POTENTIAL MARKETS

ESG CHEM , 42. 269 (1960). (33) Waggaman, W. H., and Easterwood, H. W , “Phosphoric Acid. Phosphate, and Phosphatic Fertilizers,” -4.C.S Monograpl...
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I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY

(22) Norris, E. M., Mining and Met., 25, No. 454, 481 (1944). (23) Pamplin, J. W., Trans. Am. Inst. Mining Met. Engrs., Mining Technol., 295-314 (1938) (Tech. Pub. 881). (24) Pike, R. D., IND.EKG.CHEM.,22, 344 (1930). (25) Royster, P. H., et al., U.S. Dept. Agr., Tech. Bull. 543 (1937). IND.ENG.CHEM.,24, 223 (26) Royster, P. H., and Turrentine, J. W., (1932). (27) Shreve, R. N., “Chemical Process Industries,” Chap. 18, pp. 339-342, New York, McGraw-Hill Book Co., 1945, (28) Swainson, S. J., Mining and Met., 25, No. 454, 469 (1944). (29) Tyler, P. M., and Mosley, H. R., Trans. Am. Inst. Mining Met. Engrs., 148, 83-104 (1942).

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(30) Waggaman, IT7. H., ISD. ENG.CHEM.,24, 983 (1932) (31) Waggaman, W. H., et al., U . S. Dept. Agr., Bull. 1179 (1923) (32) Waggaman, W. H. and Bell, R. E., IND. ESG CHEM, 42 269 (1960). (33) Waggaman, W.H., and Easterwood, H. W , “Phosphoric Acid

Phosphate, and Phosphatic Fertilizers,” -4.C.S Monograpll 34, New York, Chemical Catalog Co , Inc. (1927). (34) Weber, W.C., Chem. &: Met. Eng , 39, KO. 12 669 (1932).

(35) Weber, W. C., private communiration RECEIVFII October 15,1948.

Western Phosphates

POTENTIAL MARKETS ROSCOE E. BELL’ AND WILLIAM H. WAGGAMAN2 U . S. Department qf the Interior, F’ushington, D . C. Concentrated products manufactured from western phosphate rock by both the sulfuric acid process and the thermal reduction method offer opportunities for expanding an already established western phosphate industry. Fertilizers, however, represent the largest outlet for phosphate rock and though there has been a healthy growth in the consumption of these products in the western states, the main fertilizer market is in the eastern, midwestern, and south Atlantic states. The possibilities of serving economically the midwestern market with concentrated phosphates produced in the western phosphate area are discussed, and it appears that under favorable conditions

the amount of plant food in such concentrates not only can be delivered to the Midwest at a lower cost than that in ordinary superphosphate manufactured from Florida and Tennessee rock but can compete in certain Midwest areas with concentrates produced from eastern rock. Whereas triple superphosphate can be produced by the sulfuric acid process more economically than by the thermal reduction method, favorable locations and cheap electric energy in the western states make the future of the latter process appear bright for supplying the growing demand for pure phosphoric acid and chemical grade phosphate products.

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eastern and south Atlantic states have long been established and manufacturing facilities have been provided t o meet these needs. I n recent years the markets of the western, midwestern, and central states have been expanding rapidly, proceeding a t an accelerated rate throughout the war years and continuing to gronduring the postwar period. The two questions being asked by potential producers of western phosphate are: 1. Will the present demand for phosphate products decrease markedly when the price of agricultural commodities begins t o drop? 2. Can products manufactured from western phosphate roch be delivered to large, well established markets at a cost permitting them to compete with those produced from Florida and Tennessee phosphate rock?

N THE previous two papers (8,Q)the authors have reviewed

the background information on the phosphate industry, described the various processes for producing fertilizers from phosphate rock, and considered in some detail those processes that have achieved full scale operation in industry and seem best adapted to development of a western phosphate industry. Comparisons also were made of the probable or possible costs of processing phosphate rock by alternate methods in the western areas. The purpose of this final paper is to translate this information into terms that will permit determination of the most economical means of serving the important market areas in the United States and to evaluate to some extent the competitive ability of western phosphates t o serve these markets. The validity of these comparisons is, of course, dependent on an actual materialization of the conditions assumed in the foregoing papers. I n earlier reports (1) t,he western market for triple superphosphate has been defined as including seventeen states west of lllinois, Missouri, Oklahoma, and New Mexico. This trade area was defined on the basis of transportation costs from the major primary sources of supply-namely, Florida, Houston, Texas, and the western phosphate fields. The validity of this definition of trade area depends on the cost of production a t various possible producing points and shipment of the same product from the alternate point of production. The largest United States markets for fertilizer are in the midwestern, eastern, and south Atlantic states. The principal far western markets are along the Pacific Coast, especially in California. Ten years ago the consumption of fertilizer in a11 the western states was extremely limited, whereas the markets in the 1

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Present address, Bureau of Land Management, Washington, D. C. Present address, Bureau of Nines, Washington, D. 6.

