1、Designation: E 276 03Standard Test Method forParticle Size or Screen Analysis at No. 4 (4.75-mm) Sieveand Finer for Metal-Bearing Ores and Related Materials1This standard is issued under the fixed designation E 276; the number immediately following the designation indicates the year oforiginal adopt
2、ion or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the sizedistribution by scr
3、een analysis, dry or wet, of metal-bearingores and related materials at No. 4 (4.75-mm) sieve and finer.1.2 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and
4、health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:E 11 Specification for Wire-Cloth Sieves for Testing Pur-poses2E 135 Terminology Relating to Analytical Chemistry forMetals, Ores and Related Materials2E 882 Guide for A
5、ccountability and Quality Control in theChemical Analysis Laboratory33. Terminology3.1 Definitions:For definitions of terms used in this test method, refer toTerminology E 135.4. Summary of Test Method4.1 The sample is passed through a bank of standard sievesby agitation. The dry screening technique
6、 described in this testmethod may be used on any solid particles that can be dried sothat sieve blinding does not occur. The wet screening techniqueusing liquid media may be used on any insoluble solids.5. Significance and Use5.1 This test method is intended to be used for compliancewith composition
7、al specifications for particle size distribution.It is assumed that all who use this procedure will be trainedanalysts capable of performing common laboratory practicesskillfully and safely. It is expected that work will be performedin a properly equipped laboratory and that proper wastedisposal pro
8、cedures will be followed. Follow appropriatequality control practices such as those described in GuideE 882.6. Apparatus and Materials6.1 U.S. Standard Sieves, conforming to the requirements ofSpecification E 11.6.2 Mechanical Sieve Shaker.6.3 Drying Oven, of appropriate size and capable of main-tai
9、ning a uniform temperature at 110 6 5C.6.4 Sample Splitter or Riffle with 25.4-mm (1-in.) opening.6.5 Scales and Weights, of adequate accuracy.6.6 Pans, for holding samples.6.7 Brass and Fiber Bristle Brushes, for cleaning sieves andpans.6.8 Special Apparatus, for wet screening, including deep-frame
10、 sieves.6.9 Water or other liquid, for wet screening.7. Sample Preparation7.1 If necessary, reduce the sample by riffling or othersuitable means to obtain a test sample that will not overload thesieves, and dry at 110 6 5C to constant weight.NOTE 1The size of the sample is very important in sieve an
11、alysisbecause the number of particles on a sieve surface affects the probabilityof any one particle passing through the sieve at a given time. The moreparticles there are on a sieve, the greater probability that any one particleis hindered from getting into a position to pass through the opening. Av
12、oidoverloading the sieves.7.2 Screen the test sample from 7.1 on a No. 4 (4.75-mm)sieve. Weigh the material retained on the No. 4 sieve.8. Preparation of Apparatus8.1 Clean coarse sieves up to No. 80 (180 m) with a softbrass wire brush and clean the finer sieves wtih a fiber brush.Clean by brushing
13、the under side of the sieves. Gently tap thebrass frame to aid in freeing trapped particles. At times, it maybe necessary to wash the sieves in a warm soap and water1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is
14、 the directresponsibility of Subcommittee E01.02 on Ores, Concentrates, and Related Metal-lurgical Materials.Current edition approved June 10, 2003. Published November 2003. Originallyapproved in 1965. Last previous edition approved in 1998 as E 276 98.2Annual Book of ASTM Standards, Vol 14.02.3Annu
15、al Book of ASTM Standards, Vol 03.06.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.solution. After washing, dry the sieves thoroughly. If wetscreening is to be used, nest selected special deep-frame sievesafter cleaning as describe
16、d.NOTE 2As an alternative, ultrasonic cleaning of sieves is recom-mended.9. Standardization of Sieves9.1 Calibrate the sieves by use of calibrated glass spheres.Standard glass spheres are available through the NationalInstitute of Standards and Technology (NIST) and otherinternational standardizatio
