ASTM E877-2013 red 0318 Standard Practice for Sampling and Sample Preparation of Iron Ores and Related Materials for Determination of Chemical Composition and Physical Properties《测.pdf

1、Designation: E877 08E877 13Standard Practice forSampling and Sample Preparation of Iron Ores and RelatedMaterials for Determination of Chemical Composition andPhysical Properties1This standard is issued under the fixed designation E877; the number immediately following the designation indicates the

2、year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers procedures for mechanical sampl

3、ing of iron ores and related materials in a falling stream or stopped-beltsampling and preparing the gross sample to the various test samples required for each characteristic to be measured. Included asAnnexes are (1) design criteria to prevent bias, (2) statistical methods to determine quality vari

4、ation and precisions of samplingand division, and (3) a method for comparing two sampling procedures for possible systematic differences.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to

5、establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. Specific precautionary statements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related

6、 MaterialsE276 Test Method for Particle Size or Screen Analysis at No. 4 (4.75-mm) Sieve and Finer for Metal-Bearing Ores and RelatedMaterialsE279 Test Method for Determination of Abrasion Resistance of Iron Ore Pellets and Sinter by the Tumbler TestE389 Test Method for Particle Size or Screen Analy

7、sis at No. 4 (4.75-mm) Sieve and Coarser for Metal-Bearing Ores andRelated MaterialsE882 Guide for Accountability and Quality Control in the Chemical Analysis LaboratoryE1072 Test Method for Low Temperature Breakdown of Iron Ores (Withdrawn 1995)33. Terminology3.1 DefinitionsFor definitions of terms

8、 used in this test method, refer to Terminology E135.3.1.1 nominal sizetopsizein sampling, the opening of the screen of the standard series that would pass 95 % 95 % of arepresentative sample.3.1.2 precisiona measure of reproducibility of test results, using the same equipment and method, statistica

9、lly derived frommultiple data expressed at 95 % 95 % confidence level.4. Summary of Practice4.1 The precision required for the sampling and sample preparation steps is calculated based on the objectives of the testing,resulting in a sampling plan specifying the minimum weightsmasses and number of in

10、crements required for each step in theprocedure. Samples are then collected, dried, blended, divided, crushed, pulverized, and ground as required by the test methodsto be utilized.1 This practice is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Ma

11、terials and is the direct responsibility ofSubcommittee E01.02 on Ores, Concentrates, and Related Metallurgical Materials.Current edition approved Nov. 1, 2008Oct. 1, 2013. Published December 2008November 2013. Originally approved in 1982. Last previous edition approved in 20032008as E877 03.E877 08

12、. DOI: 10.1520/E0877-08.10.1520/E0877-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved

13、version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict al

14、l changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-29

15、59. United States15. Significance and Use5.1 This practice is to be used for sampling and sample preparation of iron ores and related materials, prior to use of a refereemethod for testing for compliance with compositional specifications for metal content or physical properties. It is assumed that a

16、llwho use this procedure will be trained analysts capable of performing common laboratory practices skillfully and safely. It isexpected that work will be performed in a properly equipped laboratory and that proper waste disposal procedures will be followed.Appropriate quality control practices must

17、 be followed, such as those described in Guide E882.5.2 Adequate methods for obtaining representative samples for testing the chemical and physical properties of a consignmentof iron ore are essential. The sale and use are dependent on the chemical or physical properties, or both, of an ore.5.3 The

18、criteria to prevent bias may be used for both design of a sampling system and in checking the design of an existingsystem.6. Apparatus6.1 Any mechanical sampler is acceptable that either by design or comparison, or both (as defined in AnnexA1 and AnnexA4)can be shown to take nonbiased increments of

19、at least minimum weightmass and number required and can handle these incrementsin accordance with the practice.6.2 Templates and Related Equipment, to obtain increments from a stopped belt, with bias protection in accordance with AnnexA2, are acceptable.6.3 RiffleAstationary sampler comprising an ev

20、en number of equally-sized, adjacent chutes discharging in opposite directions.For use with this practice, there must be a minimum of twelve chutes with an opening width of at least 3 times the nominalsize.topsize.NOTE 1For fine ores ( 12.5 mm) it is recommended not to exceed 312 times nominal sizet

