1374
s. D. MUZAFFAR AND RAMCHAND
Vol. 66
[CONTRIBUTION FROM THE UNIVERSITY CHEMICAL LABORATORIES, UNIVERSlTY O F THE PUNJAB ]
Equilibrium of the Ternary System Bismuth-Lead-Zinc BY S. D. MUZAFFAR AND RAMCHAND
This sys\em has been investigated to study the influence of zinc on the miscibility of bismuth
Fig. 1 .-The
Pb
three binary system invol system Bi-Ph-Zn.
ved in the ternary
and lead. It has been partially attempted by H. Fincke.' I t involves the three binary systems: bismuth-lead, bismuth-zinc, and lead-zinc, which have been investigated, and their thermal diagrams are given in Fig. l. Bismuth-Zinc System.LAt 425* the t w o metals are immiscible but as the temperature is raised their mutual solubility increases, resulting in complete miscibility a t 850'. Lead-Zinc System.2-These two metals are also immiscible a t 425' and they also become completely miscible at 940'. Bismuth-Lead System.:'-These are miscible in all proportions at 300". They form a eutectic (with 56.6% bismuth and 43.57, lead), the freezing point of which is 125'. Thermal Analysis.-Pure metals were employed throughout the work : bismuth (99.9%), lead (99.5%) and zinc (Merck Reagent). Their purity was confirmed by chemical analysis and their freezing points were found to be the same as the standards. Thermal arrests were determined by the method described by s. D. Muzaffar4 in an earlier study on the ternary system bismuth-tin-zinc; one hundred and fifty grams of each alloy was prepared by accurately weighing out the requisite quantities of' each metal on a sensitive balance. The alloys were protected from axidation during melting by a layer of charcoal on their surface. In the case of certain alloys the composition was determined by chemical analysis after the thermal analysis. Results of the thermal analysis are given in Table I. Freezing Points of the Alloys.-All alloys whose compositions lie in the area Bi-Pb-A-B-C-D-Bi (as marked in Fig. 2) form a single liquid layer at all temperatures above their melting points while those whose compositions lie in the area B-C-Zn form two liquid layers upon melting. The boundary line B-C has been established by the observations of the clear-cut cross sections of the alloys on either side of the line. The immiscible alloys show a distinct layer of zinc on the top of the frozen alloy. Compositions of the alloys on either Zfl
Fig. 2.-The phase diagram of the system Bi-Pb-Zn. The tie-lines represent freezing temperatures of the lower layer of two-liquid alloys in the zinc field.
(1) Fincke, Mdaibrosc, 17, 2581 (1027). (2) W. Spring and I,. Rornenhoff, 2. anorg. 29 (1896). (3) A. Kapp, A m . Physik, 18,29 (1807). (4) Muznffnr, J , Chcnl, sot,, 113, 2841 (1023)
THESYSTEM BISMUTH-LEAD-ZIN c
Aug., 1944
1375
side of the B-C line have been conBI firmed by chemical analysis. In Fig. 2 is also shown the position of the ternary eutectic a t TE. Its freezing point is 124' and it5 composition is %yoBi, 2% Zn, and 43% Pb. The three binary valleys TE-A, TE-D and TE-F ascend from it to the three binary eutectics situated at A, D and F, respectively. The binary valley TE-A IS essentially parallel to the Bi-Pb side as both the ternary eutectic and the binary eutectic of Pb-Zn contain about 2% of Zn, The Freezing Process.--AII alloys whose conipositions lie in the immiscible zone (B-C-Zn in Fig. 2) separate out in two layers on freezing. The upper layer consists of almost pure zinc as this metal is lighter than the other two. Zinc is the first to freeze, as its freezing point is the highest. Pb 31' . With the separation of zjnc, the Fig :1.--Isothernials of secondary (binary) arrests composition of the lower layer shifts along a line (see Fig. 2), starting from zinc, pass28 10 55 35 416 210 124 ing through the position of the alloy in question 29 55 5 40 416.5 231 125 and ending a t the boundary line B-C. When the :3 0 45 50 5 . . . . . . 126 composition of the lower layer becomes the same 31 50 44 6 ... . . . I26 32 50 40 10 414.5 . . . 125 TABLE 1 THERMAI. ARRESTS Alloy
no.
