properties of the coke quite as much as to the precise uses to which the product is put. Not all foundry coke, for example, finds its way to foundrymen. In the beehive-coke trade furnace coke is commonly 48-hour coke, and foundry coke is supposed to be 72-hour coke, which commonly comes in larger, longer, and harder pieces than furnace coke and is selected with more care to prevent the loading of the soft pieces and black ends. To compensate for this extra work and for the heavier capital charges resulting from the longer coking time, foundry coke commonly sells at 50 cents to $1 a ton more. (See Table 44.) Under the actual conditions of the market the distinction in coking time is not always observed, and some so-called foundry coke is ordinary 48-hour furnace coke from which the soft pieces and black ends have been thrown out. In the manufacture of by-product coke the universal practice of crushing the coal before coking and the facilities for screening and sizing the coke permit more precise definition of grades. In terms of size by-product furnace coke is run-of-oven coke from which the breeze and all small coke of less than say three-fourths inch in diameter have been removed. By-product foundry coke is a blocky coke whose maximum size is much greater than that of furnace coke and from which all sizes under 22 to 3 inches are screened out. Domestic coke includes all sizes of approximately 3 inches and under, exclusive of breeze. It may result from the screening of foundry coke or even furnace coke, or where the principal demand is for domestic coke it may be obtained by crushing the larger fragments. Knowing that some furnace coke and considerable foundry or domestic coke is sold for other than metallurgical use, the Geological Survey in 1923 added a question to its schedule asking for the quantity sold "for other industrial use." The replies, tabulated in Tables 35 and 36, are probably incomplete. ACKNOWLEDGMENTS This report is based upon statistical returns by the producers of coke, for whose generous and continuing assistance thanks are cordially extended. Special mention should be made of the courtesy of operators of by-product coke plants in supplying monthly returns of coke output. The railroads have furnished weekly reports of cars of beehive coke loaded, which have been indispensable in preparing the current estimates of production of beehive coke and bituminous coal. (See Tables 5 and 6.) For the statistics of imports and exports the Survey is indebted to the Bureau of Foreign and Domestic Commerce, from whose records they have been compiled by J. A. Dorsey. The statistics of world production of coke in Table 56 have been assembled by W. I. Whiteside. All the other tables have been compiled by the junior author under the direction of the senior author. NEW FEATURES IN THE PRESENT REPORT Certain innovations in the present report should be noted here. For the first time statistics are presented of the quantity of byproduct coke loaded for shipment on each railroad and waterway (Tables 54 and 55, pp. 475-477). Like the corresponding tables for shipments of beehive coke, these figures are based not on records of the railroads but on reports from the producers of coke. A change has been made in the form of reporting sales of coke. Operators have been requested to separate sales of furnace coke into "sales to affiliated corporations" and "merchant sales." Again, an inquiry as to the "sales for domestic and other use," as distinct from furnace" and "foundry," has been subdivided to read "sales for domestic use and "sales for industrial and other use," the last heading excluding, of course, blast furnace and foundry coke. The changes in the form of the figures resulting from these changes in the statistical schedule of inquiry will be clear from Tables 35 and 36 (pp. 458-463). ACCOUNTING PRACTICES OF COKE OPERATORS THAT AFFECT THE STATISTICS The term "value," as applied to coke in the reports of the Geological Survey, means the value at the ovens. For that part of the output that is sold the value is obviously the amount received for the coke f. o. b. ovens. But a considerable proportion of the coke produced in the United States is made in ovens operated by large corporations that not only mine the coal and make the coke but also operate blast furnaces and steel mills that consume the entire product of the ovens. Under such conditions the fixing of a value upon the coke and upon the coal consumed in making it is purely arbitrary. By some corporations the coke is charged to the furnace department at cost; by others a percentage of profit is added or the reported value is based on what the coke would cost if purchased. In the statistics published by the Geological Survey the value assigned to that part of the output produced but not sold has not always been arrived at in the same way, and therefore the figures of total value of all coke produced are not strictly comparable from year to year. Prior to 1918 each operator was asked to place his own value on his entire production, including coke used at the plant but not sold. In 1918 and again in 1920 the value of this part of the product was estimated by the Geological Survey by assigning to the coke produced but not sold in each State a value per ton equal to the average receipts for the coke sold in the same State. In 1919 and again in 1921, 1922, and 1923 the Survey asked the operator to place his own value on the coke used