IKDUSTRIAL AND ENGINEERING CHEMISTRY
1416
tion of the alkaline reagent, states that Alberta bituminous sand may be separated by stirring the material in a hot solution of sodium carbonate of 0.1 per cent concentration and that the solution may be used indefinitely. Of the impurities found in bituminous sand beds, clay is the most troublesome from the standpoint of practical hot water separation. The strata a t the bituminous sand quarry used by the Research Council of Alberta consisted, for the most part, of richly impregnated sand containing only a few per cent of particles passing the 200-mesh sieve. But clay partings and clay masses were frequently encountered, The experimental work presented has shown that clay in the bituminous sand reduces the yield of bitumen and causes trouble from bitumen staying in the water and being carried throughout the plant. Laboratory tests have indicated that trouble from clay can be avoided by preliminary washing of the bituminous sand in cold water. Soluble salts are probably present t o some extent in most of the bituminous sand beds, but the quantities of them encountered a t the quarry a t the experimental plant are abnormal. It is not likely that much difficulty from them
Vol. 24, No. 12
will be met if sodium carbonate is used as the alkaline treating reagent. Calcium and magnesium salts in small amounts will give trouble if sodium hydroxide is used. Pre-washing of the bituminous sand to remove excess clay would a t the same time remove dangerous quantities of soluble salts. LITERATURE CITED (1) Bartell, F. E., and Miller, F. L., IKD. EKG.C H m f . , 24, 335 (1932) ( 2 ) Clark, K. 4.,and Blair, S. M., Research Council of Alberta. Rept. 18 (1929). ( 3 ) Clark, K. A , and Pasternack, D. S., T e n t h -4nnual Rept. of Research Council of Alberta, Road Materials Section, 1939. (4) Clark, K. A,, and Pasternack, D . S., Eleventh Annual Rept. of Research Council of Alberta, Road Materials Section, 1930. (5) Ells, S. C., Investigations of Mineral Resources and the Mining Industry, Section 111, Mines Branch, Dept. Mines, Ottawa, 1929. (6) Ells, S. C., Investigations of Mineral Resources and the Mining Industry, Section I, Mines Branch, Dept. Mines, Ottawa, 1930. (i) Ells, 8.C., Mines Branch, Dept. Mines, Ottawa, Rept. 632 (1926). (8) Fyleman, E., J. SOC.Chem. Ind., 41, 14T (1922). (9) McClave, J. hl., U. S. Patent 1,594,625 (August 3 , 1926,.
RECEIVED M a y 31, 1932.
Decomposition of Dilute Sodium Carbonate Solutions at Temperatures between 147" and 2 4 3 O C. FREDERICK G. STRAUB AND REINHOLD F. LARSON, University of Illinois, Urbana, 111.
T
H E development of a disThe reactions involved in the decomposition NazC03 2H20 -2XaOH HzO +COz (2) tinct causticity in the of sodium carbonate in solutions at temperatures T h e c a u s t i c alkalinity of the water of a steam boiler between 147" and 243" C. have been investigated. boiler water was observed to inusing as a feed a natural water The reactions Na2c03 -k Hzo NUOH f crease steadily as the boiler was c o n t a i n i n g sodium carbonate NaHC03, and NaHC03 If NaOH f H20 -k heated, samples of steam and of was observed and studied by water being drawn off for analyPaul (8) in 1891. Many others C 0 2 have been found the most plausible explanation of the decomposition. Based on these sis. have since observed and studied The extent of this decomposithe phenomenon* T h e p r e s reactions, a rough calculation has been made of tion phenomenon is of imporence of carbon dioxide in the the at the above lemtance to the boiler room engis t e a m sDace and headers in peratures. neer in various ways. The maina m o u n t - i n excess of that actenance of an adequate ratio of counted for as free carbon dioxide in the feed water led several to suspect that this caus- sodium carbonate to sodium hydroxide is known to inhibit caustic embrittlement (IO). R. E. Hall and