1 2
:3 4 8 6 'I 8
9 10
11 12 13 14
15 16 17 18 19 20 21 22 23 24 25 28 27
OF
ALLOYSI N
Composition in % by weight Pb Zn
Bi
on 85 85 80
80 80 75 75 75 75 70
711 ti5 ti5 ti5 ti0 00 60 60 A0
-I
10
5 15 10 5 23 20 10 5 20 15 15 IO )
:35 :1(I 25
20
I5
L1 57 56 5 42 5 56 42 56 41 55 40 55 35
rin
THE SYSTEM
Pb-Bi-Zn
Number of Thermal arrests, layers in the OC. solidified 1 I1 Ill alloy
5 375 .i391 10
5 10 15 2 8 15 20 10 15 20 25
416 415 5 4lH
:10
4lt; 5
396 416
416 416 5
.i 10 415 6 15 415 5
20 415 8 25 415 5 2 1
2 3 5 10 415 15 416
243 924 241 310 234 240 200 205 222
126 125 125 124 125 125 124 125 125 240 126 198 125 214 124 21U 125 220 125 238 194 12ri 160 125 179 126 193 124 208 1% 124 124 . 124 . 124 . . 124 126 144 125
One One
One One One Two
One One Two Two One Two Two Two TW(J
One Two TWO
Two Two One One One One One Two Two
33 34 35 36 :3i 38 :I9
-50 50
54
:30
51
55
30
40
15 415 130 20 415 127 25 415 160 30 415 170 10 . . , 145 ... 15 415 40 415.,5 190 45 416 210 t50 416.5 226 5 . .. 169 15 415 149 20 414.5 143 30 415 ... 40 415.5 161 15 416 162 30 414 144 55 415.5 203 60 41fi.5 223 5 .. 230 10 . . . 2111 16 4lti 200 20 415.5 170 30 415 152
56
311
:3( )
40
414.5
57 58 59 60
3(I 30
62
63
2.5
5
50 55 15 25 50 65 70
414.5 414.0
25 25 25
9(I 15 Bo 50 25 10
40 41 42 43 44 45 46 47 48 49
50 51 62 53
61
50 50 45 45 4Fi 45 45 40 40 40 40 40 35 35 35 35 30 31b 30
25
35
30 25 20 45 40 15
to 5 55 45
40 30 20 50 35 10 5 65 60 55
... 417 414.5 415.5 416.5
142 . 158 ,
124 123 123 124 125
12-1 123 124 123 125 125 123 124 125 124 125 124 124 124 12:j I25 124 12:i
121 121;
..
221 124 208 123 143 122 176 . . . 212 . . .
Zn
Two Two One One Two Two Two Two Two Two T wo
'rwo
TWO
Two One Two Two Two Two Two Two TWO
*rwcl Onc ,.I M'l I .rwo ,.I "0 Two *.
Iwo
'l'W0
'rwo Two Two
Two Two Two
S..)I MUZAFFAR AND RAMCHAND
1376
Vol. 66
TABLE I (Concluded) Composition in % bf weight Bi Pb Zn
Alloy
no.
96 97 98 99 100 101
20 20 20 20 20 20 20 20 15 15 15 15 15 15 15 15 10 10 10 10 10 10 10 10 10 10 10 5 5 5 5 5 5 5 5 5 5 5
T.E.