GROWING NEEDS FOR PHOSPHATE PRODUCTS

The uses for phosphate products for purposes other thari fertilizers have been developed to a remarkable degree. In addition to such long estahlished phosphate products as baking compounds, detergents, sugar refining, and medicinal preparations, there are relatively new and expanding uses for phosphoric acid and its compounds. These include rust-resisting coatings plastics, ceramic Groducts, lubricant additions, water conditioners, textile-processing compounds, insecticides, catalysts, and improved animal-feed supplements. The fertilizer industry, however, has been and always will he the main consumer of phosphate rock; hence, in planning any large western development, the existing and potential demands for fertilizers are of prime consideration. Estimates of future fertilizer markets are difficult to make, but fundamental and irrefutable facts indicate that the consumption of fertilizers must continue to increase.

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It is well established that the total phosphorus content of many soils is relatively low. I t is also well known that certain crops markedly deplete the soil of available phosphorus; and under our present systems of waste disposal, the bulk of this essential plant nutrient consumed by man is irretrievably lost in the form of sewage. Such losses can only be economically replaced in the soil by the addition of commercial fertilizers. The removal of phosphorus (6) by crops can be fairly accurately estimated over broad areas, but such figures do not show the critical shortages in the soil or the areas where fertilizer applications will pay. They do, however, give a clue t o the ultimate need for fertilizer. Table I gives the average annual consumption of phosphorus pentoxide in the form of fertilizers for 1935-39, and for 1944-48, inclusive, as estimated by Mehring and others ( 4 , 7). These figures show that the percentage increase in the use of such fertilizers during the past 9 years has been markedly greater in the seventeen western states than in the other areas listed. TABLE I. CONSUMPTION OF PHOSPHATE FERTILIZERS Fertilizer Consumptiona, Tons PzOn North Eastern and’ Western Central Southern states, 27 United States states, 17 states, 4 1935-39 703,926 37,338 89,621 576,967 1,288,302 136,172 198,745 954,385 1944 967,980 1945 1,338,062 170,106 200 006 1946 1,534,704 199,682 254:378 1,080,644 1947 1,716,897 239,021 294,916 1,182,960 1948 1,832,318 281,113 337,155 1,214,050 0 Mehring and others, U. S. Dept. Agr., Agricultural Research Adm., Bureau of Soils, Chemistry, a n d Agricultural Engineering.

Under the stimulus of the government agricultural conservation program, through experiments conducted by the colleges, experiment stations, fertilizer companies, and the TVA, western farmers have tested fertilizer in many areas that did not use commercial fertilizer 10 years ago. Thus, there is ever-widening knowledge of the value of using phosphatic fertilizers based on actual experimental evidence. Estimates of phosphate ‘heed” (the quantity needed t o produce satisfactory crops) have been made (6) in all counties throughout the United States by the local agricultural conservation committees. These figures, in spite of their limitations, are interesting and significant. They are shown in Table I1 in comparison to the phosphate removed by crops. The data given in Table I1 point to a continued increase in the fertilizer needs of the western, midwestern, and north central United States.

TABLE11. ESTIMATED PzOj REMOVAL FROM SOIL AND ESTIMATED NEEDFOR PHOSPHORIC ACIDBY AREAS

Removal by crops, tons Need, tons

United States 1,699,064

Western States, 17 869,829

North Central States, 4 316,348

2,863,296

457,142

880,449

Eastern a n d Southern States, 27 612,887 1,526,706

For instance, in 1946, the application of phosphorus pentoxide was roughly half of the estimated need in the western area and less than one fourth of that removed in crops. It would, therefore, appear that the area is one in which increasing use of fertilizer is inevitable in future years. Unquestionably, the rapid expansion in the use of fertilizers in these states has been stimulated partly by the high prices for farm commodities, but it has been influenced also by a general drop in yields throughout the area where fertilizers have not been applied and where the fertility of the original virgin soils has been greatly depleted. It is also significant that, in order to maintain crop,production a t high

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levels in the older areas of the Unitfed States, the average annual fertilizer applications now represent double or treble the quantity of plant food removed by crops. Figure 1 shows the estimated need by states in the western and midwestern United States. WESTERN MANUFACTURING FACILITIES

The rapid riee in the demand for fertilizer in this area has outstripped manufacturing facilities. Domestic western and midwestern capacity for phosphate fertilizers expected to be in production by late 1949 is estimated a t 225,000 tons of phosphorus pentoxide annually, or less than one half of the estimated need. This is divided among various types of phosphate fertilizer as follows: Normal superphosphate Concentrated superphosphate Phosphoric acid and ammonium phosphates} Magnesium and miscellaneous phosphates

