1、Designation: C1075 10Standard Practices forSampling Uranium-Ore Concentrate1This standard is issued under the fixed designation C1075; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenthes
2、es indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These practices are intended to provide the nuclearindustry with procedures for obtaining representative bulksamples from uranium-ore concentrates (UOC) (
3、see Specifica-tion C967).1.2 These practices also provide for obtaining a series ofrepresentative secondary samples from the original bulksample for the determination of moisture and other testpurposes, and for the preparation of pulverized analyticalsamples (see Test Methods C1022).1.3 These practi
4、ces consist of a number of alternativeprocedures for sampling and sample preparation which havebeen shown to be satisfactory through long experience in thenuclear industry. These procedures are described in the follow-ing order.Stage Procedure SectionPrimary Sampling One-stage falling stream 4Two-st
5、age falling stream 5Auger 6Secondary Sampling Straight-path (reciprocating) 7Rotating (Vezin) 8, 9Sample Preparation 10Concurrent-drying 11-13Natural moisture 14-16Calcination 17, 18Sample Packaging 19Wax sealing 20Vacuum sealing 211.3.1 The primary and secondary sampling stages can beorganized in t
6、he following way:1.3.2 It is possible to combine the various elements of thesestages in different ways to give satisfactory results dependingon the agreed requirements of the contracting parties. For agiven stage, however, each procedure must be regarded as awhole. It is highly inadvisable to mix el
7、ements belonging todifferent procedures.1.4 These procedures do not include requirements forhealth, safety, and accountability. The observance of thesepractices does not relieve the user of the obligation to be awareof and to conform to all applicable international, federal, state,and local regulati
8、ons pertaining to processing, shipping, orusing uranium-ore concentrates. (Guidance is provided in CFR,10, Chapter 1.)1.5 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.6 This standard does not purport to address all of thes
9、afety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C967 Specification for Uraniu
10、m Ore ConcentrateC1022 Test Methods for Chemical and Atomic AbsorptionAnalysis of Uranium-Ore Concentrate2.2 Other Document:CFR 10 Nuclear Materials Licensing Code of Federal Regu-lations, Chapter 133. General Requirements3.1 Material Requirements:3.1.1 The uranium-ore concentrates shall be free-flo
11、wingand of a particle size not to exceed 6 mm (0.25 in.) or suchother limit agreed upon between contracting parties.3.1.2 The average moisture content shall not exceed 5.0 %weight of the uranium-ore concentrates.3.1.3 The material shall be shipped to the sampling plant in200-L (55-gal) standard stee
12、l drums that are fitted with steel1These practices are under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and are the direct responsibility of Subcommittee C26.02 on Fuel andFertile Material Specifications.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapprov
13、ed in 1986. Last previous edition approved in 2004 as C1075 93(2004).DOI: 10.1520/C1075-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Sevice at serviceastm.org. For Annual Book of ASTMStandardsvolume information, refer to the standards Document Summ
14、ary page onthe ASTM website.3Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.lids and equipped with suitable gasket, sealing rings, ands
15、ealing bungs (if applicable) to ensure weatherproofing. Thedrums shall be constructed so that the top of the drum is fullyopen when the lid is removed.3.1.4 The number of drums in a sampling lot shall notexceed 90 and the gross weight shall not exceed 45 metric tons(100 000 lb).3.1.5 Aminimum number
16、 of drums in a sampling lot may beestablished depending upon the sampling procedure used.3.2 Sampling Equipment Requirements:3.2.1 Care shall be taken in the design and operation of thesampling and all associated equipment to minimize the ex-changes of air between the atmosphere and the samplingsyst
17、em. For obvious safety reasons dust-carrying internal airmust be prevented from escaping the system. This is achievedby means of dust collectors. The latter, however, shall bedesigned and operated in such a way that a minimum amountof external air shall be allowed into the system. The purpose ofthis
18、 is (1) to limit the exchanges of moisture between theatmosphere and the UOC and (2) to prevent a size-selectivedusting. In any case, the amount of dust escaping the samplingoperations must be kept to a minimum.3.2.2 The scales for the gross and tare weights of the drumsshall be capable of reading t