55
64
65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
81 82 83 84 8.5 86 87 88 89 90 91 92 93 94
95
2 5 10 20 30 40 50 60 5 15 25 40 55 70 75 80 5 10 15 20 30 45 60 70 75 80 85 5 10 15 20 30 45 60 75 80 85 90
78 75 70
60 50 40 30 20 80 70 60 45 30 15 10 5 85 80 75 70 60 45 30 20 15 10 5 90 85 80
”IS
65 50 35 20 15 10 5 43
Number of layers in the solidified I11 alloy
Terminal arrests, OC.
I
IT
... ...
260 256 417 248 417 241 416 223 416 206 416 164 414 143 .,, 272 418.5 271 418.0 260 418 238 417 208 414.5 142 414.5 , . . 415.5 206 .., 292 ... 292 418.5 290 418.5 287 418 280 418 265 417.5 240 417.5 208 416.5 . . . 414.5 141 415.5 , . . . . . 310 420 306 419.5 305 419.5 303 419 301 419 297 418.5 288 418.5 257 418.0 236 417.0 210 415.0 185
Z...
...
123 121 124 123 123 124 123 , .
One One Two Two Two Two Two Two One Two Two Two Two Two Two Two One Two Two Two Two Two Two Two Two Two Two One Two Two Two Two Two Two Two Two Two One One
.
124 123 122 124 125 .. ,
..
. . ,
124 ...
124
... .., 124 123 124
... ... 124 ...
...
... ... 121 ...
... ...
... ...
...
124
t
9ei 360 320 1
160 120
400
-
a--Q-?F
}
0
-
0
A,&, -7
-
0
-
:
I
0
P-e-9
I
C
ri 3601
’i
320
360 320
1201
3
:
...:-. ~
-
-
160 120 .
:
m
.
b
40 50 60 70 80 90 Lead, %. 40 46 48 55 60 67 73 81 91 Alloy Nos. Fig. 4.--Cross section showing median through lead. 10
20 30
3 10 20 30
40 50 60 70 80 90 95 Bismuth, %. 85 69 55 45 35 19 12 5 1 Alloy Nos. Fig. 6.-Section of thermal diagram showing median through bismuth.
THESYSTEMBISMUTH-LEAFZINC
Aug., 1944 4001
360 320
--
1377
a -
I
ci
360 .
6 200 lG0 120
120 1601
I
Zinc,
bismuth.
TE-A-Zn and Bi-Zn eutectic in the area TE-DZn; (3) the ternary eutectic. Similar considerations apply to alloys with compositions in the bismuth or lead fields. Alloys with compositions lying on the two-solid curves, F-TE, A-TE and D-TE, show only two structures, a binary and a ternary eutectic. Furthermore, the line joining TE and Zn through G forms a valley in itself. In alloys 32, 45 and 57, whose compositions lie almost on this line, no binary eutectic is formed: they have only two structures, zinc and the ternary eutectic. Similarly the alloys on lines joining the corners Bi and Pb with TE will consist only of bismuth or lead, respectively, and ternary eutectic. o
i
-
Zinc,
75 65 55 45 35 25 15 5 0 Lead, %. 91 9293 94 95 96 97 9899 100 101 Alloy No. Fig. 7.-Section of thekmal diagram (Fig. 2) through 5%
1
:. /-~ ;;--:: 20 30 40 50 60 70 80 90
%.
^ -
z
lo!)
%.
37 44 48 56 61 71 77 89 101 Alloy Nos.
85
400
r 10
10 20 30 40 50 60 70 80 90 95
Fig. 9.-Section
of thermal diagram showing median through zinc.
