.^^ "^. .' ^'o 'bV a5°^ -1 ^'% V • ^^ ■^^^^ 1^ - * • I o •i "bV ^^-^^^ ^-^.^-^ /Jlfe\ \J^ yMM^ 'k.A^ :^^^' "^^ ^^^ *^ 1* . ' vv v-^^ ^^u.^^' . . • <^ 4 \ « • <*' .v ■-•. >^'\<-^'^ '*^o/-'?^-\o'5 ^ \.'*'^^*\*^^ v''r^*\o'5 \.'*'^^*\^^^ ^^oZ-T^ ^ ,^> V'^^'*/ '\*^'*\^*' V'^^^'*/ '^^,*^^*\^^' "-^ -. % -WW*' '^^^^ %^i^*' 4.*^'^\ "^^s ^^^\ ^'W0s j'''\ "-^w*" '^^^^ • ^o cs. no.: I 28.27:8902. I. Scrap metal s— Identification. . h Newell, R. (Raymond). II. Se- ries: Information circular (United Stales. Bureau of Mines) ; 8902. -4M»J^5rt)+ ITS2141 622s 1669'. 042] 82-600249 {■'or sale by the Superintendent of Documents, U.S. Government Printing Office Washington, O.C. 20402 CONTENTS Page Abstract 1 Introduction 1 Sorting strategy 2 Preliminary sorting 2 Object recognition 2 Color 3 Weigiit 3 Magnet testing 3 Spark testing 4 Chemical spot tests 5 Combining simple sorting methods 6 Optical emission devices 6 X-ray emission devices 8 Thermoelectric instruments 9 Eddy current testing 10 Quantitative chemical analysis 11 Other potential methods 11 Colorimetry 11 Page Ultrasonic inspection 12 Acoustic emission 12 Magnetic permeability 13 Magnetic susceptibility i3 Infrared emission 13 Galvanic measurement 13 Summary 13 References 14 Appendix A. — Suppliers of metals identification instruments 15 Appendix B. — Features of optical emission devices listed in appendix A 16 Appendix C. — Features of X-ray emission devices listed in appendix A 17 Appendix D. — Features of thermoelectric devices listed in appendix A 18 Appendix E.^<:)omparison of metals identification instruments and identification methods 19 ILLUSTRATIONS 1 . Schematic representation of spark testing terminology 4 2. Arrangement for electrographic sampling 5 3. Optical prism spectroscope 7 4. Schematic representation of basic thermoelectric sorter 9 5. Color variations with composition for high copper content copper-zinc binary alloys 12 TABLES 1 . Preliminary identification of metals and alloys by color 3 2. Preliminary identification of metals by weight 3 3. Preliminary identification of metals and alloys by magnetic response 3 4. Spark stream characteristics of metals and alloys 5 5. Spark stream colors of metals and alloys 5 A REVIEW OF METHODS FOR IDENTIFYING SCRAP METALS By R. Newell,' R. E. Brown," D. M. Soboroff,^ and H. V. Makar^ ABSTRACT As part of the Bureau of Mines program for conserving domestic mineral resources, a survey was made of the methods used for identifying scrap metals. Because of the large number of alloys currently being scrapped, correct identification of these materials is essential if they are to be recycled effectively. The methods and instruments used to identify scrap metals are described and evaluated. These include object recognition, color, density, magnetic testing, spark testing, chemical spot testing, thermoelectric measure- ments, eddy current measurements, and elemental analysis by chemical and instrumental methods. Other potential techniques are discussed also. INTRODUCTION Large quantities of scrap metals are discarded each year by industry and householders; recycling of these materials results in conservation of dwindling domestic resources and helps ease U.S. dependence on imports. Substantial energy savings are also achieved by increased use of recycled material (18).^ In order for these scrap metals to be returned to those operations where they can be recycled effectively, they must first be sorted and segregated into lots that contain similar materials. The first and most critical phase in this operation is the identification of the metal or alloy. In the routine operation of a commercial scrap yard, identification and segregation is carried out by experienced scrap sorters. The degree of separation the scrap metals receive at the scrap yard depends on the abilities of these sorters to identify the alloys with which they come into contact. This is commonly done by object recognition or by a limited number of physical or chemical tests {1, 9, 16-17, 25, 27, 30, 32-33). A widening variety of new alloys now is entering the scrap market, making recognition increasingly difficult, even for the experienced sorter. The problem is compounded further by the decreasing number of available, skilled scrap sorters. This skill in recognition can be achieved only through day-to-day, hands-on experience in the scrap yard or plant. Many of these newer alloys are chemically complex, so recycling of these alloys would be greatly facilitated if they were separated as discrete alloys rather than as a group of alloys with a common base. In fact, separation into discrete alloys is the ideal situation for all recycling operations, as it would enable recycling to be achieved without the expense of refining, diluting, and realloying. This in turn would maximize the financial return to the dealer. Identification of scrap may be accomplished by object recognition and by considering color, apparent density, magnetic properties, nature of sparks resulting when a metal or alloy is touched to a grinding wheel, chemical spot tests, and by the more time-consuming methods of chemical and spectrographic analysis. Some of the commercially available devices include fluorescent X-ray spectrographic analyzers, portable optical emission devices, and thermoelectric sorters. In addition, a number of techniques used in other fields of testing may have the potential to identify and sort certain metals and alloys. The purpose of this report is to review both currently available and potential methods of scrap