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T P E J O U R N A L O F I N D U S T R I A L A N D Eh‘GINEERIhtG C H E M I S T R Y
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industry, there naturally arise new problems concerned with the analysis of mixtures containing t h e same. Such a new material is Cyanamid, now in its fourth season in the United States, though in much older use in Europe. That it is making remarkable headway in this country, is evidenced by the fact t h a t last year’s production will be doubled this year and some 60,000 tons will be placed upon the market next year. At present, this material is marketed in two forms, a finely powdered Cyanamid, so finely divided t h a t all will pass a 60-mesh screen, and 7 5 per cent or more will pass a loo-mesh screen; and a granulated form sizing between IO- and So-mesh. The chemical composition of t h e two varieties is approximately the same, carrying nitrogen equivalent t o 18.5 per cent ammonia, nearly all in the form of calcium cyanamide. This compound is a comparatively weak one, hydrolyzing instantly in an excess of water to cyanamide and its polymers, t o ammonia, t o urea, etc. The calcium salt is so unstable in the presence of watei t h a t i t has never been isolated frorh aqueous solution. Besides calcium cyanamide, the commercial product contains free calcium hydrate, graphite, and various TABLE IV-RESULTS IN PERCENTAGES other minor impurities. The product marketed last S = Stems; L = Leaves year averaged 40 per cent calcium content in t h e Sample Total solvarious forms enumerated above, which we are going No. K?O ublesalts Ash N t o assume as hydrate for the purposes of this dis0.51 S Coronado Id., 1 Macrocystis , 18.28 36.78 2 . 3 6 Lower Cal. cussion since t h a t is t h e form most probably assumed 0.84 L Geese Id., 2 Nereocystis . . . 9 . 9 0 25.94 3.88 by t h e lime as soon as mixed in t h e ordinary com28.26 52.88 3.60 1.06 S Alaska plete fertilizer, though later it may react t o various L 15.44 3 9 . 4 0 4 . 3 4 2 . 2 7 3 Nereocystis . . 24.69 5 6 . 4 0 3 . 1 0 1.15 S Port Graham, other forms. L Alaska 14.78 3 8 . 4 4 4 . 3 0 2 . 0 2 Abroad, t h e bulk of the annual production of some S Pearse Canal, 4 Nereocystis.. . 23.88 4 9 . 4 4 1 0 . 6 6 1 . 5 3 200,000 tons finds its way into t h e soil directly, due 12.74 3 4 . 3 8 5 . 1 2 2 . 8 7 L Alaska 5 Nereocystis.. , 3 0 . 1 2 63.74 2.76 1.07 S Bet. Tangass and t o the common European practice of using unmixed 15.12 4 0 . 1 0 4 . 3 4 3 . 0 6 .I Kanagunnt Isl.. fertilizers. Only small quantities get into complete Alaska S Gulf of Eiquibel 6 Nereocystis . . . 2 7 . 0 2 5 8 . 8 6 3 . 2 2 0 . 8 1 mixtures and no question of analysis seems t o have L Alaska 19.63 4 7 . 2 6 3 . 4 6 1.04 arisen regarding such mixtures, as it is a n assumed 7 Nereocystis. . . 2 8 . 7 6 6 4 . 4 4 2 . 9 0 0 . 5 9 S Eagle Isl., Davidfact t h a t there Cyanamid is incapable of transforming 16.74 4 2 . 7 4 5 . 6 6 1.52 L son Islet, Alaska S Wrsngell S t . , 8 Nereocystis . . . 2 4 . 8 0 5 3 . 5 4 3 . 6 8 0 . 9 8 acid phosphates into an unavailable form, irrespective L Alaska 17.67 4 4 . 4 0 4 . 9 8 2.01 of t h e results yielded by the usual methods of analysis. 9 Postelsia... . . . 2 0 . 0 41. 1 4.0 1 .01 S Neah Bay, Palmaeformis. 1 3 . 9 29.90 5 . 7 1.83 L Wash. I n this country where nearly all t h e Cyanamid 10 Postelsia ... . . . 2 2 . 8 44.5 3.2 0.94 S Montara P t . , enters into such complete mixtures which are sold L Cal. Palmaeformis. 9 . 7 29.7 4.3 1.40 on the basis of analysis by Official Methods, we have 1 1 Macrocystis.. . 1 8 . 7 40.3 5.3 1.24 S St. Nicholas. . . 12.4 28.3 6.9 l . O 4 S & L Cal. presented t o us a possibility of reactions being caused Samples 9, 10 and 1 1 are from Turrentine. t o t a k e place between t h e acid phosphate and t h e with their respective analyses. An attempt t o find Cyanamid by reasons of t h e manipulation as preuniformly constant variations between stem and scribed in these methods of analysis. Results obtained leaves in content of other constituents justified t h e two after such reaction has taken place are of course not representative of t h e material as sampled. following conclusions : We can here dismiss a discussion of t h e constitution ( I ) The ash content is almost invariably larger of t h e ordinary acid phosphate of commerce. We have in t h e leaves t h a n in t h e stem of the same plant. (11) The nitrogen content is almost invariably larger already discussed sufficiently the chemical constitution and behavior of Cyanamid, but it might be well t o i n t h e laminae t h a n in the stipe of the same plant. state here t h a t our future discussion will be limited BUREAUOF S O I L S U.s.DEPT. OF AORIC.,WASHINGTON t o the granulated form because of the present lack of a method of separating undccomposed Cyanamid from THE OF ‘OMPLETE a complete fertilizer mixture other t h a n b y picking ING CYANAMID2 i t out particle by particle. This granulated form of B y H. W. HILL AND W. S . LANDIS Cyanamid is designed t o present a minimum of reWith t h e advent of new materials into t h e fertilizer actinn surface for a u .. of material, the 1 Jour. Frank. Inst., 176, 364 (1913). mixture Of any addition to the Ordinary 2 Presented at the 48th Meeting of the A. C. S., Rochester, September 8-12, 1913. remaining inactive in the interior of t h e granule.