Isothermals of the Binary Arrests.-In Fig. 3 isothermals of the binary arrests of the various alloys of this system are given. As the line joining T E and Zn does not meet any of the binary valleys, the alloys whose compositions lie on this line have no 'binary eutectic and, do not give any binary arrests. This line forms a valley by itself. The alloys with compositions farther and farther from this line give higher and higher binary arrests. Similar considerations apply to the configuration of the isothermals in both the bismuth and the lead fields. Effect of Lead on the Partial Miscibility of Bismuth and Zinc (Median through Lead).Figure 4 illustrates the &ect of adding increasing quantities of lead to a mixture of equal proportions of bismuth and zinc by weight. This is a section through the middle point of the Zn-Bi base and the apex P b of Fig. 2. The top line shows that up to SO% lead, zinc freezes out from these alloys a t almost constant temperatures. With higher 360
ci 320 360/
120 40 50 Zinc, %. 80 70 60 50 40 Lead, %. 80 818283 84 85 Alloy Nos. Fig. 8.--Section of thermal diagram bismuth. 10
20 30
60
70
80 90
10 20 30 30 20
10
85 75 65 86 87
89 90
40 50 60
Bismuth,
0
55 45 35
Lead. 91 80
(Fig. 2) through 10% Pig. lO.-Section
70 80 90
%. 25 15 5
%.
42 302516 8 4 2 1 Alloy Nos. of thermal diagram through 5% zinc.
65 51
S. D. MUZAFFAR AND RAMCHAND
1378
VOl. 66
percentages of lead the freezing point rapidly falls. Binary arrests show a minimum at 30%
lead, 35% bismuth, 35% zinc. This composition lies on the Zn-TE line (Fig. 2).
I. Tcrnaryeutffticalloy TE ( X 1.54) etchedinHCI-.FeCI,.
11. Bismutbzinc binary eutectic X 300.
.
!2
'
111. Ternary eutectic and bismuth-zinc hinary eutwtic alloy No. 8 ( X 150).
, .
,
:
I V . Alloy No. 39 (; layers of the solidifit
..
..
;.
:. P
r:
.
. '3
VI. Showiiig ( X IUU) the lower layer of the immiscible alloys consisting of three phases: (a) ternary eutectic V. Showing the upper layer of the immiscible alloys con- (fine-grained background). (h) bismuth-zinc binary eutecsisting of almost pure zinc, x 200. tic (dark blocks). and (c) pure zinc (dark lines). Fig. 11.-Photomicrographs of some of the alloys.
Aug., 1944
THESYSTEM BISMUTH-LEAPZINC
I:US
i VI]. Alloy No. 42 etched in iodine ( X 150) atid showing three phases: (a) ternary eutectic (fine-grained background), (b) lad-zinc binary eutectic (semi-dark blocks). (c) pure zinc (dark rods)
IX. Alloy No. A; ( X 150) showing two phases: (a1 ternary eutectic (fiue-grained patches), arid (b) bismuthlead binary eutectic (Imhl I h c k and white patches).
V1II. Alloy No. 45 ( X 150) shewing two phases: (a) ternary eutectic (black and white background). and (b) zinc (dark lines). This alloy lies on the line joining Zn and TE.
X. Rismuth-lead eutertir ( X
ZIX)).
XI. (X 150) etched in iodine and showing three XII. ( X 150) etched in iodine and showing three phases: (a) ternary eutectic (almost white patches), phases: ( a ) ternary eutectic (fine-grained whitish patches). (b) binary eutectic. and ( c ) zinc metal (dark liner). (b) binary eutectic, and (c) zinc metal (dark lines). Fig. 11.-Photomicrographs of some of the alloys.
