lurgy has made possible the silicon-reduction reaction for pure magnesium, calcium, and other metals. Hydrides have become useful reactants in making the rarer metals. In the nuclear field, whole new techniques are still to be applied t o industry. The development of titanium has progressed rapidly from the early work of Kroll, and the metal gives promise of soon becoming available in tonnage quantities. Zirconium is likewise under development, though it was first offered as a product of thermal halide decomposition. The hard carbides, tantalum, and vanadium are new materials finding specific placesinindustry. Surface protection has been improved with the newer resins, including the furan and the fluorocarbon types; and anodic and chemical treatments of metallic surfaces have been extensively employed. Hard surfacing, by plating, welding, or metal spraying. has improved wear-resistant parts. Electroplating has been developing on a larger scale, as in tinning. Shortages and equivalents have been problems of our economy in the past decade; and the organic chemicals industry, growing apace, ever increasingly offers products to replace or supplement the metals. Notable among the current developments are the fluorocarbon, polytetrafluoroethylene, and the silicones. The industry stands today in the position where there are few problems that cannot be solved economically, and the quest still continues for better solutions t o the difficult problems of materials for chemical engineering. Recent symposia by the Division of Industrial and Engineering Chemistry, such as the Titanium Symposium and Packaging Symposium presented a t the September 1949 national meeting, the Organic Silicon Compounds Symposium a t the April 1947 meeting, and the program on electrical insulating materials a t the April 1946 meeting, illustrate that interest in materials of construction as a program subject is still a vital part of the division’s activities. The increasing importance of materials of construction is also reflected by the appearance in the October 1947 issue AND ENGINEERING CHEMISTRY of a series of annual of INDUSTRIAL reviews devoted to contemporary developments in the field ( 3 ) .
Forging a n armor plate in 14,000-t0n press ,forge at Bethlehem Steel Co.
LITERATURE CITED
(1) Calcott, W. S., Whetzel, J. C., and Whittaker, H. F., “Corrosion Tests and Materials of Construction for Chemical Engineering Bpparatus,” New York, D. Van Nostrand Co., 1923; Trans. Am. Inst. Chem. Engrs., 15, Part I (1923). (2) Hamlin, M. L., and Turner, F. M., Jr., “Chemical Resistance of
Corrosion-resistant drum dryer used in experiments on powdered milk i s built of stainless steel
Engineering Materials,” New York, Chemical Catalog Co., 1923. (3)
IND. ENG.CHEM.,39, 1193-264 (1947); 40, 1773-936 (1948);
41, 2091-154 (1949); 42, 1950-2076 (1950). (4) Leighou, R. B., “Chemistry of Engineering Materials,” New York, McGraw-Hill Book Co., 1925.
THE
electrochemical industry includes the processes and products of the electrolytic cell and the electric furnace and is one of the most important segments of American chemical industry. I t s power requirements have increased more rapidly in recent years than those of industry as a whole, and it now consumes nearly 20% of the electrical power generated in this country. Products of this industry, such as chlorine, alkalies, and calcium carbide (the principal source of acetylene and cyanamide), are basic raw materials for a large part of the organic chemical industry. Abrasives and ferroalloys from the electric furnace are essential ingredients in the metallurgical industry. Industrial electrochemistry has had its tremendous development within the lifetime of the AMERICAN CHEMICAL SOCIETY and mainly during the past 50 or 60 years. It arose from inven-
These light-weight aircraft landing wheels are made of sand cast magnesium
R. M. Burns, Bell Telephone Laboratories, Murray Hill, N. J.
3011
S e w electrolytic chlorine-caustic units at the Hooker Electrochemical plant, Tacoma, W a s h .