21、opsize as it is required that the full width of the riffle be used sincethe accuracy of the split increases with the number of chutes. For free-flowing ores such as pellets, the 3 times top size the nominal topsize may be reducedto 112 times provided it is ascertained that there is no chute plugging

22、 for a particular ore type.6.4 CrushersCrushers may be jaw, cone, rotary, or other type that can reduce the particle size to the desired level withoutsignificant weight loss of mass (less than 0.5 %) 0.5 %) and not contaminate the sample.6.5 Pulverizers and GrindersPulverizers and grinders may be of

23、 plate, cylinder, or other type that can reduce the particle sizeto the desired level.They should be made of sufficiently hardened material to prevent contamination of the sample.Also, the weightloss loss of total mass during pulverizing should not exceed 2.5 %.2.5 %.7. Design of Sampling Operations

24、7.1 Basic Requirements:7.1.1 The characteristics to be determined and precisions desired must be known.7.1.2 The weightmass and special requirements for each test sample must be known.7.2 Overall Precision (SDM):7.2.1 Overall precision for determining the mean values of the iron content, moisture co

25、ntent, and percentage passing thespecified size sieve (in accordance with Test Methods E276 and E389), at 95 % 95 % confidence in absolute percentages are asin Table 1.7.2.2 Overall precisions for other characteristics shall be agreed upon between the parties concerned.NOTE 2Nationally or internatio

26、nally accepted measurement methods should be used to determine the characteristics desired.7.3 Equations:7.3.1 Calculate overall precision as follows:TABLE 1 Overall PrecisionConsignment,tonsIron andMoistureContent,%Specification Size, Cumulative Percent Passing50 % 90 %A 90 % 100 000 0.3 0.75 % 0.0

27、75C 0.075 (100-C) 0.75 %20 000 to100 000 0.4 1.0 % 0.1C 0.1 (100-C) 1.0 % 20 000 0.5 2.0 % 0.2C 0.2 (100-C) 2.0 %A In the formulae for calculating the precision estimates within this column,C = cumulative percent passing.E877 132SDM 52w2n S111c D12DM (1)orSDM 52w2n S111 D1D 2 1M2m (2)where:SDM = ove

28、rall precision for any characteristic,w = estimated within-strata standard deviation of a characteristic,D = estimated standard deviation of division,M = estimated standard deviation of measurement,DM = estimated standard deviation of division and measurement combined,n = number of primary increment

29、s, = number of final samples taken for measurement,m = number of measurements taken on each final sample, andc = average number of secondary increments taken per primary increment.NOTE 3Factor (1 + 1/c) is omitted from the equation if only primary increments are used.7.3.2 w and DM or w, D, and M ar

30、e estimated in accordance with Annex A3.7.3.3 When designing a new sampling installation, refer to Annex A1 for estimating w and DM.7.4 Selection of Sampling ParametersUsing the estimated values of w and DM or w, D, and M and Eq 1 or Eq 2, choosea combination of n, c, , and m to obtain the required

31、precision. It is recommended in routine sampling to use the same value ofc used in the determination of w.7.5 Minimum WeightMass of IncrementThe minimum weightmass of an increment is calculated by the following formula toensure that a particle the shape of a cube of the nominal sizetopsize shall not

32、 represent more than 10 % of its weight,mass, to avoidbias by larger particles:W 5S3/20!3sp gr/5! (3)where:W = minimum weight of increment, kg,W = minimum mass of increment, kg,S = nominal size of the ore, cm, andsp gr = specific gravity of the iron ore being sampled.NOTE 4In practice, the weightmas

33、s of primary increments may be many times greater than that obtained in Eq 3.7.6 Treatment of IncrementsIncrements will be handled individually or combined to form one or more gross samples or set(s)of subsamples from which test sample(s) for the required characteristics will be taken. Each gross sa

34、mple must follow therequirements of sampling and preparation. Each gross sample must have, as a minimum number of increments, the largest number(n) calculated from the individual characteristics taken from that gross sample.7.6.1 ExampleAssume a gross sample is required for iron analysis and moistur

