2102
INDUSTRIAL AND ENGINEERING CHEMISTRY
V d 42, No. IO
n
1
Figure 6. Photomiuographe of Copper Powder A
B
--
Run 11.4 7.77 m x m a of m p p p u I~I u r Rum 8C.' 31.3 m r n a of mppu pu li-
variation in scid Wuccntration. LIEcopper concentration was increased from 12.7 to 82 grams per liter because of the poor flow oharacteristics of tha powder8 produced a t the lower copper wnoentrsticns. CELLVOLTAQS.Cell voltage was primarily a funotion of acid concentration. At acid eoncentrations within the optimum range of 90 to 200 gams per liter, cell voltnges varied fmm 0.8 lo 1.25 volts, depending on current densi!,y, t,emporature, and oopper canceritratinn as shown in Tahlo 11. A w n n e a ~I)F:ssI-. As shown by Figure 4, apparent density Increased with increase in mppw concentration, increase in temperature, and decrease in wid concentmtion. Change in current density had little effect. Evidently the larger size particles were deposiied as plathg conditions were approached-tha! is, increased teinporaturo and copper roncfntration-rpiultirlg in powder o f higher q ) p ~ r e i i density. t Apparent density %.as also found to incrcase with increaac in total current effirioncy based on the toto1 capper deposited as powder and &F d i e r e n t copper. The difference between IW and the total current efficiency may be taken as a memure of the evolution of hydrogen. To B remarkable degree (Figure 5 ) , s p parent density of the copper posder can he eorrelsted with total metal current efficicnoy. FLOWRmn, Flow rake hicretmed with i n c r e w in wpper w n cantistion. With regard to %id concentration, flow rste reached B maximum a t diwt 100 grams oi sulfuric acid per liter (Table 11). Photomicrograph8 of coppcr powder (Figure 0) show that apparent density and Row rate o m be correlated with particle ≊ the nodular form Row8 much faster and has D higher density tfian the fcrnlike dendritic iorm of powder. Copper conoentration influenod particle shape more than any other vsriable, high concentration8 of oopper tending to promote formation of nodular pwticles. SCREENANALYSIS. As shown by Table 11 the percentage of powder finer than 2W mesh decreased with increase in temperature, ourrent density, and oopper concentration.
ACKNOW LEOGMENT
The authors are indebted to the University of Warhingtolr Experiment Station for financial Basistanee in connection with this proieot. Tho suthora also express their sincere ~ppreciationto Jack Finley for suggestions regarding soreening of the copper powders and to Darrell M e r m d T.Rreitmsyer for aasistanra in preparing the photomicmgrspha. LITERATURE CITEU
(I) American Metal Co.. LW..New York. N. Y..trade literature. ( 2 ) Baeas. "A Course in Powder M~tnllurw." New York. &inhold Publishing Corp.. 1943. (3) Comatock. Metal Pmjmaa, 35, 48.5 (193s). Elecfrochem. Sac.. 85. 97 (1944). (4) Cordiano, T~ona. ( 5 ) Furman, "Scott'a Standard Methods of Andysis." 6th mi.. Vol. 1. P. 368, New York. D. Yair Nostrand Co.. Ins.. 1935. (6) General Metals Powder Co..Akron. Ohio. trade literature.
(7) Hardy. Chaa., Inc.. New York, N. Y., trade Iiterat~m. ( 8 ) Hothersall and Gerdsm, Mef. I d . (Lowion). 66. 234 (1945).
(9)Jones, "Powder Metallrrrw." Landon. Fkiward Arnold Co.. ,097 _""*.
(10) Metsla Refining Co., Division of (iliddw Co.. Hammond. Ind..
trade literature. (11) Rowmsn, Trana. Elelrochem Btc., 85, I(i0 (1944). (121 Sohumaoher and Souden. Metal8 dllovs. .. 20,. 1327 (19441. (13) Skaupy, "Prinoiplee of Powder M~ialhtigy,"p. 22. N e w i w k . Philosophical Libraw, 1944. (14) Wulff, "Powder Metallurgy." p~ M I . Clwrlsnd. Ohio. Am. s i r . for Matals. 1942. K s c r . w m Dscernbei 8. 1949. Prasantsd Idore the Division of 1nduatri.l end Enginssting Cherniatry, 116th Meeting. A l r s n r c ~Caeurcnb ~ 8ociarr. Ran Pmnciaco, Calif. Based on tberis preacnted by Daniel W. Drumiler i n ~ ~ r t i fulfillmsol sl of the mauir~rneotsfor the degree 01 master 01 ~ e i m in ~ v ahsmicii enzin~lring.University of Washington, 8 ~ * t t l a .Wauh.
Corrections In the artiole entitled "Thermadynnmio Properties of Sulfur" [West, J. R.,IND. ENU.Cmx.,42,713 (1950)1 the third equatioii io the second column of page 715 should r e d :
CONCLUSIONS
Optimum results were obtained when conditions were such that wall amounta of hydrogen were evolved, probably due to insufficientdiffusion of copper ions to the cathode. Factors tending to deerease tho concentration of copper in the cathode film, suoh LB law tempersture, low electrolyk eopper concentration, and high csthode current density, favcrrml the deposition of copper in powder form.
hs
=
0.0. 123P
+ 0.176T t 137.9
lrt the wtiolc entitled "Pure 1 Iydrocarbons from Petroleum" [Griswotd, Chew, and Kleoke, IN^. h a . CHEM.,42, 124651 (1950)l error8 occurred in the subhedings of Table 11, page 1249.
All tabular materid on this page is far the methyloyeloherane system and "methylcyclohexme" should be substituted for "nheptane" wherever the lstter appears in the subheads