1380
F. C. NACHOD AND W. WOOD
Figure 5 illustrates a section of Fig. 2 through 591, lead. Effect of Bismuth on the Partial Miscibility of Lead and Zinc (Median through Bismuth).Figure 6 illustrates the effect of adding increasing quantities of bismuth to a mixture of equal proportions of lead and zinc by weight. This is a section throu h the middle point of the lead-zinc base and Bi ?Fig. 2). Up to'70% bismuth, zinc freezes out from these alloys at almost constant temperature. With higher percentages of bismuth, the freezing point rapidly falls to that of pure bismuth. Binary arrests show a minimum a t 40% bismuth, 30% lead, 30% zinc. This composition lies a t the Zn-TE line (Fig. 2). Sections of the diagram (Fig. 2 ) at 5% bismuth and 10% bismuth are given in Figs. 7 and 8, respectively. The sharp fall in the binary arrests at high percentages of zinc or near the zinc corner of Fig. 2 is clearly noticeable. Effect of Zinc on the Miscibility of Lead and Bismuth (Median through Zinc) .-Figure 9 illustrates the effect of adding increasing quantities of zinc to a mixture of equal proportions of bis-
[CONTRIBUTION FROM THE
Vol. 66
muth and lead by weight. There are three separate lines. The upper line represents the freezing points of the alloys. The middle one shows the binary arrests and the lowest line the freezing points of the ternary eutectic. A section of the diagram (Fig. 2) a t 5% zinc is illustrated in Fig. 10. The binary arrests show a minimum a t 55% bismuth, 40% lead and 5% zinc. As this composition lies on the Zn-TE line the primary arrest is also low and is hardly distinguishable from the binary arrest. Microscopic Investigation.-The conclusions drawn from the phase rule considerations (discussed above) are supported by microphotographs of some of the alloys as given in Fig. 11. Summary In this system a tertiary eutectic is formed with 5 5 7 , bismuth, 43% lead and 2% zinc. Its freezing point is 124'. By addition of lO-15% or more of zinc to the miscible binary alloys of bismuth and lead, the ternary alloys (thus formed) become immiscible. LAIIORE,INDIA
RECEIVED AUGUST9, 1943
RESEARCH LABORATORIES, PERMUTIT COMPANY ]
The Reaction Velocity of Ion Exchange BY F.
c. NACHOD AND w . WOOD
Many investigators have studied ion exchange termined by these experiments. The data obphenomena and approached the subject from tained by these authors are of value only for a various directions. A great number of papers particular cation exchange and a particular water come from the soil chemist and, consequently, composition. No net reaction rate could be obdeal largely with ionic distribution in soils. Other tained by their procedure. investigators have described industrial uses and Beaton and Furnas4 obtained transfer coapplications. Data on ionic equilibria between efficients by considering base exchange to be exchanger and solution have been collected. analogous to heat transfer. Their data on the However, surprisingly little information can be hydrogen-copper exchange show again that the gathered if one wants to learn something about reaction is very rapid and about 90%5 of it is the rates of reaction taking place between the ions completed in thirty minutes. in solution and in the ion exchange material. The difference between a good and a bad exOne encounters qualitative statements that the changer was shown graphically by AusterweiL6 reaction proceeds rapidly a t firstIt2and then slows His experiments show that the exchange reaction down as the equilibrium is approached. is extremely rapid and completed after approxiDuDomaine, Swain and Hougena focussed their mately fifteen minutes. The writers have endeavored to measure the attention on cation exchange softening rates. Their technique consisted in passing hard water rate of reaction of ion exchange and their results through thin layers of exchange material. The are given below. The ion exchange materials which were studied small dimension of the bed permitted disregarding concentration gradients and the authors comprise two classes. In the first class are siliceous arrived at differential rate equations. Certain materials of natural origin, e. g., the glauconite limitations of the procedure are stated by the or greensand type exchanger as well as synthetic authors (p. 553 of ref. 3) and no rate constants siliceous gel type exchangers which all are cation were given, nor was the order of the reaction de- exchangers. The organic materials which form the second class embrace cation exchangers, (1) J. R. Patton and J. B. Ferguson, Can. J Rcscarch, B18, 103 characterized by the functional groups -S03H, (1937). (2) H.F. Walton, J . F7anklm Insl., 2S2, 318 (1941). (3) J. duDomaine, R. L. Swain and 0 A. Hougen, I n d . E n g . Chem.. 86, 546 (1943).
and C. C. Furnas, ibid., SS, 1500 (1941). (5) Ref. 4, Fig. 1. p. 1503. ( 6 ) G . Austerweil, Bull. SOL. c h i m . . 151 6,57 (1939). (4) R . H. Beaton