metal identification. Within the various techniques, a number of commercially available instruments are noted. It should be emphasized that these are not intended to be complete lists, but are included to inform the reader of the types of equipment commercially available. Also, reference to specific company or trade names does not imply endorsement by the Bureau of Mines. Similarly, omission of specific company or brand names does not imply disapproval by the Bureau of Mines. ' Lecturer, School of Metallurgy, South Australian Institute of Technology, Adelaide, South Australia; work done while on sabbatical at the Avondale Research Center, Avondale, Md. ^ Physical scientist, Division of Ferrous Metals, Bureau of Mines, Washington, D.C. ^ Group supervisor, Avondsie Research Center, Bureau of Mines, Avondale, Md, ' Research supervisor, Avondale Research Center, Bureau of Mines, Avondale, Md. ^ Italicized numbers in parentheses refer to items in the list of references preceding the appendixes. SORTING STRATEGY Scrap metals are normally classified into three categories: home scrap, prompt industrial scrap, and obsolete scrap. Home scrap is generated within the melting or processing facility and is recycled back into the melting furnaces. Prompt industrial scrap, which is normally generated within fabricat- ing and manufacturing operations, may be recycled back to the melting and refining facilities if care is taken to keep it segregated and free of contamination. Obsolete scrap (or postconsumer scrap) is old scrap generated at the end of the product life cycle. This material presents the major problem for identification and segregation. Prior to sorting of scrap, it is necessary to select the groups into which the various materials are to be sorted. There is a very large number of commercial alloys available and, this number is increasing substantially as new alloys come onto the market. This wide variety of alloys makes it a practical impossibility to separate all scrap into distinct alloys. As a result, much scrap is sorted into more broadly based groups. The sorting method used needs to be tailored to enable the required separation with the highest efficiency. Standard classifications for nonferrous scrap and for iron and steel scrap have been published by the National Association of Recycling Industries (NARI) (29) and by the Institute of Scrap Iron and Steel (ISIS) (16). These designations are made on the basis of the fchemical composition and the physical condition of the material. They serve as a good basis for sorting scrap into marketable materials, and cover those items that are traded most frequently. Classifications other than those published by NARI and ISIS are also used. The following are examples of classifications: ISIS No. 209:— No. 2 bundles: Old black and galvanized steel sheet scrap, hydraulically compressed to charging box size, and weighing not less than 75 lbs per cubic foot. May not include tin- or lead-coated material or vitreous enameled material. NARI Honey: — 26-yellow brass scrap: Brass castings, rolled brass, rod brass, tubing, and miscellaneous yellow brasses including plated brass. Must be free of manganese bronze, aluminum bronze, unsweated radiators or radiator parts, iron, and excessively dirty and corroded materials. When deciding on the categories into which a material is to be sorted, the economics of the operation is of major importance. From a dealer point of view, it is best to sort into those categories that will result in the greatest dollar return. This, however, does not always result in separating the most valuable or critical groups from the scrap. Other factors such as insufficient quantities, difficulties in identification and separation may make it economically more viable to downgrade some of the more valuable or critical materials. The more valuable or critical alloys may constitute only a small fraction of the total, which, is separated, would be insufficient for sale. It may, however, be found that in order to meet a given specification, material of higher alloy content must be removed or lower grade material must be added to dilute the effect of the higher alloy. If sufficient quantities of the high alloy material are involved, and if the extra return for separating is warranted, then this material would be removed. If not, other material must be mixed with the batch so that it will meet specifications. An example of this can be found within the AISI type 300 series stainless steels. The NARI classification Sabot 125 calls for clean 18-8 grade stainless steel clips and solids containing a minimum 7 pet nickel and 16 pet chromium and a maximum of 0.5 pet molybdenum, 0.5 pet copper, 0.045 pet phosphorous, and 0.03 pet sulfur, and othenwise free of harmful contaminants. Within this series, type 316 stainless steel contains 2 to 3 pet molybdenum, and certain less-common grades also have significant amounts of molybdenum. In order to meet the specification, these grades must constitute less than 10 to 15 pet of the total; othenwise, they must be removed or diluted. In this ease, the higher molybdenum grades will usually bring a higher price due to the high cost of molybdenum, and it becomes economical to separate the molybdenum grades from the others, provided enough material is available to make up a salable parcel. The potential reward for separating material into discrete alloys increases as the value of the alloy content increases. In addition, there is a potential penalty of increasing magnitude if contaminating