associates have ticity resulted from a direct break-down of the carbonate. Paul (7') in 1919 proposed that the principal decomposition recommended the maintenance of a carbonate-sulfate ratio reaction was not toward the liberation of carbon dioxide in to prevent the deposition of a calcium sulfate boiler scale the steam, but rather that of oxygen. He apparently found (2, 6 ) , and the maintenance of a certain hydroxyl alkalinity much evidence of oxygen in the condensed steam and little to reduce corrosion (3). In order to gain this information, the authors built and carbon dioxide, and therefore proposed the following: operated a small high-pressure laboratory boiler in which all of NazCOa H20+HCOzNa NaOH 02 (1) the operations of an industrial boiler were duplicated on a conThe formate of soda then went through a complicated series of trollable scale. Various synthetic solutions of sodium carreactions forming various organic compounds, some being bonate were fed and constant water level maintained, the steaming rate being about 90 pounds (40.8 kg.), or about two reconverted with caustic soda back to sodium carbonate. Hall, Kartch, and Robb (Z),in 1927, conducted an investi- concentrations per hour. The boiler was operated a t steam gation of the noncondensable gases in the steam from a small pressures between 150 and 1500 pounds per square inch (10.54 laboratory boiler. When sodium carbonate was introduced and 105.4 kg. per sq. cm.) gage. Samples of boiler water were with the feed, carbon dioxide constituted most of the non- drawn off in a small steel bomb, cooled, and analyzed for condensable gas in the steam taken off. The oxygen content carbonate and hydroxide. The calculated results were all was exceedingly small and did not increase when sodium car- expressed as sodium carbonate and arranged in the ratio: bonate was introduced. In fact, they found no evidence for (NaOH as SazCOd X 100 = %decomposition the existence of reaction 1, and concluded that the principal (NaOH as Na,C03) NazC03 reaction was probably:
+
J'
+
+
+
+
INDUSTRIAL AND ENG INEERING C H E M I S T R Y
December, 1932
This ratio expresses the extent of the decomposition a t any particular time. Figures 1, 2, and 3 are typical of the results obtained, and indicate that this decomposition reaction is reversible in an operating steam boiler and is controlled by the amount of available carbon dioxide in the feed water, the boiler pressure or temperature, and the hydroxyl alkalinity of the boiler water. The last contention was checked by several runs in which the hydroxyl alkalinity was kept, constant by continuous blow-don-n. Figure 4 indicates that the reaction rate is fast enough to be practically independent of the steam-
1417
acid were added to aid in the complete evolution of any carbon dioxide. For very small quantities of carbon dioxide-that is, less than 20 mg.-the gases were bubbled through a Meyer's sulfur bulb containing 0.02 N barium hydroxide, and the carbon dioxide determined by titration with 0.02 N hydrochloric acid to the phenolphthalein end point. CONDETERXISATION OF HYDRATE AND CARBONATE TEXT O F BOILERw-4TER The water analyses were made using three methods: the
-4.P. H. A. ( I ) , using phenolphthalein and methyl orange indicators; the Winkler method ( I I ) , using barium chloride to precipitate out the carbonates; and the carbon dioxide-evolution method by acidification t o determine carbonates. These methods for the most part checked very well within the ex0
800
1600 E403 3200 4023 4800 S 6 C ) Total C o i c e n t r a t i o n a5 .VA,CO, P P M
FIGURE1. 400 P.
P. M.
6400
7200
100
I
Na2C03FEED c 90
ing rate. Figure 5 indicates that total ionic strength has in this range very little effect. It is apparent that with the operating boiler where constant water level is maintained a dynamic equilibrium is possible, dependent upon the above factors (4).
