1、Designation: C866 11Standard Test Method forFiltration Rate of Ceramic Whiteware Clays1This standard is issued under the fixed designation C866; 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
2、 parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the rate atwhich a layer of clay-water paste is formed from a clay-waterslip under pressure filtra
3、tion. The filtration rate is directlyrelated to such whiteware operations as filter pressing, slipcasting, and drying of ware in which water permeabilitythrough a clay-water paste is the controlling mechanism.1.2 A straight-line relationship exists between the time offilter pressing and the square o
4、f the thickness of the paste layer.The filtration rate is directly related to the filter press pressureand the void fraction of the paste layer, and is inversely relatedto the square of the clay surface area, the ratio of solids toliquid in the slip, and the viscosity of water at the testingtemperat
5、ure.1.3 The values stated in acceptable metric units are to beregarded as the standard. The values given in parentheses arefor information only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standa
6、rd 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:2C324 Test Method for Free Moisture in Ceramic WhitewareClays3. Apparatus3.1 Balance, 0.001-g sensitivity.3.2 Blender.3.3 Filter
7、Press, capable of operation at 345 kPa (50 psi).3.4 Stop Watch.3.5 Vernier Calipers, capable of measuring thickness to thenearest 0.1 mm.4. Procedure4.1 Weigh 100 g of clay, dried in accordance with TestMethod C324, to the nearest 0.1 g and mix with 300 mL ofwater measured to the nearest 1.0 mL for
8、10 min in a blender.4.2 Store the slip in a closed container for at least 24 h toallow the clay and water to reach equilibrium conditions.4.3 Remix the clay-water slurry for 5 min in the blender.4.4 Pour the clay-water slurry into the filter press and apply345 kPa (50 psi) air pressure for 30 min.4.
9、5 Relieve the pressure from the filter press and then pourthe clay-water slurry from the top of the filter cake that hasformed. A sharp movement of the wrist is required to removeall of the remaining slip from the filter press.4.6 Record the temperature of the filtrate.4.7 Reapply air pressure to th
10、e filter press for 10 min toforce some of the water from the cake that has formed.NOTE 1Some clays have a fast filtration rate and the air may passthrough the cake in less than 10 min. In this case, the air pressure shouldbe relieved as soon as the sound of air emitting from the press is detected.4.
11、8 Remove the filter cake from the press and measure thethickness to the nearest 0.1 mm with the vernier calipers.4.9 Place the cake in a drying oven at 100 to 110C for aperiod of 24 h. Weigh the dried filter cake to the nearest 0.01g.5. Calculations5.1 Calculate the filtration rate as follows:FR 5 L
12、2/T (1)where:FR = filtration rate, cm2/s,L = thickness of the wet filter cake, cm, andT = filtration time, s.NOTE 2The filtration time is based upon the 30-min period duringwhich the clay-water slip is being filter pressed and does not include theadditional 10-min period for removal of water from th
13、e cake after it hasbeen formed.5.2 The void fraction in the filter cake varies considerablydepending upon ions in the water that modify the packingstructure of the clay particles in the filter cake. Water that is1This test method is under the jurisdiction ofASTM Committee C21 on CeramicWhitewares an
14、d Related Products and is the direct responsibility of SubcommitteeC21.04 on Raw Materials.Current edition approved March 1, 2011. Published April 2011. Originallyapproved in 1977. Last previous edition approved in 2006 as C866 77 (2006).DOI: 10.1520/C0866-11.2For referenced ASTM standards, visit th
15、e ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100
16、Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.normally used for mixing with the clays should be used for thetest so that interactions between ions in the water with the clayare considered. However, in some cases distilled water may beused for mixing with the clay so
17、 that only those ions introducedwith the clay are considered in the test. The void fraction iscalculated as follows based upon the density of the clay being2.60 Mg/m3:VF 5 1 2W2.60 3 A 3 L(2)where:VF = void fraction in the filter cake,W = dry weight of the filter cake, g,A = cross-sectional area of
18、the filter press, cm2, andL = thickness of the wet filter cake, cm.6. Precision and Bias6.1 The experience of several laboratories indicates that thistest method is capable of a precision of 62 % (95 % confi-dence level).7. Keywords7.1 clay; filtrationSUMMARY OF CHANGESCommittee C21 has identified t
19、he location of selected changes to this standard since the last issue(C86677R06) that may impact the use of this standard.(1) Addition of 1.3 describing the use of units in this TestMethod.ASTM International takes no position respecting the validity of any patent rights asserted in connection with a
20、ny 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 responsible technica
21、l 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 consideration
22、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 Barr Harbor
23、 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C866 112