material is present. This is especially true for certain superalloys. These often contain significant quantities of several alloying elements, and elements that may be beneficial to one alloy may be harmful to another. For these alloys, therefore, the incentive exists for separating into discrete, uneontaminated alloys, and soph- isticated identification, separation, and cleaning techniques can be justified. For alloys of lower value, this incentive does not exist and simpler methods will suffice. PRELIMINARY SORTING The preliminary process for identifying metals involves judgmental decisions on the part of the sorter based on the shape, color, and weight of the material. This is often followed by testing with a small hand-held permanent magnet. These methods are sometimes ail that is necessary for adequate segregation. When separating into standard classifications, the physical nature and size of the material as well as its chemical composition are considered. OBJECT RECOGNITION Some alloys can be easily identified on the basis of known commercial applications. For example, cocks and faucets usually made of similar alloys (yellow brass) are quickly sorted into a "cocks and faucets" category for resale, also, certain valve bodies are typically made of red brass and can be sorted by object recognition alone. Thus, if the class of alloys from which a particular object is made is known, then the sorting process can be greatly simplified. At best, a particular designation can be assigned to the alloy; at worst, the number of possibilities can be greatly reduced. Unfortunately, a great deal of experience is required to make effective use of this method. In addition, the amount of experience required increases markedly with the diversity of the operation, as the number of alloys and objects likely to be encountered in a wide-based scrap business is much greater than in a small business. As an example of the use of this method for identification, stainless steel cutlery will be made from AISI types 410, 420, or 440 grades. Similarly, plumbing fittings may be made of red brass, semired brass, or yellow brass. These brass alloys can be distinguished from each other by color and the appearance of their drillings. Information regarding uses and applications of alloys is not usually presented in this Vvay. More usually, various alloys are listed and their applications noted along with chemical composition, mechanical properties, etc. Information of this sort is readily available in the technical literature (25, 28), from industry groups such as the Copper Development Association, the American Iron and Steel Institute, the Aluminum Association, and from the producers of the various types of alloys. This type of information can be used by the sorter to aid in identification. A wide range of alloys may be used for certain applications. This is especially true for the more complex alloys and superalloys that are required for high-temperature oxidation and corrosion resistance. Alloys of different composition can have similar applications, and the use of object recognition can serve only to define the material as a superalloy, but not make the closer separations into the specific alloy. COLOR A number of metals and alloys have a characteristic color, thus visual examination of color can be used to make an initial separation. In certain cases, a definite identification can be made on this basis. When using color to identify metals, it is important that a clean, freshly prepared surface of the base metal be examined in order to eliminate the effects of coatings, corrosion products, dirt, etc. The clean surface can be obtained by filing, grinding, drilling, or shearing. If drillings are used, it should be remembered that the color of the drillings can vary depending on the amount of pressure used to obtain the drillings and on the type of drill and bit used. The material should be examined in good light but not in direct sunlight. Artificial lights are available that will give the same characteristics as daylight. It is also important, in all cases where identification is made by the color of the break, or by drilling or filing, that the examination take place immediately. Exposure to the environment, even for a relatively short time, may change the color of the metal, making identification more difficult. A preliminary sorting based on color can be carried out according to table 1 . Table 1. — Preliminary identification of metals and alloys by color Color Metal or alloy Red or reddish Copper. Light brown or tan 90/10 cupronicl cc o -J O o I00r 90- 80- COPPER-ZINC BINARY ~i \ r- ^ •10 KEY ■ Lightness - A Red-green • Yellow-blue ^ I 10 20 30 ATOMIC PERCENT ZINC 40 Figure 5. — Color variations with composition for high copper content copper-zinc binary alloys. color differences. The lightness, red-green, and yellow-blue components are all available as direct readouts from color instruments. The results of color measurements (14) on a series of copper-zinc alloys cast into 10-by 10-by 1-mm paddles that were ground and polished before testing are shown in figure 5. The potential of colorimetry for identification of certain copper-base alloys can be readily seen. The potential of this method has also been demonstrated by the Bureau of (Vlines (26). Color measurements are affected markedly by the method used to prepare the sample surface. Some of these effects are peculiar to certain regions of the color spectrum; whereas others are not limited to any particular color region. An