tions and developed as.an experimental art. Many of its early practitioners had little chemical knowledge. Papers before the Society commented upon the scarcity of chemists in industry and the best methods of t,raining industrial chemists. Later during the 189O’s, electrolytic or electrothermal products were announced a t chemical meetings, and there developed a growing interest in the application of t’he electric current in chemical processes. Electrochemical methods for the production of white lead, chlorates, paranitro compounds, caustic alkalies, and graphite were described. One interesting reference (IO) mentions the successful disinfection of sewage by the electrolysis of sea n-atw. Wit,h continued expansion of electro processes in the first years of the century, more and more papers of industrial importance appeared. The first volume of the Journal of Industrial and Engineering Chemistry refers editorially to elect.ric furnace steel ( 2 2 ) and to the manufacture of carbon electrodes ( 1 6 ) . In subsequent volumes, it is possible to follow the important developments of the electrochemical industry down to the present time. For example, the entire issue for March 1947 is composed of 53 papers on the development, production, handling, and chemistry of fluorine and fluorine compounds. Later issues of this journal contain other papers presented before symposia on fluorine chemistry which have become an annual feature, sponsored by the Fluorine Chemistry Subdivision of the Division of Indust’rial and Engineering Chemistry. ELECTRODEPOSITION OF M E T A L S
Electroplating is the oldest commercial electrochemical process. Edward Weston constructed the first dynamo for electroplating about 1875. The substitution of this device for batteries as a power source not only increased the attention given t o the chemical control of plating baths but led to the firm establishment of the plating industry. From job shop operation, electroplating has developed into large manufacturing units in diversified industries. This expansion n-as stimulated by the mass production of automobiles, modern plumbing fixtures, and household appliances. The use of chromium-nickel coatings, beginning about 1925, has proved most suitable in these fields. Among important developments in electroplating in recent years have been “bright” nickel and zinc, very heavy coatings of nickel and of chromium, and high-speed methods of plating steel sheet or strip stock. For example, electrot,in, plated a t the rate of 1000 feet per minute, was promoted as a conservation measure in the recent war. This process has continued t o expand and now account’sfor a large fraction of domestic tin plate manufacture. The depletion of high grade ores makes electro-winning methods of metal extraction attractive. This is part,icularly true of the complex lead-zinc ores not amenable t o pyromet8allurgicalniethods. These methods and electro-refining for attaining high purity have been increasingly extended in recent years t o the production of copper, zinc, cadmium, antimony, chromium, CDbalt, and manganese.
Solid silver b u s bars carry electricity to magnesium cells at Dow’s plant in Michigan
ELECTROLYTIC PROCESSES AND PRODUCTS
The electrolytic reduction of aluminum from a fused salt bat,h by Charles M. Hall in 1886 initiated the development of the electroprocess industry. Hall’s invention was put in commercial operation two years later by the Pittsburgh Reduction Co., which in 1907 became the Aluminum Co. of America. From the first plant containing tTvo cells operating at 1800 amperes and producing 50 pounds of aluminum a day, the industry grew until in 1943 there were 16 huge plants xith cells operating a t 40,000 to 50,000 amperes and a total capacity of over 2 billion pounds a year. Most of this expansion was inspired by military requirements, but postwar demand has been such as to maintain the production level above one billion pounds a year. Active developments toward cost reduction and improved purity are continuing (3,9 ) . Magnesium has a more recent history. First produced in 1852
I n this unit ut the American Can Co., tin i s electrodeposited OTL steel 302
February 1951
*
*
INDUSTRIAL AND ENGINEERING CHEMISTRY
by Bunsen by electrolysis of fused magnesium chloride, it attained small scale commercial production in the first decade of the century. This was followed in 1916 by the Dow continuous chloride process utilizing salt brine as the basic raw material. By 1923 production had reached 300 pounds per day. During the period from 1920 to 1939, production of the metal doubled every 2 years. After 1939, the output increased, even more rapidly, reaching a peak of 380,000,000 pounds in the war year 1943. In the latter period, raw material sources were broadened to include sea water, dolomite deposits, and potash by-products, thereby presenting many new chemical engineering and design problems. The electrolytic alkali-chlorine industry, which has in recent years doubled in size every 5 or 6 years, is one of the most striking features of modern industry. Indeed, chlorine production which is 99% electrolytic has come to be the best index of the chemical industry since a wide variety of chlorinated compounds consume nearly 80% of the production. About 75% of the caustic alkali production is electrolytic and finds use mainly in chemicals, textiles, rayon, films, cleaning agents, and petroleum refining (11). Experimental work on chlorine-alkali cells resulting in early patents dates from the 1880’s. The first commercial installation for electrolytic chlorine was a t Rumford Falls, Maine, in 1892 (14). This was followed in the next few years by other installations in New England and to larger developments a t Niagara Falls, Wyandotte and Midland, Mich., and on the Pacific Coast. Of the 330 cell patents since 1883, only 16 have stood the test of time and continue to operate (20). From 40 tons of chlorine a day from 5 plants in 1900, production has grown to 5000 tons a day from 58 plants in 1949 (6, IS). Over 