17、n organizations.9.2 Use of the microscopic method in the appendix ofSpecification E 11 is also permissible to assure that the sievesmeet specification.10. Procedure10.1 Dry Screening:10.1.1 For Samples Containing Less than 10 % Passing aNo. 200 (75-m) SieveNest the selected sieves and fit a panbelow
18、 the bottom sieve. Place the material which passed theNo. 4 (4.75-mm) sieve from 7.2, in the top sieve. Cover andclamp the nested sieves in the mechanical shaker and shake forthe time interval specified in 10.1.3.10.1.2 For Samples Containing More than 10 % Passing aNo. 200 (75-m) SieveWash the mate
19、rial which passed theNo. 4 (4.75-mm) sieve from 7.2 on a No. 200 (75-m) sieveuntil the solution passing through the sieve is clear (see 10.2).Save the material passing the sieve. Dry the sieve fractions inaccordance with 10.2.4.2 and process the retained fraction inaccordance with 10.1.1.10.1.3 Leng
20、th of Screening Time or End PointThe screen-ing time or end point is when additional periods of shaking failto change the results on any sieve used in the test by more than0.3 %. The screening time may vary from 3 to 30 min or moredepending on the type of material. Determine the exact time foreach m
21、aterial experimentally.10.1.4 WeighingRemove the clamp and cover. Transferthe contents of each sieve to a tared pan, tapping and brushingthe sieves to remove any lodged particles. Record the weight ofeach sieve fraction.10.1.4.1 Weigh and record material washed on a No. 200(75-m) sieve, as described
22、 in 10.1.2 and submitted to wetscreening as described in 10.2, the same as in the other sieves.10.1.5 CalculationSum the weights of each of the sievefractions. The total shall be within 1 % of the weight of theoriginal test sample or the analysis must be repeated from 7.1with another test sample. Th
23、e weight of the test sample used forcalculation is the total of the sieve fractions. Calculate thepercent retained on each sieve as follows:Material retained, % 5 Wr/Wt! 3 100 (1)where:Wr= mass retained on each sieve, andWt= total mass of all sieve fractions.Calculate the percent passing the finest
24、sieve as follows:Material passing, % 5 Wp/Wt! 3 100 (2)where:Wp= mass passing the finest sieve, retained on a pan orfilter, andWt= total mass of all sieve fractions.Obtain the percent cumulative by adding each percentretained on each sieve as the series progresses.10.1.6 Report:10.1.6.1 Report the f
25、ollowing data: sieve size, weight re-tained on or passing through sieve, percent retained on sieve,and percent cumulative.10.1.6.2 Present the data of a screen analysis graphically asa cumulative direct plot or a cumulative logarithmic plot. Fromthe plots, the percentages remaining on any set of ope
26、ningsother than those of the testing sieves used, can be found byinterpolation and in this way the redistribution of the samematerial by any assumed set of openings can be determined.10.2 Wet Screening:10.2.1 Wet screening can be carried out on a single sieve byhand washing or through use of a mecha
27、nical shaker. Similarly,a nest of screens can be used preferably through use of aspecially adapted mechanical shaker.10.2.2 Washing of a sample on a single sieve causes thefinest particles to be removed quickly from the larger or coarserparticles. It also has the advantage of breaking up aggregates
28、offine particles and removing the slime coatings from coarseparticles, making a product more amenable to dry sieveanalysis. The liquid used for washing is generally water, but forspecific cases some other nonreacting liquid can be used. Drythe retained fraction and return to the sieve or nest of sie
29、ves fordry screening as described in 10.1.10.2.3 For more accuracy or reproducibility of tests, use acontrolled volume of liquid. To accomplish the results re-quired, a set volume of liquid cannot be determined to meet allconditions, but through experimentation for specific cases,such requirements c
30、an be accomplished.10.2.4 Single Screen Testing:10.2.4.1 Place the material which passed the No. 4 (4.75-mm) sieve from 7.2 in a deep-frame sieve. Wash the materialon the screen in accordance with 10.2. Continue washing untilthe liquid passing the sieve is clear.10.2.4.2 DryingWash the material on t
31、he sieve into adrying pan. Dry in an oven at 110 6 5C. Recover the materialfrom the retained washings by using a filter press or byevaporation, then dry in an oven at 110 6 5C.10.2.4.3 Weighing, Calculation, and ReportTransfer thecontents of the sieve to a tared pan as described in 10.1.4 andweigh.