After the large sample was cut a t 2 . 1 0 P.M., i t was taken from t h e water and kept out. till 3.50 P . M . before re-immersion. It was cut off Pt. Vincente, California in t h e vicinity of the beds now being cut b y commercial organizations, Lat. 33 ’ 2 2’ 3 0 ” , Long. I 18’ 20’. Sub-samples 1-6 and 2 2 were taken where the large sample was c u t ; 7 , while steaming t o Pt. Vincente; 8-11, while steaming t o Avalon; 1 2 , on t h e way t o San Diego; and t h e others in San Diego Bay. During t h e course of analysis of the numerous samples of kelps which have been recently analyzed in this laboratory, it was observed t h a t in every instance, where stems and leaves of t h e same plant were separately analyzed, t h e total salt content, and similarly t h e potash content, in t h e stipe exceeded t h a t of t h e laminae. This observation is of particular importance since Dr. Cameron in a recent‘ review of the kelp work, and on t h e basis of the analytical d a t a then available for all stipes and all leaves, irrespective of the relations in individual plants, offered t h e opinion t h a t there were no characteristic differences in this respect. Table I V gives a list of such samples
1
Jan., 1914
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I n order t o substantiate our theory regarding t h e A sample drawn for analysis, according t o the Official Method from such a fertilizer mixture, is required t o be hydrate we performed t h e several experiments. An ground, such grinding breaking up t h e granules. acid phosphate analyzing by t h e official method 0 . 2 9 This broken-down mass is then treated with water in per cent insoluble PsOs, condition fairly dry, was used excess, liberating the lime of t h e former granule t o in all the experiments. I. I n t o t h e point of four dry folded filters were placed, action on the phosphoric acid, such procedure violating every principle upon which the inactivity of t h e respectively, 0 , 0 . 2 5 , 0.7 j and 1.00gram of dry calcium granulated form of t h e Cyanamid was founded. The hydrate. On top of each were poured quickly 2 grams results of any such analytical procedure are not rep- of t h e above acid phosphate and analysis according resentative of the real conditions existing in t h e to the Official Methods started immediately. No chance for mixing or reaction was given. The results mixture as sampled. Let us examine more closely the nature of t h e possible obtained were as follows: reactions taking place when acid phosphate and Weight Ca(0H)z Insoluble PzOs Gram Per cent Cyanamid are mixed. The Cyanamid contains a n 0 00 0 29 equivalent of 74 per cent calcium hydrate which un0 25 1 69 doubtedly reacts immediately with any free acid in t h e 0 55 4 54 1 00 4 47 acid phosphate t o form a mono-calcium phosphate, such reaction being accompanied by the considerable The lime remained in t h e point of the filter in one heat evolution always noted on such mixing. The lump and probably represents the extreme case of one consequent high temperature of t h e mass, coupled large granule of unreacted Cyanamid in acid phoswith t h e water content of the same, may even cause phate. Our experience with acid phosphate mixtures t h e hydrate t o react with t h e mono-calcium phos- would lead us t o believe t h a t absolutely no reaction phate t o form t h e di-calcium phosphate, b u t as far as had taken place between t h e hydrate and the acid we can ascertain by other t h a n chemical analysis, we phosphate before the first water was added. do not believe this second reaction progresses very The other extreme of the powdered Cyanamid acid far, or t h a t i t takes place a t all in cold, dry mixtures. phosphate mixture conditions would be approximated I n proof of this last contention we have mixed sufficient b y mixing the hydrate and t h e acid phosphate in t h e Cyanamid with acid phosphate t o neutralize t h e free filter. This was done in the next experiments. acid and left t h e pile t o cool. After cooling more 11. A very quick rough mix was given the acid Cyanamid was added t o the mass without sign of a phosphate hydrate mixture before adding t h e water. second reaction