Plants 15 2

PzOs, Tonu 137,000 80,000 7,000

By comparing western production with fertilizer requirements, i t is easy to see why acidulated phosphates have been shipped from eastern plants t o meet western needs. Actually some phosphate originating in Florida, processed a t Baltimore, and shipped t o mixing plants in Portland, Ore., finds its way into the markets of Idaho and Montana. The total transportation costs in this case amount t o over 40% of the retail price of the fertilizer. Obviously this is a situaticn that will be corrected if western manufacturing capacity can be expanded economically to meet the needs of the entire area. I n recent years phosphate fertilizer manufacturing capacity has been expanded in the F a r West and the Midwest. Midwestern expansion has been entirely in ordinary supei phosphate production, whereas over half of the western expansion has been in low-analysis products. There now appears to be no deficiency of manufacturing capacity for ordinary superphosphate. Although there is no way of accurately measuring t h e actual market demand for concentrated phosphates in relation t o ordinary superphosphates, the concentrated products have been used in a wider area than is now served because of inadequate supplies. I n all of the plains and Rocky Mountain and far-western areas a marked preference for concentrated phosphate fertilizers has been apparent in the past. It thus appears that the market demands are somewhat related to the economy of using concentrated phosphate fertilizers. Thus the nationwide capacity for concentrated phosphates would appear to be far below that which could be used and probably would be used were it available, The conventional phosphate fertilizer produced in greatest quantity in this county is ordinary or normal superphosphate, containing 16 to 20% PzO~.Where adequate sources of phosphate rock and low cost sulfuric acid are available and comparatively short hauls are involved in transporting the raw materials, ordinary superphosphate is often the cheapest phosphatic fertilizer in bulk, f.0.b. the factory. On the other hand, especially where the finished product must be shipped long distances and handled and rehandled before i t reaches the ultimate consumer, concentrated phosphate fertilizers are much more economical, since the somewhat higher initial manufacturing expense is more than offset by the saving in distribution costs. In fact, a tabulation of OPA ceiling prices throughout the country showed that in 1945 the delivered price of Concentrated superphosphate was, almost without exception, significantly lower per unit of PzOa than ordinary superphosphate. Increases in freight and other handling charges since that time probably have increased the spread in favor of concentrated superphosphate. Furthermore, ordinary superphosphate cannot be used alone in mixed fertilizers if the analysis of these fertilizers is to be stepped up in accordance with the rscommendations of agronomists and market demands.

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Figure 1.

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Rail Mileages from Montpelier, Idaho, to Important Potential Markets for Western Phosphorus Products

Both greenhouse and field experiments by various government and state agricultural agencies have proved the value of concentrated phosphates, and the principal limitation on their use is insufficient supply. This is particularly true in the western area of the United States, where the development of a successful industry that can serve well established and broadening markets depends on the production of concentrated phosphate products. California provides a large and attractive market for western producers. This market may, of course, be served by any one of several alternate types or locations of plants. WESTERN PHOSPHATE ROCK COULD ECONOMICALLY SERVE WESTERN MARKETS

A comparison of the shipping costs (g), in terms of PzOS,for raw phosphate rock and the various products manufactured therefrom was given diagrammatically in the first of this series of articles (8) and the projected probable costs of manufacturing elemental phosphorus, phosphoric acid, and triple superphosphate a t strategic points in the western area (by thermal reduction and sulfuric acid methods) were estimated in the second article of this series (9). The economic possibilities of serving the far western and midwestern areas with concentrated products manufactured from western phosphate depend on whether the cost of production plus freight charges to consuming centers are equal t o or less than those of similar products manufactured from Florida and Tennessee phosphate rock. I n the case of the far western states, there appears to be no question that their needs for phosphoric acid, high grade phosphate compounds, and concentrated fertilizer products can be served most economically by the phosphate deposits in Utah, Idaho, Wyoming, Qnd Montana. Even though these phosphate fields are 800 to 1000 i..iles away from some of the large markets,

TABLE 111. ESTIMATED COSTPER TONO F PLAKT Foon (PtOb) DELIVERED TO RETAILBRS I N CdLIFORNIA

~~2:~&L%~t~ Triple Superphosphate (48% PzOd (IS& PtOg) Produced in Produced in Idaho Conversion cost, total Transportation costd Total bulk cost a t retail Doint

Produced in Calif. $ 61.12a 31.39 92.51

Salt Lake City by wet process $52.21b 20.04 72.23

by electricfurnace Drocess 3 62.85C 21.32 84.17

22.25

8.32

8.32

44.50

18.64

16.64

$98.19 5110.13 $159.26 t o consumer a Based on $4.50 rock, $5.54 freight Idaho to Calif., $8.00 sulfuric acid, and $2.70 per ton of product for conversion cost. b Table IV (9). C Table VI1 (9). d Based on a 200-mile shipping distance from factory t o consumer.

TABLEIv. RELATIVECOSTS OF HaPo4 ~IASUFACTURED AT SALT LAKE CITY, UTAH, AND MAKUFACTCRED I N CALIFORNIA FROM PHOSPHORUS PRODWED II\TIDAHO (Delivered to California distributors) Cost per T o n of PnOr Electric-furnace process elemental phosphorus produced in Idaho and Wet process liquid phosphoric aoid shipped t o Calif. for eonversion t o (53% PzOr) produced DhosDhoric acid in Salt Lake City Manufacturing cost per S57. 2Ba $68.19b unit Transportation cost 31.90 12.24 ... 5.000 Conversion t o Hd'04 Total t o California 889.18 $86.43 a Table I11 (9). b Table V (9). Table VI (9).

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ESTIMATED COSTOF PRODUCING PSO6 AS PHOSPHORIC ACID (85% H3P04)AT TAMPA, FLA.

