tared Gooch crucible, wash with the minimum amount of water, dry at 110” C. and weigh as PbSOa. D. Wash the residue from step 31B (ammonium acetate extraction) free of acid with distilled LTater, transfer to a porcelain crucible, ignite a t not above cherry-red heat for not more than 0.5 hour, and weigh as BaSO4. E. Evaporate the filtrate from step 318 plus that from the calcium determination to less than 300 mi. Determine magnesium as in step 30C. LITERATURE CITED
( I ) Am. Soc. Testing Materials, Philadelphia, Pa., Manual on In-
dustrial Water (1953).
(2) Ibid., pp. 108-13. (3) Ibid., hiethods for Chemical Analysis of Metals pp 92-4 (1950). (4) Ibid., Standards, Part 5, pp. 807-33 (1952). (5) Ibid., Part 7, pp. 1082-1263. (6) Ibid., pp. 1203-6. (7) \ , I h i d.., no _ . . 1216-20 ~ _ ~ . ( 8 ) Ibid., Speciel Tech. Pub. 116, 10j-14 (1951). (9) Scott, W. W.,“Standard Methods of Chemical Anrtlysis,” 5th ed., Vol. 1, pp. 235-7, F e w York, D. Van Nostrand Co., ~~
1939. (10) Treadwell, F. P., and Hall, W. T., “Analytical Chemistry,” 9th ed., Vol. 2, pp. 318-19, New York, J. Kiley 8r Sons, 1942. (11) Itid., PP. 324-7 (12) Washington, H. R., “Chemical Analysis of Rocks,” 4th ed., Kew York, J. Wiley 8r Sons, 1930. RECEIVED for review SEPTEMBER 14, 1953.
ACCEPTEDFebruary 19, I954
Scheme for Analysis of Industrial Water J
J. H. PHILLIPS AND K. G . STOFFER The Babcock & W’ilcox Co., Research Center, Alliance, Ohio
At the request of the Executive Committee of A4STMCommittee D-19, a task group was appointed to set up a scheme for analysis of industrial water, including a comprehensive list of the properties and constituents of industrial water for which analyses are made. The scheme divides the properties and constituents into four principal categories based on whether they are affected or unaffected by contact with the atmosphere, and according to the type of sample or sampling conditions required. A system of lines and sample group blocks is employed to associate properties and constituents with their appropriate sample groups and to indicate possible successive analyses of several constituents from a preceding analysis. The scheme for analysis of industrial water should become an important analytical aid for i t brings together in a manageable outline form the methods for determining the many properties and constituents of industrial water.
I
T HAS become apparent over the past several years that, in order to provide proper uniformity among laboratories, it is necessary to have available for ready refeience an analytical outline or scheme incorporating the many accepted physical and chemical methods for water analysis. Such a scheme would not only facilitate close agreement among laboratories but would also be of immeasurable assistance t o the individual analyst charged with industrial water control. The Executive Committee D-19 of the American Society for Testing Materials shared the desire for such a scheme, and in 1950 a task group was appointed by Subcommittee IV of ASThl Committee D-19 t o operate under the chairmanship of J. H. Phillips. senior author of this paper, to set up an aeceptable scheme for analysis of industrial m t e r . It Ras the hope of the committee that it would be possible to establish a scheme which would be workable for any industrial water sample and which, after refinement, could be included in the ASTM “Manual on Industrial Water” as a standard procedure. It was not difficult t o determine the desired scope of such a scheme. To be of real value t o the analyst the order of application of the many methods for chemical and physical measurements needed t o be indicated to permit the determination of existing constituents and properties in logical sequence. As might be imagined, the niechanics of arranging the analyti-
970
cal methods in a logical order proved to be the most difficult part of the problem. This is understandable when it is realized that there are not less than 50 individual constituents and properties which need to be included in order to set up a practical, workable scheme. The complexity of the problem became apparent when it mas first attempted to set down all these tests in sequence and t o indicate by one means or another the interrelationship of the various analyses to each other. The fact that certain constituents and properties may be adversely affected by sampling procedures and contact with air, or both, also prcsented a complication in the arrangement. In order to acquire some idea of what schematic outlines, if any, were being used in other laboratories, members of the task group submitted outlines of water analyses being used in their laboratories. None of these, of course, was as comprehenfive iis the scheme €or analysis desired by ASTM, but they did indicate constituents and properties of importance t o various agencies and industries. The order of sequence, if any, and the different physical arrangements of the schemes were also indicated. The outlines submitted by task group members were peculiar t o individual laboratory needs. Some were set up in the familiar block type of outline commonly used in qualitative analysis schemes; others simply enumerated the properties and constituents in an order suited t o specific needs; and still others used a
