INDUSTRIAL AND ENGINEERING CHEMISTRY
924
covered by the chart t$e ammonia content is as follows: September, 2.50; October, 2.72; November, 2.83; December, 2.86; January, 2.94; February, 3.26; and March 3.35 mg. per 100 grams. Conclusion
It is an axiom in the egg business that with an advance in price deliveries should be delayed in anticipation of fur-
Vol. 19, No. 8
ther advances, and as prices decline the goods should be rushed to market in order to avoid losses by continued declining prices. The consumer can take advantage of this trade custom by watching the wholesale quotations published each day in the newspapers. He should purchase the best grade of cold-storage eggs in the early part of the season when the price of the non-storage eggs is high and advancing, but when the prices begin to drop he should buy the non-storage variety.
Effect of Weathering 'on the Softening and Solidification Points of Coal' By T. E. L a y n g and A. W. Coffman UNIVERSITY OF ILLINOIS, URBANA, ILL.
ANY methods have been used for the storage of coal, but none have been perfect, so that it is necessary to furnish a control test for storage which will enable the consumer to move his coal a t such a time as will conserve to the best advantage the heating and coking properties of the fuel. It was with the hope of establishing such a control test that this study of the effect of weathering on the softening and solidification points of coal was undertaken.
M
A p p a r a t u s and M e t h o d
The apparatus and manipulation used for the determination of the softening and solidification points of coal are described in detail by Layng and Hathorne2 in their work on the determination of the temperature of plasticity. I n brief, this method consists of passing nitrogen through a small mass of 20- to 6 0 - m e s h c o a l , simultaneously h e a t i n g the coal mass in a combustion tube surrounded by an electric furnace. As t h e temperature increases the coal softens and offers resistance to the flow of the nitrogen, setting up a back pressure which is measured by means of a manometer. The pressure and temperature are noted a t regular intervals. Description and P r e p a r a t i o n of Samples
The following samples of coal were used : (1) Taylor-English coal from Vermilion County, Ill. 2) Ziegler coal from Franklin County, Ill. 3) Pocahontas coal No. 3, W. Va., from the coke plant of the Inland Steel Co., Chicago, Ill. (4) Vinton Colliery coal from Mine No. 6, Vinton, Pa. ( 5 ) Elkhorn coal from the Elkhorn Seam, Latcher County, KY. (6) Two samples of Vermilion County coal which had been in storage for 6 weeks. One sample was from the outside of the storage pile and the other was taken at a point in the pile where localized heating had led to spontaneous combustion. (7) Jellico County, Ky., coal.
f
Received March 31, 1927. :THIS JOURNAL, 17, 165 (1925). 1
(8) O'Gara Coal Co., Saline County, Ill. (9) United Electric Coal Co., Mine No. 4, Vermilion County,
Ill. (10) Hickory Hill coal, Gallatin County, Ill.
All samples were obtained fresh. A11 were ground through a coffee mill and sized to pass through a 20-mesh but not
through a 60-mesh screen. Oxidations mere carried out under a stream of oxygen in a constant-temperature oven at 110" C. All preheated samples were heated in the tube of the apparatus immediately before the test was made. In determining the temperatures of plasticity a rate of heating of 2" C. per minute was used over the critical range. Interpretation of Results
Table I lists the res u l t s obtained on five different coals that had been weathered by. acc e l e r a t e d oxidation at 110" C. f o r v a r i o u s p e r i o d s of t i m e . It should be noted that such a weathering increases t h e t e m p e r a t u r e of i n i t i a l p l a s t i c i t y , decreases the m a x i m u m pressure, and decreases the temperature of solid coke formation; furthermore, that such an oxidation progressively decreases the quality of the coke formed. Figures 1 and 2 show typical sets Figure 2 of data dotted graDhically. Table I aiso-shows similar data for a coal taken from storage. I n this case also the changes took place in the portion of coal which had undergone excessive weathering. This shows that the changes of a coal upon oxidation are of such a nature that it should be possible to use the softening and solidification points as an indication of the extent of weathering. Coals that are plastic over a greater range of temperature are more difficult to oxidize and may consequently be stored with less difficulty. Table I1 shows results obtained upon preheating coals to various temperatures in both air and nitrogen and then cooling in the same atmosphere before determining their range of plasticity. A temperature of 150' C. in air s e e m to be the maximum to which a coal can be heated without being
INDUSTRIAL A N D ENGINEERING CHEMISTRY
August, 1927
Table I-Temperatures of Initial Plasticity, Maximum Pressure, and Coke Formation for Fresh and Oxidized Coals MAX. TEMP. COKE MAX. FORMA- COKE TIMEOF INITIAL PRESSURS PRRSSURE T I O N QUALITY OXIDATION^ PLASTICITY Mm. c. O c. HOWS c. TAYLOR-ENGLISH, VERMILION COUNTY, ILL.
376 382 383 395 399
504 430 324 90 13
378 404 396 376
998 360 230 74
390 432 418
3:
Poor Weak Very weak Powder Powder
445 480 470 470 452
ZIECLER,
FRANKLIN
465 467 438 426
512 512 482 477
COUNTY,
Fresh coal 1.5 2 3 4 Fresh coal 1.75 3.5 7
POCAHONTAS
418 432 438 436
1244 1386 240 174
403 418 405 463 417
1800 1289 1172 473 246
385 388 395 398
755 510 324 23
518 545 431 495
600 495 576 535
Strong Denser Weak Very poor
Fresh coal 42 56 90
VINTON COLLIERY, M I N E N O . 6, VINTON, PA.