.L
t
g BO n E
p. 70
T E ~ T FSO R TEUEEQUILIBRIU.\IDAT.\ In order to correlate the results obtained from the above steaming boiler with true equilibrium data, a series of tests to I , 40 I I I obtain the latter was undertaken. 0 I 2 3 4 5 6 7 8 3 IC APPARATUS.An electrically heated vessel of approxiHours on Line mately 42,000 cc. was charged with solutions of various mix150 P. P. M. Na,CO, FEED FIGURE 2. tures of sodium hydroxide and sodium carbonate and heated to various temperatures. The amounts of solution charged varied from 22 to 35 kg., leaving a space above the solution perimental error involved (9). The evolution method was for steam formation and the accompanying carbon dioxide. found most reliable. EXPERIMENTAL DATA. Data obtained are given in Table I. The boiler thus formed was so arranged that steam could be The constants K , K ' , and K" were calculated as follows, slowly withdrawn, and a sample of water withdrawn through a filter a t the bottom into a steel bomb, cooled, and analyzed a t using mole fractions and partial pressure of carbon dioxide in room temperature. The essential apparatus is shown in atmospheres (Pco,): Figure 6. The amounts of steam withdrawn varied from 300 (hTaOH)2X P C O ~ NaOH X P C O=~ K , =R to 900 grams, and the rate of withdrawal was varied from 3 to Na2CO3 Na2C03 10 grams per minute. NaOH X GO2 = K,, COz DETERMINATIOK. The steam withdrawn was passed Na2COs directly into an Erlenmeyer flask and kept a t 100' C. by a gas I n order to compare these data with data on the previous burner. A refluxing condenser was used to retain the condensed steam and pass on the noncondensable gases. These operating boiler, the corresponding percentage decomposition were passed through granulated zinc to take out any hydrogen was also calculated. In the latter portion of the table are sulfide o r i g i n a t i n g in the given data obtained on exp e r i m e n t s in which large rubber connections, dried by 70 passing through anhgdrone, +; a m o u n t s of sodium sulfate and finally passed through a c'z were added to i n c r e a s e the Wesson b u l b c o n t a i n i n g ionic strength. I n t h i s 40 a s c a r i t e and anhydrone to range ionic strength seems absorb the carbon dioxide. E30 t o have little influence, al1600 2400 3200 4000 4800 5600 6400 7200 8000 Carbon dioxide-free air was though in the previous boiler Total Alkalinityias Na2C03 P P M into the tests its effect was n o t i c e FIGURE3. EFFECTOF PARTIAL PRESSURE OF COz ON DEflask beneath the water leVel, able. COMPOSITION OF Na2CO8AT 150 POUND STEAM PRESSURE, 400 and a few drops of s t r o n g P. P. M. FEED There appears to be con-
5 90
5 90 + f 80
++ mc :a0 u a
co"
k E70
fZ70 c? 8 63 50
FL
n
60 Total
0
400
800
I200
1600
2000 2400
2800
3200
3600
T o t a l C o n c e n t r a t i o n a s NA,C03 P P M
FIGURE 4. VARIABLE STEAMING RATE150 POUND PER SQUARE INCH,150 P. P. M. NaLC03
Alkalinity
a s h!a2CO3 P P M
FIGURE5. DECOMPOSITION OF Na2COs IN PRESENCE OF LARGEAMOUXTS OF NazSO, Curves represent decomposition obtained with Nark304 abpent. Approximate ratios NazS04 t o alkalinity a8 NazCOa are indicated
INDUSTRIAL AND ENGINEERING CHEMISTRY
1418
Vol. 24, No. 12
TABLEI. RESULTSOF TESTSIN EQUILIBRIUM BOILER PARTIAL TE6T
TEMP. O
c.
