INDCSTRIAL Ah-D ENGINEERI.1'G CHEMISTRY
October 15, 1930
From the distributor the liquid passes to the percolator through a glass pressure-regulating tube, L, 9 mm. inside diameter and 1.6 meters long. This tube must be wide enough so that the air can escape at the top of the tube a t the same time the liquid runs down. The chief purpose of this wide tube is to regulate the pressure of the liquid in the percolator so that it will always pass through a t the same rate, whether the soil in the percolator is fine or coarse. If it is coarse, the liquid percolates through without much pressure. If it is fine, and difficult for the liquid to pass through. the liquid fills up in the pressure tube until the pressure is enough to cause it to pass through as fast as it comes from the distributor. If the percolator is clogged so that the liquid does not pass away through it, there is a side outlet near the top of the pressure tube through which the liquid runs to a waste collector, M. From this it is returned to the main reservoir to be used again. The percolator is a wide glass tube 48 mm. in diameter drawn out to 5 mm. diameter a t the bottom. I n the bottom is a porcelain filter plate on which rests a layer of paper pulp 4 to 8 mm. thick. On this is placed sand, then the material to be extracted, 20 grams of soil. When the soil is very fine it is mixed with an equal or greater bulk of clean acid-washed white sand in order to permit more easy percolation. By the aid of the sand and the pressure-regulating tube, above the percolator, the rate of flow through the material is made the same, regardless of the nature of the material. The pressure tube passes through a rubber stopper in the top of the percolator. Collecting System
The collecting system to receive the percolate consists of R series of wide-mouth liter bottles fitted with 2-hole rubber
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stoppers. I n one hole of each stopper is a glass tube about 6 mm. inside diameter, and 5 to 6 em. long, which serves as air outlet. I n the other hole is the vertical stein of a glass T-tube of 4 to 5 mm. inside diameter. The different bottles are connected into a train by short pieces of rubber tubing joining the T of each bottle to the next. The T of the first bottle is connected to the outlet tube of the percolator by a rubber tube. When the system is in operation, the liquid coming from the percolator passes into the first collecting bottle, through the downward limb of the T. When the bottle is full, the liquid passes on through the horizontal part of the T and drops into the next collecting bottle. Thus the whole train is filled without personal attention after it is once started. For the system to work well the top of each bottle in the train should be about 4 mm. higher than the preceding bottle. This causes each to be completely filled before the liquid passes to the next bottle, and prevents any siphoning from first to second, etc. It may be thought that there will be some mixing or diffusion of the liquid passing through the T-tubes with the contents of the filled bottles over which it passes. Something of this does happen, but the amount is unimportant. The rubber connector between the percolator and the first collecting bottle may be easily disconnected a t any time in order to catch some of the percolate for a test as to completeness of the extraction. When it is necessary to refill the reservoirs, A , pinch clamps, Ab, are closed, Aa is opened to a vacuum pump, and thus the liquid is drawn up into the reservoirs through tube, Ac, from a lower supply bottle. Literature Cited (1) Sullivan, IYD. E A G CHEM, Anal E d , 1 , 233 (1929).
Determination of Beryllium in Aluminum' H. V. Churchill, R. W. Bridges, and M . F. Lee ALUMIXUM RESEARCHLABORATORIES, NEW
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H E separation 01 ueryllium from aluminum has been of much interest, if we may judge from the amount of work which has been done on the problem. From 1798 to the present time investigators have given this separation considerable study, and the increasing interest in beryllium as a constituent of light alloys has created a demand for an analytical method which can be used to determine accurately a small amount of beryllium in an aluminum alloy. The combination Havens-8-hydroxyquinoline method described herein meets this demand. Previous Methods
There are many proposed methods in the literature with claims of clean-cut separations. Some are satisfactory if the ratio of aluminum t o beryllium is not too large. However, the accurate determination of 0.25 per cent beryllium in aluminum would be a very difficult task by any of these methods. An exhaustive study of various methods was made by Britton ( 2 ) who states that, of the many methods proposed, only four are capable of giving quantitative results. They are the decomposition by boiling sodium hydroxide solutions (3, 10, 12, 1 4 , and the methods of Parsons and Barnes (9), Wunder and Wenger ( I S ) , and Havens ( 5 ) . 1
Received June 6. 1930.