example of the effect of surface preparation is the amount of lead streak produced in alloys containing that element, which in turn affects the reflectivity of the metal in the blue regions. Besides the need for careful surface preparation, commer- cially available colorimeters have two major deficiencies when applied to scrap sorting. The sample areas required are relatively large because the optical efficiencies of the instruments are not high, and the instruments are designed for use under laboratory conditions. Both of these may possibly be overcome by the use of fiber optics systems for the incident and reflected light paths. ULTRASONIC INSPECTION Ultrasonic inspection makes use of mechanical waves above the audible range. Because the ultrasonic waves are based on mechanical phenomena, they are particularly useful for determining the integrity and structure of materials. In addition, ultrasonic energy can be readily introduced into materials, and the resulting wave motion is easily trans- mitted. An ultrasonic beam impinging on an interface between two media, for example, the test object and its surroundings, is partly reflected and partly transmitted in accordance with well-known physical laws. The characteristic that determines the amount of reflection is the acoustic impedance which is the product of the density of the medium and the velocity of the sound waves within it. IVIetals and alloys of different compositions have different impedances. This then gives rise to a possible identification method based on the propagation of ultrasonic waves in the material. Such an identification method would, however, be greatly affected by the internal structure of the material being tested, for example, a flaw can be detected as its impedance is different from that of the surrounding materials. ACOUSTIC EMISSION Acoustic emission is the energy that is released when a material is stressed either gradually or suddenly. The energy is released in the form of a sound wave that travels through the material from the point of origin to the limits of the structure. The energy of each pulse is characterized by a frequency of about 40 kHz, which is well above the frequency of audible sound or vibration. The acoustic emission coming from a material under stress can be sampled by means of a probe pressed against the material. The probe is a transducer, which changes the shock wave energy into electrical waves. This electrical signal is transmitted to the electrical measuring system which rejects the vibration and sound portions of the probe signal and amplifies the acoustic emission for measurement and display on a decibel meter. The size of the reading for a given material is a measure of the strain being produced in the metal. Because different materials behave differently under stress, and because sound waves propagate at different rates in different materials, it is possible that acoustic 13 emission could be used in metal identification. As with ultrasonic methods, acoustic emission is very sensitive to the physical and structural condition of the material. The full potential of acoustic emission has not yet been realized as it is a relatively new field. MAGNETIC PERMEABILITY The magnetic permeability, \x., is a characteristic parameter of a material. It is usually convenient to define another quantity, known as the relative permeability, [jlr, as the ratio of the permeability of the material to the permeability of empty space. Materials may be classified in terms of their relative permeabilities. Diamagnetic materials have relative permeabilities a little less than unity; paramagnetic materials have relative permeabilities a little greater than unity. Ferromagnetic materials are those that have relative permeabilities considerably greater than unity. Magnetic permeability is a function of composition, and, thus has some potential as a means of identifying metals and alloys. Differences in magnetic permeability are, in fact, used in preliminary sorting with a hand magnet, although in this case no attempt is made to assign quantitative values to the permeability. Unfortunately, magnetic permeability of ferro- magnetic materials is greatly influenced by the past magnetic history of the material. The permeability of paramagnetic and diamagnetic materials is greatly influenced by the presence of ferromagnetic impurities. The greatest potential for the use of magnetic permeability appears to be in the identification of slightly ferromagnetic materials. MAGNETIC SUSCEPTIBILITY Magnetic susceptibility describes the magnetic response of a substance to an applied magnetic field. Since magnetic susceptibility varies with composition among other factors, it is possible that use could be made of differences in magnetic susceptibility for identification. Commercial instruments are available for measuring the volume magnetic susceptibility of mineral drill cores, hand samples, or outcrops. It is possible that they could be adapted for use with metals. INFRARED EMISSION The infrared portion of the spectrum covers wavelengths from about 750 to 10^ nm. These are the wavelengths between those of visible light and the microwaves used in the highest frequency radar systems. For convenience, this band is said to consist of the near infrared (750 to 1 ,200 nm), the intermediate infrared (1,200 to 7,000 nm) and far infrared (7,000 to 10^ nm) regions. Infrared radiation is naturally emitted by all objects because of the thermal agitation of their molecules. This motion increases as the temperature