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western states, and has proved very effective. Nevertheless, even though this acid can be produced and shipped in concentrated fornl, it requires (From Florida pebble phosphate, 33% PaOs, by sulfuric acid method. annual production, 33,000tons PzOs, equal to 53,400tons 85% HsPOh special tank cars and carriesa freight - rate substantiCapital investment (exclusive of rock-grinding plant) ally higher per unit of plant food than other: conReal estate $ 10,000 Buildings 500,000 centrated fertilizers. It would appear possible, Equipment 1,300,000 Total $1,810,000 therefore, t o ship elemental phosphorus to phosUnit phoric acid-consuming centers and convert, it into % -,Per Short Ton of ProductQof the latter compound close to existing markets. PaOs Hap04 (85%) Total St% This advantage is illustrated in Table IV where Ton Quantity Cost Quantity Cost Cost Raw materials the projected cost of phosphoric acid manufactured $ 5.01 14.72 $ 8.14 Phosphate rock (33% PzOP) $ 2.52 Freight to Tampa, Fla. 1.00 3:23 3.23 1:99 1.99 5.85 a t Salt Lake City, Utah, by the wet process and 1.10 3.24 0.55 1 78 Grinding rookb Sulfuric acid (100% H~SO,) 10.08 &z & i:ig 15.96 46.99 delivered in California is compared with the cost Total cost of materials .. 5.80 $39.06 *. $24.08 70.80 of phosphoric acid manufactured in California Conversion Power kw.-hr. 0.01 115 $ 1.15 71 0.71 2.08 from elemental phosphorus produced in Idaho. Labor,' operating, supervision .. .. 2.65 .. 1.64 4.83 The figures given in Table IV show that, even Labor, maintenance .. .. 2.00 .. 1.23 3.32 Evapdration Labor laboratory (steamand peroffice tono) 1105 1 87 0.75 1.96 1: i5 ::$: though the expense of manufacturing electric-furGeneral plant materials expense .. .. .. .. 0.44 .. .. nace acid under the assumed western conditions Maintenance 1.50 Depreciation (over-all), 7.5% .. . . 4.11 . . 2.53 7.43 is substantially higher than that of wet process acid, 1.65 .. Insurance and taxes, 3% .. .. 1.02 3.00 Total cost for conversion .. , , $16.21 .. 9.98 29.20 the saving effected by shipping elemental phosGrand total .. .. $55.27 .. $34.04 100.00 phorus more than offsets the additional producBased on recovery of 94% PzOs. tion cost. Phosphoric acid derived from elemental b Total cost of grinding rock (per short ton) including depreciation. PhosPhorus has the further advantage of high 0 Per ton of steam derived from average c o h a t $5.00 per ton assuming efficiency of 50%. purity, which makes it more economical than wet-process acid in the manufacture of high grade chemicals and food products. they are not only much closer than those of Florida and TenUnder present conditions, the same reasoning applies to the nessee, but the potentialities for processing western rock are such manufacture of ammonium phosphate fertilizers; but, if anthat the continued manufacture of finished products therefrom hydrous ammonia becomes available from sources close to the appears definitely assured. A comparison of retail ceiling prices phosphate deposits, the production and shipment of ammonium under the OPA for ordinary superphosphate and triple superphosphate rather than superphosphate should prove more ecophosphate shows that the triple superphosphate has been reaching nomical. The commercial products normally sold are 11-48-0 and the consumers in this entire area a t a very considerable saving to 16-20-0, although there are possibilities of manufacturing a the consumers. The price differential amounts to from $20 product of considerably higher analysis. The 11-48-0, in the to more than $50 per ton of phosphorus pentoxide. West, carries the same freight rate per ton as triple superI n Table I11 the estimated cost of phosphorus pentoxide (in phosphate (0-48-0), and the nitrogen gets a "free ride," thus the form of superphosphate), manufactured in California and greatly reducing the transportation cost per unit of plant food. delivered to retailers in that state, is compared with that of phosphorus pentoxide in triple superphosphate manufactured in Idaho and Utah by the sulfuric acid and electric-furnace methods. TABLEVI. ESTIMATED COST OF PRODUCING Pz06AS TRIPLE SUPERPHOSPHATE (48y0 AVAILABLE P p 0 5 AT ) TAMPA, FLA. The ceiling price figures verify the validity of this comparison in that San Francisco retail prices for ordinary superphosphate (From pebble phosphate and phosphoric acid derived from sulfuric acid process; annunl production of triple superphosphate, 97,000tons) manufactured locally in 1945 amounted to $154.17 per ton of Capital investment Pz06 as contrasted with $120.93 for triple superphosphate proRealestate $ 5 000 Buildings 618:OOO duced in Anaconda, Mont. Equipment 223,000 These figures illustrate the economy of locating processing Total $846,000 plants close to the phosphate deposits, producing a high-analysis -Per Short Ton of Product% product, and shipping direct to the retailer and consumer. per Triple of Even triple superphosphate produced by the electric- or blastShort Superphosphate PzOa Total Ton Quantity Cost Cost' Cost furnace process may 'be expected to reach the retailer and conRaw materials sumer a t a much lower cost per unit of plant food than can the Phosphoric acid (85% 034.04 0.55 $18.72 $39.00 82.64 ordinary superphosphate produced in California. HaPOd" Phosphate rock (33% PzOs) 2.52 1.13 2.35 5.00 I n addition to triple superphosphate, other concentrated Fr$,ghtonrocktoTampa, 1.00 0:45 0.45 0.94 2.00 B la. phosphate products are assuming great importance. These can Grinding rockb 0.55 .. 0.25 0.52 1.10 either be manufactured close to the phosphate rock deposits or Total for materials .. 170 20.55 9642.81 90.74 be shipped as intermediates for final processing close to the conConversion 0.01 8 $ 0.08 $ 0.17 0.37 suming markets. .. .. 0.30 0.75 1.60 Although the phosphorus produced by the electric- and blast. . . . 0.27 0.56 1.19 furnace processes has a limited market in elemental form, its .. 0.26 0.55 1.18 office concentration is such that it can be shipped at a lower cost per Maintenance materials . . .. 0.10 0.21 0.44 .. unit of plant food than any of the other common phosphateGeneral plant expense 0.10 0.21 0.44 Depr>cJation (over-all), 0.65 1.35 2.86 bearing materials (with the exception of potassium metaphosI.070 Insurance and taxes, 3% .. .. 0.26 0.55 1.18 phate). Moreover, this phosphcrus can readily be oxidised and Total operating cost .. .. $ 2 . 0 8 $ 4.35 9.26 converted into phosphoric acid from which almost any desired Grand total .. .. $22.63 $47.16 100.00 phosphate product is obtained. a I n actual practice more dilute acid is employed. Liquid phosphoric acid is being applied directly to the soil b Total cost of grinding rock (per short ton) including depreoistion. through irrigation water, especially in a number of the South-