INDUSTRIAL AND ENGINEERING CHEMISTRY
V O ~46, . No. 5
Boiler Water Chemistry SA%IPLE SOURCE Sampling procedures shall be ~n a c c o r d a n c e w i t h applicable ASTM m e t h o d s
SAMPLES FOR CONSTITUENTS UNAFFECTED BY AIR CONTACT
SAMPLES FOR CONSTITUENTS AFFECTED BY AIR CONTACT In order to obtain the true c o n c e n tration of properties and constituents affected by air contact during sampling, o r during the Interval between sampling and anaiysis. it i s n e c e s s a r y to employ special methods or equipment, o r both, far sampling. and preferably. to c a r r y out the determinations immediately. If determinations a r e not made i m mediately in the field, it m u s t be realized that laboratory resuits reported for these constituents are based o n the sample in a n a s received condition, and are not n e c e s s a r i l y representative of the water sampled, since the iaboratory usually has no control ovei, o r knowledge of, . the sampling methods used. (Note I . )
Sampies f o r which these propert i e s and constituents are to be determined may or may not be filtered in the laboratory prior t o analysis, depending upon the nature and the amount of undissolved material, the method of analysis used, and the specific iniormation required. if the analysis i s to be representative of the sample a s collected at the source, the amount and composition of the undissolved material present should be determined. Spectrographic and X-ray diffraction examinational the undiss o l v e d material i s of value in connection with these procedures. (Note 1.)
first draft was completed and submitted to the members of t,he task group for study. This fmt draft, which was placed on a single large page, divided t,he properties and constituents being determined into two main groups-those affected by contact with air and those unaffected by contact with air. Little effort was made to assemble the properties and constituents into a logical sequence in the first draft. Rather, emphasis was placed on the physical arrangement of the outline and its appearance. For purposes of simplicity and clarity the name of the Eample group was placed a t the top of the page along with a short statement explaining what types of properties and constituents were included in the group. Each property and constit’uent of each group was tabulated down the left side of the page under that particular group tit’le. Each property or constituent’ which required a separate portion of the sample for analysis was connected by a line drawn to the group tit,le a t the top of the page. Where an analytical scheme for consecutively removing a series of elements from a single sample aliquot was possible, or where it was desirable to determine one or more constituents on a single portion of the sample by a scheme of successive analyses of filtrates or aliquots, the constituents determined in the scheme were connected by lines drawn t’o the appropriate preceding constituent in the analytical scheme, inst’ead of to the group title. Response to the first draft indicated that although the general arrangement and appearance were satisfactory per se, additions were necessary to show the correct, relationship between the various parts of the scheme. Referenced notes were needed to show the effects of oxidation, loss or gain of carbon dioxide, storage, light, type of container, and changes in concentration of one constituent brought about by change in its equilibrium with another constituent. Determinations not covered by existing ASTM specifications also needed to be considered. I n an attempt to draft a second scheme which would satisfy most, of these considerations arid a t the same time would be concise enough to be of value to the analyst, the plan to divide water samples into two groups mas continued. The first main group of‘ samples, “Constit’uents &4ffectedby Air Contact,” was furthersubdivided, as shown in Figure 1, into samples for analyses which can be made on flow samples continuously and automatically and samples for analyses which must be made on individual aliquots. The second main group, “Constituents Unaffected by Air Contact,,” was subdivided into determinations xvhich can be made on separate portions of a single sample, and determinations which, Tvhile the constituent’ is not affected by air contact, must’be made on separately collect’ed samples. Such a division permitted the scheme to be arranged on four separate pages, each containing only one subdivision or class of samples. A schematic indication of these sample divisions was given as the first part of the outline. It was decided that an alphabetical listing was the most satisfactory way to arrange the many propert’ies and constituents in the first three sample groups. The fourth sample subdivision, “Separate Samples for Constituents Unaffected by Air Contact,” pertained only to a limited number of analyses, such as the determination of chloroform extractable matter, and presented no particular arrangement problem. Other arrangements, such as listing first the most commonly determined constituents, or lis& ing by an anion and cation grouping, would be satisfactory for some laboratories and unsatisfactory for others. The alphabetical listing seems more universally favorable.