19、o the nearest 0.2 kg (0.5 lb) andshall be fitted with a print-out or data processing system, orboth. They shall have a capacity of 600 kg (1300 lb). Theweigh scale shall be calibrated and adjusted if required, at thebeginning, middle, and end of each lot weighed. Test weightsshall be certified by a
20、statutory authority and shall be traceableto national or state standards.3.2.3 All sampling containers shall be clean and dry beforeusage.4. Primary Sampling, Falling Stream1 % In One Stage4.1 ScopeThe falling-stream procedure provides for re-moving a large number of increments of the material as it
21、 fallsfreely at a uniform, controlled rate. All of the material in a lotpasses through the system and is subject to incrementalsampling.4.2 Sampling Equipment Requirements:4.2.1 A schematic diagram of a typical falling-stream sam-pling facility is shown in Fig. 1. Subsequent procedures aredescribed
22、by reference to this equipment.4.2.2 The flow of material through the falling-stream systemshall be controlled by a rotary valve discharging to the hopperor pan of the first stage vibrating feeder.The rate of flow shouldnot exceed 4.5 3 102m3(1.6 ft3)/min and also should becontrolled so that the cut
23、ter obtains from the falling stream atleast 1 cut/2.8 3 102m3(1.0 ft3) of material.4.2.3 The first stage vibrating feeder should be adjusted sothat the depth of the material in the trough (pan) does notexceed 50 mm (2.0 in.), and that the entire vertical crosssection of the falling stream is totally
24、 intercepted by the cutterhead.4.2.4 The samplers should be designed and constructed asfollows:4.2.4.1 Approximately 1 % of the falling stream shall bediverted by the cutter. With small lots (for example, less than10 tons), however, a larger percentage may be implemented inorder to fulfill the requi
25、rements of the secondary samplingstage.4.2.4.2 The horizontal linear speed of cutter heads shall notexceed 15 cm (6 in.)/s.FIG. 1 Schematic Diagram of Falling-Stream Primary Sampler In One StageC1075 1024.2.4.3 The width of the cutter head shall be no less than 30mm (1.25 in.), that is, a minimum of
26、 five times the allowableparticle size.4.2.4.4 It is recommended that the cutter heads be con-structed of stainless steel to improve their durability andreliability.4.2.4.5 The top edges of the cutter heads shall be beveled toform knife edges.4.3 Procedure for Obtaining the Primary Sample:4.3.1 Clea
27、n and dry the tops of the drums if necessary,transfer them by means of a roller conveyor to the weigh scale,and record the gross weight to 60.2 kg (60.5 lb).4.3.2 After the gross weights of the drums in a lot have beenobtained, dump the contents of each drum into an elevated bin.4.3.3 Equip the dump
28、er with a vibrator and a dust collectordesigned and operated in accordance with 3.2.1.4.3.4 After the drum is emptied, tare weigh the empty drum,lid, drum ring, and bolt.4.3.5 Equip the bin into which the drums are dumped suchas to facilitate the flow control and the transfer of material fromthe bin
29、. The bin should have a conical bottom with a dischargeopening or a size that will provide the desired flow.4.3.6 The rotary valve discharge is received on an elongatedvibrating feeder that stabilizes a consistent flow rate.4.3.7 Remove a portion of the falling stream and receive itin a convenient s
30、urge bin mounted on a weighing system.4.3.8 The contents of the surge bin are then fed to thesecondary sampling system (see Sections 7-9).4.3.9 Let the material not diverted by the cutter fall freelyinto a second bin from which the drums may be refilled if sodesired.5. Primary Sampling, Falling Stre
31、am1 % In TwoStages5.1 ScopeThe falling-stream procedure provides for re-moving a large number of increments of the material as it fallsfreely at a uniform, controlled rate. All of the material in a lotpasses through the system and is subject to incrementalsampling.5.2 Special Sampling Equipment Requ
32、irements:5.2.1 A schematic diagram of a typical falling-stream sam-pling facility is shown in Fig. 2. Subsequent procedures aredescribed by reference to this equipment.5.2.2 The flow of material through the falling-stream systemshall be controlled by a rotary valve discharging to the hopperor pan of
33、 the first stage vibrating feeder.The rate of flow shouldnot exceed 4.5 3 102m3(1.6 ft3)/min and also should becontrolled so that the cutter obtains from the falling stream atleast 10 cuts/2.8 3 102m3(1.0 ft3) of material.5.2.3 The first stage vibrating feeder should be adjusted sothat the depth of
34、the material in the trough (pan) does notexceed 50 mm (2.0 in.), and that the entire vertical crosssection of the falling stream is totally intercepted by the cutterhead.5.2.4 The samplers should be designed and constructed asfollows:5.2.4.1 Approximately 10 % of each falling stream shall bediverted