of the object increases and decreases as the temperature de- creases until it stops at absolute zero. Since all molecules are made up of electrical charges, the oscillations of these molecules cause the radiation of electromagnetic energy. The intensity, frequency, and wavelength of this electro- magnetic energy are controlled by the temperature and size of the source and by the emissivity of the material. The emissivity is the ratio between the radiation emitted from a body and the radiation emitted from an equivalent blackbody. The value of the emissivity varies with the material and the surface finish of the body. Since the composition of the material affects its emissivity, and hence the amount of radiation energy emitted from a body at constant temperature, some potential exists for the application of emissivity in metals identification. However, surface finish and shape play a greater role so careful surface preparation would be required. Three fundamental types of infrared instruments are commercially available. Infrared thermometers make non- contact temperature measurements of the object area of interest. Process control instruments measure the tempera- ture of the object or area of interest and generate a control signal to maintain that object or area at the desired temperature. Thermographs, also known as infrared camer- as, scan a large area of interest and form an image that shows the varying amounts of infrared radiation being emitted by different parts of that area. These instruments could possibly be adapted for metals identification. GALVANIC MEASUREMENT A difference in electrical potential always exists between two dissimilar metals. If these metals are placed in contact or othenwise electrically connnected, this potential difference produces electron flow between them. The current is a function of the composition of the two materials and thus provides a method of metal identification. A comparative method using galvanic measurements for distinguishing type 31 6 stainless steel from Durimet T (22 pet Ni, 19 pet Cr, 2.5 pet Mo, 1 pet Cu, balance Fe) has been described by the International Nickel Company (17). These two alloys cannot be distinguished by standard hydrochloric acid and sulfurous acid chemical spot tests because they react similarly. In the galvanic method, a known specimen of one alloy and the unknown specimen are immersed in a 1 0-pct HCL solution and are connected to the terminals of a to 1 milliampmeter. No permanent deflection of the ampmeter needle identifies the known and unknown specimens as the same alloy. A permanent deflection of the needle identifies the unknown specimen as a different alloy than the known specimen. Similar methods could be used for other alloys. SUMMARY A large number of methods and instruments used in identifying metals are compared in appendix E. Unfortunate- ly, there is no one method or instrument capable of rapid and accurate identification of every combination of composition and physical condition. Complete chemical analyses, when properly performed, will give the required accuracy but require long times, a high degree of operator skill, and expensive laboratories and equipment. Manual and instru- ment methods with the required speed of identification often lack accuracy or versatility. Most of the identifying instruments have been developed for use in confirmation of identity; that is, they are basically comparators. They work well in this context to confirm both the identity and correct treatment of wrought and cast stock and finished articles withing their analytical capabilities. When used for scrap identification, complicating factors such as changes in the physical character of the material and the presence of dirt, grease, platings, and corrosion products may affect the operation of the instrument. In addition, the need is more for an identifier rather than a comparator, as the range of materials likely to be encountered is greater and varies more rapidly than in a production situation. These 14 problems are greatest for obsolete scrap, as identification of prompt scrap may be greatly facilitated by a knowledge of, and cooperation with, the source of the material. The suitability of the methods and instruments described in this report for a given application may be gaged from experience and manufacturers' data. Confirmation requires testing of appropriate samples. Many manufacturers offer a service in this regard and some will dedicate their instruments at the factory to fit the customers' requirements. REFERENCES 1. American Iron and Steel Institute. Tool Steel Trends, Winter 1971. New York, 1971. pp. 2-9. 2. American Society for Testing and Materials. ASTM Standards. Chemical Analyses of Metals; Sampling and Analysis of Metal- Bearing Ores, Part 12. Philadelphia, Pa., 1977, 858 pp. 3. Burkhalter, P. G. Detection Limits for Silver by Energy Dispersion X-Ray Analysis Using Radioisotopes. J. Appl. Radiation and Isotopes, v. 20. 1969. pp. 353-362. 4. Burkhalter, P. G. Radioisotopic X-Ray Analysis of Silver Ores Using Compton Scatter for Matrix Compensation. Anal. Chem., v. 43. January 1971. pp. 10-17. 5. Burkhalter. P. G. Radioisotopic X-Ray Analytical Techniques for Gold and Silver Ores. Section in Internal. Atomic Energy Agency Pub.. 'Nuclear Techniques and Mineral Resources," Vienna, 1968, pp. 365-379. 6. Burkhalter, P. G. X-Ray Intensity Measurements From Ores Using Semiconductor Detectors and Radioisotopic Excitation. Symp. on Low Energy X- and Gamma-Ray, Sources and Applications, Gordon and Breach, New York, 1971, pp. 147-163. 