TABLE V.

c

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down at Clinton, Iowa, are given in Tables XI and X I I , respectively. (85% HJ’04) The figures given in Table XI make it appear (From Tennessee phosphate rock, 33% PzOa, by sulfuric acid method; annual production, that western-produced wet process triple super33,000tons PnOa equal to 53,400tons 85% HIPOI) Capital investment (exclusive of rock-grinding plant) phosphate can be expected t,o reach certain midReal estate 8 25,000 Buildings 500,000 western markets in competition with that, produced Equipment 1,300,000 ill Florida and Tennessee. It is also apparent Total S 1,525,000 that western-produced electric-furnace triple superUnit phosphate can be expected to reach a niidmestern -Per Short Ton of Produoto% of Short P2O6 Hap04 Tota market a t a cost per unit of plant, food about equal Ton Quantity Cost Quantity Cost Cost to that produced by the wet process a t a midRaw materials $ 3.79 3.23 112.24 Phosphate rock (33% PnOsj western point, although the cost will probably be Grinding rock6 0.55 1.78 1:99 $ Sulfuric acid (100% Hesod 12.07 2:b7 31.02 1.59 19.01 50.52 substantially higher tilan that of Florida, TeI1Total cost of materials .. .. 545.04 .. 527.65 73.44 nessee, or western wet process triple superphosConversion Power kw.-hr. 0.01 115 5 1.15 71 $ 0.71 1.90 phate. This comparison emphasizes the imporLabof,’ operating a n d super.. .. 2.66 .. 1.64 4.35 tance of direct shipment of a product from the vision .. 2.00 .. 1.23 3.26 Labor maintenance .. 0.46 1.22 manufacturing point to the retail outlet. Each Labor: laboratory and office 0.75 Evaporation, steam per ton i : 05 1 :.87 . 0.44 1.96 i:i5 , . intermediate stop and reshipment adds materially General plant expense .. .. Maintenanoe materials .. 1.50 .. 0.93 2.46 t o the cost because the transportation charges Depreciation (over-all), 7.5% .. ., 4.11 .. 2.54 6.73 are much higher per unit on short shipments than 1.02 2.71 Insurance and taxes, 3% .. .. 1.65 .. ~Total cost for conversion .. .. $16.21 .. 010.01 26.56 on the long hauls. Grand total .. .. $61.25 .. $37.66 .. The low cost of shipping elemental phosphorus a Based on recovery of 94% PnOa. per unit of PZOSequivalent offers some possibilib Total cost of grinding rock (per short ton) including depreciation. ties for delivery of this material to certain midwestern points for conversion into phosphoric acid close to established markets. From the figures given in Table X I 1 it appears that wet procI n considering any new development, however, it must be ess (unpurified) phosphoric acid produced a t a rnidwesterri borne in mind that there is a disadvantage in dividing an enterpoint may be expected to be a somewhat cheaper source of phosprise between two points. The extra overhead involved may be sufficient to offset the transportation advantages gained by phorus pentoxide than that derived from western elemental phosphorus shipped t o the same point. The higher purity of the shipping the more concentrated products. electric-furnace product would make it of greater value to the chemical trade, and there might be instances where the specific POSSIBILITIES OF SUPPLYING MIDWESTERN MARKETS WITH PRODUCTS DERIVED FROM WESTERN PHOSPHATES market for chemical phosphorus would be so associated with a need for phosphoric acid for tlie fertilizer industry that the The far western market alone, however, is not sufficient to be higher cost of electric-furnace acid would be justified. Obviously. highly attractive to new phosphate developments. Large exthe charges would be dependent, on specific conditions not subpansion of the western phosphate industry depends on its ability ject to adequate treatment in this paper. I t is recognized, to SUpply the large midwestern markets. I n this area, western however, that diversity of market outlets, as would be possible phosphates compete with those produced in Florida, Tennessee, and Texas. TABLE VIII. ESTIXATED COSTOF PRODUCING P z O AS ~ TRIPLE The important midwestern market for triple superphosphate SUPERPHOSPHATE (48% AVAILABLE Pz05j A T COLUMBIA OR may be served from several sources. The most probable alterhfT. PLE.4SANT, TENN. natives are as follows~

TABLE VII. ESTIMATED COST

O F PRODUCING AT COLUMBIA OR MT.