NaOH Mrn./liter 40.3 29.0
NaaCO, Mrn./liter 2.99 9.25
IONIC STRENQTH Mrn./liter 49.27 56.75
PREWURE
DECOMP.
coz
COz ATMOB. x 10-4
% 87 61
P. p. m. 18.2 65.6
0.329 1.19
179.0 108.2
10.54 10.54 0.987 0.987 2.12 8.81 9.40 16.52 16.52 6.7
232.0 190.4 91.0 100.0 121.0 83.9 82.4 34.7 49.6
37.6 32.5 21.0 22.7 29.6 31.3 31.5 19.9 24.2 20.2
3.37 2.90 1.87 2.02 2.63 2.79 2.81 2.24 2.16 1.80
357.0 534.0 1500.0 1840.0 1785.0 1580.0 2780.0 1450.0 3080.0 1490.0 1420.0 1580.0 1890.0 947.0 825.0 3140.0 2260.0 2710.0
60.2 70.5 75.5 76.1 62.0 47.1 66.0 66.0 75.0 59.0 55.6 55.2 58.0 51.9 48.7 67.2 50.5 43.9 40.9 39.8 155.0 192.0 143.0 158.0 101.0 102.0 128.0 269.0 246.0 220.0 218.0 147.0 122.0 226.0 260.0 183.0 209.0 183.0 178.0 144.0 218.0 144.0 126.0 207.0 130.0
3.34 3.90 4.19 4.22 3.44 2.61 3.66 3.66 4.16 3.27 3.14 3.06 3.22 2.88 2.70 3.73 2.80 2.44
30 39
147 147
60 50 35 35 29 23 22 42 42 66
185 185 185 185 185 185 185 185 185 185
6.19 5.86 43.5 44.0 41.0 26.8 26.15 17.45 20.6 51.9
1.735 1.9 2.05 1.91 2.945 7.56 7.8 14.51 14.0 17.45
11.4 11.56 49.7 49.8 49.84 49.45 49.6 60.98 62.5 104.25
63.6 60.7 91.4 92.3 87.5 61.1 69.9 37.6 40.0 59.8
230.0 230.0 21.5 21.5 46.2 194.2 204.0 360.0 360.0 146.0
4-28 4-30 C A B 6-25 33 4-13-5 28 4-14-1 37
208 208 208 208 208 208 208 208 208 208 208 208 208 208 208 208 208 208 208 208 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243 243
5.9 7.6 19.8 24.15 28.8 33.6 42.2 22.01 41.0 23.0 25.6 28.6 32.6 18.25 16.96 46.7 44.7 61.6 49.1 80.0 4.45 8.5 7.93 7.65 6.05 2.73 4.51 18.7 14.0 15.45 16.0 23.1 23.05 41.0 41.4 22.9 26.2 26.1 25.8 17.45 31.75 17.1 15.7 51.1 46.6
1.98 1.47 3.3 3.02 2.75 2.17 1.56 9.0 2.83 9.1 9.54 8.91 8.4 13.41 13.97 5.94 7.83 8.3 18.5 9.06 1.54 0.283 0.49 0.623 1.237 2.357 1.82 0,834 2.22 1.932 1.791 0.32 0.557 1.49 2.76 9.72 9.08 9.21 9.35 13.3 8.94 13.85 14.55 6.09 17.1
11.84 12.01 29.7 33.21 37.05 40.11 46.88 49.0 49.49 50.3 54.22 55.33 57.8 58.48 58.87 64.52 68.19 86.5 104.6 107.2 9.1 9.35 9.4 9.52 9.76 9.8 9.97 20.7 20.66 21.25 21.37 24.1 24.72 45.47 49.68 52.06 53.44 53.73 53.85 57.35 68.57 56.65 59.35 69.37 97.84
69.4 72.5 75 80 84 88.6 92.4 55.0 88.1 56.0 57.5 61.7 66 40.5 37.8 79.4 74 79 57.0 81.6 59.0 93.3 89.0 85.0 71.2 36.6 55.4 91.7 76.0 80.0 81.6 97.0 95.2 93.2 88.2 53.5 59.0 58.6 56.8 39.7 64.0 38.1 35.0 80.6 58.0
298.0 185.0 171.0 129.0 80.0 28.2 33.0 365.0 70.0 348.0 280.0 232.0 203.0 516.0 543.0 116.0 120.0 80.3 209.0 42.7 375.0 44.5 61.7 88.4 149.0 616.0 358.0 83.6 271.0 191.6 170.0 14.3 20.6 58.0 117.0 543.0 505.0 451.0 451.0 762.0 429.0 816.0 816.0 172.0 334.0
;-7-K 54 41 25 D F 65
G 57 18 17 16 15 13 14 3 9 11 12 7-8 6 32 27 19 20 36 36 53 21 40 40 26 63
TEMP.
