Relation of Ash Composition to Fusing Temperature in Anthracite OSCAR W. PALMENBERG 50 Church Street, New York, N. Y.
T
HIS investigation was undertaken to de-
TABLE I. ANALYSES OF COAL,FLOAT, AND SINKPORTIONS termine why some anthracite coals clinker CoalA Coal B Coal C Coal D C o a l E C o a l F Coal G Coal H and others do not. Samples of No. 1buckCoal portion: wheat coal were obtained from cars shipped Fusion t e y ofash, 5. 2850 2417 2350 2732 2850 2850 Ia 2790 from the mines. From each car 1000 pounds 17.99 14.53 15.33 12.48 13.74 11.70 15.54 10.98 Ash, % 1.505 1.501 1.505 1.598 1.486 1.550 1.511 1.491 Sp. gr. or more of coal were gathered during unloadAnalysis of coal ing a t the pier. The gross sample was well ash, %: mixed on a suitable platform built for the Silica 52.53 52.67 55.26 54.59 52.80 52.49 52.13 53.18 Iron oxide 7.72 10.17 9.96 7.66 7.65 9.08 6.16 8.01 purpose. It was reduced to about 30-35 pounds Alumina 35.50 34.84 35.00 35.70 37.28 36.38 37.56 35.02 Lime 0.62 1.15 1.08 1.01 1.19 0.92 1.00 0.32 by mixing and quartering, and was placed in Magnesia 0.29 0.17 0.38 0.22 0.28 0.26 0.14 0.25 a bag and sent to the laboratory. This bag 0.75 0.82 SOS 0.60 1.08 0.94 0.87 1.06 0.50 Floatportion, % 55.7 67.9 76.8 82.0 78.8 79.1 32.2 78.6 sample was thoroughly mixed and halved Fusion iemp. of into two samples consisting of opposite quarters. I I I I I I ash, F. I I 6.27 6.36 6.87 7.65 7.20 4.63 5.31 Ash. % 7.02 Each sample gave about 15-17 pounds of coal. 1.440 1.436 1.427 Sp. gr. 1.462 1.424 1.446 1.450 1.456 One was used for the work and the other reAnalysis of float ash, %: served for future use. 51.43 50.31 Silica 51.04 52.80 51.40 52.53 53.58 53.23 The 15-17 pound sample was cut down twice 7.42 6.74 7.04 6.02 7.19 7.14 Iron oxide 6.28 7.07 Alumina 39.02 38.60 41.00 38.69 40.33 40.98 35.09 36.02 to about 3-4 pounds; this coal was placed in Lime 1.17 0.93 0.43 0.80 0.86 0.83 0.50 1.00 0.29 0.08 0.37 0.41 0.02 0.30 0.22 Magnesia 0.07 a container filled with carbon tetrachloride, 0.50 0.62 0.61 0.91 0.61 0.75 0.64 sos 0.43 thoroughly stirred, and allowed to settle. The Sink portion, % 44.3 32.1 23.2 18.0 21.2 20.9 67.8 21.4 remaining coal was used for the coal portion. Fusion temp. of ash F. 2714 2372 2300 2642 2496 2460 I 2894 The float portion was skimmed off with a ladle 32.23 34.41 36.42 39.32 39.94 31.62 32.55 23.01 Ash, % 1,690 1.738 1.730 1.783 1.797 1.701 1.661 1.605 so. Rr. having a fine-mesh screen bottom, and the - Analysis of sink carbon tetrachloride was poured carefully ash, %: 53.13 through the screen. In this way a clean cut 52.74 51.04 56.00 53.65 53.73 56.65 Silica 56.94 11.36 8.02 10.52 8.75 10.42 9.92 5.67 7.61 Iron oxide was made between the particles of coal hav34.59 33.45 33.99 33.50 33.95 36.61 31.26 Alumina 32.41 0.48 1 . 4 9 0.89 0 . 8 9 0.71 0.49 0.30 Lime 0.38 ing a greater and smaller specific gravity than 0.43 0.81 0.81 0.67 0.77 0.32 0.55 Magnesia 0.56 1.91 1.35 1.13 1.06 0.97 1.12 0.66 the fluid. The carbon tetrachloride had a SOa 1.00 Iron: gravity of 1.58; it is the most convenient fluid 0.96 1.05 1.48 1.53 1.06 0.96 0.88 Incoalportion 1.39 to use without impairing the composition of the 0.57 0.44 0.16 0.40 0.12 0.30 0.35 Infloatportion 0.24 0.96 0.52 0.89 1.13 0.66 0.84 0.58 Insinkportion 1.15 coal. Coal, float, and sink portions of the rMean Iron Oxide Silica Alumina original coal sample were thus obtained. Each 8.30 53.21 35.91 Coal ?’ of these portions was ground and prepared to 6.74 52.04 38.72 Floak h a 100-mesh laboratory sample for analysis. 9.03 54.23 33.72 Sink, ‘9% a I = infusible. Analysis was made on a portion of the ash used for the fusion test. Titanium and phosphorus were not determined since they are usually presTABLE 11. ANALYSES OF ASH ARRANGED IN CONSECUTIVE ent only in small quantity in anthracite ash. They do not ORDER IN ACCORDANCE WITH THE RATIO OF IRON OXIDETO THE SUMOF SILICAAND ALUMINA affect the fusion of the ash materially and were therefore Sample Fusion Temp. Iron Oxide Silioa Alumina Ratio omitted. The figures for alumina would include both. F. % % % The fusion tests of the ash were made according to the sink 2300 11.36 51.40 33.99 7.5 B sink 2372 10.42 52.74 33.45 8.3 A. S.T. M. method on ash cones but in a Meeker blast furnace 10.62 53.13 34.59 8 3 2496 instead of the pot furnace. Readings were made with an 2417 10.17 52.53 34.84 8.6 9.96 52.87 35.00 8.8 C coal 2350 optical pyrometer to determine the temperature of the muffle. F sink 2460 9.92 53.65 33.95 8.8 9.08 52.49 36.38 9.8 F coal 2850 The author has been using this furnace since 1908 for thou8.75 56.94 32.41 10.2 A sink 2714 sands of fusion tests on all types of coal. H coal 2798 8.10 53.18 35.02 10.9 8.02 56.00 33.50 11.1 2642 The limit of temperature obtainable in the muffle was 2894 7.61 56.65 31.26 11.5 7.66 54.59 85.70 11.7 2732 2900’ F. All coals having ash that would not soften or 7.66 52.80 37.28 11.8 2850 7.72 55.26 35.50 11.8 change a t this temperature were termed “infusible.” A coal 2860 7.42 51.04 39.02 12.2 Infusible The tests reported in Tables I and I1 show that, although Infusible 7.14 53.58 35.09 12.4 Infusible 7.07 53.23 H float some coals had a relatively low fusing ash, in every case the 40.98 36.02 12.7 12.6 7.19 50.31 Infusible C float 7.04 52.63 38.69 13.0 float portion or pure coal portion gave infusible ash. The F float Infusible 6.74 52.80 38.60 13.5 Infusible gravity of the separated portions represented the mixture of Infusible 6.16 52.13 37.56 14.6 6.28 51.40 41.00 14.7 E float Infusible the particles making up the sample. A float Infusible 6.02 51.43 40.33 15.2 5.67 53.73 36.61 15.9 These results indicate that the ash from the pure coal porG sink Infusible tion of anthracite has the highest fusion temperature, irrespec-
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1058
AUGUST, 1939
INDUSTRIAL AND ENGINEERING CHEMISTRY
tive of the result of the original coal, and t h a t the iron seems to be the determining factor. As the ratio between the iron oxide and the sum of the alumina and silica approach 12, the coal ash becomes less fusible. The iron, silica, and alumina are the principal constituents of the coal ash and constitute
1059
more than 96 per cent of the whole. The iron oxide is highest in the sink portion, alumina is highest in the float portion, and silica is highest in the sink portion. This investigation was made on anthracite coals from the upper, middle, and lower Pennsylvania coal basin.