Pz06 AS PHOSPHORIC ACID PLEASANT, TENN.

2;

1::;

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Lvet process triple superphosphate produced in Salt Lake City or a t other western points 2. Furnace triple superphosphate produced in southeastern Idaho or western Montana 3. Wet process triple superphosphate produced in Florida using Florida rock, and gulf coastal sulfur 4. Wet process triple superphosphate produced a t a midwestern point, using Florida rock and gulf coastal sulfur 5 . Wet process triple superphosphate produced in Tennessee, using Tennessee rock and gulf coastal sulfur I n any case, the objeot is to get the product t o the retailer a t tlie lowest possible cost. In order to weigh the relative merits of these alternatives the estimated cost of manufacturing phosphoric acid and triple superphosphate in the West (9) must be compared with similar e.;timates for Tennessee, Florida, and midwestern producing piints. These latter detailed estimates are given in Tables V t o X, inclusive. By merely adding the freight charges to the production costs, t h e total delivered cost of phosphorus pentoxide in the form of either phosphoric aaid or triple superphosphate may be obtained for any given midwestern market. As specific exa nples, the cost of phosphorus pentoxide in triple superphosp h t e and phosphoric acid from various assumed sources laid

(From Tennessee phosphate rook and phosphoric acid derived from the sulfuric acid process; annual production of triple Superphosphate, 97,000tons) Capital investment Real estate $ 10,000 Buildings 6 18,000 Equipment 223,000 _ _Total s551,000 Unit Cost -Per Short Ton of ProductTriple _Superphosphate p206 Total Ton Quantity Cost Cos; Cost Raw materials Phosphoric acid (8570 37.66 0.55 $20.71 $43.15 83.62 HaPOd a Phosphate rock (33% p l o s j o , 45 1.71 3.56 6.87 Grinding rockb .A2 1.00 - - - _ 0.25 _ 1.00 $22.67 $47.23 91.49 Total for materials Conversion Power kw.-hr. O.’Ol 8 S 0.08 S 0.17 0.32 .. 0.36 0.75 1.44 supervision Operating and Labor, maintenance .. .. 0.27 0.56 1.08 .. .. 0.26 0.55 1.07 Labor, laboratory a n d office .. 0.10 0.21 0.47 Maintenance materials General plant expense .. .. 0.10 0.21 0.47 Depreciation (over-all), .. ,. 0.65 1.35 2.61 7.5% 0.26 0.55 Insurance and taxes, 3% Total operating cost .. $ 1.86 S 4.35 8.5 Grand total .. ,. 824.07 $51.58 100.00 a I n actual practice more dilute acid is employed. b Total cost of grinding (per short ton) including depreciation.

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TABLE IX. ESTIMATED COST OF PRODUCING PzO5 AS PHOSPHORIC ACID (85% HsP04) IN MIDDLEWEST (From Florida pebble phosphate, 33% PzOe, by sulfuric acid method; annual production, 33,000tons PnOa equal t o 53,400tons 85% HoPOd Capital investment (exclusive of rock-grinding plant) Real estate $ 10000 Buildinsrs 500:OOO Equipment 1,300,000 Total $1,810,000

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with phosphorus to either the chemical or fertilizer trade, would be of considerable importance in the long range stability of the industry. UNDEVELOPED POTENTIALITIES