KENSINGTOV.
PA.
Efforts to apply these methods to the determination of beryllium in aluminum led to the conclusion that only the Havens method possessed reasonable possibilities of securing accurate results and t h a t these could be obtained only by repeated separations. Another method considered was that of Moser and Niessner (8) wherein aluminum is precipitated by a saturated ammonium acetate solution containing 3 per cent tannin, the beryllium remaining in the filtrate. This procedure was rejected because it could not be used in the scheme of analysis without an extra separation for iron. The use of 8-hydroxyquinoline described by Berg ( I ) , Hahn and Vieweg (4))and Robitsrhek (11), and applied to the separation of beryllium from aluminum by Kolthoff and Sandell (6) and Lundell and Knowles ( 7 ) , has been thoroughly investigated. It is the opinion of the authors that this method gives the most satisfactory separation of aluminum from beryllium. An objection is the large amount of expensive reagent required in making an analysis when the ratio of aluminum to beryllium is large. For example, in the determination of 0.1 per cent beryllium in aluminum it is necessary to take a &gram weight to secure enough beryllium for a satisfactory precipitation. The precipitation of aluminum in this case would require a quantity of 8-hydroxyquinoline which, a t current prices, would be prohibitive.
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AiVALYTICAL EDITIO?;
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The use of a conibinatioii of the two best methods, the Havens and 8-hydroxyquinoline, was suggested, and has provided a satisfactory solution to the problem. K h e n the separation of aluminum from beryllium becomes tedious and difficult by the Havens method, the 8-hydroxyquinoline method is most efficient. This procedure enables the analyst to evaluate his Havens separation because ignition of aluminum oxyquinolate precipitate reveals the amount of aluminum which the Havens method hac: failed to remove.
final Havens separation and separated from the berylliuni by the 8-hydroxyquinoline precipitation. For 5 per cent beryllium the Havens method alone would haTe given 5.09 and 5.08 against a true value of 5.04 per cent beryllium, which would be considered satisfactory for most purposes. However, when the ratio of aluminum to beryllium is increased from 20:l to 1 O O : l and higher, the Havens separation fails to give satisfactory results. Recommended Procedure
Figure 1-Hydrogen
Chloride Gas Generator
Experiment a1
h standard solution of beryllium chloride was made from pure beryllium carbonate and hydrochloric acid. The solution was standardized by two methods, precipitation with ammonia and with 8-hydroxyquinoline. The methods gave concordant results. High-purity aluminuin metal (99.90 per cent aluminum) was used as a source of this element. Keights of metal taken varied from 0.5 to 5.0 grams depending on the ratio of beryllium to aluniinuni desired. It appeared necessary to have about 3 mg. of beryllium present to insure satisfactory precipitation, so the weight of sample m s increased accordingly. Samples of metal were dissolved in hydrochloric acid, the desired amount of beryllium added as chloride, and the beryllium determined by the procedure as given i n the recommended method. The results are giwn in the following table: W T . AI
TAKES Grams 0'5 01 . 50 1.0 1.0
'"
J.0 5.0
A1 LEFTB Y F I U 4 L H4YENS
SZPARATIOV Gram 0.0005 0.0004 0.0014 0.0070 0.0024 0.0127 0 0058 0.0042
WT Be
TAKEY Gram 0.0504 0.0504 0.0101 0.0101 0.0025 0.0026 0 0012 0.0012
Be
FOUND Gram
0,0503 0,0506 0.0102
0.0103 0.0026 0,0025 0.0010 0.0011
ERROR Gram -0.0001 +0. 0002 -0.0001 -0,0002 +o . 0001 0,0000 -0.0002 -0.0001
The interesting feature in this table is the second column of figures showing the amount of aluminum left by the
