INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY Bond, F. C., presented before the Am. Inst. Mining Met. Engrs., Columbus, Ohio (September 1949). Bransom, 9. IC., and Dunning, W. J., Zbid., 68,80(1949). Bremner, J. G., and Colpitts, J. E., Trans. Inst. Rubber I n d . . 24, 35 (1948). Brown, C. O., IXD. END.CHERI., 40,No. l I , 7 9 A (1948). Burden, H., and Barker, A., J . Inst. Metals, 75,51(1948). Chem. Eng. News, 27,246 (1949), Ibid.,p. 714. Ibid., p. 1240. Zbid., p. 1478. Zbid., p. 1552. Zbid., p. 1828. Zbid., p. 3077. Chem. Znds., 63,405,407,414 (1948). Zbid., 64,260 (1949). Ibid., p. 808. Zbid., 65,628,529 (1949). Chem. Proc. Preuiew, 12,No. 6,91 (1949). Coughanoor, L. W., and Norton, F. H., J . Ant. Cerum. Sac., 32, 129 (1949). Deryagin, B., Fridlyand, R., and Krylova, V., Dokludy. Akad. Nauk. S.S.S.R., 61,653 (1948). Deslisle, L., J . Metuls, 1,228 (1949). Drake, C., IND. ENQ.CLIEM., 41,780 (1949). Enoksson, B., Nature, 161,924 (1948). Epstein, B.,IXD. ENG.CEIEM., 40, 2289 (1948) Green, Henry, "Industrial Rheology and Rheological Structures,'' New York, John Wiley & Sons, 1949. Greg& S. J.,and Jacobs, J., Trans. F u r r h y Soc., 44,674 (1948). Gdlstrom, D.K.,and McNew, G. L., Anal. Chsm., 20, 1174 (1948). Hersey, J. C.,.patents pending. IND. ENQ.CHEW,41, 1099-1250 (1949). Keenan, A.G.,J . Chenz. Education, 25,666 (1948). Kiselev, A.V., and Mikos. N. M.. J . Phus. Chem. (U.S.S.R.),22. 1048 (1 948). I
JR., AND
1
(35) Klovere, E. J., Eny. Min. J., 150, No.6,80 (1949). (36) Kunkel, W.B.,J . Applied Phys., 19,1066 (1948). (37) Kwong, J. N. S., et al., Chem. Eng. Progress, 45,608 (1948). (38) Legsdin, A, and Sohenck, F. Id., Eng. Min. J., 150, No. 4, 88 (1949). (39) Loveland, R. P., etaZ., J. F'runkZinIn,ut.,'246,459 (1948) (40) Martsell, S.,Acta PoZGech., No. 30 (1949). (41) Myers, J., presented beforc -the Am. Inst. iWining Met. Engru., Columbus, Ohio (September 1949). (42) Nijhawan, S. D.,and Olmstead, L. B., Soil Sci. 9oc. Am., Proc 12,60 (1947) (Pub. 1948). (43) Nordquist and Moeller, presented before the Am. Inst. Minirlg iMet. Engrs., Columbus, Ohio (September 1949). (44)Olevskit, V. A.,Garnyl Zhur., 122,No.1,30(1948). (45) Paint, Oil, Chem. Review,111, 66 (1948). (46) Putnam, H. M.,Verre silicates ind., 13,98 (1948). (47) Robison, H. E.,and Martin, 9. W., J. Ph,ys. & Colloid Chcm., 53 860 (1949). (48) Ross, S.,J . Am. C h m . Soc., 70,3830 (1948). (49) Schmidt, L. D., McGee, J. P.,McSlone, M. C., (.%em. err^ Progress, 44,737 (1948). (50) Schofield, R,. K., and Talihuddin, O., Dkcusilions Flzraclau-Soc.. 3,51 (1948). (51) Siesholta, €1. W., and Cohan, I-,,IT., IND.ENQ.CKEM.,41, 300 (1949). (52) Sinclair, D., and LaMcr, V. K., Chem. Revs., 44,245 (1949). (53) Smith, JulianC., C/hm.In&., 65,357(1949). (64) Tanner, C. B.,and Jackson, N.1., Sod2 Sci. Soe. Am., Proc., 12. 80 (1947) (Pub. 1948). (55) Totterman, H., Finska Kemistsumjmdeta, Medd., 55,34 (1946), (56) Tovarev, V. V., Ginsburg, Y. N., Massil'on, T,K., Tsammt 13, No.7, 12 (1947). (57) Weaton, D., A.I.M.E. meeting. (58) Work, L. T.,IND. ENQ.CHSM.,41, 21 (1949). (59) Yudowitoh, K.L.,J . Appl,ied Phys., 20, 174,(1949)R E S E I V ~ Nnvernhei. D 8. 1940.