I n the second article of this series (9) i t was pointed out that potassium metaphosphate could be shipped more cheaply per ton of plant food T i __. nit (P~06 and &O) than other fertilizers. This prod% -Per Short Ton of Product"of uct offers attractive possibilities as a fertilizer, Short PzOa HaPo4 Total Ton Quantity Cost Quantity Cost Cost especially on certain soils in the midwestern and R a w materials north central states which are deficient both in Phosphate rock (33% PzOs) 2 52 $ 8 14 $ 5.02 10.16 Freight, rock to Middle West 7:14) 3.23 23:06) 1.99 14.23 28.90 phosphorus and potash (7). The existence of natGrinding rockb 0.55 1.78 1.10 2.22 Sulfuric acid (100% HpSOd) 12.07 2.57 31.02 1.59 19.01 38.48 ural deposits of rock phosphate and potash salts Total cost of materials .. 5.80 $64.00 3.58 $39.36 79.76 in the same general area in the West makes this Conversion product worthy of further consideration if and Power kw.-hr. 0.01 115 $ 1.15 71 $ 0.71 1.43 Labor,' operating and super. ., 2.65 .. 1.64 3.32 when the technological problems involved in its vision manufacture are fully worked out and demonLabor, maintenance . . .. 2.00 1.23 2.48 Labor, laboratory and office 0.75 0.46 0.93 strated on a commercial scale. Evaporation, steam per tone 1.'05 1:87 1.96 i:i5 1.21 2.45 General plant expense .. .. 0.44 .. 0.27 0.54 The experimental development by TVA of a conMaintenance .. .. 1.50 .. 0.93 1.88 Depreoiation, 7.5% .. .. 4.11 .. 2.54 5.14 tinuous process for conversion of the extremely 1.02 2.07 Insurance and taxes, 3 .O% .. .. 1.65 .. active yellow phosphorus to the relatively stable Total cost for conversion . ., $16.21 . $10.01 20.24 red phosphorus also has intriguing possibilities. Grand total *. . $80.21 $49.37 100.00 By this means it might be possible t o further reBased on recovery of 94% PaOs. b Total cost of grinding rock (per short ton) including depreciation and taxes. duce the high transportation cost of elemental c Per ton of steam derived from average coal a t $5.00 per ton assuming efficiency of 50%. phosphorus from a western production point to a distant market, In its shipping characteristics pure red phosphorus is comparable with sulfur a n d TABLEX. ESTIMATED COSTOF PRODUCING PzOsAS TRIPLE SUPERPHOSPHATE (48y0AVAILABLE P z O ~IN ) MIDDLEWEST a good case mibht be made for a similar freight ( F r o m Florida pebble phosphate and phosphoric acid derived from sulfuric acid process; rate. Comparison of base rates (1946) for a 1500annual production of triple superphosphate, 97,000tons) mile shipping distance shows about 0.5 cent per Capital investment Real estate 9 5,000 ton-mile for sulfur as against 1.7 cents per mile Buildings 618,000 Equipment 223,000 for yellow phosphorus. Such freight savings, if reTotal $846,000 alized, would warrant considerable investments cost -Per Unit Short Ton of P r o d u c h yo in conversion of the phosphorus to the more stable Triple of form. __ Pros S r r t - Superphosphate Total Ton Quantity Cost Quantity Cost Cost The occurrence of vanadium and other minor R a w materials 1.15 $56.60 80.29 in association with the western phosphate 0.55 $27.15 Phosphoric acid (85% H a p 0 1 ) ~$49.37 Phosphate rock (33% PzOs) 2.52 1.13 2.35 3.33 rock justifies further investigation of methods for 7.14 0:45 3.21 Freight, rock to Middle West 0:94 6.69 9.48 Grinding rockb 0.55 -220.25 ,. ___ 0.52 0.74 their recovery as by-products from the manuTotal for materials .. "O0 $31'74 2'09 $66.16 93.84 facture of phosphates. The technology of recovConversion Power, kw.-hr. 4 0 .01 ., 8 0.08 $ 0.17 0.24 ering vanadium from wet process phosphoric acid Labor, operating and super, . .. 0.36 .. 0.75 1.07 already has been developed and preliminary work vision Labor, maintenance .. . . 0.27 0.56 0.79 Labor, laboratory and office .. .. 0.26 .. 0.55 0.78 of the Bureau of Mines indicates that there are Maintenance supplies .. .. 0.10 .. possibilities of its economic recovery in the therGeneral plant expense .. .. 0.10 .. Depreciation (over-all), 7.5% .. .. 0.65 .. .35 1 90 mal reduction processes. By-product credits, Insurance and taxes, 3% .. .. 0.26 .. 0.55 0.78 $ 2.08 . $ 4.35 6.16 which in the case of vanadium might be considTotal (operating) .. . Grand total .. . $133.82 .. 870.51 100.00 erable, could alter the relative competitive posia In actual practice more dilute acid is employed. tion of a particular manufacturing process or b Total cost of grinding (per short ton) including depreciation. plant location. These are only illustrative of possible technological advances which may have a significant effect on the development andutilizationof thelargewesternreserves of phosphate rock. DELIVERED COSTPER TONOF PLANT TABLE XI. ESTIMATED FOOD ( P ~ 0 6 AS ) TRIPLESUPERPHOSPHATE DELIVERED TO CONCLUSION CLINTON, IOWA, FROM VARIOUS SOURCES This analysis of the potentialities of the western phosphates Wet ElectricProcess, Furnace leaves much to be desired because the situation is still more or Salt Process Wet Wet Wet Lake Southeast& Process Process Process, less in a state of flux. Conditions vary widely from one point City Idaho Midweak to another in the vast western phosphate area. A number of Manufactuling cost per ton s52.21 $62.85 $47.16 $70.51 $51.5B the conditions essential to an expanded industry are not yet Transportatiun 21.32 21.32 22.21 10.84 16.90 realized, Especially important undeveloped potentialities are cost per ton low cost power at the phosphate mines, large scale coke production Total bulk cost at 981.35 midwestern renear the mines, and developed sources of sulfuric acid. As more tail outlet per complete knowledge is gained of the character and availability of ton the raw materials and energy sources, a more comprehensive and 1

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COSTAT MIDWESTERN POINT OF Pz06 TABLE X I I . DELIVERED IN LIQUIDPHOSPHORIC ACID DERIVED FROM WESTERNPRODUCED ELEMENTAL PHOSPHORUS (Compared with cost of PZOSi n wet process acid produced locally) Acid Derived from Electric-Furnace Wet Process Acid Phosphorus Produced Produced Locally in Idaho Cost of manufacturing $80.21 $74 19 Cost of transportation 14.41 Cost of conversion ... 6.00 ___ Total $80.21 $94.60