1 FLOW SAMPLES
(See Fig. 2) Flow samples shall be used i n determining these properties and constituents at the sample source. This information may be continuously and automatical. l y determined, indxated, and recorded.
SEPARATE SEPARATE SEPARATE SA&IPLES PORTIONS SAMPLES OF A SINGLE SAMPLE (See F i g . 4 )
which these properties and constituents are to be d e t e r mined require that the sample containers be sealed against a i r contact during the interval between sampling a n d analysi or the sampl must be chemi cally fixed i m mediately afte
-
served
in
the
case of samples
to
be analyzed f o r these constituents.
h-ote 1. If the property or conktituent to he determined may he affected by reaction of the sample with the sample contaiper, a separate sample should he collected in a special container that will not itself contaminate the sample. Container6 of polyethllene or similar material are gencrally satisfactory for this purpose.
Figure 1.
Outline of Principal Sample Groups
combination of these two forms. Kone of the outlines in its original form could be used as a basis for developing a scheme containing as comprehensive a list of properties and constituents as is now proposed for the ASTM scheme for analysis At one time during the study of the problem it was thought that, because of the complexities of outlining such a list of analyses in a way that sould indicate all the interrelationships existing among them, some simplification might be achieved bg first dividing the scheme for analysis into three primary divisions covering raw and treated waters, boiler and phosphated waters, and evaporated waters and steam condensate. Further consideration, however, showed that perhaps all the analyses involving these three classes of water could be included in a single outline. After several attempts a t such a composite outline, the
May 1954
OUTLINE OF PRINCIPAL SAMPLE GROUPS
I n preparing the outline of principal groups the subcommittee had to decide how much detail should be included concerning the various sample divisions and what should be mentioned concerning actual field sampling techniques. It had t o determine how much detail should be given concerning samples
INDUSTRIAL A N D ENGINEERING CHEMISTRY
971
PROPERTIES AND CONSTITUENTS AFFECTED BY AIR CONTACT F l o w s a m p l e s s h a l l be u s e d In d e t e r m i n i n g t h e s e p r o p e r t i e s a n d c o n s t i t u e n t s at the s a m p l e source. T h i s i n f o r m a t i o n m a y be continuously and automatically determined, indicated, and r e c o r d e d . E L E C T R I C A L CONDUCTIVITY: D I125 HYDROGEN: T H E R M A L CONDUCTIVITY METHOD (NOTE 2 OXYGEN: T H E R M A L CONDUCTIVITY METHOD
Note 2. Where an ASTM method is not indicated, refer to Chapter VI of the AST,M Manual on Industrial Water.
PROPERTIES AND CONSTITUESTS AFFECTED BY AIR CONTACT a r e t o be d e t e r m i n e d require t h a t the s a m p l e c o n t a i n e r s be s e a l e d a g a i n s t air c o n t a c t during the i n t e r v a l between s a m p l i n g a n d a n a l y s i s ; or the s a m p l e s muit be c h e m i c a l l y
ALKALINITY OR ACIDITY:
CALCULATED AMMONIUM I O N CALCULATED BICARBONATE ION: ( S E E
Figure 2. Flow Samples
affected by air contact, solubilities of gases and salts, and effect of container material. Actually, much of this information is given in the ASTM methods vhere the specific instructions apply Much of this material was not included because it \%asfelt that the more specific the outline n a s made, the inole exceptions to its application would be found. For example, in describing procedures to be followed at the sample source, the use of coolers and condensers or both wheie the sample source is above atmospheric pressure was originally mentioned. Directions n ere also given which applied only when those constituents which are soluble in the sample under operating conditions are to be determined. These details were included in the second draft of the scheme for analysis, but were abandoned in the third draft in favor of a sentence covering all cases, “Sampling procedures shall be in accordance with the applicable ASTN methods” ( 1 , 8 ) . Thus, the analyst is referred to the correct ASTRl sampling procedure, whether it covers industrial water, boiler water, or steam, or whether it is a special procedure such as is used in sampling for the determination of dissolved oxygen. Following the statement regarding sampling procedures, the outline provides for dividing samples into two groups. The phrase “air contact” includes not only oxidation, but also loss of gases and absorption of atmospheric gases. In order to obtain the true concentration of constituents affected by air contact during sampling, or during the interval b e h e e n sampling and analysis, it is necessary to employ special methods and equipment or