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NICKEL-METAL, OXIDE(18) D.wiron Co., Bull. 112, “Durimet 20.” (19) Findlay, R. A., Natl. Petroleum News (Tech. Section), 37, 326-8, 386,388 (May 2,1945). (20) Flournoy, R. W., Corrosion, 7, 129-33 (1951). (21) Fontana, M. G., Chem. Eng.,53, No. 10,114-15 (1946). (22) Friend, W. Z., Ibid., 58, No. 8,222 (1951). (23) Friend, W. Z., Chem. & Met. Eng.,No. 9,203-6 (1946). (24) Friend, W. Z., J. Am. Oil Chemists SOC.,25, NO. 10, 353-8 (1948). (25) Friend, W. Z., and Mason, J. F., Jr., Corrosion, 5,355-68 (1949). (26) Friend, W. Z., and Teeple, H. O., Oil & Gas J., 44, 87-101 (March 16,1946). (27) Gergstrom, R. E., and Lientz, J. R.,.Paper Trade J . , 124, No. 1, 42-6 (1947). (28) Groggins, P. H., “Unit Processes in Organic Chemistry,” Chap. XIII, Polymerization, New York, McGraw-Hill Book Co., 1947. e (29) Haines, G. S., IND. ENG.CHEM.,41,2792-7 (1949). (30) Haynes Stellite Division, “Hastelloy High Strength, NickelBase Corrosion-ResistantAlloys,” 1950. (31) Hightower, J. V., Chem. Eng., 55, No. 7, 105-7 (1948). (32) IbidE., 56, No. 1 , 9 2 4 (1949). (33) Ibid., 56, NO.6, 92-6 (1949). (34) Holmberg, M. E., and Prange, F. A,, IND. ENG.CHEM.,37,103033 (1945). (35) Illium Corp., “Illium Corrosion Data,” Bull. 105-A (1946). ENG.CHEM.,39,236-434 (1947). (36) IND. (37) International Nickel Co., Corrosion Reptr., 3, No. 3 (July 1948); “Chlorinations, Dry, Moist, 8.79Wet.” (38) Ibid., 4, No. 1 (January 1949); Notes on Cellulose and Viscose Rayon.” (39) Ibid., 4, No. 3 (June 1949); “Phosphorus and Some of Its Compounds.” (40) Ibid., 5, No. 2 (November 1950); “Dyes, Reflectors of Light and Learning.” (41) Ibid., 5, No. 3 (February 1951); “Fluorine Comes Out of Its Corner Fighting.” (42) International Nickel Co., Inc., “Corrosion-ResistingProperties of the Austenitic Chromium-Nickel Stainless Steels,” 1949. (43) International Nickel Co., Inc., “Engineering Properties and Applications of Ni-Resist,” 1949. (44) International Nickel Co., Inc., “Inconel X. A High Strength, High Temperature Alloy,” 1949. (45) International Nickel Co., Inc., Process Industries Quart., 6, No. 3 (1941). (46) Ibid., 10, No. 3 (1947). (47) Ibid., 11, No. 2 (1948). (48) Ibid., 13, No. 1 (1950). (49) International Nickel Co., Inc., Tech. Bull. T-3 (1948).

(50) Ibid., T-6 (1949). (51) Ibid., T-13 (1948). (52) Ibid., T-29 (1945).