7. Burkhalter, P. G., and H. E. Marr III. Detection Limit for Gold by Radioisotopic X-Ray Analysis. J. Appl. Radiation and Isotopes, v. 21, 1970. pp. 395-403. 8. Campbell, W. J. Applications of Radioisotopes in X-Ray Spectrography. Ch. in Radiation Engineering in the Academic Curriculum. International Atomic Energy Agency, Vienna, 1975, pp. 225-258. 9. Campbell, W. J. Energy Dispersion X-Ray Analysis Using Radioactive Sources. X-Ray and Electron Methods of Analysis, ed. by William Parrish. Plenum Press, New York, March 1 968, pp. 36-54. 10. Department of Defense, Defense Supply Agency. Defense Scrap Yard Handbook. DSAH4160.1TM755-200, NAVSANDA PUB 5523, AFM 68-3 MCO P401.2A, June 1966, 204 pp. 11. Feigl. F. Spot Tests, Inorganic Applications. V. 1, 4th ed., Elsevier, Publishing Co., New York, 1954, 400 pp. 12. Gabler, R. C, Jr., R. E. Brown, and J. G. Haymes. A Computer Program for AA Data Processing. Am. Lab., February 1971, pp. 10-16. 13. Gabriel, A., H. W. Jaffe, M. J. Peterson. Use of the Spectroscope in the Determination of the Constituents of Boiler Scale and Related Compounds. Proc. ASTM, v. 47, 1947, pp. 1111-1120. 14. German, R. M., M. M. Guzowski, and D. C. Wright. Color and Color Stability as Alloy Design Criteria. J. Metals, v. 32, No. 3, March 1980, pp. 20-27. 15. Green, T. E. Atomic Absorption Graph Paper. Atomic Absorption Newsletter, v. 7, No. 5, 1968, p. 98. 16. Institute of Scrap Iron and Steel Inc. Handbook. Institute of Scrap Iron and Steel, Washington, D.C., October 1979, 110 pp. 17. International Nickel Co., Inc. Rapid Identification (Spot Testing) of Some Metals and Alloys. 1947, 47 pp. 18. Kusik. C. L., and C. B. Kenahan. Energy Use Patterns for Metal Recycling. BuMines IC 8781, 1978, 182 pp. 19. Lister, D. B. Applications of Energy Dispersive X-Ray Fluorescence. Pres. at 21st Annual I.S.A. Analytical Instrumentation Symposium, Philadelphia, May 6-8, 1975, pub. in Anal. Instr., v. 13, 1975, pp. 143-151. 20. Marr, H. E., III. Mathematical Smoothing of Digitized X-Ray Spectra. BuMines IC 8553, 1972, 15 pp. 21. Marr, H. E., III. Rapid Identification of Copper-Base Alloys by Energy Dispersion X-Ray Analysis. BuMines Rl 7878, 1974, 15 pp. 22. Marr, H. E., III. Six Models for Interelement Correction in X-Ray Analysis. Advances in X-Ray Analysis, v. 19, 1975, pp. 167-180. 23. Marr, H. E., Ill, and W. J. Campbell. Evaluation of a Radioisotopic X-Ray Drill Hole Probe: Delineation of Lead Ores. BuMines Rl 7611, 1972, 28 pp. 24. Marr, H. E., Ill, and W. J. Campbell. The Processing of Energy Dispersion X-Ray Data in a Timesharing Computer. Advances in X-Ray Analysis, v. 16, 1973, pp. 206-216. 25. Materials Engineering. V. 90, No. 6, December 1979, 378 pp. 26. Maynard, A. W., and H. S. Caldwell, Jr. Identification and Sorting of Nonferrous Scrap Metals. Proc. 3d Mineral Waste Utilization Symp., Chicago, III., Mar. 14-16, 1972, ITT Research Institute, Chicago, III., 1972, pp. 255-264. 27. Maynard, A. W., and D. A. Wilson. Chemical Spot Tests for Aluminum Alloys. BuMines Rl 7544, 1971, 15 pp. 28. Metal Progress. V. 118, No. 1, Mid-June 1980, 202 pp. 29. National Association of Recycling Industries, Inc. NARI Circular NF-80, Standard Classifications for Nonferrous Scrap Metals. New York, New York, 1980, 12 pp. 30. National Association of Recycling Industries, Inc. Recycled Metals Identification and Testing Handbook. New York, 1979, 45 pp. 31 . National Bureau of Standards. Tables of Spectral-Line Intensities. NBS Monograph 145, pt. I and II, 2d ed., U.S. Government Printing Office, Washington, D.C., 1975, 600 pp. 32. Obrzut, J. J. Tests That Will Help To Identify Metals. Iron Age, V. 221, No. 45, Nov. 13, 1978, pp. 55-58. 33. Ostrofsky, B. Materials Identification in the Field. Mater. Evaluation, v. 36, No. 9, August 1978, pp. 33-39, 45. 34. Peterson, M. J., and H. W. Jaffe. Visual-Arc Spectroscopic Analysis. BuMines Bull. 524, 1953, 20 pp. 35. Peterson, M. J., A. J. Kauffman, Jr., and H. W. Jaffe. The Spectroscope in Determining Mineralogy. The Am. Mineralogist, v. 32, 1947, pp. 322-335. 36. Rowsey, J. H., C. E. Snavely, and C. D. Luce (assigned to Huntington Alloys, Inc., Huntington, W. Va.). U.S. Pat. 4,156,840, May 29, 1979. 37. Slavin, M. Quantitative Analysis Based on Spectral Energy. Ind. and Eng. Chem., v. 10, Aug. 15, 1938, pp. 407-411. 38. von Alfthan, C, P. Rautala, and J. R. Rhodes. Applications of a New Multielement Portable X-Ray Spectrometer to Materials Analysis. Advances in X-Ray Analysis, v. 23, Plenum Press, New York, 1979, pp. 27-35. 39. Wilson, M. L. Nondestructive Rapid Identification of Metals and Alloys by Spot Test. Technical Support Package for Tech. Brief 70-10520, NASA Langley Research Center, Hampton, Va., 1973, 78 pp.; available for consultation at Bureau of Mines Avondale Research Center, Avondale, Md. 15 APPENDIX A.