both for sampling, and it is preferable to carry out the determinations immediately. If determinations are not made immediately in the field, it must be realized that the laboratory results reported for these conatituents are based on the sample in an as-received condition and are not necessarily representative of the water sampled. This is especially true if the laboratory has no control over, or knowledge of, the sampling methods used. Fortunately, a few properties and constituents which fall into the affected by air contact category, as shown in Figure 2, can be determined by instrumental methods on samples flowing in a closed system. Analyses of this type are valuable because they reveal the actual condition of the water a t the soulce. Electrical conductivity of very high purity water such as condensate is a good example of this type of property. Water with a conductivity of 3 micromhos pcr em. in a closed system may have its conductivity changed t o 10 niicromhos per cm. through exposure t o the atmosphere for a few seconds. The determination of pH of flow samples and the determination of dissolved oxygen and hydrogen by thermal conductivity methods are also made on flow samples. The majority of constituentv affected by air contact, however, cannot be specifically determined on flowing samples. Figure 3 shows this group in detail. Ferrous iron, nitrites, and sulfites are some of those constituents which must be determined on samples taken in containers sealed against air contact during the interval between sampling and analysis. I n some instances, for example, dissolved oxygen samples must be chemically fixed immediately
972
S U L F U R DIOXIDE CALCIUM AND MAGNESIUM HARDNESS: D1 I26 (NOTE 3 ) CALCIUM HARDNESS: D 1126 (NOTE 3 ) MAGNESIUM: ( N O T E 3 ) CARBON DIOXIDE, CARBONATE, BICARBONATE: D 513
CHLORINE: D 1253 HARDNESS ( S E E CALCIUM AND MAGNESIUM HARDNESS) (NOTE 31 HYDROXIDE ION. D 514 IRON, F E R R I C : D 1068 IRON, FERROUS: D 1068 NITRITE ION: D 1254 OXYGEN, DISSOLVED. D aaa pH: E 70 (NOTE 3 ) P H E N O L I C - T Y P E COMPOUNDS: (NOTE 2 ) SULFIDES AXD HYDROGEN SULFIDE: D 1255 [ALSO S E E NOTES 2 A h D 4 ) HYDROGEN S U L F I D E SULFIDES S U L F U R DIOXIDE, S U L F I T E , AND BISULFITES: (NOTE 2) BISULFITE ION: CALCULATED ( N O T E 4 ) S U L F I T E I O N CALCULATED (NOTE 4 ) S U L F U R DIOXIDE: C A L C U L A T E D (NOTE 41
I
I
I
I
I
Note 3. These properties and constituents are usually determined on separate portions of a single sample that has not been sealed against air contact, because, in most instances, it is either not possible or not practical t o obtain separate, sealed, or chemically fixed samples for these determinations. When determinations of these properties and constituents are requested on samples that have not been protected against air contact or that have not been chemically fixed, note should be made qualifying the analytical results i n this regard (see Fig. 4). Note 4.--In order to calculate these constituents correctly, the pH value of the sample must be noted simultaneously with the taking of the sample. The truest pH value would be from a flow.ing source (see Fig. 2).
Figure 3.
Separate Samples
after sampling in order t’o preserve the specific character of the sample a t the sample source. Determination of the ionic species of ammonia, carbon dioxide, hydrogen sulfide! and sulfur dioxide belong in this subdivision. Differentiation and distribution of the ionic species within each of t,hese groups is generally dependent upon a reliable pH determination. Curves or nomographs are available ( 1 , 3, 4 ) showing the per cent composition of the sample in terms of each of these ions a t all pH levels. Also included in this analytical subdivision are determinations such as calcium and magnesium hardness, which, although they are usually made on samples which have not been protected against air contact, are affect’ed t o some extent by loss or gain of carbon dioxide. Occasionally, however, a single scaled sample arrives a t the laboratory with a request for the determination of several properties and constituent’s,and among these are three or four constituents which rightfully belong in the air affected class. I n such cases these analyses must usually be made on the water after it has been exposed to air to some extent. Analyt,ical results in these instances, while t’hey provide morc or
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
Vol. 46,No. 5
Boiler Water Chemistry
PROPERTIES AND CONSTITUENTS NOT AFFECTED BY AIR CONTACT (Note 5) Separate portions of a single s a m p l e m a y be u s e d for determining t h e s e properties and constituents individually, or in s o m e cases, in a sequence of analyses. The customary precautions agalnst contamination by air-borne solids, o r too long storage i n unsuitable containers (Note 11, . . m u s t be observed i n the c a s e of s a m p l e s t o be analyzed for t h e s e constituents. *ALUMINUM D 857 BARIUM. (NOTE 2 BROMIDE ION: (SEE IODIDE ION CALCIUM: D 511 OR D 1126 *CALCIUM AND MAGNESIUM HARDNESS: D 1126 (NOTE 5) CALCIUM HARDNESS MAGNESIUM HARDNESS CHEMICAL OXYGEN DEMAND