32、Calculate and report the data as described in 10.1.5 and10.1.6.10.2.5 Multiple Screen Testing:10.2.5.1 Nest the selected deep-frame sieves and fit a pancontaining a drain pipe to the bottom sieve. Place the materialpassing the No. 4 (4.75-mm) sieve from 7.2 into the top sieve.Place a sieve cover equ
33、ipped with two inlet pipes on the topsieve and clamp the nested sieves in the mechanical shaker.Connect the inlet pipe to the liquid supply and the drain pipe toa collection container. Start the mechanical shaker and turn onthe liquid supply. Continue the washing until the dischargeliquid is clear.
34、Turn off the liquid supply and allow the shakerto continue operation for a few minutes.E27603210.2.5.2 Remove the sieves from the shaker, and dry thesieve fractions in accordance with 10.2.4.2.10.2.5.3 Weighing, Calculation, and ReportTransfer thecontents of the sieves to tared pans as described in
35、10.1.4 andweigh. Calculate and report the data as described in 10.1.5 and10.1.6.11. Precision and Bias11.1 PrecisionIt is generally agreed that errors in screen-ing arise from the way in which screening is done. Selection ofthe sample loading of the sieves, sieves themselves, and thefinal weighing,
36、all influence the reproducibility or accuracy ofscreening. Some particle wear occurs, but for the No. 4 andfiner sieves, this wear is usually insignificant. Brittleness,hardness, weight of charge, and the mode of operation of themechanical shaker influence slightly the results of the test. It isagre
37、ed, however, that normally any variations due to thesefactors would not effectively alter the results of the test. Thesize and shape of the particles significantly influence theprobability of passing when sizes of aperture and particle areclose. Screening time is important, but it cannot be said tha
38、t aspecific time of screening should be used for all types ofmaterials. End point of time of screening for different materialsis to be established by experimentation.11.2 If the sample is known to contain naturally occurringferromagnetic material, it shall be demagnetized in a 60-Hzfield of not less
39、 than 300 Oe.11.3 It is not practicable to specify the precision of theprocdure in this test method because the precision is related tothe quantity of sample tested, the distribution of particles andthe shape of the particles, which vary for each type of materialtested.11.4 BiasNo information on the
40、 accuracy of this testmethod is known. The accuracy of this test method asmeasured by calibration of sieves using standard referencematerials, is not directly transferable to metal-bearing ores andrelated materials.12. Keywords12.1 analyzing; ores; particle size; related materials; screenanalysisAPP
41、ENDIX(Nonmandatory Information)X1. SUMMARY OF U.S. SIEVE, TYLER SCREEN, AND ISO EQUIVALENTSU.S. Standard Sieve No. Tyler Screen Number,meshISO Designation4 4 4.75 mm5 5 4.00 mm6 6 3.35 mm7 7 2.80 mm8 8 2.36 mm10 9 2.00 mm12 10 1.70 mm14 12 1.40 mm16 14 1.18 mm18 16 1.00 mm20 20 850 m25 24 710 m30 28
42、 600 m35 32 500 m40 35 425 m45 42 355 m50 48 300 m60 60 250 m70 65 212 m80 80 180 m100 100 150 m120 115 125 m140 150 106 m170 170 90 m200 200 75 m230 250 63 m270 270 53 m325 325 45 m400 400 38 mE276033ASTM International takes no position respecting the validity of any patent rights asserted in conne
43、ction with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsi
44、ble technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful co
45、nsideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100
46、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E276034
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