Feb., 1917
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
I n analyzing t h e crop results obtained, the following facts are noted: Acid phosphate has returned a crop increase over 6 times as profitable per acre as has raw rock phosphate. Acid phosphate has returned a c m p increase over 7 times as profitable per dollar invested as has raw rock phosphate. Each pound of phosphorus in acid phosphate has returned a crop increase valued a t zS1/3 cents. Each pound of phosphorus in raw rock phosphate has returned a crop increase valued a t 3l/? cents. A pound of phosphorus in acid phosphate has returned a crop increase over 8 times as valuable as t h a t returned b y a pound of phosphorus in raw rock phosphate, By taking t h e prices used in this paper for f a r m crops, t h e increases obtained by t h e application of phosphates would give a value of S 3 8 . 8 j per t o n for acid phosphate a n d $ 8 . 4 0 per t o n for raw rock phosphate. If t h e prices for farm products were reduced 2 0 per cent t h e acid phosphate would h a y e a value of $3 I . 08 per t o n a n d t h e raw rock phosphate a value of $ 6 . 7 2 per ton. T h e acid phosphate would still show a good profit a n d t h e raw rock phosphate would be used a t a loss. By calculating t h e phosphoric acid in all t h e crops grown, i t is found t h a t 2 2 4 lbs. of PzO6have been recovered in t h e total increase caused b y acid phosphate a n d 147 lbs. of P20s have been recovered in the total increase caused by raw rock phosphate. These amounts of P205are approximately 1/12 of t h e phosphoric acid applied in t h e acid phosphate and ‘/85 of t h e phosphoric acid applied in t h e raw rock phosphate. Nineteen samples of raw rock phosphate were taken on t h e Indiana market in 1 9 1 j b y the inspectors of t h e State Chemist. The analyses of these samples show a n average of 2 8 . 8 per cent total P z O j a n d a n average of I . 8 per cent ammonium citrate-soluble P206; 1 . 8 per cent of all t h e raw rock phosphate used in t h e 8 2 tests would indicate a n available phosphoric acid amount of 804 lbs. or over 5 times as much as was removed b y t h e increased crops caused b y t h e ram rock phosphate in 3 ] / * years. On t h e Scottsburg field,’ which has been running for IO yrs., raw rock phosphate came t h e nearest t o paying as large a profit as acid phosphate, t h e net returns per acre for t h e Io-yr. period being $31. j 2 for t h e acid phosphate a n d $19.51 for t h e raw rock phosphate. On t h e Scottsburg field, 88 lbs. per acre of citrate-soluble PsOr were added i n acid phosphate in I O yrs. and 2 6 lbs. oi Pz05were removed in t h e increased crops. If I . 8 per cent is considered t h e measure of t h e citrate-soluble phosphate in t h e rock phosphate used, then 7 2 lbs. of citrate-soluble phosphate were added per acre in raw rock phosphate in I O yrs. while 26 lbs of P206 were removed in the increased crops. IhDIAN.4
A G R I C U L T U R 4 L EXPERIMIBKT STATIO&‘
THE ACTION OF CALCIUM CARBONATE ON ACID PHOSPHATE’ By
EGBERT W. MAGRUDER
T h e reaction which takes place between calcium carbonate a n d acid phosphate is one of great interest both t o t h e farmer and t o t h e fertilizer manufacturer. I t has been generally taught t h a t calcium carbonate should not be mixed with acid phosphate because i t would act on the mono- and di-calcium phosphates and convert t h e m into t h e tri-calcium phosphate, which is insoluble in water and slowly available t o plants. Consequently t o find t h a t hlr. J. S. Burgest, State Agronomist of North Carolina, in Bulletirz 2 2 0 of t h e North Carolina Department of Agriculture, recommended t h a t ground limestone and acid phosphate be mixed in t h e proportions of 1 2 0 0 lbs. of t h e Eormer to from 400 t o 1000 Ibs. of t h e latter, was very much of a shock to me. hlr. Burgest says: “ N o a t t e m p t has been made t o leave t h e impression t h a t acid phosphate mixed with ground limestone will not revert to what is called di-calcium and, t o some extent, t o tri-calcium forms. But these forms of phosphorus are still available to t h e crops, while t h e iron a n d aluminum phosphates are entirely out of reach of t h e plants.” T o how great a n extent acid phosphate is converted into iron or aluminum phosphates in t h e soil I do not know, but in t h e Eastern and Southern states experimental results have uniformly shown t h a t acid phosphate gives much better results and is more profitable t h a n ground phosphate rock. Di-calcium phosphate is, of course, a valuable fertilizer, and tri-calcium phosphate which has been formed b y t h e reversion of acid phosphate would, without doubt, be more available t o plants t h a n ground phosphate rock on account of its fine subdivision. If reverted phosphate is better for crops t h a n acid phosphate, t h e fertilizer laws all need amending and t h e manufacturers of acid phosphate need t o change their methods of manufacture. They should p u t out no mono-calcium phosphate, b u t only di- a n d tricalcium phosphates. T h e only recent experiments on t h e reaction between limestone and acid phosphate I have seen are those of Dr. R. N. Brackett,2 of Clemson College, South Carolina. His limestone contained only a trace of phosphoric acid, a n d his acid phosphate was of t h e following composition: Total phosphoric a c i d . , .................... 16.84 Water-soluble phosphoric a c i d . , . . . . . . . . . . . . . 1 3 . 5 5 Insoluble phosphoric acid.. . . . . . . . . . . . . . . . . 1 .33
The following mixtures were used and results obtained : No.: 1 Lbs. acid phosphate., . . . . . . . . . . . . . . . . . . 1 4 . 0 Lbs. ground limestone., 6.0
................