1
1
CHLOROFORM-EXTRACTABLE MATTER: D 1178 (SEE FIG. 1 SEPARATE SAMPLES FOR CONSTITUENTS UNAFFECTEDBYAIRCONTACT
-
CYANIDE: NOTE 2 FLUORIDE I O N D 1179 HARDNESS: (SEE CALCIUM AND MAGNESIUM HARDNESS) HYDROXIDE ION D 514 IODIDE AND BROMIDE I O N D 1246
*IRON, TOTAL: D 1068 L E A D (NOTE 2) *MAGNESIUM: (SEE CALCIUM AND MAGNESIUM HARDNESS
ORGANIC MATERIAL: (SEE SOLIDS) NOTES 2 AND 5
CALCULATED (NOTE 4 ) POTASSIUM: D 1127 “SILICA: D 859 (SEE ALSO SOLIDS) CALCIUM: D 511 I MAGNESIU‘M: D 511 SULFATE: D 516 SODIUM: D 1127 *SOLIDS: D 1069 (SEE NOTES 5 AND 6 ) ALSO ESTIMATED FROM ELECTRICAL CONDUCTIYIT; (D 1125)] ORGANIC: D 1069 SILICA D 859 CALCIUM: D 511 MAGNESIUM: D 511 SULFATE: D 516 SILICA: D 859 CALCIUM: D 511 MAGNESIUM: D 51 1 SULFATE: D 516 SULFATE: D 516 (SEE ALSO SOLIDS AND NOTE 5) TANNIN AND LIGNIN: (NOTE 2 )
I
I/ I
I
~~~
I
Note 5. These constituents generally are not affected by air contact; however, many in this category are affected to some degree not only by the atmosphere, but also by storage, container material, light, temperature changes, and others. For example, high carbonate water containing appreciable amounts of calcium and magnesium may he rapidly influenced by a loss of COBand precipitation of ealcium. For this reason calcium and magnesium are included in both Figures 3 and 4. Note 6.-The analytical scheme outlined above is intended primarily to apply to total solids. To be a true analysis of the sample as received it may be necessary to separate the solids intofloating solids, suspended solids, settled solids, and dissolved solids. Analyses of any or all of these various types of solids can then be made using the above scheme and procedures; or, if the quantities involved in any of these solids categories are insufficient for chemical analysis, X-ray diffraction and spectrographic examination may be of value.
Figure 4.
May 1954
Separate Portions of a Single Sample
less valuable information, should be qualified with regard to the proper value of the sample, and attempts should be made, if practical, to ensure improved sampling procedures a t the sample origin. Samples for the determination of constituents and properties unaffected by air contact (Figure 4) may or may not be filtered in the laboratory prior to analysis, depending on the nature and the amount of undissolved material, the method of analysis used, and the specific information required. If the analysis is to be representative of the sample as collected at the source, the amount and composition of the undissolved material present should be determined. Spectrographic and x-ray diffraction examination of the undissolved material may be of value in connection with these procedures. hIost analyses are included in this category, and all but one or two of these can be made on separate portions of a single water sample. Chloroform extractable matter is one of the determinations which must be made on an individually collected sample, and special directions are specified in the ASThf method for obtaining samples for this determination. Another test which might require special sampling considerations is the examination of floating liquids. However, the majority of determinations may be made on separate portions of a single sample. The metals, the alkali group, alkaline earths, etc., are included in this group. Sone of these constituents is generally affected by air contact; however, over a period of time, some are affected to some degree not only by the atmosphere but also by length of storage, container material, light, and temperature changes. For example, high carbonate water containing appreciable amounts of calcium and magnesium may be rapidly altered by a loss of carbon dioxide and precipitation of calcium. For this reason, calcium and magnesium are included in both the affected by air and unaffected by air categories. In the determination of solids, a schematic arrangement was used for the consecutive determination of organic material, silica, calcium, magnesium, and sulfate ion in a sequential analysis, as shown in Figure 4. The outline was arranged to indicate that if solids and organic material were not first determined, calcium, magnesium, and sulfate ion could be determined on the filtrate from a silica determination. The third draft of the scheme for analysis, containing the material described, was completed earlv in 1953. At that time Subcommittee IV aubmitted it, with a few corrections that were suggested a t the last task group meeting in January 1953, to the ASTM for acceptance as a tentative method. One of the more important corrections suggested a t that time was that no suggested procedure be given for constituents for which there are no ASTM methods. Since the committee will eventually adopt methods for these constituents as -4STM standards, the space for the method designation in such cases was left blank. A note was made referring the analyst to Chapter 6 of the ASTM “Manual for Industrial Water” (I), which contains general instructions. This suggestion was incorporated in the third draft of the scheme which was submitted to ASThf for adoption as a tentative method. Further information on the scheme is contained in ASTM preprint, Method D 1256-53T (2). IMPORTANCE OF SCHEME FOR ANALYSIS
