1、Designation: C 400 98 (Reapproved 2006)Standard Test Methods forQuicklime and Hydrated Lime for Neutralization of WasteAcid1This standard is issued under the fixed designation C 400; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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 testing of quicklime andhydrated lime for use in the treatment of waste acid
3、solutionsand includes the characterization of the liming material and ofthe acid waste.NOTE 1When agreed upon by the manufacturer and the purchaser,this method may be used directly to evaluate the lime requirement for aplant waste acid and in the preparation of the lime slurry; the pH, the time,temp
4、erature, and other conditions of treatment may be adjusted toconform to plant practice. Otherwise the test shall be performed asdescribed in this method.NOTE 2Under some conditions of test the lime requirement may varysubstantially from that indicated by ultimate chemical analysis or by theuse of a
5、determination of available alkalinity by titration to a stoichio-metric end point.1.2 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 standard to establish appro-priate safety and health practices and d
6、etermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C50 Practice for Sampling, Sample Preparation, Packag-ing, and Marking of Lime and Limestone ProductsE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3. Terminology3.1 Defi
7、nitions:3.1.1 neutralization coeffcientthe number of parts of limerequired to neutralize one million parts by weight of sulfuricacid solution (1.5 %) to a pH of 4.4 in 30 min (see Note 1).3.1.2 pHa measure of the hydrogen ion concentration of asample and representing the logarithm of the reciprocal
8、(nega-tive logarithm) of the activity of hydrogen ions, calculated asfollows:pH5log1H!152logH1!where:H+= activity of hydrogen ions.4. Significance and Use4.1 Since all limes and waste acid solutions are different,this test method evaluates the relative quantity of a given limeneeded for the neutrali
9、zation of a specific quantity of acid.4.2 Liming materials have a specific basicity factor ormeasure of alkalinity which can be used for comparing theirrelative neutralizing power. It avoids dependence on chemicalanalysis and is determined as grams of calcium oxide equiva-lents per kilogram of limin
10、g material.4.3 Likewise, specific waste acids have an acid value thatcan be expressed as grams of hydrochloric acid equivalent perlitre of acid waste. This value is related on a stoichiometricbasis to lime neutralization requirements of a liquid acid waste.5. Apparatus5.1 pH Measuring Apparatus, con
11、forming to the require-ments of Section 5, Apparatus, and Section 6, Reagents andMaterials, of Test Method E70. A time-pH recording device orattachment is desirable but not required.5.2 Analytical Balance, capable of reproducing resultswithin 0.005 g.5.3 Stirrer, motorized, capable of rotating at sp
12、eeds from120 to 600 r/min.5.4 Miscellaneous EquipmentChemically resistant glass-ware,3metal stands for support of the equipment, etc.6. Purity of Reagents6.1 Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shall1These test methods are u
13、nder the jurisdiction of ASTM Committee C07 onLime and are the direct responsibility of Subcommittee C07.05 on Chemical Tests.Current edition approved June 1, 2006. Published July 2006. Originally approvedin 1957. Last previous edition approved in 1998 as C 400 98.2For referenced ASTM standards, vis
14、it the 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.3Borosilicate glass has been found satisfactory for this purpose.1Copyright ASTM International,
15、100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.conform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, where suchspecifications are available.4Other grades may be used, pro-vided it is first ascertained that the reag
16、ent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.6.2 Unless otherwise indicated, references to water shall beunderstood to mean distilled water.7. Test Method Afor Determining Lime Requirement forthe neutralization of a standard sulfuric acid or
17、waste acidsolution within a time limit of thirty minutes.7.1 Reagents:7.1.1 Sulfuric Acid, Standard Solution (1.5 6 0.05 %)Thoroughly mix 15.8 g of concentrated sulfuric acid (95 %H2SO4) with water, dilute to 1 L, analyze to within 0.005 %H2SO4, and store in a suitable stoppered bottle.7.2 Preparati
18、on of Sample:7.2.1 Take samples of quicklime and hydrated lime inaccordance with Methods C50.7.2.2 QuicklimeWeigh a sample of quicklime (2.50 60.01 g) ground to pass a No. 50 mesh sieve. Add to a 500-mLtall-form beaker containing 50 mL of boiling water andcontinue to boil for 2 min. Remove from hot
19、plate and continuestirring with a magnetic stirrer until the slurry reaches roomtemperature (at least 10 min).7.2.3 Hydrated LimeMix a sample of hydrated lime (2.506 0.01 g) with 50 mL of water in a 500-mL tall-form beakerfor at least 10 min.7.3 Procedure:7.3.1 Place the pH electrodes within the bea