CORRESPONDENCE Hydrogenation of Nickel Carbonyl SIR: Under the above heading Litkenhous and Mann ( 5 ) published an important paper discussing the mechanism of the hydrogenation of carbon monoxide in the presence of nickel. They started with nickel carbonyl and hydrogen as the reactants. Since no hydrogenation occurred before the complete decomposition of nickel carbonyl, we can presume that the reactions actually took place between carbon monoxide and hydrogen in the presence of nickel liberated from the carbonyl. The products of reaction were carbon, water, and methane. The proportion of nickel carbonyl t o hydrogen was so adjusted that, after complete decomposition of the former, a mixture of carbon monoxide and hydrogen in the proportion 1 to 1 by volume was obtained. The analysis of the final gas mixture after reaction a t 10, 25, 50, and 75 atmospheres pressure showed that carbon monoxide and hydrogen were also consumed in the proportion 1 to 1by volume. This fact suggests that possibly carbon was deposited according to Litkenhous and Mann's reaction 12, CO
+ Hz e C + HzO
(12)
and that methane and carbon dioxide were produced by their reaction 6, 2CO
+ 2Hz e COz + CHI
2 c o ec
+ CO?
+ 2Hz0 e CHI + C02
(8)
occur simultaneously. The rnecbanism of methane and carbon dioxide formation as a result of reaction 8 was accepted by Litkenhous and Mann. In support of their view they put foward the argument that this reaction reached equilibrium even a t 250 C. while the other possible reactions were far from equilibrium. Sabatier ( 6 ) , however, showed that the removal by superheated steam of carbon deposited on a nickel catalyst is primarily due to the reaction: O
C
+ 2Hz0
COS
+ 2Hz
+ HzO e COz + H2
(10)
These facts indicate that probably reactions 12 and 6 actually occurred in the system. The question arises as to whether the constancy of Litkenhous and Mann's data a t 250" C. was due to some other cause. Log10 K , calculated for the reaction, CO
+ Hz0 e COz +Hz
(7)
from their experimental data at 250" C. also gave fairly constant values in six cases, as the following figures show: Expt. No.
33c 33D 34c
LOglaK3)
Expt. NO.
LogloKp
-0.6683 -0.6216 -0.6552
35c 35D 36C
-0.6780 -0.6721 -0.6678
However, it is true that these figures are far from the correct value of log,, K , a t 250" C. The question arises as to why the figures are practically constant in the cases cited above. Since ~ c o / ~ H in , the final gas mixture was practically equal to 1 in the above cases, from reaction 7 :
+
IogloK, = lO@;lO(pCO,/pH,O) loglo 1
+ 3Hz e CHI + Hz0
which occurred a t equal speed. But the fact that the concentration of water vapor was not equal to that of methane or of carbon dioxide rules out the possibility of explaining the experimental facts by reactions 9 and 7. Another way of explaining the experimental data is that reactions 12 and 8, 2C
CO
(6)
This view is further supported by the fact that carbon dioxide and methane were produced in equal volumes. It is also possible to explain the formation of the final products by the consumption of carbon monoxide and hydrogen in the proportlion 1 to 1 by volume as due to the reactions, CO
Bahr ( 3 ) observed that superheated steam at 300" C. reacts with nickel carbide principally according to reaction A. According to Armstrong and Hilditch ( I ) , around 300" C. reaction 6 takes place exclusively on a nickel catalyst in a 1to 1 mixture by volume of carbon monoxide and hydrogen. In a humid mixture of carbon monoxide and hydrogen, the nickel catalyst accelerates reactions 6 and 10 (4):
(4
But if reaction 8 was more readily accelerated by a nickel catalyst, it should have taken place in preference to reaction A. Bahr and
=
constant
It follows, therefore, that loglo ( ~ c o , / ~ H , owas ) also a constant. Considering that only reactions 12 and 0 were occurring in the system, the partial pressure of carbon dioxide in the final gas mixture would be proportional to the resultant rate of reaction 6, and that of water vapor would be proportional to the resultant rate of reaction 12 in the forward direction. It follows, then, that pcoz PH20
- constant X
resultant rate of reaction 6 resultant rate of reaction 12
Since the reactants were identical in all respects in all the experiments, the ratio of rate of reaction 6 to rate of reaction 12 in both forward and backward directions will be constant; an increase of pressure accelerates both reaction rates equally so that the ratio of resultant rate of reaction 6 t o resultant rate of reaction 12 is also constant. Consequently, ~ c o , / ~ Hwill ~ o be a constant, which was actually the case. It follows, therefore, that log,, ~ C O ~ * / ~ H , Owill * also be a constant a t constant temperature. But since the partial pressure of methane was almost equal to that of carbon dioxide in the final gas mixture,