This is a report of the development of the scheme for analysis of industrial water to its present status. hfuch work remains to be done to tailor the scheme to fit all needs of the water analyst. Neither is it desirable to design an outline which is an inflexible scheme of analysis allowing no analytical freedom, nor is it desirable to make an outline so general that it loses its value to the analyst. Rather, the best outline will comprehensively cover the field of analysis of industrial water but will also allow the analyst to exercise common sense. For example, the best pH value would be one determined on water flowing at the source
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
973
before the sample has a chance to come in contact' n-ith the atmosphere. Often, hon-ever, t,his type of pH measurement cannot, be made because of lack of proper equipment a t the sample source or other practical considerations, and the sample must be taken in one location and transported t,o another for analysis. This does not mean that a p H measurement not made on a flowing sample would be of no value or even incorrect. From a practical standpoint, the analyst must determine the p H of the sample he has, but he must exercise discret'ioii in evaluat'ing his datma. As an .kSTlI method, this scheme for analysis will have an important role in industry. I n addit'ion to the value of MT3I methods in standardization of procedures and in cases of litigation and arbitration, this method will enable different companies interested in similar n-ater problems to undertake cooperative st,udies involying m t ' e r analyses. These can be easily carried out on t,he common ground of ASTRI procedures. Agencies ryhich are unfamiliar rvith water analysis and which wish to set up analytical facilities d l find this BSTAI scheme a valuable guide. Thus this ,scheme for analysis of indust,rial water is an important analyt'ical aid. I t brings together in a manageable outline form for em>- reference the multitude of accepted procedures required today for determining the many propert,ies and constituents in industrial water. It gives the analyst an easily comprehensible picture of the course t,o be folloived in malting a desired series of analyses. Publication of the scheme will serve still another purpose. The difficulties of applicat'ion nil1 be brought' to the attention of tmherepresentatives of industries making frequent' use of water analysis methods, and alteration and correction can hF: made.
Comments and suggested improvements are therefore wlcomed by the authors of this paper. .&CKXOW'LEDGMENT
The authors wish to express their appreciation to the officers and members of Coninlittee D-19 of -4STlI and in particular to Max Hecht, chairman of Committ'ee D-19, F. E. Clark, chairman of Subcommittee IT.', and to t,he task group responsible for drafting the scheme for analysis of industrial water--T7'. L. Lamar, U.S. Geological Survey; W. d.Lower, Duquesne Light Co. ; J. K. Rummel, Shepard T. Powell Consulting Engineers; J. F. J. Thomas, Department of Mines and Technical Surveys of Canada; and ITT. A. Kirklin, Hercules Powder Co. The authors' appreciation is also expressed to the ASTM for permission to reproduce the illust'rations that appear in Method D 1256-53T. Acknowledgment is also given t o D . S . Felgar of The Babcock 8: Wilcos chemical research section for valuable assistance in the development of t,his scheme. LITEH-ITURE CITED
(1) Am. SOC. Testing Materials, M a m a l on I n d z ~ s t r i u l T-l'atei, Tech. Pub. 148 (1953). (2) Am. Soc. Testing llaterials, Method D 1255-53T, Preprint 50, 37 (1953). (3) Am. Yoc. Testing Materials, Standards. 1952, Pt. 7. (4) McKinney, 1). S.,Ani. Sac. Testing Materials, Proc. 41, 128,s (194 1).
HECEIVEDf o r reriew September 14, 1953.
A c c E P r m Febrcary 10, 1054.
Calcium silicate
Calcium phosphate
Calcium carbonate
Calcium sulfate
Magnesium silicate
Magnesium phosphRte
Magnesium phosphate and silicate
Iron silicate
Research Samples of Scale Formation Deposits formed in 48 hourb i n experimental boilerfi (12 X )
974
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 46, No. 5