(53) Landau, R., and Rosen, R., ISD. ENG.CHEM.,39, 281-6 (1947). (54) LaQue, F. L., and Clapp, W. F., Trans. Electrochem. Soc., 87, 103-25 (1945). (55) LaQue, F. L., and Mason, J. F., Jr., Proc. 16th Mid-Year Meetinn. Div. of Refining, Am. Petroleum Inst., 30 MIII, 103-19 (1950). (56) Lee, J. A., Chem. Eng., 54, KO.9,122-4 (1947). (57) Lee, J. A., “Materials of Construction for Chem-cal Process Intries,” New York, McGraw-Hill Book Co., 1950. (58) McBride, G. W., Chem. Eng., 55, No. 10, 94-7 (1947). (59) Myers, W. R., and DeLong, W. B., Chem. Eng. Progress, 44, 359-62 (1948). (60) Nathorst, H., “Stress Corrosion Cracking of Stainless Steels,” Bull. 6, Welding Research Council, New York, 1950. (61) O’Conner,J. A., Chem. Eng., 56, No. 12,88-91 (1949). (62) Olive, T. R., Chem. & Met. Eng., 47, No. 11,770-5 (1940). (63) Olive, T. R., Chem. Eng.,56, No. 10, 107-12 (1949). (64) Palmer, J. A., ModernPZastics, 21, No. 11, 141-8 (1944). (65) Paul, R. J., Corrosion, 5,43942 (1949). (66) Pilling, N. B., and Ackerman, D. E., Trans. Am. Inst. Mznzny Met. Engrs., 83,248 (1929). (67) Porter, R. W., Chem. Eng., 53, fio. 10, 94-8 (1946). (68) Potts, R. H., and McBride, G. W., Ibid., 57, No. 2, 124-7 (1950). (69) Prine, W. H., Materials &Methods, 30, No. 12,43-6 (1949). (70) Rudge, A. J., Chemistry &Industry, 16,247-53 (1949). (71) Sefing, F. G., Petroleum Refiner, 29, KO.1,97-101 (1950). (72) Starr, B., Chem. Eng., 56, No. 8, 92-5 (1949). (73) Stout, W. W., “Secret,” Chrysler Corp., 1947. (74) Teeple, H. O., Paper Trade J., 131; No. 19, 28, 30-2; No. 20, 19-23; NO.21, 14, 15, 18, 19,21-5 (1950). (75) Tracy, A. W., and Hungerford, R. L., Proc. Am. SOC.Testing Materials, 45,591-617 (1945). (76) Treseder, R. 8. and Watchter, A., Corrosion, 5, 383-91 (1949)’. (77) Uhllg, H. H., “Corrosion Handbook,” New York, John Wiley & Sons, 1948. (78) Weiss, J. M., Heat Eng. (October, November, December 1944). (79) Williams, R., Jr., Chem. Eng., 55, No. 9, 118-21 (1948). (80) Ibid., 56, NO.7,92-4 (1949) (81) Worthington Pump & Machinery Corp., “Technical Information, on Worthite,” BUZZ. W-350-B4E (1951). (82) Zapffe, C. A,, “Stainless Steels,” Am. Soc. Metals, Cleveland, 1949. (83) Ziels, N. W., and Schmidt, TV. H., Oil & Soap, 22,327 (1945). (84) Zima, G. E., and Doescher, R. N., Metal Progress, 59, KO. 5. 660-3 (1951). RECEIVED for review October 17, 1951. ACCEPTED January 15, 1954

METALLURGICAL NICKEL ANALYSIS W. D. MOGERMAN Batten, Barton, Durstine, and Osborn, 383 Madirion Ave., New York, N.

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historical review is given of analytical difficulties that delayed general recognition of Cronstedt’s discovery of nickel. The nickel methods most widely used in metallurgical laboratories for determining nickel in both small and large quantities are discussed. Some practical hints are proposed fcr eliminating certain sources OF error in gravimetric work.

ART of the purpose in this symposium is to do honor to Axel Fredrik Cronstedt, who discovered nickel in 1751 and is chiefly remembered today on that account (6). In his own day Cronstedt was probably better known as the author of an unusual book on mineralogy, published in 1758 (3). Cronstedt’s proposed new element, nickel, was not accepted as a demonstrable fact by many of his scientific colleagues and so i t tended t o be overlooked for a long time (9). Some of his skeptical colleagues thought that Cronstedt was being deceived by a tricky mixture of

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copper and iron. The blue color of the substance in ammoniacal solution was attributed t o copper, and its magnetism t o the presence of iron. Some experimenters actually reported that the new substance was not magnetic. Nevertheless, these were the most reasonable opponents n ith whom Cronstedt contended, because they based their doubts on laboratory evidence, faulty though that evidence may have been. There were others who based their arguments against nickel on the theory that there could be no additional metallic elements because six “true metals” had been known since Biblical days, and six “half metals” already existed. That made twelve metals altogether, and to discover more would conflict with the twelve signs of the zodiac. So the controversy continued, fueled for a half century or more by bad analysis. But Cronstedt’s book, though i t was also controversial, was an indisputable fact that could not be dismissed with logic of this

