T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
200
E Q U I P M E N T CASE FOR FIELD TESTS
The equipment as shown in Fig. a is intended for testing gas wells f0.r flow of gas and for making the absorption tests of t h e gas for gasoline. The receptacle E may serve either as a sample container or as a n absorber. After absorption of gasoline vapors from a measured volume of natural gas in t h e field t h e charcoal containing t h e absorbed vapors is sent t o the laboratory for distillation t o determine t h e gasoline content of t h e gas as described above.
Vol.
11,
No. 3
subsequently recovering t h e gasoline b y distillation. The method possesses several distinct advantages: I-The apparatus is simple t o construct, easy to operate, and is readily portable. a-The method gives information both as t o yield and gravity of gasoline and offers possibility of construction of an apparatus for determination of t h e vapor tension of t h e gasoline. This work was started under the direction of t h e Bureau of Mines and was continued under t h e Research Division of t h e Chemical Warfare Service.
SUMMARY
GASMASKRESEARCH SECTION RESEARCH DIVISION CHBMICAL WARFARE SERVICE,IT.S. A. AMERICAN UNIVERSITY EXPERIMENT STATION WASHINGTON, D. C.
The principle of this method for testing natural gas for gasoline content consists in absorbing t h e vapors in a solid absorbing medium such as charcoal, and
I
ORIGINAL PAPERS METHODS OF VARNISH ANALYSIS
PREPARATION O F T H E VARNISHES
B y W. T. PEARCE
Received June 15, 1918 INTRODUCTION
At t h e present time t h e status of varnish analysis is not good. It is generally agreed t h a t t h e following of a n y of t h e published methods will give results t h a t vary in t h e hands of different analysts and t h a t do not represent either t h e quantities or qualities of t h e materials used. The consensus of opinion among varnish chemists is t h a t a complete chemical analysis would reveal little as t o t h e relative merits of' competitive grades of varnishes. This opinion needs t o be fully investigated. The literature on varnish materials clearly indicates t h e need of more work on t h e physical and chemical properties of resins and t h e need of research on t h e analysis of oil mixtures. Varnish analysis t o date seems t o consist chiefly of t h e following determinations : thinners (turpentine, benzine, etc.), resins, rosin, oil, and drier. Tests for factory control include specific gravity, viscosity, hardness of film, drying test, and panel test. I n outlining t h e work t o be carried out in this laboratory, we thought it wise t o make up a few varnishes, differing widely in composition in order t o investigate t h e accuracy of existing methods. Along with this we have studied t h e problem of identifying and estimating t h e different oils used. ---RESINS-Estimated
No.
........................
2
15.8
Found 13.82 (D) 2 0 . 0 4 (T) 15.65 (B)
3..............................
5..
6..
............................ .............................
17.1
13.0
-ROSIN--Estimated
................................
40.35 19
------OIL---
---'rHINNERS--
Estimated
Found
Estimated
--BENZINE-Found Estimated Found
36.9
8.01
?!I,}
34.3
iZ:hf)(D)
57.7
56.93
48'3
~
34.5 ~
33.0 ~
46.4
$:3 :1?:.}3 (D)(B)
85
Ej:ii)(B)
80
77.66 (B)
80
:z:ttf(B)
40
39.01
17.47 17.23b)
:::%I
;!:E
(D)
1'23
1 15
20
Found
4 :;)
20
..............................
The linseed oil was kept at zooo C. for a hrs. with oxide of lead added. The constituents of t h e varnishes used for the analyses reported in this paper are: No. a-Sierra Leone copal, rosin (colophony), linseed Chinawood oil, turpentine, and drier; No. 3-rosin, oil, drier, and turpentine; No. 5-East India copal (white), rosin, menhaden, Chinawood and linseed oils, drier, benzine, and turpentine; No. 6-East India copal (white), soy bean, Chinawood and linseed oils, drier, turpentine, and benzine; K-Sierra Leone copal and
4.54
R ....................... K ................................
MATERIALS U S E D
4 0 . 9 8 (D) 34.81 (S) 3 3 . 5 6 (B)
Q ........................
M
About 2 0 per cent more of t h e resin was taken t h a n we wished t o use. When it seemed t o have cooked enough we weighed t h e kettle and contents t o get t h e weight of t h e resin left. This loss in weight was between 2 0 and 30 per cent, except in t h e cases where only rosin was used, and then it was nearly 7 per cent. The hot boiled oil (or oils) was then added and t h e kettle and contents weighed t o get t h e weight of oil added. This mixture was cooked in the usual way. A kettle of t h e same dimensions containing a volume of oil equal t o t h a t in t h e varnish was heated t h e same length of time at t h e same temperature t o give t h e loss in weight of the oil in t h e varnish. I n this way we were able t o calculate t o within one per cent of t h e oil and resin in t h e material. The loss in weight of t h e oils was between I and 2 per cent.