___
C. S. GROVE,
Vd. 42, No.
--
1. B. GRAY
SYRACUSE UNIVERSITY. SYRACUSE, N. Y.
1 growth, describing ne!? aorlr which bears on the cluesof the reality of the Toliner layer, utilizing data obtained 117 interferometric methods Dislocations in crystal grovi th have been discussed by Burton, C'abrern, and Frank ('7). They claim that the discrepancj l ~ e tneen obaerved and theoletical values ran he reconciled by rccog nizing that the crystals that grow '3re not perfect. Real crystals voutain dislocations and in low suppisaturations do not grcm Miihout the presence of disloeationfi. Gay (17) has shown by a study of dendritic cnystal growth of the monohydrate of polashiurn hydroxide that the ratio of growth rateq, perpendicular t c RATE AND THEQRY the crystal faces, is not changed. A dendrite is therefore not Studies on rates of crystal growth and on theoretical factor+ different from normally gromn crystals, but only the edges grop controlling crystallization have not progressed to s u c c ~ s ~ f n l whereas the faces do not. Bragg (8) has described rcsaarrh 3 1 conclusions as rapidly as new techniques and skills in this field x-ray method8 of determining crystal structure and the structuit have developed. Wells ( 4 8 ) has contributed an interesting and configuration of atoms within a moleculc. informative review, containing 142 references, on crystal growth Some correlation of crystal phenomena may be obtained froru This review covers various topics under the following headings: the work of Finch, Wilman, and Yang (14), who state thtii cathodic crystal growth is influenced primarily by: ( a ) the ra k Theoretical, including relations between internal structure and of arrival of the metal ions; ( b ) their mobility on the cathod? face development surface before becoming part of a growing crystal; ( c ) the atoniii Studies of the growth of single crystals arrangement in the substrate surface on which the ions are ad Effect of impurities on crystal habit Oriented overgrowths sorbed and discharged; ( d ) the concentration of the electrostatic Perfection of internal structure and of crystal faces field near the projecting parts of the more or less rough cathode Miscellaneous topics, including supersaturation and nucleus surface; and ( e ) the presence or absence of other ions, molecules, formation and technique of growing single crystals or colloidal substances which can be adsorbed or codeposited on the rathode. Thomson (49)has published a critical review on the kinetics NTEHEGT in the btudg irid ( l e i eiogiiirnt of c.rystallizatiori processes has increased during the past year. This may bP due in part to the publicity glwn in technical and popular journals on the growth and use of large migle crystals. Theie are other developments and studies, howevri , Jqbich have been desciibed recently in the techn 1 and scientific literature Some of the more important papers 011 ciystalli7ation are ieviewed herewith under the following topics: Rate and Theory, ?hase Equilibria; Industrial Crystallization; and Lar gc Smgli~ Crystals
liori
January 1950
INDUSTRIAL AND EN
G
I N E E R I N G CHEMISTRY
29
Laboratory Crystallizer Unit at Strutherr Wells Corporation, Warren, Pa.