Use a 5-gram sample if the beryllium content is leas than 0.25 per cent, and 1 or 0.5 gram if higher percentages are expected. Dissolve the sample in 1: 1 hydrochloric acid using 25 cc. per gram of sample. Saturate the solution with hydrogen sulfide. Filter off the precipitated sulfides and any undissolved material present, and wash free from acid. Boil off the hydrogen sulfide, and evaporate until the solution begins to crystallize, wash down the sides of the beaker, cool, add a n equal volume of ether, and pass dry hydrogen chloride through the solution until the two phases are conipletely miscible and for an hour thereafter. The gas may be conveniently generated by the apparatus shown in Figure 1. To avoid excessive loss of ether, it is xell to cool the beaker during the saturation with hydrogen chloride. Filter through a Gooch crucible or similar device, refiltering if the filtrate is cloudy. Wash thoroughly n i t h a solutioii made by saturating with hydrogen chloride a 1: 1 mixture of ether and hydrochloric acid (sp. gr. 1.19). Dissolve the aluiniiiurn chloride from the filter with a small amount of hot water, and reprecipitate n-ith hydrogen chloride as before. Combine the two filtrates and evaporate to small volume. If the sample was 5 grams, make another ether-hydrochloric acid separation t o aroid an excessive amount of precipitate in the later separations. Add 5 cc. of 1:3 sulfuric acid and evaporateto fumes. Add a little water, boil to solution of salts, filter off silica, and wash the paper well. Add 2 drops of rosolic acid as indicator, and neutralize the solution with ammonium hydroxide. Boil briefly and filter. TVash twice with hot slightly ammoniacal 1 per cent ammonium chloride. Dissolve the precipitate with hot 1 : l hydrochloric acid, dilute to 100 cc., and reprecipitate as before. Filter and wash with the solution previously used. Dissolve this precipitate in hot 1:1hydrochloric acid and wash the paper well. Keutralize with ammonium hydroxide to methyl red and make just acid with hydrochloric acid. K a r m the solution to 60" C. and add an excess of %hydroxyquinoline. Add 2 N ammonium acetate until iron, aluminuni, and titanium are precipitated, and 25 cc. in excess. An excess of 8-hydroxyquinoline is indicated by the yellow color of the supernatant liquid after the precipitate has settled. Filter and wash four times with cold water. Heat the filtrate to 60" C., and add ammonium hydroxide until the solution is alkaline to methyl red indicator, then 2 cc. in excess. Allow to cool, and filter, using suction. Wash four times with water containing 1 per cent ammonium acetate. Place in a weighed porcelain crucible provided with a lid. Dry and ignite a t 500" C. until the paper is burned off, then a t 1000" C. for an hour. Cover the crucible and cool 111 a sulfuric acid or activated alumina desiccator. When cool, weigh as quickly as possible with the crucible still covered. The gain in weight of the crucible represents beryllium ouide. Deduct a determined blank. Beryllium = beryllium oxide X 0.3605 Kale-Iron must be in the trivalent state to insure complete separation n i t h the %hydroxyquinoline The treatment outlined wlll assure this
To prepare the 8-hydroxyquinoline solution triturate 5 grams of the solid reagent with 10 cc. of glacial acetic acid, and when completely dissolved pour into 200 cc. of water
INDUSTRIAL A N D EYGINEERING CHEVISTRI-
October 15, 1930
heated to 60" C. One cubic centimeter of this solution will precipitate 2.9 mg. of alumina and approximately equal quantities of ferric and titanium oxides. T o prepare rosolic acid indicator solution, dissolve 0.080 gram of the solid in 100 cc. of 1:I ethyl alcohol. Literature Cited (1) Berg, Z . anal. Chem., 70, 341 (1927); 71, 23, 171, 321, 369 (1927); l a , 177 (1928); 76, 191 (1929). (2) Britton, Analyst, 46, 359, 437 (1921); 47, 50 (1922).
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(3) Gmelin, Pogg. Ann., SO, 176 (1840). (4) Hahn and Vieweg, 2. m o l . Chern., 71, 122 (1927). ( 5 ) Havens, A m . J . Scr., 4, 111 (1897). ( 6 ) Kolthoff and Sandell, -7. A m . Chem. Soc., SO, 1900 (1928). (7) Lundell and Knowles, Bur. Standards J . Research, 3, 91 (1929) (8) hloser and Niessner, dlonatsh., 48, 113 (1927). (9) Parsons and Barnes, J . A m . Chem. Soc., 28, 1589 (1906). (10) Penfield and Harper, A m . J . Sci.. 32, 107 (1886). (11) Robitschek, J . A m . Ceram. Soc., 11, 587 (1928). (12) Schaffgotsch, Pogg. Ann., SO, 183 (1840). (13) Wunder and Wenger, Z . anal. Chem., 51, 470 (1912). (14) Zimmerman, Ibid., 27, 61 (1887).