1,500,000 tons of electrolytic caustic soda were made in this country in 1948. By-product hydrogen from chlorine-alkali cells finds extensive use in hydrogenation processes and in the production of hydrogen chloride. Both hydrogen and oxygen are also produced on a large scale by the electrolytic decomposition of dilute caustic solutions. Electrolytic processes are widely employed for the production of hydrogen peroxide and the per salts. Electrolytic chlorate was mentioned in 1889, and as early as 1897 the manufacture of chlorates and perchlorates was begun a t Niagara Falls. Since that time, cell design, solutions, and processes have been considerably modified. The demand for these products has never attained high proportions. -The present annual production of chlorates is about 25,000 tons, divided about equally between the sodium and potassium salts. The domestic production of perchlorates was increased during the period 1941-45 from an estimated 1000 tons to 20,000 tons to supply demands created by wartime uses (17, 21). The recently increased interest in organic fluorine compounds has led to considerable expansion in the production of elemental fluorine. The direct fluorination of organic compounds (18) has become a valuable commercial process. There has been considerable exploration of the use of electrochemical processes in the production of organic chemicals. Between 1939 and 1945, millions of pounds of mannitol and sorbitol were manufactured by the electrolytic reduction of glucose ( 1 ). ELECTROTHERMAL PRODUCTS
The higher temperatures, close temperature control, and cleanliness of electrothermal heating have led to the wide use of the electric furnace in chemical and metallurgical manufacture. Graphite, calcium carbide, phosphorus, abrasives, and ferroalloys we among the principal products. The first three of these, and in addition metallic calcium, were prepared in a laboratory electric furnace as early as 1839 by Robert Hare a t Philadelphia (2). The &st synthetic abrasive, Carborundum, was invented by Acheson in 1891. Forty-five years later, the annual electric energy required in its manufacture had attained 87,000,000
303
kw.-hr., and considerable further expansion occurred during the war. Among more recent abrasive products of the electric furnace are fused alumina, boron carbide, and tungsten carbide. Acheson observed about 1895 that graphite was produced a t furnace temperatures above those suitable for making silicon carbide. The process was commercialized with the founding of the Acheson Graphite Go. in 1900, and the product soon competed successfully with natural graphite in the manufacture of electrodes, crucibles, lubricants, and dry cell components. Calcium carbide, which can be made commercially only in the electric furnace, received its first industrial development about 1892 Within 5 years, production of the carbide supplied eight plants engaged in the manufacture of acetylene. Reaction of calcium carbide with nitrogen to form cyanamide was first commercialized in 1905, and this product within 30 years had attained an annual production of 1,500,000 tons. Today with acetylene and cyanamide the bases for a large section of the synthetic organic chemical industry, calcium carbide has an annual production of nearly 700,000 tons. Phosphorus and phosphoric acid are produced electrothermally from a mixture of phosphate rock, coke, and silica. In 1947 the production of phosphorus was 86,000 tons. The development of the alloy steel industry, which began in the early years of the century, was dependent upon the electric furnace production of ferroalloys. A wide variety of these addition alloys could not be obtained in satisfactorily high purity by blast or open-hearth furnace methods. At the present time the annual production of ferroalloys is of the order of 3,000,000 to 4,000,000 tons. P R I M A R Y CELLS AND S T O R A G E BATTERIES
By the time the Society was organized, primary cells had had a 76-year evolutionary history from the pile of Volta t o the Leclancht! cell, forerunner of the dry battery of today. Sixteen years had elapsed since Plant6 had invented the storage battery. Until very recently, neither of these devices for obtaining electrical energy from chemical reactions underwent much further development beyond improvement in structural design and chemical purity of ingredients. The development of portable radio equipment, flashlights, and hearing aids gave impetus to new and improved dry cells, and lately cells involving a variety of chemical reactions have been invented. For example, there are the Leclanch6-type cells with porous carbon cathodes which are depolarized by air or by chlorine (7, 8); caustic soda cells with zinc anode and either cupric or mercuric oxide cathodes; perchloric acid cells with lead dioxide anodes and lead cathodes (16); and finally a magnesium-silver chloride cell utilizing water as electrolyte ( 4 , 18). The rise of the automobile industry brought about a spectacular increase in the use of storage batteries. This development accounts for the major portion of the half-billion-dollar annual output of these batteries. The standard lead-lead dioxide with sulfuric acid electrolyte of Plant6 has led the field. The alkaline type of nickel-iron cell developed by Edison and the more modern version employing nickel and cadmium electrodes have never threatened this supremacy. For full-float type of service, such as is employed in the telephone industry, a very marked improvement in performance and life has been obtained by substituting calcium for antimony as hardening agent for grids (6, 19). LITERATURE CITED
(1) (2) (3) (4) (5)
Creighton, H. J., Trans. Electrochem. SOC.,90,15 (1946). Doremus, C. A,, Ibid., 13, 347 (1908). Frary, F. C., Ibid., 94, 31 (1948).
Haring, H. E., Ibid., 90, 540 (1946). Haring, €I. E., and Thomas U. E., Ibid., 68, 293 (1935). (6) Heilborn, A., J . Electrochem. Soc., 97,121C (1950). (7) Heise, G. W., and Schumacher, E. A., Trans. Electrochem. SOC., 74,365 (1938).