two separated crystal faces and only betweerr crystaIlo~raphlcullg-~~~h~c~li~ Davies ( 9 ) has discussed crystal formation in mcrose deposiidentical faces. tion. Work has been continued by Whelan, Galkowski, and Van Hook (60) on the kinetics of sucrose crystallization. They Work has been reported by Kikolaev (28) on a study of sparingly soluble crystalline precipitates. Magnesium hydroxide state that the slope of the relative velocity of crystallizatiori against impurity (nonsugar) curve, on semilog coordinates, w a ~made by dropwise precipitation. The results show tthat growth of crystals takes place only on actual addition of preoipidefines the coefficient, which may be called the specific melastant and not between additions. sigenic factor of the product under study. Zhvirblyanskii, Srikantan (41) has shown by means of classical equations that Volobueva, and Abragam (64), studying impure sucrose soluthe supersaturation coefficient is inversely proportional to the tions, have shown that the rate of crystallization and size of the crystals can be expressed by the empirical equation: S = KPm, size of the particles with which the solution is in equilibrium. The solubility theory can be applied successfully to three comwhere S = rate of crystallization, P = weight of crystals in grams, K = coefficient characterponent aqueous soIutions istic of the absolute meansaturated with mixed crvsing of the rate of crystaltals, according to Pozner lization, and rn is an expo(55). Pines (53) describes a nent less than unity. Starodubtsev and Timokdetailed mathematical treatment of nucleation, hina (42) have carried out experiments on sodium which yields the following chloride and potassium results : iodide. T h e s e c r y s t a l s , The rate of nucleus when crushed and heated growth is a nonmonotonous function of their diameter. to cause conglomeration, It is zero for nuclei of the FOURTE8Y BRU8H DEVELOPMENT COMPANY show bridges connecting the critical diameter, which are Cryald Grown Seed PI crystal grains. This conin equilibrium with the glomeration OCCLUS between Synthetic Quartz Crystst wlrition.
30
INDUSTRIAL A N D E N G I N E E R I N G C H E M I S T R Y
Vol. 42, No. 1
addition of increasing amounts of the ammonium salts of phosphate, carbonate, sulfate, fluoride, iodide, nitrate, and thiocyanate ions changes the outward habit of crystals from dendrites to rosettes, then to plates, and finally t o cubes. Belopol'skii and Margolis ( 3 ) have determined the kirietics of crystallization of sodium bicarbonate from supersaturated solutions. Their results indicate that addition of sodium sulfate, sodium nitrate, and sodium chloride accelerates crystallization of sodium bicarbonate. P H A S E EQUILIBRIA
Solubility and phase equilibria data have been published for a number of systems of two or more components which have water as solvent. Such data relate the composition of the crystalline phase in a complex system, the composition of liquid phase, and the temperature. Listed M o w are the systems for which recent data have been presented:
KC1-KzSOr-Hz0 Urea-KzB04-Hz0
KNO8-P\'aNO~-MpO COURTESY BELL TELEPHONE LABORATORIES
Rotary Crystallizer for Growing
EDT Crystals
The typical incubation period, during which no crystallization takes place until a certain critical size of nucleus is attained, has a pronounced minimum as a function of the degree of supersaturation. The final nucleus size is a,monotonous function of the supersat,uration. Gorskii ( I S ) derived a method for the calculation o f the Jurface energy zt, the boundary between crystal and melt-for example, in a one-component system-utilizing the temperature function of the spontaneous nucleus formation (nucleation). The velocity of crystallization of a substance is stated by Pinheiro (34) to be no longer only a problem in the physicochemistry of surfaces and interfaces, but to involve two additional factors: the velocity of formation of crystal nuclei and the velocity of growth of the nuclei formed. Yoshida (63) has discussed the phenomena of crystallization arid melting. He states that) the presence of cybotactic crystiils in a liquid call be used t o explain: the formation of crystal nuclei and their growth in a supercooled liquid; x-ray diffraction patterns of a liquid; and the structural change of a metal by cold working or nnuealing. Schlain, Prater, and Ravitz (39) have reported a study on the distribution of impurities in crystallization of ammonium and potassium alums. They state that, over r? wide range of impurity concentrations, the mole fraction of the impurity in the crystals was foui~dto be proportional t o the mole fract,ion of t,he impurity in the solution. Arimcri ( 1) has shown that crystalline hydrated alumina (bohmite) could be formed by passing ammonia gas, a t high pressure and at 120" t o 150" C., into a basic solution of amnionium alum. Nakhmanovich, Lyubin, and Khai ( 8 7 ) have discussed the crystallizability of xylose sirups. By their methods, they find 1 hat calcium acetate and calcium oxalate accelerate crystallization; calcium sulfate delays crystallization; and magnesium sulfate has no effect. A study of crystallization of ammonium chloride from aqueous solutions by Til'mans (44)shows that the
INDUSTRIAL CRYSTALLIZATION
A number of improvements are reported, in patents and other literature, describing techniques of producing crystalline solids. A process for making ammonium alum from the acid liquors produced during the activation of bentonite clays is described in a patent by Peer (80). Ammonium sulfate is added to the acid liquor. On cooling ammonium alum is obtained. Crystalline aluminum sulfate is made from noncrystallin& commercial aluminum sulfate in a process patented by Wilson ( 5 2 ) . The latter substance contains 40 to 5Q% water and appears to be a glasslike solid which is not dissolved readily in water. Processes for making ammonium nitrate (61) and calcium nitrate ( 1 0 ) are also described. In a process for making ammonium phosphate (83) the production of seed crystjals is separated from the growth of crystals. Imperfect crystals are eliminated by inspection of seeds before they are allowed to grow to full size. Calcium cyanamide crystals of low dust content ( 2 2 ) are produced by mixing calcinm cyaitamide, water, and calcium nitrate as a paste in a ball mill. Ca(OCI)~.ZCa(OH)2of improved filterability is prepared from calcium hydroxide by adding hypochlorite a t 25 to 40 O C. ( S I ) . A process for making sodium or pot.assium tetraborate is patented by May (2.4)in which sodium hydroxide, sodium carbonate, or sodium acid carbonate is mixed with potassium penta.borat,e. Kitroguanidine (36') is crysta!lized from methanol, ethanol, or acetone tjo obtain a crystal size and shape that can be handled as a slurry up to 50% in niolteri trinitrotoluene. In another process ( 1 6 ) nitroguanidine is crystallized from an aqueous solution containing ethylenediamine or a similar substance. .A more stable product is obtained in this way. Improvements in equipment for crystallization are described in several patents (89,38,46,49). A large plant for making ammonium sulfate is described by Bamforth ( 2 ) . It is a 350,000-ton-per-year plant for making fertilizer a t Sindri, India, which utilizes the Kryatal-type equipment for crystallization of ammonium sulfate. In addition to this specific installation of crystallizing equipment Bamforth ( 2 ) discusses the principles of crystallization and thcir applicat,ion to large scale production. The products for which Kryst,al-
INDUSTRIAL AND ENGINEERING CHEMISTRY
January 1950
31
Flawless growth was found to depend on the uniform supply of a solution of constant supersaturation t o the growing faces. ture.
LITERATURE CITED
(1) Arimori, Tsuyoshi, J.Soc. chem. Ihd.Japan, 45,370(1942).