35、 by each cutter.5.2.4.2 The horizontal linear speed of cutter heads shall notexceed 15 cm (6 in.)/s.FIG. 2 Schematic Diagram of Falling StreamC1075 1035.2.4.3 The width of the cutter head shall be no less than 30mm (1.25 in.), that is, a minimum of five times the allowableparticle size.5.2.5 It is r
36、ecommended that the cutter heads be constructedof stainless steel to improve their durability and reliability.5.2.6 The top edges of the cutter heads shall be beveled toform knife edges.5.3 Obtaining the Primary Sample Procedure:5.3.1 Clean and dry the tops of the drums if necessary,transfer them by
37、 means of a roller conveyor to the weigh scale,and record the gross weight to 60.2 kg (60.5 lb).5.3.2 After the gross weights of the drums in a lot have beenobtained, dump the contents of each drum into an elevated bin.5.3.3 Equip the dumper with a vibrator and a dust collectiondesigned and operated
38、 in accordance with the conditions of3.2.1.5.3.4 After the drum is emptied, tare weigh the empty drum,lid, drum ring, and bolt.5.3.5 Equip the bin into which the drums are dumped suchas to facilitate the flow control and the transfer of material fromthe bin. The bin should have a conical bottom with
39、 a dischargeopening of a size that will provide the desired flow.5.3.6 Set the rotary valve to deliver approximately 4.2 to4.5 3 102m3/min (1.5 to 1.6 ft3/min). This rate should notvary during the course of sampling of the entire lot.5.3.7 Remove a portion of the falling stream and divert it toa sec
40、ond vibrating elongated feeder and cutter of similar designwith a reciprocating cutter.5.3.8 Direct the material diverted by the second stage cutterto a tared primary sample container, and close with a suitablelid depending on the secondary sampling procedure to be used(see Sections 7-9).5.3.9 Let t
41、he material not diverted by the first- and second-stage cutters fall freely into a second bin from which the drumsmay be refilled if so desired.5.3.10 Since approximately 10 % of each falling stream isdiverted, the primary sample container will contain approxi-mately 1 % of the entire lot. In no ins
42、tance shall the totalsample weight vary more than6 5 % of the calculated value forthe equipment employed.6. Primary SamplingAuger Sampling Procedure6.1 ScopeThe auger-sampling procedure provides for theremoval of a core sample of the material from each drum bymeans of a tube that contains a rotating
43、 auger. Each drum ofmaterial passes through the system and is subject to individualsampling.6.2 Special Equipment Requirements:6.2.1 The auger sampler shall be designed and constructedso that approximately 0.5 % weight of the ore concentrate iswithdrawn from each drum. Experience with a variety ofur
44、anium-ore concentrates show that a range from 0.3 to 0.7 %can be expected. A schematic diagram of a typical auger-sampling facility is shown in Fig. 3. Subsequent procedures aredescribed by reference to this equipment.6.2.2 A tumbler shall be provided that is capable of rotatingthe sample drum about
45、 its axis at approximately 25 r/min.Before the tumbling operation, the sample drum shall be closedwith either of the following:6.2.2.1 A conical top fitted with a flow-control valve if thereciprocating cutter procedure is to be used for secondarysampling, or6.2.2.2 A plain lid fixed by a metal band
46、and bolt closure ifthe Vezin procedure is to be used for secondary sampling.6.2.3 In order to achieve the operating limits required for theauger-sampling system the following design parameters arerecommended:6.2.3.1 The auger shall be constructed of suitable material(for example, tool or stainless s
47、teel) and shall have thefollowing dimensions:(1) Auger TubeThe outside diameter shall be 50 to 60 mm(1.968 to 2.375 in.) and the inside diameter shall be 43 mm(2.375 to 1.687 in.).(2) Length of Auger Helix Within the Auger Tube, shall beapproximately 1400 mm (55 in.).(3) Pitch of Helix, shall be app
48、roximately 25 mm (1 in.)apart.(4) In operation, the end of the auger should protrude 6 to 25mm (0.25 to 1.0 in.) below the auger tube.6.2.3.2 The auger shall be made to have a minimumclearance allowing free rotation within the auger tube. Theauger shall be capable of being rotated electrically and,
49、whenoperating, shall turn at approximately 240 r/min.6.2.4 The auger sampling system may be used as a single ordouble facility depending on design. In the latter case, twodrums are sampled simultaneously with the two augers feedinga common hopper that discharges by means of a 75-mm (3-in.)flexible tube into a single sample drum of 200-L (55-gal)capacity.6.3 Obtaining the Primary Sample Procedure:6.3.1 Clean and dry the tops of the drums if necessary,transfer them by means of a roller conveyor to the weigh scale,and record the gross weight to 60.2 kg (60.5 lb). Pas
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