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NICKELMETAL, OXlDF kind. It was unusual in that he insisted, apparently for the first time, that mineral classification should be based on definite knowledge of chemical composition rather thanmerely on observed physical properties. It was evidently common practice in those days to classify minerals with respect to crystal form, color, hardness, and so on. Basing his opinions on extensive experience with blowpipe analysis, which is more or less a lost art nowadays except as it survives in the guise of spectrochemistry, Cronstedt was able to show t h a t the older classifications of minerals into various kinds of earths, stones, fossils, and “bezoars,” or stonelike objects with magical properties, were confusing and likely to mislead the &dent as to the true nature and utility of the mineral. Cronstedt really had little patience with magic, but he had t o speak softly for many people of his time still were addicted to it. For instance, in one of his papers he pointed out that even twelve metals, which u a s considered by some folks as the upper limit, was already greater than the number of planets revolving around our sun: and this fact was offered as pretty forceful evidence that nickel might be an acceptable thirteenth ( 4 ) . Apparently, some of the more conventional mineralogists of the time resented Cronstedt’s remarks about the need for analysis, even if they did not object to the existence of nickel. Extractive metallurgy was then being practiced in Sweden with considerable practical success, and some of these practical metallurgists felt that as they had by their methods successfully guided extensive mining operations and had long occupied university chairs without the aid of chemical analysis, it was presumptuous of a young fellow t o point out fundamental shortcomings in their habits of thought. It must be admitted that there was some justice in their attitude, because suitable quantitative methods to handle their problems were still largely unknown. Two centuries ago, forward-looking technical men pinned their faith on empirical methods and these men were probably right in sticking to their own methods until something better was available, because analysis was still largely in the realm of theory, and they had had plenty of trouble with that. . Nevertheless, Cronstedtwas also right in pointingout the potential value of analysis, even merely qualitative analysis. His discovery of the (‘half metal,” nickel, was based on a number of shrewd observations and tests of a qualitative or roughly quantitative kind (8). In fact, many of the classical papers of this period are singularly lacking in quantitative analytical data. Some of the ablest chemists of the 18th Century spent years of work proving that nickel was not composed of iron and copper, that platinum was not composed of iron and gold, and so forth (1,9). Cronstedt sensed the fact that much of the prevailing confusion would vanish if analytical methods, even qualitative methods, were better developed. Reliable and accurate quantitative procedures were too much to expect in the middle of the 18th Century, even from him. I n his book Cronstedt adhered to this point of view, and time has borne him out (6). H e should therefore be credited as a pioneer of chemical analysis, one of those who blazed a path for Lavoisier, the man who later insisted on quantitative methods and arbitration by the analytical balance at every step. I n fact, Lavoisier was so thoroughly converted to the use of the balance that he went all the way and proclaimed, “Chemistry is the science of analysis.” This statement does not seem so extravagant even today, when one stops t o consider how much synthesis depends on analysis t o stay on the right track. D E T E R M I N A T I O N OF NICKEL IN S M A L L A M O U N T S

The great activity during recent years in the development of colorimetric, photometric, spectrophotometric, polarographic, and other physical methods of analysis has also been applied to the determination of nickel. Before World War I1 such methods were mainly applied to rapid determinations of small amounts of nickel, with only fair accuracy. But during the last decade the rapid development of instrumental techniques haa vastly extended