2 15.5 4 5
3 17.0 3.0
1
10.0 10.0
LAPAVETTE 1
See Iodiaoa Bull 187, 1061
!Presented at 53rd Meeting of American Chemical Society, New York City, September 2 5 to 30, 1916. 2 THIS J O U R N A L , 7 (1915). 620.
T H E J O U R h T A L OF I N D U S T R I A L A N D E-VGINEERING C H E M I S T R Y
Ij6
PERCENTAGE ANALYSESOF M ~ X T T I R E S No. 1 h-0. 2 No. 3 No. 4 W-S Ins. W-S Ins. TV-S Ins. W-S Ins. i l ~ r i l 21st. Immedi-~ ‘ately after mixing.. 6 . 1 5 1.07 8.30 1 . 1 5 10.50 1 . 2 4 2.40 0.83 h l a y 10th . . . . . . . . . . . 3.05 . 1.30 84 1 26 8.66 1.37 0 . 9 9 0 . 9 8 J u n e 1 2 t h . . . . . . . . . . . 3.31 1.39 2:39 1.66 8.15 1.59 1.10 1.11 Sept. 13th . . . . . . . . . . . 3.38 1.46 3.31(a)1.33 8.05 1 46 0.87 1.08 ( a ) This is probably a n error as an anafysis in November, 1913, gave about five per cent water-soluble Mixture
T‘ol. 9! S o . z
A CONTRIBUTION TO THE THEORY OF EMULSIFICATION BASED ON PHARMACEUTICAL PRACTICE’ Ry LEO ROONA N D RALPHE. OESPER
~
Received Xovember 2 2 , 1916
ISTRODUCTORY
The practical knowledge of emulsions, which has I was surprised t h a t more insoluble phosphate been handed down t o the pharmacists from generation was not formed in these mixtures, especially t h e half t o generation, has been surveyed by physical chemists, and half mixture. but this pharmaceutical experience’ has been neglected I n order t o test t h e effect of larger mixtures t h a n almost entirely as an aid in developing a rational theory used by Dr. Brackett and also to t r y the effect of of emulsification. Several theories of emulsification fresher acid phosphate. I made u p some mixtures last have been proposed which differ according t o t h e factor summer a n d used acid phosphate a month old and held responsible for t h e stability of t h e emulsion, but some which h a d been made only a few days and was objection has been raised t o all of them. It is probable warm when mixed. I used ground oyster shells in- t h a t none of these theories is of universal application, stead of ground limestone. and though each may cover special cases or classes TABLE I-MATERIALS USED of emulsions, their inadequacy is generally admitted. Percentages Phosphoric Acid The surface tension theory upheld by Plateau,Z Material Total Insoluble Water-Soluble New acid phosphate.. . , . . , . . . . , , . . . . . 19.33 2.41 15.78 Quincke3 and notably Donnan4 was shown t o be Month-old acid phosphate., . . . . . . . . . , . 18.13 1.04 14.80 Ground oyster shells.. . . , . . . . . . . . . . . , . 0 . 5 1 .... ,.... inadequate when Pickering5 emulsified “solar distilTABLE 11-MIXTURFS A N D RESULTSOF ANALYSES late” with t h e aid of such materials as t h e basic sulAcid Phosphate Used: -OLD--NEW-fptes of iron a n d copper, hydrous ferric. oxide, etc., Date Phosphoric Acid (%) Phosphoric Acid (70) MIXTURE Analyzed Insol. Water-Sol. Insol. Water-Sol. materials which do not influence surface tension. The 190 lbs. Acid Phos.. , . 8/16 ’2.50 15.05 0.82 13.72 viscosity theory, whose origin is obscure, was attacked 14.00 0.24 11.28 10 lbs. Oyster Shells. , 9/20 2.70 Theory 2.32 14.99 1.02 14.06 by Hillyer,G who pointed out t h a t although extreme 0.79 13.38 180 Ibs. Acid Phos.. , . 8/16 2.45 14.50 l.5Q 3.05 20 lbs. Oyster Shells. , 9/20 3.44 7.08 viscosity was an important factor in t h e preparation Theorv 2.22 14.20 0.99 13.32 of some pharmaceutical emulsions, nevertheless, viscous 160Ibs. Acid Phos .... 8/16 2.40 12.15 0.84 11.10 40 Ibs. Oyster Shells.. 