation at timetr t mm m Starting position of particles diameter x i r i m m Statistic
39、al average positional change in one direction for large number of particles: root mean square distance r TB,t m m Distance from rotation axis to liquid-air interface of sample (vortex radius) S mm m Distance from rotation axis to centrifuge wall (inner disc radius) R mm m Centrifuge speed (rev/min)
40、N r min 1 Distance from rotation axis to measurement zone (measurement radius) M mm m Thickness of measurement zone M m m Distance for minimum acceptable resolution relative to measurement zone ( M) M minp m Mass fraction of particles less than diameter x i F i dimensionless Measured concentration (
41、relative) C dimensionless Ratio (M/S) 2 y dimensionless y i (x i /x j ) 2 (Kamacks) y ij dimensionless Centrifugal angular velocity ( 2 60 N ) rad s 1 BSISO133181:20013ISO -813311:(1002E) 4 ISO 1002 All rights rsedevre 4P r i n c i p l e s 4.1 General Centrifugal sedimentation methods are based on t
42、he rate of settling, under a centrifugal field, of particles in a liquid. The relationship between settling velocity and particle size reduces to the Stokes equation (1) at low Reynolds numbers. The Reynolds number should not exceed 0,25 if the inaccuracy in determining the value of Stokes diameter
43、is not to exceed 3 %. Stokesian sedimentation analyses depend on the applicability of Stokes law. This law defines the relationship between particle size and the change in settling distance (within the suspending fluid) of the particle as a function of the time that the particle has fallen after rea
44、ching its terminal settling velocity, and in a gravitational field. This relationship may be expressed as: () = 2 slS t fall 18 gx t h (1) The Stokesian diameter of the particle may then be inferred from the distance it has fallen in a given time, t. = () fall St sl 18 h x gt (2) The basic principle
45、s of gravitational sedimentation are unaffected in a centrifugal analysis, except that the factor g in Stokes law see equation (2) now becomes a variable according to the speed and radius of rotation of the particle. In centrifugal sedimentation, the velocity of a given size of particle is not const
46、ant but increases as the radius of rotation increases with particle settling distance. The force due to gravitational acceleration, g, is replaced by 2 , where is the centrifugal angular velocity. The settling distance, h fall ,i nt i m e ,t, is replaced by ln(M/S)f o r time, t. The Stokes diameter,
47、 x St , at measurement radius time, t,i sg iv enby / St 2 sl 18 ln MS x t (3) Particle concentrations are determined by the attenuation of a white light or an X-ray beam. Sedimentation techniques may be classified as either incremental or cumulative. Incremental methods are used to determine the sol
48、ids concentration (or suspension density) of a thin layer at a known settling distance and time. Cumulative methods are used to determine the rate at which solids settle from the suspension. The cumulative method is not included in this part of ISO 13318. The sample may be introduced either as a thin layer of dispersion on top of the spinning liquid medium, the line- start incremental technique, or uniformly dispersed throughout the sedimentation medium, the homogeneous incremental technique (Figures 1 and 2). BSISO133181:20014ISO -813311:(1002E) ISO 1002 All rights rsedevre 5 Key