50 46
185 185
48 51 45
208 208 208
4.66 6.06 36.1
2.36 1.8 5.14
49 52 43 44 47
243 243 243 243 243
5.5 7.14 34.1 34.5 37.3
1.91 1.31 5.21 5.2 5.1
* c.
42.7 243.1
63.6 76.2
10.11 10.5 63.1
41.07 42.7 240.8
49.8 62.7 77.9
10.11 10.6 60.5 61.0 64.5
41.56 43.0 231.2 233.1 244.6
59.0 73.0 76.6 77.0 78.5
siderable inconsistency in the constants calculated. On the basis of reaction 2, K should be the equilibrium constant if activities can be disregarded. This constant would include the ratio of activities. The inconsistencies do not appear to be influenced by ionic strength; consequently, activities are probably not an important factor. It appears that reaction 2 is not adequate. An investigation was made of the possibility of the existence of appreciable amounts of bicarbonate ion in the boiler water, At room temperature the reaction represented by
+
+
Na2COs H20 NaOH NaHCOs (3) is known to be displaced far to the left, and the amounts of bicarbonate existing are very low. A calculation of free energy (6) indicates this to be true, and also indicates that the above
K
co2ATMOB: x
10-4
3180.0 690.0 1630.0 1136.0 1210.0 610.0 278.0 475.0 5040.0 3440.0 3380.0 3490.0 3400.0 2820.0 9300.0 10370.0 4400.0 6490.0 4920.0 4600.0 2520.0 6930.0 2470.0 1980.0 10600.0 6050.0
PARTIAL PRESSURE
COz P. p . rn. 230.0 62.0
NaL!Oa NazSOd Mm./liter Mm./liter 1.735 10.5 5.56 63.6
NaOH Mm./titer 6.2 35.6
TE6T
IONIC STRENQTHDECOYP. Mm./liter %
20.2 13.6 12.6 9.53 6.91 3.04 2.44 27.0 5.18 25.7 20.65 17.2 14.96 38.1 40.1 8.55 8.85 5.91 15.4 4.6 53.7 6.4 8.85 12.86 20.6 88.0 42.4 12.0 39.0 27.5 24.4 2.04 2.95 8.24 16.7 77.8 72.5 64.6 64.6 109.8 61.5 116.9 116.9 24.7 47.6
x
10-4
x
K
10-4
x
K'
10-4
4.44 3.72
x
K' 10-4
K"
x
10-4
1.01 0.84
2.21 4.42 5.48 4.08 4.50 2.88 2.88 3.65 7.65 7.02 6.28 6.22 4.20 3.48 6.45 7.14 5.22 5.96 5.22 5.08 4.11 6.22 4.11 3.59 5.9 3.71
x
K" 10-4
10.53 2.84
234.0 647.0
37.6 18.4
3.37 1.64
424.0 306.0 132.0
31.5 22.6 9.74
290.0 460.0 2470.0
62.2 76.0 68.5
2.43 2.96 2.67
460.0 289.0 217.0 194.0 188 0
66.0 41.5 31.0 27.9 26.9
1045.0 1610.0 6920.0 6400.0 7350.0
190.0 226.0 203.0 185.0 197.0
5.42 6.45 5.80 5.29 6.52
I
reaction may be reversed and displaced to the right with increase in temperature. This points to the probable existence of considerable bicarbonate in a boiler water, and this probably is an important factor. The carbonate and hydroxide, as determined in these tests and in all other boiler water analyses, are the quantities after the equilibrium of reaction 3 has been disturbed by cooling and releasing the pressure. The bicarbonate has thereby been reduced, with a resultant increase in normal carbonate a t the expense of the hydroxide. They are the factors of equilibrium a t room temperature, and may differ considerably from those a t boiler temperatures. This may account for some of the inconsistency in the data and results. It was noticeable that in the steaming boiler the percentage decomposition apparently reached a maximum value of about
I N D U S T R I A L A N D E K G I N E E R I N G C H E hl I S T R Y
December, 1932
