1、Designation: C400 98 (Reapproved 2013)1Standard Test Methods forQuicklime and Hydrated Lime for Neutralization of WasteAcid1This standard is issued under the fixed designation C400; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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.1NOTECorrected erroneous references in 7.4.2.1 and 7.4.3.1 in December 2017.1. Scope1.1 This test method covers the tes
3、ting of quicklime andhydrated lime for use in the treatment of waste acid 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 w
4、aste acid and in the preparation of the lime slurry; the pH, the time,temperature, 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 varysubstant
5、ially from that indicated by ultimate chemical analysis or by theuse of a 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
6、 this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the
7、Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C50 Practice for Sampling, Sample Preparation, Packaging,and Marking of Lime
8、and Limestone ProductsE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3. Terminology3.1 Definitions: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
9、.1.2 pHa measure of the hydrogen ion concentration of asample and representing the logarithm of the reciprocal (nega-tive logarithm) of the activity of hydrogen ions, calculated asfollows:pH 5 log1H!152logH1!where:H+= activity of hydrogen ions.4. Significance and Use4.1 Since all limes and waste aci
10、d solutions are different,this test method evaluates the relative quantity of a given limeneeded for the neutralization 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 avo
11、ids dependence on chemicalanalysis and is determined as grams of calcium oxide equiva-lents per kilogram of liming 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 stoichiom
12、etricbasis to lime neutralization requirements of a liquid acid waste.5. Apparatus5.1 pH Measuring Apparatus, conforming 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 A
13、nalytical Balance, capable of reproducing resultswithin 0.005 g.1These test methods are under the jurisdiction of ASTM Committee C07 onLime and Limestone and are the direct responsibility of Subcommittee C07.05 onChemical Tests.Current edition approved July 1, 2013. Published August 2013. Originally
14、approved in 1957. Last previous edition approved in 2006 as C400 98 (2006).DOI: 10.1520/C0400-98R13E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards
15、 Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision
16、 on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.3 Stirrer, motorized, capable of rotating at speeds from120 to 600 r/min.5.4 Miscellaneous EquipmentChemically resistantglass
17、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 shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society, wh
18、ere suchspecifications are available.4Other grades may be used, pro-vided it is first ascertained that the reagent 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 distill
19、ed water.7. Test Method Afor Determining Lime Requirement forthe neutralization of a standard sulfuric acid or 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) wi
20、th water, dilute to 1 L, analyze to within 0.005 %H2SO4, and store in a suitable stoppered bottle.7.2 Preparation 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. Ad
21、d to a 500-mLtall-form beaker containing 50 mL of boiling water andcontinue to boil for 2 min. Remove from hot 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 w
22、ater in a 500-mL tall-form beakerfor at least 10 min.7.3 Procedure:7.3.1 Place the pH electrodes within the beaker 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
23、g ofH2SO4(1.5 6 0.05 %) into a separate 500-mLbeaker.Add thisacid to the sample in a single motion and record 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
24、 30 min reaction in the first test. Repeat theprocedure at least four times or until sufficient data areavailable 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 N
25、eutralization Rate Curves:7.4.1.1 Plot pH versus time in minutes for each of thelime-acid ratios used in the initial 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 then
26、eutralization rate curves described in 7.3.2, against grams oflime used per 1000 g of H2SO4(1.5 %).7.4.3 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 (7.3.2),correct for the actual acid concentration, and
27、calculate as partsof lime required per million parts of H2SO4(1.5 %) as follows:N 5 1.5/Z! 3X 31000where: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
28、.5.1 The precision and bias of this test method has not beendetermined at this time. Replicate samples are recommended.8. Test Method BFor Determining Acid Value-BasicityFactor Relationship8.1 Procedure:8.1.1 Basicity FactorWeigh 2.804 g 6 1 mg of the samplethat has been prepared to pass a No. 100 (
29、150-m) sieve andtransfer to a 500-mL Erlenmeyer flask containing approxi-mately 20 mL of cold water. (For quicklime samples, heat toboiling to ensure complete slaking). Add from a buret 100 mLof 1.0 N hydrochloric acid and stopper with a two-hole rubberstopper (Note 3). The quantity of acid may be i
30、ncreased ordecreased depending on the equivalent strength of the materialbeing tested. Place the flask on a hot plate and boil for 15 min.(Glass beads may be added to prevent bumping.) Remove theflask from the hot plate and cool in water. Add several drops ofphenolphthalein indicator solution and ti
31、trate the excess acidwith 0.5 N sodium hydroxide solution. Calculate the basicityfactor as follows:Basicity factor 5 V1N12 V2N2!/W# 30.02804where:V1= HCl (mL) required for titration of the sample,N1= normality of HCl,V2= NaOH solution (mL) required for titration of the excessacid,N2= normality of Na
32、OH solution, andW = sample (g).NOTE 3A water-cooled condenser with a tapered, ground-glass jointand a magnetic stir plate may be used during the boiling step.3Borosilicate glass has been found satisfactory for this purpose.4“Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-cal
33、 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 StatesPharmacopeia.”C400 98 (2013)128.1.2 Acid ValuePipet 10 mLof the sample o
34、f acidic wasteinto a 250-mL Erlenmeyer flask. This quantity may be in-creased 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 for 3 min. Filter through a smallBchner funnel with the aid of vacuum. Wash the residue ont
35、he 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:Acid value 5 V1N12 V2N2!/V# 30.03646where:V1= NaOH solution (mL) required for titration of thesamp
36、le,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 Basicity FactorCalculate the acid value-basicity factor relationship as follows:Acid valueBasicity factor30.76915 lime or lime
37、stone productkg! per litre of Acidic Waste.NOTE 4When agreed upon between the manufacturer and thepurchaser, Test Method A may also be used.8.2 Precision and Bias:8.2.1 The precision and bias of this test method has not beendetermined at this time. Replicate samples are recommended.9. Keywords9.1 ac
38、id value; alkalinity; basicity; lime requirement; limingmaterial; neutralization; neutralization coefficient; pH; wasteacidASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expr
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