35、e determination and a separate gross samplefor size distribution and tumble test. Also assume from 7.4 the number of increments required to obtain precision desired is asfollows:Moisture 30 incrementsIron 20 incrementsSize 50 incrementsTumble 25 increments7.6.2 ExampleTake 30 increments for iron ana

36、lysis and moisture determination and 50 increments for size distribution andtumble test, if the sampler has the capability (for example, computer controlled). If, however, alternative increments are used, take50 increments for each gross sample. If one gross sample is to be used for all the determin

37、ations, use 50 increments.7.7 Special Precautions:7.7.1 Samples for size determination or other tests requiring uncrushed particles must be taken prior to crushing.7.7.2 Samples for moisture determination must be protected from ambient conditions. A subsample should be taken at leastevery 8 h and th

38、e total moisture of the consignment should be the weighted average of these samples. The 8-h period may beextended provided the sample is protected from moisture change (for example, refrigerated). To avoid moisture change, samplesmust be prepared as quickly as possible, with minimum handling, and m

39、ust be kept in sealed containers while awaiting any stageof preparation prior to the initial weighing. Moisture samples should not be crushed below 14-in. sieve (6.3 mm) and the minimumweightmass of samples used should conform with Eq 4 (8.6.1). Mix sample prior to moisture determination.E877 133FIG

40、. 1 Procedures for Calculating Standard DeviationFIG. 2 Sampling Plan for Determination of Precision of Sampling and Quality VariationE877 1348. Sampling and Preparation Procedure (See Fig. 3 for examples)8.1 Collect throughout the movement of the consignment, in accordance with Annex A1 or Annex A2

41、, the number of primaryincrements, as determined in 7.4 (with a minimum of 20). Start at random within the first stratum, then sample at equal mass ortime intervals. If the ore is handled in such a way that there is a cycle to the variability of a characteristic, it must be ascertainedthat the sampl

42、ing cycle is not in phase with the handling cycle.8.2 If the required number of increments is collected prior to completion of the movement of the consignment, additionalincrements shall be taken at the same interval until ore handling is complete.8.3 If secondary increments (c) are used, they shall

43、 be taken at equal time intervals with a maximum time such that c is 1 orgreater.FIG. 3 Flowsheet ExamplesE877 1358.4 Increments are treated individually or combined to form a gross sample(s) or subsamples, or both, in accordance with finaltest sample requirements in conjunction with precision requi

44、rements, as determined in 7.3.1.8.5 At this stage, individual test samples are obtained by a combination of division (weight(mass reduction) (8.6), crushing andpulverizing (8.7), and drying (8.8), as directed in Section 8.8.6 Division of gross sample, subsamples, or increment must conform with the f

45、ollowing rule:8.6.1 The minimum weightmass of the total divided sample must be greater than:W25S33sp gr/5! (4)where:W2 = weight of the divided sample, kgW2 = mass of the divided sample, kgS = nominal size at that division level, cm, andS = nominal topsize at that division level, cm, andsp gr = speci

46、fic gravity of the ore being sampled.8.6.1.1 The equation is based on the concept that the weightmass of the largest piece should be less than 0.5 % of theweightmass of the divided sample.8.6.2 Divide the sample by one of the following procedures:8.6.2.1 A mechanical sampler operated in accordance w

47、ith the guidelines in Annex A1.8.6.2.2 RifflingUse a pan the same width as the riffle chutes to feed the ore for division.Add increments of ore to the pan andgently agitate the pan over the center of the chutes, feeding the ore at a constant rate, so that any ore particle has an equal chanceof falli

48、ng to either side of the device. Select the half of the divided sample to be included in subsequent sampling steps, at random.Thoroughly clean the equipment between samples. WarningUse proper dust collection to protect the operator from finerespirable dust particles.8.6.2.3 Manual Increment Division

49、 (Note 5)Mix the entire sample and spread on a flat nonmoisture-absorbing surface so thatthe sample forms a rectangle of uniform thickness. Divide into at least 20 segments of equal area. With a flat bottom, square-nosetool, take scoopfuls of approximate equal size from each segment from the full depth of the bed. These scoopfuls must have aminimum weightmass in accordance with Eq 3. Combine the scoopfuls to form the divided sample.NOTE 5Manual increment division, although very effic