1、Designation: C 1075 93 (Reapproved 2004)Standard Practices forSampling Uranium-Ore Concentrate1This standard is issued under the fixed designation C 1075; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 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 These practices are intended to provide the nuclearindustry with procedures for obtaining representative bulksamples from uranium-ore
3、 concentrates (UOC) (see Specifica-tion C 967).1.2 These practices also provide for obtaeining 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
4、C 1022).1.3 These practices 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-stag
5、e falling stream 4Two-stage 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 sta
6、ges can beorganized in the 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 high
7、ly inadvisable to mix elements 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,
8、state,and local regulations 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 purpor
9、t 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 health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 967
10、 Specification for Uranium Ore ConcentrateC 1022 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 conc
11、entrates shall be free-flowingand 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 in20
12、0-L (55-gal) standard steel drums that are fitted with steellids and equipped with suitable gasket and sealing rings to1These practices are under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and are the direct responsibility of Subcommittee C26.02 on Fuel andFertile Material Specifica
13、tions.Current edition approved April 15, 1993. Published June 1993. Originallypublished as C 1075 86. Last previous edition C 1075 86.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Sevice at serviceastm.org. For Annual Book of ASTMStandardsvolume inform
14、ation, refer to the standards Document Summary 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.ensure weatherpr
15、oofing. The drums shall be constructed so thatthe top of the drum is fully open 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 A minimum number of drums in a sampling lot may beestablished
16、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 samplingsystem. For obvious safety reasons dust-carrying i
17、nternal 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 is (1) to limit the exchanges of moisture bet
18、ween theatmosphere and the UOC and (2) to prevent a size-selectivededusting. In any case, the amount of dust escaping thesampling operations must be kept to a minimum.3.2.2 The scales for the gross and tare weighings of thedrums shall be capable of reading to the nearest 0.2 kg (0.5 lb)and shall be
19、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 statutory authority and shall be traceable
20、to 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 fallsfreely at a uniform, controlled rate
21、. 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 by reference to this equipment.4.2.2 The f
22、low 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 cutter obtains from the falling stream atlea
23、st 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 intercepted by the cutterhead.4.2.4 The
24、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 tonnes), however, a larger percentage may be implementedin order to fulfill the requirements of the secondary samplingstage.
25、4.2.4.2 The horizontal linear speed of cutter heads shall notexceed 15 cm (6 in.)/s.4.2.4.3 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.4.2.4.4 It is recommended that the cutter heads be con-structed of stainless ste
26、el to improve their durability andreliability.FIG. 1 Schematic Diagram of Falling-Stream Primary Sampler In One StageC 1075 93 (2004)24.2.4.5 The top edges of the cutter heads shall be beveled toform knife edges.4.3 Procedure for Obtaining the Primary Sample:4.3.1 Clean and dry the tops of the drums
27、 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 dumper with a vibrator and a dust c
28、ollectordesigned 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. The bin should have a conical
29、 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 uniformizes the flow rate.4.3.7 Remove a portion of the falling stream and receive itin a convenient surge bin mounted on a weighing system.4
30、.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 Stream1 % In TwoStages5.1 ScopeThe falling-
31、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 Requirements:5.2.1 A schematic diagram of a
32、 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 the first stage vibrating feeder. The
33、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 the material in the trough (pan) does
34、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 by each cutter.5.2.4.2 The horizontal
35、 linear speed of cutter heads shall notexceed 15 cm (6 in.)/s.5.2.4.3 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 recommended that the cutter heads be constructedof stainless steel to improve their durabi
36、lity and reliability.FIG. 2 Schematic Diagram of Falling StreamC 1075 93 (2004)35.2.6 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 means of a roller conveyor to
37、 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 in accordance with the condit
38、ions 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 a dischargeopening of a size
39、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 second vibrating elongated feeder
40、 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 the material not diverted by th
41、e 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 instance shall the totalsample we
42、ight 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 auger. Each drum ofmaterial p
43、asses 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 ofuranium-ore concentrates show th
44、at a range from 0.3 to 0.7 %LEGEND1. Auger drive2. Hollow auger tube3. Sight glass4. Powder valve5. Auger helix6. Drum to be sampled7. Sample drum8. Hydraulic lifting cradleFIG. 3 Schematic Diagram of Auger Primary SamplerC 1075 93 (2004)4can be expected. A schematic diagram of a typical auger-sampl
45、ing 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 its axis at approximately 25 r/min.Before the tumbling operation, the sample drum shall be closedwith either of the fo
46、llowing: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 and bolt closure ifthe Vezin procedure is to be used for secondary sampling.6.2.3 In order to achieve the operating lim
47、its 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 steel) and shall have thefollowing dimensions:(1) Auger TubeThe outside diameter shall be 50 to 60 mm(1.968 to 2.375 in.
48、) 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 approximately 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
49、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, 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 Samp