Lacquer Studies I-Development of an Abrasion Test for Use with Nitrocellulose Lacquers* William Koch HERCLLES PollDER
HE measurement of the
co%lP?'IY,
EYPERIVHVTAL S T & T I O V K E V X I LhT J
The equipment, theory of development of t h e test, The regulated air stream is and t h e Practical use of t h e proposed method for measobtained by introducing air resistance of a protective coating t o &brauring abrasion of lacquer films are described in this from a pressure line into the paper. Practical results are included, not only on glass equalizing reservoir. sion or wear is of practical One outlet tube from this significance whenever such experimental laboratory lacquers, b u t on a variety of a coating is subject to \Tear. commercial products as well. reservoir leads to the adjustIt has theoretical interest able water leg through which when the results are correlated with the results of other a small constant stream of excess air is bubbled. Regulation methods of test. Wear resistance aids in studying the by this means is accurate within + Z mm. of water. The relation of the different components of the protective coating other outlet tube leads the regulated air stream t o the abrasion to one another in affecting the properties of the final coating, apparatus past the manometer openings. The colored-water and thus assists in determining proper formulation. This will manometer is the only one used a t present and is simply a be the subject of another paper. means of checking the constancy of the air pressure. Other physical tests, such as hardness, mandrell, tensile Figure 2 illustrates the appearance of a lacquer film on its strength, and elongation, do not give results which can be glass support with duplicate abrasion patterns after the end interpreted easily in terms of wear resistance. point has been reached. Figure 3 is a n enlargement of a Sward has given a review of numerous tests which have single pattern with the arrow pointing t o the tiny holes actubeen described in recent years ( 2 ) . His considerations led ally worn through the lacquer film. When following an abrahim to choose loose sand falling under the force of gravity in a sion determination, no difficulty is experienced in observing coniined tube. The simple and practical features of his test the first appearance of these ciny holes, which constitutes the appealed to the author. It mas desired, however, to make end point. The entire pattern becomes frosted almost imthe test more rapid by having the abrasive strike the film mediately and the tiny holes when they appear (always in under the increased force of an air blast. This necessitated the same position) are very clear and sharp. constructing an enclosed apparatus with access to a regulated The abrasion factor or index is obtained by weighing the air stream. Experiments also indicated the desirable features abrasive in the container before starting and again a t the of using a finer abrasive. The construction of such an ap- end of the determination. A small constant correction is paratus does not detract from the simple and practical plan subtracted from the weight of the abrasive used to allow for of Sward's instrument. I n addition i t is more compact, more the quantity of abrasive in the constricted tip below the rapid, and accurate. cut-off after the abrasive stream has been shut off. Discussion of Test LVeight of abrasive used in grams Abrasion factor = Figure 1 shows the assembled apparatus. The abrasive Film thickness in cm X 1000 in the weighed container at the top flows in a fine stream under It should be noted that the pattern is very symmetrical the force of gravity through a constricted orifice into the and shows a spot wear. The shape and sJmmetry of the confining tube. Here it meets the air stream introduced 1 ) ~ of the insealed side tube and is distributed Over the pattern are governed entirely by the design and construction entire cross section of the confining tube. It leaves the con- of the apparatus. I n prelimillary work a large number of fining tube with definite force and strikes the lacquer film on different construction designs were tried. The present type the glass plate supported in a plane whose inclination is 45 was finally chosen because of the very symmetrical pattern, degrees from that of the descending abrasive. The abrasive Figure 4 shows the constricted tip fitted to the confining tube by means of a rigid ground-glass joint. The air-inlet tube is then falls into a container in the confining box below. The sharply defined abraded area is easily observed through fused into the confining tube and this whole assembly iS rigidly the glass window in the door, because the inside of the box is clamped in a fixed position with a clamp attached to the backilluminated by a small shielded light bulb fastened in the back board (see Figure The actual dimensions of these members are unimportant of the box. and can be adjusted to meet the needs of the individual user. 1 Received July 15, 1930. Presented before the Division of P a i n t and constriction be adapted The diameter Of the Varnish Chemistry a t t h e 80th Meeting of t h e American Chemical Society, to the size of the abrasive used. -4170- to ZOO-mesh CarCincinnati, Ohio, September S t o 12, 1930
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