COURTE8V BELL TELEPHONE LAEIORATORIEI
EDT Crystals 1 = Crystals formed spontaneously
P = Seed plate cut from crystal
3 = Seed cap cut from ayrta 4 = EDT crystal bar
5 = Seed formed by capping plntc
type equipment have been used are listed. MilJer and Saeman (26)have pointed out that a modified Oslo-Krystal pilot plant vacuum crystallizer produced crystalline ammonium nitrate that was equal to, or superior to, present commercial fertilizer grade ammonium nitrate. The effect of dewaxing aids such as asphalt on crystallization of wax from a propane solution was studied by Chamberlin, Dinwiddie, arid Franklin ( 8 ) : Microscopic observations were made of the wax crystals formed when a propane solution of a paraffin distillate was cooled. When a dewaxing aid is present in small amounts the wax crystallizes in spherical particles on which grow a shell of needles as further wax deposits. When no dewaxing aid is present the wax forms in plates. The rate of filtration of wax from oil is higher for the plate-type crystal b u t the recovery of oil is higher for the needle-cluster type. G R O W T H OF L A R G E SINGLE CRYSTALS
*
*
The techniques of growing single crystals for piezoelectric or other uses have continued under development. There are several papers describing equipment, procedures used, and the effect of variables which determine rate of growth and shape of the crystals. Sodium chlorate, zinc sulfate, or magnesium sulfate crystals can be grown in an apparatus described by Bouhet and Lafont (6). A crystallization flask and a solution flask are connected by a thermosiphon. The former contains a seed crystal and the latter a quantity of the substance to be grown into a large crystal. Circulation between the two flasks permits controlled growth of the seed crystal. An apparatus of a similar type is the subject of a patent assigned t o Menteau (26). The growth of artificial quartz crystals in sizes up to 3 X 2 X 0.5 cm. is described by Franke and Longchamp (16). The preparation of barium titanate crystals is described by K a y (20). Pessel (32)describes the use of a n alternating field of one or more components, one of which is the natural vibration frequency, to assist in making a monocrystalline body. The growth of ethylenediamine tartrate ( E D T ) crystals for piezoelectric applications is discussed b y Walker and Kohman ( 4 7 ) . An apparatus is described in which crystal growth from seeds takes place at constant temperature. A solution saturated with EDT at a given temperature is fed into a tank containing seed crystals held at a constant but somewhat lower tempera-
(2) Bamforth, A. W., Ind. Chemist, 25,No. 289,81(1949). (3) Belopol’skii, A. P., and Margolis, F. G., J. AppEied Chem. (U.S.S.R.), 20,331 (1947). (4) Blidin, V. P., J.Gen. Chem. (U.S.S.R.), 17,1381 (1947). (5) Bouhet, Charles, and Lafont, Robert, Compt. rend., 226, 1823 (1948). (6) Bragg, Lawrence, Science, 108,455 (1948). (7) Burton, W. K., Cabrera, N., and Frank, F. C., Nature, 163,398 (1949). (8) Chamberlin, N. F., Dinwiddie, J. A., and Franklin, J. L., IND. ENO.CHEM.,41, 566 (1949), (9) navies, J. G.,Intern. Sugar J:,50,155(1948). (10) Directie van