T H E J O U R N A I , OF I N D U S T R l d L A N D E N G I N E E R I N G C H E M I S T R Y .
Sept., 1 9 1 1
of the same resist.ance wound in the old n-ay on brads driven in a board, and not more than one-third the time is required for winding. The network may be conveniently stayed by the use of a little asbestos cement. The glassblowing and bending is all of a simple character and can easily be done in three or four hours; and the winding of resistances and making' connections should require no longer time. ,
673
The temperature may be lowered by raising the apparatus above the source of heat. Electric lights, encased in compartments made of asbestos board, are used in this laboratory for heating the extraction flasks, but the apparatus described may be
USIVERSITY O F >rAlSE,
OROSO
[COXTRIBUTION
PROS1
?"E
CHEJIICAL
AGRICCLTURAI.
DEPARTMENT OF
THE
0SLAHO)l.L
EXPERIMENT STATION.]
A NEW FORM O F EXTRACTION APPARATUS. B Y C. K . F R A N C I S . Received July 15, 1911
The apparatus1 (Fig. I ) consists of a modified condenser, A, and an improved flask, B , together with a n extraction tube, C:. There are no ground joints, the one seal necessary being made with mercury. No support is required for the flask. The condenser used in the apparatus shown is of the Hopkins type, provided with a special extraction chamber, EC, and a dropping tube, DT.* The lower part of the extraction chamber is partially constricted on opposite sides about I O mm. above the bottom. The two constrictions are so made (Fig. 2 , I N ) that each extends nearly one-half the cricumference of the tube without meeting on either side. This arrangement leaves the internal diameter, 3 cm., unchanged in two diametrically opposite places and reduced t o about 2 . 7 cm. for the remainder of the circumference. The modifications of the Knorr flask are two knoblike perforated projections (Fig. 3. PP) ion opposite sides of the neck and about 1 5 mm. above the base of the shoulder. These projections are so placed that they fit into the extraction chamber where the internal diameter is greatest. The holes (Fig. 3, HO) in the neck of the flask are about 3 mm. in diameter. These permit ample passage for vapor and return for the liquid which would otherwise collect around the neck of the flask. The extraction tube (Fig. I , C) is 9 cm. long, 2 . 2 cm. external diameter and has a stem about 2 cm. long. It may be packed with cotton, asbestos, etc., together with the sample, and supported on the flask as shown in Fig. I . A spiral spring of copper wire laid crosswise and pushed down on the charge prevents the contents from being forced out of the tube by expansion of vapor. The regular paper shells may be used in place of glass tubes if supported on very small funnels. The flask may be locked into the condenser by inserting the neck into the extraction chamber and giving the flask ti quarter turn. This system fixes the flask securely and it cannot be accidentally pulled over or disturbed in any way. N o support for the flask is necessary; this is especially convenient when heating with electricity or with warm water. A modification of a piece of apparatus designed by G . L. Holter and which has been in use in this laboratory for several years. Any of the ordinars condensers mas be modified in the same way.
Fig. 1.
found convenient where there is waste steam or warm water available. The arrangement is economical in the use of solvents; 30 cc. of ether are ample for the usual f a t extractions.
674
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T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y .
The position of the holes in the neck of the flask prevents any appreciable amount of condensed vapors
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Sept.,
191I
from collecting outside of the flask. The apparatus is especially applicable to alkaloidal and fat ex-
PP
G
improved
&Wf F/qsk Fig 3
tractions. The cost is much less than that of the older forms of extraction apparatus. E. H. Sargent & Co., Chicago, Ill., have recently made a large number of these special condensers and flasks for this laboratory. STILLWATER, O K 1 A
Fig. 2 .
ADDRESSES. THE CONSERVATION O F OUR METAL RESOURCES.' By ALBERTE. GREENE,Electro-Metallurgical Engineer, American Eiectric Smelting and Engineering Co.. Chicago, Ill.
'
My theme before this congress is the conservation of our metal resources. Just as we are conserving the timber in the forests, utilizing the land we have heretofore called desert, using the exhaust steam of steam engines and greatly increasing their power, so also in the metallurgy of our base metals we are beginning to conserve a 0 . I per cent. of metal here and a I per cent. of metal there, which have hitherto g-one t o waste. Most of you are aware of the great progress made in recovering copper or silver or gold out of lowgrade ores that only contain a very small percentage of these metals. Now in another field there is a loss which has been going on before our eyes with apparently no attention and it is a lobs which amounts to millions of dollars per year. I t is affecting not only large corporations but small producers even to a greater extent. The loss to which I refer is the loss of metal in the processes of making steel and other metals from ores. In the production of the 2 0 million tons of steel per annum in this country there is a loss of metal b y oxidation during the conversion process which proba1 Presented before the Congress of Technology a t the Massachusetts Institute of 'technology, Boston, April, 1911.
bly aggregates one million tons. Most of this metal is lost in the slag and some of it can be reduced again by smelting the slag in the blast furnace, but in the Bessemer process a large part is blown out of the vessel in fine dust which is difficult to collect. The loss of metal by oxidation in the Bessemer process alone probably aggregates over 500,000 tons per year. Another significant fact is that a very considerable part of the metal lost by oxidation consists of elements which are more valuable than iron-such as manganese and silicon. Those elements are usually required b y specification in the finished steel, and although the iron ore usually contains enough of them, and the blastfurnace process usually reduces them into the iron in sufficient quantity to meet specifications without any additions, yet in the Bessemer and open-hearth processes they are almost invariably oxidized again and practically lost. When one remembers these facts and what it costs to reduce these metals into the iron and that after they are oxidized out they have to be replaced by expensive alloy additions to the steel, it seems as though this were an excellent opportunity to apply conservation theories to advantage. M y object in this paper is to point out how such losses as these can be and are beginning to be dimin-