— SUPPLIERS OF METALS IDENTIFICATION INSTRUMENTS Spot Testing Kits Company and location Chemet Products San Francisco, Calif. Koslow Scientific Co. North Bergen, N.J. Company and location Agstan Instrument Co. Hudson, Mass. Analytical Precision Technology Co. Coatesville, Pa. Applied Research Laboratories Sunland, Calif. Baird Corp. Bedford, Mass. Cooperfieat Rahway, N.J. Spectrex Co. Redwood City, Calif. Technics Springfield, Va. Company and location Caliber Reston, Va. Columbia Scientific Industries Corp. Austin, Tex. Inax Instruments Ltd. Ottawa, Ontario, Canada Kevex Corp Foster City, Calif. Pitchford Scientific Instruments Canonsburg, Pa. Princeton Gamma-Tech Princeton, N.J. Texas Nuclear Austin, Tex. Company and location Acromag Inc. Wixom, Mich. Alloy Surfaces Co., Inc. Wilmington, Del. Analytical Associates Detroit, Mich. Chemet Products San Francisco, Calif. Foerster Instruments Inc. Coraopolis, Pa. Greenberg Engineering Co. Bala-Cynwyd, Pa. Koslow Scientific Co. Edgewater, N.J. Technicorp Wayne, N.J. Company and location Foerster Intruments, Inc. Coraopolis, Pa. Halo Instruments, Inc. White Plains, Md. Magnaflux Corp. Chicago, III. Telephone Company and location Telephone (415)752-5939 Systems Scientific Laboratories (201)482-7734 Newark, N.J. (201)861-2266 Optical Emission Devices Telephone Instrument (617)562-3219 Agstan MA/C (215)384-1300 Metals Analyzer (213)352-6011 (617)276-6000 Quantotest 36000, Horst-Anders (Fuess) Metal Spectroscope. Spectromobile (201)388-4500 Clandon Metascop (415)365-6567 Vreeland Spectroscope (703) 569-7200 Spectrotest X-Ray Emission Devices Telephone Instrument (703)471-1905 Caliber III (800)531-5003 (512)258-5191 (613)829-5068 CSI 740 Inax 600, Inax 540 (415) 573-5866 Kevex Analyst 6600 (412)745-1555 Portaspec (609)924-7310 PGT-810, PGT-100 (512)836-0801 Alloy Analyzer 9266 Thermoelectric Devices Telephone Instrument (313) 624-1541 Metal Tester 1101-B (302)575-1555 ACD-1 (313)369-9400 Thermoelectric Comparator TC-78 (415) 752-5939 Therm Ergy Meter (412)262-2025 Tevotest 3.205 (215)839-3380 Sortometer (201)941-4484 Electrosep 2001 (201)696-2321 W.T. Alloy Separator Eddy Current Instruments Telephone (412) 262-2025 (301) 868-7888 (312) 867-8000 Company and location Parker Research Dunedin, Fla. Sensor Corp. Scottdale, Pa. Telephone (813) 733-6081 (412) 887-4080 16 APPENDIX B.— FEATURES OF OPTICAL EMISSION DEVICES LISTED IN APPENDIX A Instrument Type Optical system Wavelength Excitation Sampling Cost' range, nm method requirements Agstan MA C Spectroscope- Grating: 1,180 380-700 Fixed elec- Takes material $7,000 comparator. lines/mm. trodes. from wire to ingots. Metals Analyzer. Mod- do Prism 390-700 Fixed elec- Small, flat sur- $6,000 el D.V. trode. face. Quantotest 36000 Spectrometer- Grating: ' 2,400 240-450 Hand-held None $36,000 comparator. lines/mm. pistol. Horst Anders (Fuess) Spectroscope- 1 .5 prisms 420-650 Cu, Fe, or C Small, flat sur- $13,000 Metal Spectroscope 87A. Spectromobile comparator. '390-680 electrodes. face. Spectrometer- Grating: 1,667 200-600 Hand-held None $40,000 comparator. lines/mm. pistol. Clandon Metascop . . . Spectroscope . . Amici straight- 420-650 W or Mo do $4,000 vision pnsm. '390-650 electrode. Vreeland Spectro- do Grating: 590 400-700 Fixed elec Metal powder . $4,000 scope. lines/mm. trode. Spectrotest Spectrometer- Grating: ^2,400 200-760 Hand-held None $43,000 comparator. lines/mm. pistol. Mobility Size, in Weight, lb Power require- Analytical capabilities ments Agstan MA/C Mobile, on 24 X 24 X 310 115 V, 60 Hz All elements within wavelength wheels. 41.5 range and detection limits. Metals Analyzer, mod- Fixed NA NA 220 V, 60 Hz Do el D.V. Quantotest 36000 Mobile, on 37 X 24 X 264 110-220 V, 50- Any 10 selected elements. wheels. 26 60 Hz Horst Anders (Fuess) Metal Spectroscope 87A. Spectromobile Fixed NA NA 1 1 0-220 V, 50- All elements within wavelength ion limits. 60 Hz range and detect Mobile, on 48 X 34.6 X 396 110-220 V, 60 Any 5 elements from 24. wheels. 26.4 Hz Clandon Metascop . . . Portable 13 X 4.7 X ^17 110-220 V, 50- All elements within wavelength 1.8 60 Hz range and detection limits. Vreeland spectro- Fixed, table top. 24 X 18 X 35 1 1 5-220 V, 50- Do. scope 16 60 Hz Spectrotest Mobile, on 39.4 X 29.5 331 110-220 V, 60 Up to 24 elements in groups of 8. wheels. X 27.5 Hz NA Not available. ' Approximate, subject to change. ^ Paschen-Runge mounting, ' With camera. ■* 20 lb in case. 17 APPENDIX C— FEATURES OF X-RAY EMISSION DEVICES LISTED IN APPENDIX A Instrument Radiation source Detector Capabilities Analytical capabilities Caliber III . Radioisotope: Cd-109 Li-drifted Si (' ) Elements Ti to U; JD to 20 elements or Am-241 . per determination. Can store 640 standards. CSI 740 . Radioisotope: Fe-55, Proportional counter. Analysis . Elements K to U (surface and Cm-244, Cd-109, sample probes); Al to Cr (light Am-241. element probe), groups of 4 per 32 elements in determination. Inax 600 and 540 . . . . Radioisotope: 1-125. Li-drifted Si (' ) Elements K to U; from 8 to 36 elements simultaneously. Kevex Analyst 6600 . . X-ray tube or radioisotope. Li-drifted Si (' ) All elements heavier than Ti; 19 elements per determination. Can store 175 alloys. Portaspec . W X-ray tube Proportional counter. Analysis . . . . . Elements from Ti to Ag and Ba to U. PGT810 . Radioisotope: Cd-109, Li-drifted Si or intrinsic C ) Elements from Al to U: Up to 20 Fe-55, Am-241 , Ge. elements per determination. Can Co-57, and others. store 100 alloys PGT100 . Radioisotope: variable. Proportional counter or Analysis . Maximum of three preselected depending on user Li-drifted Si. elements per determination. needs. Alloy Analyzer 9266 . . Radioisotope: Fe-55 or Gain-stabilized {' ) Analysis for Cr, Mn, Fe, Co, Ni, Cu, Cd-109. scintillation counter Nb, Mo, W, and Ti or V. Can store plus filters. 100 alloys. Cost Mobility Electronics Probe Power Size, in Weight, lb Size, in Weight, lb requirements Caliber III . $45,000 Mobile, on NA NA NA NA 110 V, 5 A, 60 wheels.^ Hz clean powerline. CSI 740 . $20,000 Portable . NA <20 NA NA 110 V, 60 Hz supply or battery (rechargeable) Inax 600 and 540 .. . . . $28,000 do . 