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the range and quality of such methods. As a general rule nickel is not separated from all other elements prior t o determination by these methods, so the procedures generally call for tricky details of operation to avoid the harmful effect of interfering elements. Speed and low cost are essential in modern control work, and highly specialized analysts have developed great skill in working in the presence of interfering elements that would probably discourage a beginner, or even a specialist in other fields of analysis. It is reported that about 125 papers dealing with instrumental methods for the determination of nickel have been published during the last half century, most of them in recent years, Although many of these methods are designed to estimate small amounts of nickel only, up to about 1 or 2 mg., the remarkable sensitiveness of the new techniques has extended the range downward to very small amounts, while a t the same time the reported accuracy has permitted the extension of the methods upx-ards so that high percentages are also estimated with precision. A prime consideration in favor of these methods is that they can be applied in the presence of other elements that were once considered to be fatal interferences. For example, it is claimed that nickel can be determined in low nickel steels (containing about 275 iYi) with greater accuracy when spectrophotometric methods are applied to aliquots, than by the use of the standard gravimetric and volumetric techniques usually applied to such amounts of nickel in steels ( 2 ) . When larger amounts of nickel are in question, as in the stainless steels and magnet alloys (containing as much as 20%), acceptable routine results can be obtained by instrumental techniques with speed and economy (7). These instrumental techniques are mainly colorimetric methods based on the reaction of nickel with dimethylglyoxime in the presence of powerful oxidizing agents in strongly basic solutions. It is even reported that by using a differential colorimetric procedure, nickel can be determined in samples containing 98% or more of the element with accuracy of &0.05%. For this work the green color of nickel in perchloric acid solution is compared with a known standard solution of nickel in a spectrophotometer (8). In other words, the rapid empirical methods that have proved so successful in steel analysis are being extended in many cases to the nickel-bearing materials of the nonferrous industry But just as iron in large amounts is rarely determined in a steel laboratory, so too nickel is not generally determined in routine work when it is a principal constituent of an alloy. The customary procedure with commercial nickel and high nickel alloys is to determine all theminor constituentsand to deduct the total from 100%. This method has its drawbacks, but it is certainly rapid and convenient and satisfactory enough for many purposes. A t any rate it is the best that can be done for routine work in the existing state of knowledge D E T E R M I N A T I O N OF NICKEL IN L A R G E A M O U N T S

For standard sample work and as a check on the composition of important materials, it is frequently desirable to determine nickel directly, even when it is present in large amounts. The analyst then finds himself surprisingly limited in his choice of methods. Only two standard gravimetric methods are widely used for large amounts of nickel. These are precipitation by dimethylglyoxime and electrodeposition. The volumetric cyanide method still finds use in some laboratories for rapid routine work. The scarcity of suitable gravimetric methods may account for the fact that nickel was so late in being discovered. Many other elements are more generously endowed with characteristic insoluble precipitates, some of which have been known for centuries. But all the methods now in use for nickel are of fairly recent origin. Therefore, most chemists of the 18th Century were not able to detect this element, despite the fact that nickel in low percentages (about 0.1%) is rather widely distributed in nature.

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NICKEL-METAL, OXIDE The highly specific affinity of nickel for dimethylglyoxime and certain other oximes in alkaline citric or tartaric acid solutions may be considered a stroke of luck t h a t is rare in the atomic family. Certainly it is a particular godsend for nickel analysis, which would otherwise be seriously hampered. SOURCES OF ERROR IN G R A V I M E T R I C W O R K

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For practical purposes, the two graviinetric methods, dimethylglyoxime and electrodeposition, are still relied on for most of the work with significant amounts of nickel. Both methods have their drawbacks and sources of error t h a t could be serious in unskilled hands. Nickel dimethylglyoxime is slightly soluble in t h e methyl or ethyl alcohol which is generally used to dissolve the reagent. As a consequence, t h e tendency is t o keep the alcohol in t h e nickel solution at a minimum, under 20%. Also, during digestion on a steam bath as carried out in some laboratories, there is a tendency to lose alcohol by fractional distillation. There is danger at this point that some of the excess dimethylglyoxime reagent will come out of solution and precipitate.with t h e nickel salt. This will produce high results if the precipitate is merely dried a t 110’ C., as is recommended in some textbooks. A temperature of 110” C. will remove alcohol and water but not invisibly occluded reagent. Most people will not take the time and trouble t o ignite this precipitate t o NiO. This source of error can be averted by drying the precipitate t o constant weight a t 150’ C., which volatilizes the excess reagent. A little mystification is also introduced when ferrous iron is present. The filtrate then exhibits a strong red color, which is often mistaken for more nickel. Naturally, this colored material will not precipitate on standing but slowly vanishes as the iron is oxidized b y air. The main source of error in the electrodeposition of nickel arises from the effect of cobalt. This element, in company with nickel as it generally is, has a tendency t o attack the platinum anode. I n such cases there is a variable loss on the anode, depending on the length of electrolysis. Some of the platinum lost from the anode is deposited on the cathode with the nickel and some of it stays in solution. That tends t o make the results for nickel a little high. On the other hand, not quite all the nickel is deposited, which tends to make the results a little