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exact analysis may be made. Moreover, the history of freight rate structures indicates clearly t h a t with the development of new industry and the shipment of large tonnages of products, downward adjustments of freight rates may be justified and approved. Obviously, such adjustments will vitally affect the ultimate economic picture. I n the light of present knowledge and experience, however, the following general conclusions concerning the future of the western phosphate appear warranted. 1. Both the thermal reduction and sulfuric acid methods for manufacturing concentrated phosphate products from western rock offer opportunities for greatly expanding a n already established western phosphate industry. 2. Concentrated products manufactured from western rock by these processes may be expected to serve the far western area more economically than ordinary superphosphate derived from either eastern or western phosphate deposits. 3. Concentrated phosphate fertilizers manufactured from western rock by the wet process may be expected to compete in large midwestern markets with similar products derived from Tennessee and Florida rock. 4. Concentrated phosphate fertilizers produced in the West

Vol. 42, No. 2

by the thermal reduction process mag be expected to be more costly than concentrated phosphates produced in the East by the sulfuric acid process. 5. Concentrated phosphates provide a much cheaper source of plant food t o consumers in the Midwest than do ordinary superphosphates; western produced (wet or thermal process) concentrated phosphates may be expected t o compete readily with ordinary superphosphate in this area. 6. Triple superphosphate may be expected to be produced more cheaply by the sulfuric acid process than by the electricfurnace process in the western area. 7. Since elemental phosphorus carries a much lower freight rate per unit of PzOb than concentrated phosphoric acid, the logical procedure for obtaining this acid a t points of consumption far distant from the phosphate rock deposits would bt to ship elemental phosphorus t o such points and cGnvert it into phosphoric acid close to established markets wherever the volume of business would justify dividing the enterprise. BIBLIOGRAPHY

(1) Bell, R. E., U. S.Dept. Interior, Bonneville Power Administra-

tion, Rept. Preliminary Analysis of Western Phosphate Industry (1946). ( 2 ) Bell, R. E., and Griffith, D. T. Ibid., Transportation Costs as They Affect New Phosphorus Industries in the West (1947). (3) Madorsky, S. L., and Clark, K. G., IND.ENG.CHEM.,32, 244-8 f19401. (4) Illehring, A. L., Wallace, H. M., and Drain, Mildred, J . Am. SOC.Agronomy, 37, No. 8 (rlugust 1945). ( 5 ) U. 8. Dept. Agr., Bur. Chem. Soils and Agr. Eng., Rept. Nutrient

Status of Soils in Commercial Potato Producing Areas of Atlantic and Gulf Coast (1946). (6) Ibid., Production and Marketing Adm., Rept. Fertilizer Consumption and Estimated Annual N e e d s in U. s. (1947). ( 7 ) U. S. Dept. Agr. Fertilizer Rev. (May-June 1948). (8) Wagganian, W. H., and Bell, R. E., ISD. ESG. CHEM.,42, 269 (1950). (9) I b i d . , p. 276. REC~IVE February D 23, 1919

Prediction of s rinkage i Addition Polymeri J

FRANK S. NICHOLS AND RALPH G . FLOWERS Apparatus Department, General Electric Company, Pittsfielcl, M a s s .

A

method of predicting, from its structural formula, the per cent shrinkage of a vinyl- or allyl-type monomer during polymerization is described. A curve shows the relation between shrinkage and volume of revolution of the monomer molecule about its major axis. A method is given whereby this volume may be readily calculated.

T

HE fact t h a t vinyl-type monomers shrink considerably dur-

ing polymerization is well known, but a search of the literature discloses very few quantitative data on this phenomenon. Before the advent of thermosetting resins such as diallyl phthalate and copolymers of unsaturated alkyds, the principal use of vinyl resins was in the form of thermoplastic molding powders, where the shrinkage during polymerization was of no importance. T l i ~ preparation of castings by polymerization of the monomer in a mold was restricted almost entirely to preparing sheets of acrylictype resins and work on dental prosthesis. I n the past few years, however, the availability of thermosetting polyesters has opened up a large field of casting and low pressure laminating with these resins. Here, the shrinkage is of vital importance; first, because

in casting it is necessary to allow for shrinkage in calculating mold tolerances, and secondly, because in the production of castings and laminates of any but the smallest sizes, the shrinkage sets up stresses which may result in cracks or voids in the product. This study was therefore undertaken in an attempt to correlate the degree of shrinkage with some easily ascertainable property, thus permitting the prediction of the degree of shrinkage. Knowing this shrinkage, it would be possible t o select an appropriate monomer for a particular application without the necessity of screening a large number of possible monomers. I n a paper describing the shrinkage obtained in polymerizing ring compounds, Tobolsky el al. ( 4 ) point out that the shrinkage in a vinyl-type polymerization is connected with the exchange of a van der Waals bond and a double bond for two single covalent bonds. It would seem likely, then, that there is an approximately constant shrinkage which can be assigned t o a difunct'onal group when i t polymerizes. The per cent shrinkage should, therefore, be directly related t o some molecular quantity. Although data for shrinkage are not generally available (except for proprietary copolymers of undefined compositions), the litera-