but not sold. These changes in the form of inquiry must be borne in mind in considering Tables 3, 35, 36, and 40. These differences in accounting practice also affect the relative proportions of the output reported as "sold" and as "used by producer.' Between the blast furnaces, which are the largest users of coke, and the coke plants there exists a close business relation, which in many plants amounts to identity of ownership. Among such affiliated interests the line between sales and interdepartmental transfers is difficult to draw, and a large part of the furnace coke reported as sold actually goes to iron furnaces that are in some way connected with the coke companies. (See Tables 35 and 36.) THE COKE-PRODUCING INDUSTRIES SUMMARY Coke is produced in the United States by a group of four industries, which are related in the sense that the product is to some extent interchangeable but which are sharply differentiated as to location, method, equipment, and organization. Besides that produced in the familiar beehive and by-product ovens, coke is obtained in the refining of petroleum, in the manufacture of coal gas, and in the refining of coal tar. Petroleum coke may be dismissed with a few words. In refining crude oil there is often an ultimate residue in the form of a porous, carbonaceous mass. Its properties are much like those of coke made from coal, except that it is finer in texture, lacks the strength required for metallurgical coke, and is extraordinarily low in ash. The production of petroleum coke in recent years, according to statistics collected by the Bureau of Mines, has been as follows: Petroleum coke produced and in stock in the United States, 1917-1923, in net tons In the coal-gas industry, as in petroleum refining, the coke obtained is a by-product. The process of carbonization is essentially the same as that in by-product ovens, though the type of oven is different. The coals used are selected for their yield in gas rather than for their coking qualities, and the coke formed is too soft for foundry or furnace use. It is, however, well adapted to the manufacture of water gas, a fact which has led to the common association of coal-gas and water-gas plants. Thus, out of 2,877,787 tons of gas-house coke produced in 1922, 51.8 per cent was used in making water gas, in heating retorts, or for boiler fuel about the plant where it was produced. The remainder, 1,387,658 tons, was sold, largely as domestic fuel, for $12,032,244. Neither petroleum coke nor gas-house coke is adapted for metallurgical purposes, the use which consumes the great bulk of all the coke produced. Practically, therefore, the coke trade is concerned only with beehive coke and by-product coke, and to them the statistics of this report are confined. Although their product is interchangeable, there are fundamental differences between the beehive and by-product industries which must be kept in mind in examining the tables of this chapter. The competitive relations between the beehive and by-product industries have been discussed in previous reports of the Geological Survey and need not be treated here. 'U. 8. Geol. Survey Mineral Resources, 1918, pt. 2, pp. 1446-1447, 1921; idem, 1921, pt. 2, p. 374, 1923. Permanently higher prices for coal and gradually expanding markets for the by-products continue to foster the development of by-product coking, and the manufacture of beehive coke assumes more and more the character of an auxiliary agency called upon to furnish only the peak requirements of the metallurgical industry in times of active business. Between the coal-gas and the by-product coke industries the line is increasingly difficult to draw. Adaptation of the by-product oven to the needs of city gas manufacture has brought into existence a number of installations of by-product ovens as a part of existing gas utilities. Still other coke plants that are financially independent of public utilities nevertheless supply gas under contract to publicutility distributors. From one point of view these plants are a part of the manufactured-gas industry. But considered with reference to coke-oven design and the technique of coke manufacture, and still more significantly with reference to the supply and demand for coke, they belong to the coke industry. In the practical operation of a by-product coke plant the fact that the gas may be sold to a public utility and distributed through the city mains is of less consequence than the fact that the coke must be marketed in competition with other coke for foundry, furnace, or household use. For the purpose of this report all installations of by-product ovens are included as a part of the by-product coke industry, and plants manufacturing coal gas and coke-oven gas on the same premises have been asked to make separate reports for these two branches of their business. The statistics here presented will therefore differ from the tabulations of the Census Bureau, for example, which classifies such installations of coke ovens as a part of the manufactured-gas industry. On pages 798 and 799 of Mineral Resources for 1922, Part II, will be found a summary of the output of manufactured gas and byproducts from all sources, including both coke ovens and coal-gas, oil-gas, and water-gas plants, from which the relation of the by-product coke industry to other methods of gas manufacture may be seen. The principal statistical facts of the coke industry in 1923 are presented in Table 1. |