caused by this second addition. The N o indication of reaction having taken place here was same result was obtained with a complete fertilizer apparent. mixture, the first addition of Cyanamid serving t o Weight Ca(0H)z Insoluble PzOs Gram Per cent neutralize t h e free acid and dry out the mass, and no 0 25 7 94 further reaction took place on second addition, as 0 75 11 42 evidenced by thermochemical and physical observation. Analyses by t h e official method, however, From the results of these two experiments we conhave shown an apparent loss of availability on this clude t h a t if free Cyanamid or free calcium hydrate second addition, thus furnishing another reason for in any form are present a t sampling, t h e Official questioning its applicability t o a Cyanamid mixture. Methods of Analyses do not yield results indicative Believing as we do t h a t reaction will take place be- of t h e actual conditions in the pile a t t h e time of tween free calcium hydrate and acid phosphate during sampling. The apparent loss of phosphoric acid in the chemical manipulation of analysis by t h e official an actual mixture, as determined by this official method, methqds, particularly where t h e calcium hydrate has would lie somewhere between t h e results as indicated been locked up in granules of Cyanamid, we deter- in Experiments I and 11, because t h e conditions exmined t o t r y a few experiments t o substantiate these isting in t h e original pile as to distribution of t h e views. The grinding and the leaching with water hydrate is somewhere between t h e extremes of the one p u t both the lime and t h e phosphoric acid into solu- . large granule and the more even distribution of t h e tion and reaction will ensue causing precipitation hydrate, but there is no doubt t h a t i t does become in both the filter and the receiving beaker, according quite serious. t o conditions. Any precipitation of phosphoric acid It is a very simple matter t o prove the existence in t h e filter means a low result for water-soluble. of free hydrate in a fertilizer mixture containing Digestion of the water-insoluble residue with neutral granulated Cyanamid by actually picking out t h e citrate in the presence of t h e hydrate again causes granules of unreacted or undecomposed Cyanamid. reaction and precipitation as insoluble during t h e Other means of attempting t o ascertain the degree t o digestion, giving results for insoluble phosphoric acid which the Cyanamid reacted on t h e acid phosphate having no relation t o the content in the original in a complete fertilizer mixture failed. Two mixtures sample. We are even of the opinion t h a t the neutral studied from a thermo-chemical standpoint showed citrate digestion breaks up calcium carbonate if present approximately t h a t three-quarters of the powdered and causes precipitation of insoluble phosphoric acid, Cyanamid and one-third of t h e granulated Cyanamid though it will not react with the mono-calcium phos- had entered into reaction, but we look upon this as phate either dry or in water solution. only a crude approximation because of the lack of
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essential thermo-chemical data. We have not, a t this time, found a mechanical or chemical method of isolating the undecomposed Cyanamid particles from a complete fertilizer mixture, other t h a n b y hand-picking, which a t best affords a partial separation of the coarser particles. A s a concrete example of the proof of such undecomposed Cyanamid present in a fertilizer mixture might be cited t h e case of a ten-ton batch made up as indicated below: FORMULA 1000 acid phosphate 125 granulated Cyanamid 200 muriate of potash 300 garbage tankage 375 filler
PER CENT P20r I N ACIDPHOSPHATE GARBAGE TANKAGE Free a c i d . . . . . . . . . 3 . 6 4 .... Water-soluble.. . . . 12.64 0.15 Citrate-soluble.. , . . 4 . 5 3 2.55 Available. . . . . . . . . 1 7 . 1 7 2.io Insoluble.. . . . . . . . 0 . 2 9 1.19 Total. , , . , . , . . 1 7 , 4 6 3.89
This batch was stored in a bin, surrounded on all sides b y similar bins containing similar mixtures, and t h e center of the mass rose 70' C. in four days after mixing, and then slowly cooled off. Six weeks after mixing, a sample was drawn while still warm t o the hand, from which sample we picked out sufficient undecomposed Cyanamid for analysis. This Cyanamid was clean and free from adhering acid phosphate, which realiy seeme'd t o have as great a n affinity for t h e garbage tankage as for t h e Cyanamid. T h e separation in this manner offered difficulty only because of t h e presence of the dark-colored particles of t h e tankage and t h e dark colored filler used, and not because o f . adherence of t h e acid phosphate. An analysis made directly on the