95 per cent, beyond which it was very difficult to go. I n Table I1 are given data indicating the maximum decomposition attainable for various feed water concentrations. The distilled water fed the last five hours was the purest water
1419
The authors know of no simple and sure way to detect bicarbonate in the presence of hydroxide a t boiler temperatures, although with sufficient data it may be possible to calculate the amount. On the assumption that the bicarbonate is proportional to the partial pressure of the carbon dioxide in the rapor phase, the constants K’ have been calculated from reaction 3 thus: KaOH X Pco2 = K’ Na2C03
1;i
iY
a**‘ .8ma
FIQURE 6. ESSENTIALS OF EQUILIBRIUM APPARATUS
available in large quantities-namely, condensate from the radiators in the building. It had a very slight methyl orange alkalinity, and a carbon dioxide-evolution test, disclosed a maximum of about 5 p. p. m. carbon dioxide. I t is probable that the maximum decomposition attainable would be slightly higher if an absolutely carbon dioxide-free water were used. Since determination of carbonate by titration methods is in this range difficult and open to error, another test was run to check the titrations with the evolution method for carbonates, the hydroxide being determined by difference. Table I11 gives the data obtained] and substantially checks data in Table 11. These tests tend to affirm the existence of a bicarbonate content difficult to break down or dissipate. TABLE11. MAXIMUMDECOMPOSITION OF SODIUM CARBONATE OBTAINABLE WITH VARYINQ COMPOSITION O F
FEEDWATER (Boiler filled with 80% NaOH and 20% NazCOI evpressed aa NadZ03; temperature, 208’ C.) ELAPSED NO TIME NaOH Na?COa ALKALIBITS D E C O M P . Hours %
using mole fractions of carbonate and hydroxide as analyzed. Considerable grouping of the constants occurs, thereby indicating that reaction 3 is probably the controlling reaction. Using mole fractions of carbon dioxide instead of partial pressures gives the constants K” in which the pressure variation in the constant K’ is eliminated. The variation of constants K” should be that due to temperature only, provided correct data could be used in their calculation. Using data obtained from the laboratory operating boiler, constants K’ and K” were calculated and the results obtained are shown in Table IV. The partial pressure of carbon dioxide was calculated from the decomposition data and not from direct quantitative measurements of carbon dioxide. It is interesting to note that these constants fall within the ranges covered by the equilibrium constants, although they are in general slightly lower. This would suggest that the decomposition rate is so fast that an equilibrium condition is approached even in an operating and steaming boiler. TABLE IV. RESULTSOF TESTSIN LABORATORY OPERATINQ BOILER PARTIAL
PRESSURE GO1
FEED DENarCOa TEMP. COMP. P. p . m. C. % ’ 400 189 67.5 400 208 73.0 400 243 79.0 400 189 65.0 400 208 72.5
Iomc
NaOH Na;COt Mm./liter 52.68 30.6 7.35 33.1 6.34 52.1 50.1 35.8 4.75 71.0 39.3 10.58 68.7 43.8 8.30
STRENQTH
ATMO’B.