20.60 20.53
(B)
:$:::)
38.67 (B)
59.7
21.52 (B)
81
61.33 (B) 78.48 (B)
~
13.8 ~
13.93
f
~
Mar., 1919
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
linseed oil; >kauri Chinawood oil.
and linseed oil; M-rosin
and
METHODS O F ANALYSIS
For t h e thinner and ash we used t h e usual methods. F o r rosin we used McIlhiney’s method substituting Wolff’s esterification method in t h e place of Twitchell’s a n d making a few other minor changes. For t h e separation and estimation of resins and oils we used Boughton’s,l Darner’s,2 and Twitchell’s, and Scott’s methodc;. RESULTS
I n t h e table below we have used the following abbreviations: B = Boughton’s method; D = Darner’s method; T = Twitchell’s method; S = Scott’s method. CONCLUSIONS
The results of t h e analyses show t h a t Boughton’s method, although it is long and tedious, is satisfactory for resins and oils. We believe i t gives t h e actual values t o within one per cent. The estimation of rosin is accurate t o probably three-tenths of one per cent. We have spent a good deal of time endeavoring t o find a shorter method. As t h e extracting in Boughton’s method is made with ether from an aqueous solution containing alcohol, we tried t o find a solvent t h a t would not require alcohol t o break the emulsion. A large number of solvents were tried b u t none gave good results. This problem will be included in our next year’s work. ACKNOWLEDGMENT
The writer wishes t o express his thanks t o Dr. E. F. Ladd, who not only suggested the work but gave advice and encouragement while it was in progress. CHEMICAL LABORATORY
AGRICULTURAL COLLEGE AGRICULTURALCOLLEGE, N. D.
NORTH DAKOTA
THE REDUCTION OF TUNGSTIC
0 x 1 ~ ~ 3
By C. W. DAVIS Received August 19, 1918
Powdered metallic tungsten is being produced a t the present time b y several industrial concerns for use in the manufacture of alloys. The available literature on the seduction of tungstic oxide t o the metal, although extensive, fails t o give definite information concerning t h e conditions involved. The following work was undertaken t o supplement existing data. G E S ERAL
lIennicke4 shows t h a t tungstic acid, as it comes from the filter press after its precipitation with acid, contains considerable water. When air dried, there is still over 7 per cent total water in t h e material. This must be removed before reduction, for t h e steam t h a t would be liberated during the heating would cause the material t o fly in all directions, thus tending t o separate the tungstic oxide from t h e reducing material (when carbon in some form is used) due t o the great difference in their specific gravities. Even when dried in a 1
Bureau of Standards, Technologic P a p e r 65.
* N. D. Agr. Expt. S t n . , Pain8 Bulletin, 1, No. 6 . 3
4
Published by permission of the Director of the U. S. Bureau of Mines. “Die Metallurgie des Wolframs,” 1911, p. 183.
20I
current of air at 100’ C., 3.7 per cent total water remains. To get a sufficiently dry product, t h e material must be dried in a current of air a t about 5ooo C. This may be done in either reverberatory or revolving furnaces. For all reduction experiments, t h e tungstic oxide was thoroughly dried a t j o o o C., t h e color changing from a pure yellow t o a greenish yellow. For a satisfactory reduction, the dried tungstic oxide must be in a state of fine division, and if reduced with some form of carbon, should be completely mixed with it. The most satisfactory treatment consists of grinding together t h e tungstic oxide and t h e carbon in a tube mill. Steel or wooden balls should be used, as Mennickel states, for porcelain or flint introduces more impurities. The purpose t o which t h e finished product is t o be put, however, determines t h e permissible impurities. When t h e tungsten powder is t o be added t o molten steel for t h e manufacture of tungsten steel, traces of iron or manganese are not injurious, and silica goes into the slag. It is well, as Mennicke and others’ suggest, t o use some form of binding material when preparing this mix for reduction. Since t h e specific gravities of tungstic oxide and carbon are so different, their segregation during t h e processes of reduction is quite apt t o occur. Colophonium, being itself a good reducing agent, easily obtained in a pure condition, and easily pulverized, is t o be recommended. The quantity of this material used b y different operators varies from I O t o 3 0 per cent of the carbon requirement of the reduction. PRELIMINARY EXPERIMENTS
The material used in the experiments described in this article was an impalpable, canary-yellow powder. As received, t h e tungstic acid gave off 8.3 per cent of water a t a temperature of j o o o C. Analysis of the tungstic oxide, dried a t 500’ C., showed a tungstic oxide content of 99.4 per cent; insoluble in potassium hydroxide, 0 . j j per cent (largely silica). The reduction processes used are conveniently treated in two sections, t h a t of using some form of solid carbon being t h e more common, while t h e reduction performed b y some reducing gas gives a purer product. I n both cases, the reduced material must be cooled in a reducing atmosphere as t h e powdered tungsten readily oxidizes when heated. The oxidation, once started, is pyrophoric in action, and is incandescent after the removal of t h e source of heat. The temperature necessary for the reduction of tungstic oxide t o the metal, using some form of carbon, is given variously, ranging all t h e way from red heat up t o t h e temperature obtained with t h e electric furnace. The following preliminary tests on small samples show what takes place: Tungstic oxide was mixed with carbon (sugar charcoal). The samples were placed in porcelain crucibles, t h e covers being luted on with fire clay. The results in Table I indicate t h a t a t a temperature of 6 ; 0 ° t o X