INDUSTRIAL AND ENGINEERING CHEMISTRY
304
(9) (10) (11) (12)
W.,Schumacher, E. A., and Cahoon, S . C., J . Electyochem. Soc., 94,99 (1948). Klagstrum, H. A., IND.ENG.CHEM.,37, 608 (1945). Langley, J. W., J . Am. Chem. Soc., 16, 49 (1894). MacMullin, R. B., J . Electrochem. Soc., 96,21C (1949). Mullen, J. P., and Howard, P. L., Trans. Elect,ocitem, Soc., 90,
(13) (14) (15) (16)
Murray, R. L., IND.ENG.CHEM.,41,2155 (1949). Parsons, C. L., J . Am. Chem. Soc., 20,568 (1898). Roush, G. A., J. IND.EXG.CHEW.,1, 286 (1909). Schrodt, J. P., Otting, W. J., Schoegler, J. O., and Craig, D. X . ,
Vol. 43, No. 2
( 8 ) Heise, G.
529 (1946).
Trans. EZectTochem. SOC.,90,405 (1846). (17) Schumacher, J. C., Ibid., 92,45 (1947). (18) Simons, J. H., and co-workers, J . Electrochem. Soc.. 95, 47 (1 945). (19) Thomas, U. E., Farster, F. T., andHaring, H. E., Trans. Electrochem. Soc., 92,313 (1947). (20) Vorce, L. D., Ibid., 86, 69 (1944). (21) White, N.C., Ibid., 92, 15 (1947). (22) Whitney, W. R., J. ISD. ESG. CHmr., 1, 64 (1909).
L. H. FLETT
THE
dyestuff industry was the earliest of the great synthetic organic chemical industries. It supplied a need which nature had t'aken care of since the first man daubed his skin and clothes with vegetable dyes. Katural dyestuffs had been a coveted article of international trade. With prices ranging up to several hundred dollars a pound, they were economically important enough to upset the trade balance between nations. The accidental discovery of mauve, the first synthetic dye, by Perkin in 1856 and t'he subsequent establishment of a synthetic organic chemical industry have had a most profound effect on mankind. The synthetic organic chemical industry has furnished an unending parade of useful chemicals to enrich our civilization beyond imagination. The ready availability of healing drugs, fine fabrics made with synthetic fibers, easily molded synthetic resins, rubber, flavoring materials, detergents, and all of the other synthetic substitutes of nature's gift,s can be traced to the fundamental industrial organic chemistry unfolded in the early development of t8hesynthetic dyes. At first, advances in the synthetic dye industry were rather slow, but before the turn of the century the dye industry was world wide. Although the impact of t,he Perkin discovery was world wide, the chemistry of dyestuffs and the dyestuff industry developed and flourished in Germany more than in any other country. Possibly this was a result of the educational system which a t that time developed and inspired great numbers of young organic chemists, whose fundamental studies unlocked the secrets of color chemistry. During that period, many American chemists found it advisable to complete their st>udiesin Germany. At the outbreak of World War I, the synthetic organic chemical industry, which included t,he dye indust'ry and the synthetic drug industry, was a monopoly of the Reich, because German technical and scientific advances had far outstripped the rest of the civilized world. When the hostilities of World War I started, the English government established a blockade of German ports and effectually cut off American imports of the German dyes which had become a necessary part of our economy. Later when xve entered World War I, intermediat.es and dyes became a very necessary part of our military preparation. I n 1914, the combined dyestuff capacity of the United States was only a small fraction of our normal requirement,s. American dyestuff manufacturers had been successful in the commercial development of a small group of dyestuffs, but they ha,d neither the variety of dyes nor the capacity t o supply American needs. Most of the organic chemists available in the United States had
been educated in Germany aiid m r on ~ the staffs of aradcniic institutions; industrial oiganic chemists were practically unknonn. However, when urgent necessity demanded expansion of the American dye and drug industry beyond the means of the fern dye chemists available the enthusiasm and the adaptability of these American chemists soon made themselves felt, and by the time World War I came to a close in 1918, there was a wcll established line of organic dyes and synthetic drugs. What Jvas more important, there had been developed a substantial group of experienced industrial organic chemists. The end of the war found the dye manufacturers in an untenable situation. Because of the necessity of developing a large number of dyestuffs, it had not been possible to develop highly efficient commercial processes. The possibility of competition from German factories with know-how and cheap labor seemed to many people to be an insurmountable handicap to the future. Through the efforts of many individuals, including Francis P . Garvan and the members of the Division of Dye Chemistry of the AMERICANCHEMICAL SOCIETY, a tariff was established which has permitted the American dye industry to grow and to become the greatest dye industry that the world has ever seen and a strong factor in our national defense. During the postwar period of uncertainty, many chemists n ho by that time had become highly skilled in organic research left the industry t o enter other new organic chemical ventures. These trained scientists became the nucleus of the vast American organic chemical industry on which our country now depends for the many organic cheniicds 1%hich have long since become national necessities. After World War I, the . h c r i c a n dye industry, encouraged by
L. H. Flett, National Aniline Division, New York, S . Y.