X 10-4
K’ K* X 10-4 X l o - *
5.66 8.92 18.8 5.41 8.89
23.5 46.6 142.0 20.1 46.5
1.92 2.58 4.05 1.646 2.60
400 400 400 400 400
243 189 208 243 189
79.0 63.5 71.0 78.0 61.0
66.8 89.4 86.3 83.8 108.3
47.7 48.0 53.6 58.9 55.2
6.35 13.8 10.9 8.3 17.7
18.8 5.28 8.7 18.6 5.08
141.0 18.4 42.7 132.0 16.5
4.03 1.50 2.37 3.76 1.35
400 400 150 150 150
208 243 189 208 243
70.0 77.5 81.0 84.0 87.0
104.3 100.8 49.6 48.9 48.2
63.5 70.2 36.7 38.0 39.4
13.6 10.2 4.3 3.62 2.94
8.6 18.4 2.57 3.86 7.77
40.0 127.0 22.0 40.5 104.0
2.22 3.62 1.795 2.25 2.98
50 50 50
189 208 243
88.0 89.0 89.7
48.0 47.7 47.6
39.8 40.3 40.6
2.72 2.49 2.33
13.4 22.0 46.7
1.09 1.22 1.33
F E E D 160 P. P. M .
0.75 1.25 1.75 2.25
2415 2450 2610 2680
7 8 9
2.75 3.25 3.75 4.25 4.75
2563 2620 2830 2650 2790
10 11
5.25 5.75
1
2 3 4
660 710 750 750
3860 3930 4210 4300
82.9 82.0 82.1 82.6
4080 4130 4300 4020 4240
83.4 84.0 87.0 87.2 87.2
3900 3990
89.6 90.4
F E E D SO P. P. M .
5
6
680 660 560 510 550
P E E D 10 P. P. M
2640 2720
400 390
F E E D D I S T I L L E D W A T E R A B O U T S P. P. M. COS
12 13 14 15 l6 17
6.25 6.75 7.75 8.75 9.75 10.50
2570 2640 2515 2565 2460 2200
280 245 220 180 190 210
3680 3745 3550 3580 3450 3120
92.5 93.5 93.8 95.0 94.5 93.5
TABLE111. MAXIMUMDECOMPOSITION OF SODIUM CARBONATE OBTAINED USINQDISTILLED WATERiks FEED (Boiler charged R-ith approximately 95% NaOH as NazCO3, and 5% NanCOi; total alkalinity as NazCOa, 2400 p. p. m.) ELAPSED NO. TIME NaOH NazCOs ALKALINITY D E C O M P . €€OUT8 7 .”” 1 0.5 1760 120 2450 95.1 2 1.5 1562 71 2140 96.7 3 3.5 1420 83 1960 95.8 4 4.25 1700 88 2345 96.2 6 5.25 1263 91 1776 94.9
0.915 1.36 2.68
LITERATURECITED Methods of Water Analysis,” New York, 1925. (2) Hall, Smith, Jackson, Rohb, Kartch, and Hertzell, Mining and Metallurgical Investigations, Carnegie Inst. Tech. and Bur. Mines, BuZ2. 24 (1927). (3) Ibid., pp. 85-132. (4) Larson, R . F., Trans. Am. SOC.Mech. Ens., 54, No. 16 (1932) (5) Lewis and Randall, “Thermodynamics,” McGraw-Hill, 1923. (6) Partridge, Schroeder, and Adams, Preprint, Annual meeting of Am. SOC. Mech. Engrs., New York, N. Y., Kov. 30-Dec 4, 1931. (7) Paul, J. H., “Boiler Chemistry and Feed Water Supplies,” 1st ed., pp. 68-9, 137-9, Longmans, Green, 1919. (8) Paul, J. H., Trans. SOC.Engrs., 1891, 147-86. (9) Straub, F. G . , IND. E N Q . CHEM.,Anal. Ed., 3,290 (1932). (10) Straub, F. G . , Univ. 111. Eng. Expt. Sta., Bull. 216 (1930). (11) Treadwell and Hall, “Analytical Chemistry,” p. 592, Wiley, 1915; J. Am. Chem. SOC.,38, 959 (1916).
(1) Am. Public Health Assoc, “Standard
R E C E I V E D June 13, 1932. Part of research being conducted in the Chemical Engineering Division of the Engineering Experiment Station, University of Illinois, and financed by the Utilities Research Commission of Chicago. Released by permission of the Director of the Engineering Experiment Station.