12 X 4.5 16.5 7.25 X 4.75 7.5 Rechargeable X 15.75 X 10 battery. Kevex Analyst 6600 . . . $50,000 Fixed=. ... NA NA NA NA NA. Portaspec . . $12,000 Portable . "18.5 X 12 X 9 NA 55 13 X 4.5 18 8 NA 115 V, 60 Hz. PGT810 . . $40,000 Fixed .... NA NA NA. PGT 1 00 . . $10,000 Portable . '9.5 X 11.5 35 5 75 X 4 5 105-125 V 60 X 20 X 12 Hz. Alloy Analyzer 9266 . . . $20,000 do . 9.5 X 4 X 9 '8 7 diam, 2.75 5 deep 5 Ni-Cd rechargeable batteries. NA Not available. ' Analysis, supply. ' Base. matching, identification. ^ Requires dust-free temperature controlled environment. ^ Can have hand-held remote detector. " Power 18 APPENDIX D.— FEATURES OF THERMOELECTRIC DEVICES LISTED IN APPENDIX A Instrument Electrodes Probe material Control method Measurement modes ACD-1 Probe and alligator clip. Thermoelectric Comparator TC-78. Analog, two sensitivity ranges: 1 division — 10 or 50 |jlV. Analog, 1 division — 100 jjlV. Analog, 5 sensitivity ranges: 1 division — 0.9 to 7 |xV. Metal Tester Probe and base Cu Constant temperature 1101-B. plate. difference: 95° to 145° C. W Control tip voltage. Temperature 315° to 345° C. Dual Probes or probe Cu Control tip voltage. and ground plate Temperature — 95° C for small parts. Therm Ergy Meter File, alligator clip. Hard steel file. Operator (file) Analog, alloys identified on and pick. Cu clip, and scale, steel pick. Tevotest 3.205 Probe and alligator Cu, Ni, or Ci-Ni Constant temperature Analog, 5 sensitivity ranges clip or probe and alloy. differential — 55° C. 1 division — 1 tp 100 |jlV. ground plate. Sonometer Probe and base plate. Noncorrosive Constant temperature Analog or digital. differential Electrosep 2001 File, alligator clip, and Hard steel file, pick. Cd-plated steel clip, and steel . pick. W. T. Alloy Probe and alligator Interchangeable Separator. clip. probe tips, Cu clip. Operator (file) Digital. Constant tip temper- ature— 150° C. Analog or digital or combined. Cost Metal Tester 1101-B.. ACD-1 Thermoelectric Comparator TC-78 . Therm Ergy Meter. . . . Tevdtest 3.205. Sortometer: 508 DSE . . . . 510 Electrosep 2001 W. T. Alloy Separator: 850 $1,500 $600 $1 ,300 $300 $4,400 $6,400 $1,700 $500 $2,700 Weight, lb Power requirements Additional comments' 1 4 Mains power None. 5 do Do. 10 do Do. ^4 Operator (file) Combines thermoelectric and turboelectric effects. 12 Mains power or batteries. None. 21 Mains power Some models also make use of thermal conductivity. 15 do Do. 1 Operator (file) and display Sample and hold display, (battery). 10-12 Mains power Models 950 ($2,110) and 850/950 ($3,460) available. ' All units are portable. ^ In case. trU.S. Government Printing Office : 1982 - 383-884/8706 19 APPENDIX E.— COMPARISON OF METALS IDENTIFICATION INSTRUMENTS AND IDENTIFICATION METHODS Instrument Property used Analysis Mobility Weight, lb Power requirements Qualitative to semi- Portable, mobile, and 20-300 Mains power, quantitative fixed units available, analysis. Comparison of pre- Mobile 300-400 Do. selected elements for confirmation of identity. Quantitative analysis, Fixed but may use NA Do. alloy matching, hand-held remote identification. detector. Analysis and in Portable 10-60 Mains power or some cases identi- batteries. fication. Identification by com- do 5-20 Mains power, bat- parison with pre- teries, or mecha- vious results. nically. do do 5-10 Mains power or batteries. None. Spectroscope Mobile spectrometer. Emission of optical radiation of char- acteristic wavelength. do X-ray fluorescent Emission of X-rays spectrometer. of characteristic wavelength. Portable X-ray do Thermoelectric Production of ther- moelectric voltage. Eddy current Induction of eddy currents. Spot tests Chemical reaction . . Qualitative or semi- quantitative analysis. Portable kits available. 1-2 User skills Sample prep. Cost Advantages Limitations Safety features Spectroscope Technical or Flat sample from $4,000- Rapid check for Cannot detect Arc could cause semitech- piece. None for 13,000 particular ele- elements and eye damage. nical. portable units. ments. emissions in UV region. Fumes pro- duced. Mobile spectrometer. Semitech- Semiclean sur- $40,000- Rapid nondestruc- Limited to con- Do. nical — none . face. 45,000 tive identity confirmation. firmation only. X-ray fluorescent Technical to Sample cut from $40,000- Rapid quantitative Limited to higher Potentially haz- spectrometer. semitech- piece. 50,000 analysis or atomic No. ele- ardous radia- nical. identification. ments. Matrix sensitive. tion source. Portable X-ray Semitech- nical. Clean surface. $10,000- 25,000 Rapid nondestruc- tive analysis. do Do. Thermoelectric do do $500- 6,500 do Structure sensi- tive. Different materials may give same readings. Hot probe tip could cause burns. Eddy current Semitech- Clean flat surface. $1 ,500 do Structure-shape Potential shock nical. -5,000 sensitive. Diffe- rent materials may have simi- lar responses. hazard may exist for some models. Spot tests Semitech- Clean surface. $50-300 Usually rapid. Sensitive to oper- Uses acid and nical — none essentially non- destructive. ator interpreta- tion. Reactions masked by other elements. other poten- tially danger- ous chemi- cals. NA Not available. ■\o^ \"-^'/ V^-> ^/'^^V V^^*/ \"^^> .. \ \ * «? <»>^. o^ .0^ ,' ^°v ^-^^^ *^o. '•^Tr» .0-' "V *"^* /r ^^'t '• ** ** -• V ..iliL'. '^ 'o ^^..^^ /^lfe\ %„./ y^£^ \^^^ y^^, \/ *^^ ,♦' Too / \^^-*\^*'.. V'-- **'"** • 6.'^ ^. o ^0 f^ -^^^^li!(&: ^-1 q -^^'^' •^^^^ bV" & >••. •'b 'u^«f,- .^ »*' .40*. . ;• ,/\-.^- *«'\ \1^.- /\ •.^.- A V jp-n^. V ^9^ - * ->^ o, ^^'^^ • i> . » • I .y . * 4 LIBRARY OF CONGRESS 002 959 863