de Staatsmijnen in Limburg, Dutch Patent 62,998 (April 15, 1949). (11) Dolique, R., and Pauc, M., Truv. SOC.pharm. Montpellier, 6,86 (1946-47). (12) Ib.id., p. 89. (13) Ibid., p. 91. (14) Finch, G. I., Wilman, E., and Yang, L., Discussias F a r b y SOC.,1, 144 (1947). (15) Foster, G.H.,and Williams, E. F., U. 5. Patent 2,445,478( J u l ~ 20, 1948). (16) Franke, Immanuel, and Hout de Longchamp, Marthe, Compt. rend., 228, 1136 (1949). (17) Gay, R.,Bull. soc.frang. midrul et crist., 72,251(1949). (18) Gorskii, F.K., J . Exptl. Theoret. Phys. (U.S.S.R.), 18,45 (1948). (19) Henry, J. L., and King, G. B., J . Am. Chem. Boc., 71, 1142 (1949). (20) Kay, H. F., Acta Cryst., 1, 229 (1948). (21) Lightfoot, Wm. J., and Prutton, C. F., J . A m . Chem. Sac., 71 1233 (1949). (22) Lonsa Elektrisitatswerke und chemische Fabriken A.-G., Swiss Patent 233,857(Nov. 16,1944)(23) Malone, E.J., U. 8. Patent 2,472,303(June 7, 1949). (24) May, F.H., Ibid., 2,455,595(Dec. 7,1948). (25) Menteau, Charles, French Patent 930,077(Jan. 15,1948). (26) Miller, Philip, and Saeman, W. C., IND.ENG.CIIEM.,40, 154 (1948). (27) Nakhmanovich, M. I., Lyubin, B. O., and Khai, D. M., J. Applied Chem. (U.S.S.R.), 22, 172 (1949). (28) Nikolaev, A. V., Ibid., 20,187 (1947). (29) “Patelhold” .Patentverwertungs and Elektro-Holding A.-G,, Swiss Patent 238,142(June 30,1945). (30) Peer, E. S.,U. 8. Patent 2,467,271(April 12,1949). (31) Pennsylvania Salt Manufacturing Co., Brit. Patent 574,979 (Jan. 29, 1946). (32) Pessel, Leopold, U.8.Patent 2,447,362(Aug. 17,1948). (33) Pines, B. Ya., J . Exptl. Theoret. Phys. (U.S.S.R.), 18,29 (1948). (34) Pinheiro, H. M.,Anais asaoc. quim. Brasil, 6,246(1947). (35) Posner, E., J . Phys. Chem. (U.S.S.R.), 22,637(1948). (36) Pritchrtrd, E. J., and \$right, G. F., Can. J. Research, 25F,257 (1947). (37) Ravich, M.I., and Ginsburg, F. B., Bull. m a d . sci. U.R.S.S., Classe sci. chim., 1947,No.2,141. (38) Reali, Antonio, Ital. Patent 424,581 (AUK.25, 1947). (39) Schlain, David, Prater, J. D., and Ravits, 5 , F., IND.ENR. CHEM., 41,834 (1949). (40) Shpunt, S.Ya., J . Applied Chem. (U.S.S.R.),20,685(1947). (41) Srikantan, B. S.,J. Indian Chem. SOC.,25,57 (1948). (42) Starodubtsev, S. V.,and Timokhina, N. I., Doklady Akad. Nauir S.S.S.R., 62,619 (1948). (43) Thomson, G.P., Proc. Phus. SOC.(London),61,403(1948). 18,1752 (1948). (44) Til’mans,Yu.Yn, .I. Gen. Chem. (U.S.S.R.), (45) Uchida, Shogo, J . SOC.Chem. Ind. Japan, 45,682 (1942). (46) Vahl, Laszlo, Dutch Patent 63,024(iMay 16,1949). (47) Walker, A. C.,and Kohman, G. T., Bell Telephone System, Tech. Pubs. Monographs. B-1562(1948). (48) Wells, A. P.,Ann. Repts. Progress Chem. (Chem. SOC.London), 43. 62 (1946). (49) Wetkspoor, N.V., Dutch Patent 62,553(Feb. 15,1949). (50) Whelm, Wm. P., Jv., Galkowski, T. T., and Van Hook, Andrew, Proc. A m . SOC.Sugar Beet Technol., 5 , 552 (1948). (51) Wilkins, P.J.,Biit.Pntent577,179 (Mays, 1948). (52) Wilson, Wm. S.,U. S. Patent 2,452,024(Oct. 19,1948). (53) Yoshida, Usaburo. Mem. Coll. Sci., Kyoto Imp. Univ., A23, 207 (1941). (54) Zhvirblyanskii, Y u . M., Volobueva, A. K., and Abragam, D . R.. Sakharnaya Prom., 1, 10 (1949). RECEIVED November 3, 1949.