20、ker about12 in.(13 mm) above the surface of the lime slurry sample. Set themotor stirrer to the highest speed at which splattering orimmersion of the electrodes does not occur. Measure 250 g ofH2SO4(1.5 6 0.05 %) into a separate 500-mL beaker.Add thisacid to the sample in a single motion and record
21、the pH as afunction of time for a period of 30 min (see Note 1).7.3.2 Test a second slurry sample using more or less than250gofH2SO4(1.5 6 0.05 %), as indicated by the pH valueobserved after 30 min reaction in the first test. Repeat theprocedure at least four times or until sufficient data areavaila
22、ble to give a family of curves that indicate pH at 30 minas a function of grams of lime per 1000 g of H2SO4(1.5 %),with particular emphasis in the region of pH equals 4.4.7.4 Results:7.4.1 Neutralization Rate Curves:7.4.1.1 Plot pH versus time in minutes for each of thelime-acid ratios used in the i
23、nitial series of tests. This family ofcurves serves as the basis for calculation of the lime require-ments.7.4.2 Lime Requirement Curve:7.4.2.1 Plot the pH in 30 min, as determined from theneutralization rate curves described in Section 10, againstgrams of lime used per 1000 g of H2SO4(1.5 %).7.4.3
24、Neutralization Coeffcient:7.4.3.1 Interpolate the quantity of lime required to achieve apH of 4.4 in 30 min from the lime requirement curve (Section11), correct for the actual acid concentration, and calculate asparts of lime required per million parts of H2SO4(1.5 %) asfollows:N51.5/Z!3X31000where:
25、N = neutralization coefficient (see 3.1.1),X = grams of lime per 1000 g of H2SO4(1.5 %), andZ = concentration of the H2SO4to the nearest 0.005 %, asdetermined by analysis.7.5 Precision and Bias:7.5.1 The precision and bias of this test method has not beendetermined at this time. Replicate samples ar
26、e recommended.8. Test Method BFor Determining Acid Value-BasicityFactor Relationship8.1 Procedure:8.1.1 Basicity FactorWeigh 2.804 g 6 1mgofthesample that has been prepared to pass a No. 100 (150-m)sieve and transfer to a 500-mL Erlenmeyer flask containingapproximately 20 mL of cold water. (For quic
27、klime samples,heat to boiling to ensure complete slaking). Add from a buret100 mL of 1.0 N hydrochloric acid and stopper with a two-holerubber stopper (Note 3). The quantity of acid may be increasedor decreased depending on the equivalent strength of thematerial being tested. Place the flask on a ho
28、t plate and boil for15 min. (Glass beads may be added to prevent bumping.)Remove the flask from the hot plate and cool in water. Addseveral drops of phenolphthalein indicator solution and titratethe excess acid with 0.5 N sodium hydroxide solution. Calcu-late the basicity factor as follows:Basicity
29、factor 5 V1N12V2N2!/W#30.02804where:V1= HCl (mL) required for titration of the sample,N1= normality of HCl,V2= NaOH solution (mL) required for titration of theexcess acid,N2= normality of NaOH solution, andW = sample (g).NOTE 3A water-cooled condenser with a tapered, ground-glass jointand a magnetic
30、 stir plate may be used during the boiling step.8.1.2 Acid ValuePipet 10 mL of the sample of acidicwaste into a 250-mL Erlenmeyer flask. This quantity may beincreased or decreased depending on the strength of the acidicwaste. Add an excess of 25 to 30 mL of 0.5 N sodiumhydroxide solution and boil fo
31、r 3 min. Filter through a smallBchner funnel with the aid of vacuum. Wash the residue onthe funnel with water. Add several drops of phenolphthaleinindicator solution to the filtrate and titrate the excess sodiumhydroxide with 1.0 N hydrochloric acid solution. Calculate acidvalue as follows:4“Reagent
32、 Chemicals, American Chemical Society Specifications,” Am. Chemi-cal Soc., Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see “Reagent Chemicals and Standards,” by JosephRosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesPhar
33、macopeia.”C 400 98 (2006)2Acid value 5 V1N12V2N2!/V 3 0.03646where:V1= NaOH solution (mL) required for titration of thesample,N1= normality of NaOH solution,V2= HCl (mL) required for titration of the excess NaOHsolution,N2= normality of HCl, andV = sample (mL).8.1.3 Relationship of Acid Value to Bas
34、icity FactorCalculate the acid value-basicity factor relationship as follows:Acid valueBasicity factor3 0.76915 lime or limestone product kg! per litre of Acidic Waste.NOTE 4When agreed upon between the manufacturer and the pur-chaser, Test Method A may also be used.8.2 Precision and Bias:8.2.1 The
35、precision and bias of this test method has not beendetermined at this time. Replicate samples are recommended.9. Keywords9.1 acid value; alkalinity; basicity; lime requirement; limingmaterial; neutralization; neutralization coefficient; pH; wasteacidASTM International takes no position respecting th
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38、adquarters. Your comments will receive careful consideration 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 s
39、tandard is copyrighted by ASTM International, 100 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).C 400 98 (2006)3