particles, as separated without attempting t o clean t h e m off in any way, gave 48.5 per cent calcium hydrate and 0.1.5per cent phosphoric acid, showing the presence of the hydrate in t h e particles as sampled. The granules of Cyanamid showed decomposition of t h e cyanamide and the presence of moisture, which probably is the cause of t h e lessened percentage of hydrate found in them. We have endeavored t o show here t h a t t h e Official Methods of Analysis give results in no way indicative of t h e character of the sample as taken where free calcium hydrate or Cyanamid is present in the mixture. Such results show an apparent loss of availability t h a t has no real significance as far as concerns t h e condition of t h e material before analysis. Granulated Cyanamid remains for a large part unacted upon even in additions as high as 300 Cyanamid t o 1000 acid phosphate and a t temperatures as high a s 110' C. It is more decomposed in t h e manipulation incident t o analysis b y the official methods t h a n in the mixing with t h e acid phosphate, if we can believe t h e results of some recent investigations we have made. We regret t h a t we cannot offer a solution t o this problem, which not only concerns t h e Cyanamid industry, b u t t h e larger fertilizer industry as a whole who have been striving t o use limestone fillers in their mixtures for the great beneficial effects following the use of such fillers. The use of such material is now prohibited because of the great loss of availability shown on analysis b y the Official Methods. We believe t h a t i t is impossible for calcium carbonate, as well as t h e hydrate we have worked with, t o transform
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a n acid phosphate past the dicalcium stage under the ordinary conditions of mixing and batching of t h e semi-dry materials employed to-day. B u t we do know t h a t t h e digestion with neutral citrate will cause reaction of any free hydrate with the di-calcium phosphate a t t h a t stage of t h e manipulation, and t h e same must be true of t h e carbonate, though we have not made a direct investigation t o prove this statement. I n our own work we have found t h a t t h e dilute weak acids frequently recommended for analysis of t h e Basic Slags show practically no loss of available in acidphosphate mixtures containing u p t o 300 pounds of granulated Cyanamid and 1000 pounds of acid phosphate t o the t o n of complete mixture, even though t h e temperature of t h e mass rose t o over 110' C. and remained high for many weeks. Such methods do show a loss of available for additions of powdered Cyanamid much in excess of 125-150 pounds t o the 1000 of acid phosphate, though this amount has, in many cases, been exceeded by a proper choice of inactive diluents in t h e complete mixture. The results of analysis of Cyanamid acid phosphate mixtures b y these last-named methods agree more closely with other physical and thermochemical data t h a n do those obtained b y the Official Methods. We believe t h e great importance of a comprehensive study of t h e reactions between acid phosphate and calcium hydrate and calcium carbonate under t h e mixing conditions existing in actual fertilizer practice would lead towards a solution of t h e use of a limestone filler for fertilizer mixtures, and everyone appreciates t h e great agricultural advantage t o be derived from t h e use of such a material in t h e industry. The problem should be approached from several angles, not all purely chemical, as we have shown t h e failure of a chemical method t o produce results characteristic of the material worked upon in our case as described above. NIACARA FALLSONTARIO
A STUDY OF THE MILK OF PORT0 RICAN C O W S By HOWARD J. LUCAS,R . DBL VALLB SARRAGA AND J. ROMAN BENITEZ Received September 15, 1913
This work was undertaken for the purpose of .determining how, and t o what extent, the milk from the native Porto Rican cows varies from t h a t of other countries. and to what extent t h e use of different grasses as food affects its composition. The so-called native cow does not seem t o be of any particular breed, b u t appears t o be t h e result of the mixing of different strains introduced into t h e island from time t o time. There seems t o be no attempt on the part of the people t o divide t h e cattle into different breeds on t h e basis of color, and consequently no attempt has been made t o do so in this work. The value of cattle in Porto Rico does not depend entirely upon its use as a source for meat and for milk, but rather upon the fact t h a t the oxen form t h e most common beast of burden, and are used in all parts of the country for performing the heaviest kinds of work, such as hauling, plowing, rough farm labor, etc.