513 535 530 656 478
595 590 584 600 540
Good Denser Very dense Medium Verypoor
Fresh coal 56 90 104 140
ELKHORN, LATCHER COUNTY, KY.
431 434 438 430
480 490 483 453
Very porous Denser Weak Powder
Fresh coal 15 20 300
VERMILION COUNTY, ILL., FROM STORAGE PILE
373 375 Q
219
86
413 417
481 469
Weak Powder
detrimental to its coking properties, while preheating may be carried on to higher temperatures in an inert atmosphere without affecting the nature of coke formed. In some cases preheating coal is beneficial to its coking properties. This should be indicative of the extent to which heating should be allowed to progress in storage. Table 11-Temperatures of Initial Plasticity, Maximum Pressure, and Coke Formation for Fresh and Preheated Coals MAX.
ILL.
Poor Weak Very poor Powder
Qutside of pile: storage 6 weeks Inside of pile: local heating
Temperature of oxidation, l l O o C.
925
TEMP.
PREHEAT-
COKE
INITIAL PRES- M A X . FORMA-COKE PLASTICITY SURE PRESSURE TION QUALITY c. Mm. OC. 'C.
ING TREATMEXT
Temp. O
c.
Medium
JELLICO COUNTY, KY.
372 374
754 550
420 424
401 474
361 368 377 375
104 94 780 480
410 390 439 452
444 420 473 490
350 380 380 360 367 383 396
780 560 386 206 12 40 40
O'GARA COAL CO.,
480 420 407 402 394 400 415
Good Fresh'coal Better t h a n 150 original Poor 200 Verypoor 250 Good 300 Fair 350
Air Air Nitrogen Nitrogen Nitrogen
S A L I N E COUNTY, ILL.
497 466 470 488 510 445 458
Fair Fair Weak Powder Powder Fair Powder
Fresh coal 150 200 250 350 250 350
Air Air Air Air h'itrogen Nitrogen
U N I l E D ELECTRIC COAL CO., VERMILION COUNTY, ILL.
349 349 390
911 530 17
442 404 413
HICKORY
356 350 345
504 454 314
491 461 434
Fair Good Powder
HILL. GALLATIN COCNTY.
404 410 396
491 434 435
Fair Fair Poor
Fresh coal 250 350
Nitrogen Nitrogen
ILL.
Fresh coal 300 350
Nitrogen Nitrogen
Preparation and Properties of Diethyleneglycol Dinitrate"" By Wm. H. Rinkenbach PITTSBURGH EXPERIMENT STATION, U. S. BUREAUOF MINES,PITTSBURGH, PA.
I ETHYL ENEGLYCOL dinitrate, CH2(Nos). CH2.0.CH,. CH2(K03),not having as yet been described in the literature, a study of its synthesis a n d p r o p e r t i e s was undertaken as a part of a program dealing with the glycols and their nitric esters. Preparation
Diethyleneglycol dinitrate may be obtained by the nitration of diethylene glycol with mixtures of nitric and sulfuric acids. Yields, emulsification, and safety of the operation depend upon the type of nitrating mixture used. The principal properties of the compound have been studied and recorded. Although comparatively insensitive, the compound is explosive when mixed with similar compounds. For this reason it will probably be of some interest i n explosives practice, particularly because several of the other properties found add to the value of the compound from this viewpoint.
Wurtz3 found that nitric acid reacts with diethyleneglycol to yield glycolic, oxalic, and another unnamed acid but did not try the effect of a mixture of nitric and sulfuric acids. Nitrating mixtures containing varying percentages of water and of nitric and sulfuric acids were made up in the usual way. A measured quantity was cooled, and to this was added a weighed quantity of diethylene glycol, which was purified as described in a previous paper.4 It was added in small portions with continuous agitation of the mixture, care being taken to maintain the temperature between 5' and 10" C. The time required to complete the nitration was usually 30 minutes. The results varied considerably with the strength of the acid employed. With the most concentrated acids the diniReceived March 30, 1927. Published with approval of the Director, E. S. Bureau of Mines. * A n n . chim., [3], 69, 317 (1863). 4 Rinkenbach, THISJOURNAL, 19, 474 (1927). 1
trate separated as an oily, upper layer, which decomposed vigorously when allowed to stand in contact with the spent acid at the same temperature for a short time, or when the temperature of the liquid was allowed to rise slightly during the course of separation. With the least concentrated nitrating acids no separation took place or there-was formed an emulsion of the oily product in the spent acid which would not separate within 1.5 hours. I n this case it was necessary to pour the mixture into ice and water and separate the dinitrate, which then settled out. Xtrating acids of composition intermediate between these extremes gave emulsions which separated into two layers within 1.5 hours. In either case the volume of the crude product was measured immediately after separation or precipitation. It was then washed one or more times with ice water, twice with a 2 per cent solution of potassium carbonate, and three more times with ice water; each washing was carried out in a separatory funnel and accompanied by agitation. The pufified material was then placed in a sulfuric acid desiccator to remove traces of moisture and the weight of pure product determined. Table I summarizes the experiments. The results indicate that the nitration should be carried out a t a temperature not above 10" C., that the product is unstable in contact with spent acid containing free nitric