low. The final net outcome represents a compensation of errors, which often brings about a result surprisingly close to the truth. The effect of cobalt on the anode can be overcome by adding a gram or two of t h e reducing agent sodium bisulfite, but t h a t step is likely t o contaminate the cathode deposit with sulfur, which must be determined and deducted from the nickel. This is a troublesome operation and the result is t h a t analysts generally prefer t o endure the loss of platinum a t the anode. AE the platinum appears in a black spongy form, it is sometimes mistaken by analysts for a n illegitimate form of carbon and so reported. These errors are not large and are accepted as part of the facts of life for routine work in many laboratories. On the other hand, for more careful work laboratories can reduce these errors by precipitating the nickel with dimethylglyoxime prior to electrodeposition. This step has the virtue of removing cobalt. It takes longer, but it is a good way to avoid the errors due to the effect of excess reagent on the dimethylglyoxime precipitate and also t h e effect of cobalt on the anode during the subsequent electrodeposition of the nickel. Most of these points are well known among specialized analysts, but apparently they have not taken their place i n the textbooks yet. LITERATURE CITED (1)

(2) (3) (4)

(5)

Bergman, T. O., “Essays Physical and Chemical,” pp. 420-2 and 426-32, Edinburgh (1791). Cooper, M. D., Anal. Chem., 23, 875 (1951). Cronstedt, A. F., “Forsok til mineralogie eller mineralrikets upstiillning,” translated by Brunnich, as “System of Mineralogy,” 1770. Cronstedt, A. F., “Fortsetrung der Versuche die mit einer Erztart pus der loser Koboltgruben sind angestellt worden,” Kungliga Svenska Vetenskaps Academien, 1754; German translation in AbhandZ. NaturEehre, 16, 38-44 (1756). Cronstedt, A. F., “Svenskt Biografiskt Lexikon,” Stockholm,

1931. (6) Cronstedt, A. F., “Versuche mit einer Erztart von den lockern

Koboltgruben,” Kungliga Svenska Vetenskaps Academien, 1751; German translation in Abhandl. Naturlehre, 13, 2937 (1755). (7) Culbertson, J. B. and Fowler, R. M., Steel, 122, 108 (May 24, 1948). (8) Gentry, C. H. R., MetaZZurgica, 38, 108 (1948). (9) Thenard, C., Phil. Mag., 20, 63-70 (1805). RECEIVED for review October 17, 1951 ACCEPTEDJanuary 28, 1952.

NICKEL OXIDES Relation between Electrochemical Reactivity and Foreign /on Content ROBERT L. TICHENOR’ Thomas A. Edison, Inc., West Orange, T h e marked electrochemical effects of adding lithium, bismuth, and iron to the nickel electrode of alkaline storage batteries have been known for many years. Heretofore, no adequate explanation of how additions of these metals affect the electrode has been published. The theory given in this paper explains these effects using the following postulator: Electrolytic oxidation and reduction of nickel oxide are terminated by creation of insulating barrier layers of nickel oxide adjacent to the electronic conductor. “Foreign” ions such as those of lithium, bismuth, and iron enter into the crystal of nickel oxide b y substitution, replacing nickel ions. *The presence of these foreign ions affects the stability of the oxidation states of adjacent nickel ions. This change in stability retards or promotes oxidation of the nickel oxide, it also affects the growth of the insulating barrier layers. Both factors may affect the extent to which the oxide can be oxidized or reduced.

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HE best known electrochemical effects of adding “foreign” ions t o nickel oxides are: (1) the increase in electrochemical capacity of nickel oxideelectrodes in potassium hydroxideelectrolyte when lithium hydroxide is added t o the electrolyte, (2) the increase in electrochemical capacity of nickel oxide electrodes when a small amount of bismuth hydroxide is added t o the nickel oxide, and (3) the decrease in electrochemical capacity of nickel oxide electrodes when a small amount of ferric hydroxide is added to the nickel oxide. These effects were discovered by Thomas A. Edison many years ago during the development of alkaline storage batteries. While the knowledge of them has been of considerable importance commercially, very few attempts t o explain their mechanism have been published. Thus Crennell and Lea (2) and Foerster ( 4 ) sug-

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1 Present

address, E. I. du Pont de Nemours & Co., Inc., Waynesboro,

Va.

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