9/20 2.99 4.30 1.57 1.05 materials, such as j o per cent glycerine or 6 per cent Theory 2.03 12.62 0.93 11.84 gum solution. are not able t o emulsify kerosene or 1.65 10.08 1.14 10.58 140 lbs. Acid Phos.. , . 8/16 3.26 1 .SO 1.95 0.65 60 Ibs. Oyster Shells., 9/20 cottonseed oil, though dilute, comparatively mobile 0.89 10.36 Theory 1 .84 11 .05 5.55 1.12 7.60 100 lbs. Acid Phos ... . 8/16 1.95 soap solutions do so easily. 2.32 0.30 1.11 0.35 100 lbs. Oyster Shells 9/20 7.89 0.77 7.40 Theory 1.46 While admitting t h e favorable influences of high I n studying this table there are some inconsistencies, viscosity and low surface tension, Pickering7 p u t forth t h e view t h a t the deciding factor is t h e formation of b u t taking t h e results as a whole it is seen: I-That t h e new acid phosphate is acted on more films of insoluble particles around t h e droplets. Donnan* attacked this hypothesis bitterly, b u t BancroftQ readily b y t h e oyster shells t h a n the older. pointed out t h a t t h e criticism was beside t h e point a-That action begins a t once. a n d t h a t t h e theory was not intended t o be a com3-That t h e action continues on standing. plete one. Clowes*o has described experiments in which 4-That t h e greater t h e amount of oyster shells these films were distinctly visible and he attributes t h e greater t h e action. 5-That with 30 a n d jo per cent shells virtually their action in part t o a purely mechanical action in keeping t h e particles from coalescing, in part t o lowerall of t h e water-soluble phosphoric acid disappears. These results, on t h e whole, agree with Dr. Brackett’s, ing of surface tension a n d in part t o repulsive action of t h e electrically charged particles. I intend t o make further analyses of these samples. Fischer” has recently proposed t h a t emulsification I t has generally been considered t h a t water-soluble or mono-calcium phosphate is more valuable t o crops is due t o , or accompanied b y , the formation of a hyt h a n citrate-soluble, or di-calcium phosphate. If dration colloid compound. He says: “ I n reviewing t h a t is t r u e then mixing larger quantities of calcium the empirical instructions for t h e preparation of emulcarbonate with acid phosphate would reduce t h e sions, and in our own attempts t o formulate such as value of t h e phosphate very greatly, b y reducing would always yield permanent results, we were struck the water-soluble phosphoric acid t o the vanishing point with the fact t h a t their production is always associated and also by increasing t h e insoluble phosphoric acid. 1 The work reported in this article constitutes the basis of a thesis -4s t h e fertilizer laws are a t present, fertilizer manu- submitted by Leo Roon to the Faculty of the Graduate School of New University, in part fulfillment of the requirements for the degree of facturers certainly could not afford t o mix much calcium York Master of Science. carbonate with their acid phosphates on account of t h e 9 Pogg. A n n , 14 (1870), 44. 3 117cd .4nn., 35 (ISSS), 589. high insoluble phosphoric acid which would he produced. 4 Z . phys. Chem., 31 (1899). 42. As this question is a very important one t o both 6 J . C h e m . Soc., 9 1 (1907). 200. 6 J . A m . Chem. Soc., 25 (1903), 513. farmers and fertilizer manufacturers, I have thought 7 2. Koll. C h e m . . 7 (1910), 11. i t well t o make public my results in order t o have more a Ibid., 7 (1910), 214. light thrown on t h e subject. 9 J . Phys. Chem., 16 (1912), 504. F. S. ROYSTERGUANOC O M P A N Y NORFOLK, VIRGINIA
10 11
I b i d . , 20 (1916), 415. Science, 43 (1916), 468.
