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By Erwin S. Sperry

The presence of small amounts of tellurium in certain binds of copper, and its exceptionally deleterious* influence in producing red-shortness of this metal, led the author to conduct a few experiments on the influence of tellurium on the properties of brass. While these experiments were not intended to be exhaustive, they demonstrate that, as far as the rolling of brass is concerned, tellurium, unless it occurs in far greater amounts than exist in refined copper, cannot be called an injurious impurity. In comparatively large amounts it appears to impart cold-shortness to high-brass. Tellurium, the rare element that it is considered to be, has recently been extracted on a large scale from the slimes of an American electrolytic copper-works. They have, in attempts to discover some commercial use for it, sent it out promiscuously and gratuitously in quantities which would lead the young chemical student to fancy that a rare element exists only in name. Through the courtesy of Mr. R. L. Whitehead, of Baltimore, the author was able to obtain somewhat over 2 lbs.,? and use it in quantities which, at the market price, would be prohibitive. In order to add specific quantities of tellurium to brass, a rich alloy of copper and tellurium was previously made. The method was as follows, viz.: Nine and one-half lbs. of Lake copper were melted un-. der charcoal in a new plumbago crucible, and then pound of tellurium was added in small portions at a time. The mixture was stirred with a plumbago-stirrer and poured into

Jan 1, 1903

By R. C. Allen, Ralph Arnold

The writers have no new system and no new principle of taxation to propose. The general subject of taxation is as old as governments are and as familiar to taxpaying Americans as the general thesis on the inalienable rights of man. We believe, therefore, following the committee of the National Tax Association, that improvement in the general conditions of taxation, including mine taxation, maybe brought about mainly through a better adjustment of known and tried principles and methods of taxing to modern complex forms of property and income, and that not much is to be expected from abandonment of experience for new ways and means, methods and principles, should anything new be discovered, which in our opinion is very doubtful. The committee referred to has constructed the general framework of its Model System of State and Local Taxation1 on familiar forms of taxing, by eliminating some that ' have proved bad, suggesting improvements in others, and adopting the best, leaving plenty of room for the accommodation of the general plan to the varying conditions of taxation in the several states. Unfortunately, the taxation of mines is dismissed by the committee with the statement that the subject has been reassigned for further investigation and report by a special sub-committee, frankly recognizing that the peculiar difficulties of this phase of the subject require special study and investigation. Much may be hoped for from the labor of this sub-committee if the problem is approached from the viewpoint of recommendations already published. In this paper, the writers state their opinion on some of the broader aspects of mine taxation with too little attention to the grounds on which they rest. Contrary to inclination space requirements compel them to resort to summary statements without adequate discussion for a satisfactory presentation of the whole subject. All they can do is to qualify the witnesses and record the testimony. The senior writer was introduced to the practical aspects of the subject of this paper in 1913, when, as State Geologist of Michigan, he was

Jan 1, 1920

By Dean F. Winchester, C. D. Johnson

The so-called Rocky Mountain region is here made to include Colorado, Idaho, Montana, northern New Mexico, Utah and Wyoming, an area of great distances and relatively sparse population. Conditions of distance, transportation and markets have had their retarding influence on devolopment and production but the increase in facilities and markets in recent years has provided additional incentive for more thorough search for new productive areas and the more complete development of the known fields. The low prices of crude during the past year have offset, to a certain extent, the desire for increased production and much of the effort has been directed therefore to outlining new areas rather than to attempts to increase production from known fields and thereby add to the already sufficient supply above ground. During the year just closed the Rocky Mountain region has seen consistent efforts to outline new areas and these efforts have been reasonably successful. In this area a very large part of the land is government property, and by cooperation between the government, the private owner and the company it has been possible to carry on development in a scientific manner, providing for the maximum recovery of valuable products at least cost and at times when prices were best. Due to the fact that in the Rocky Mountain region costs of exploration and development are relatively high because of natural circumstances, it has been the policy of operators to drill test wells only on structures where they controlled a large proportion of the land. Even community lease programs have been effected in certain areas, thus obviating the necessity of offset drilling and the attendant uneconomical and even wasteful production. Oil production in the Rocky Mountain states has shown a slight increase during the year, the average daily production for November being 78,124 bbl. as against an average in January of 76,681 bbl. The total production during the first 11 months of the year, according to the U. S. Burcau of Mines, was as follows:

Jan 1, 1929

By H. P. Greenwald

THE rapidly increasing use in coal mines of portable auxiliary fans, which are generally "blowers" employed in connection with canvas tubing, raises questions concerning the hazards of such equipment, especially where the practices are opposed to established methods of ventilating face workings. Half a dozen or more coal-mine explosions and some fires have been attributed to the use of auxiliary fans; moreover, competent mining engineers have found many dangerous installations and methods of use-for example, intermittent running of the fans in gassy mines with consequent accumulations of firedamp at the faces. These facts have led the U. S. Bureau of Mines to issue this recommendation: "In the interest of safety, the Bureau of Mines, Department of Commerce, recommends that auxiliary fans or blowers should not be used in coal mines as a substitute for methods of regular and continuous coursing of the air to every face in the mine." The comparatively recent introduction of new types of mining machines, mechanical loaders, face conveyors, and slabbing machines has encouraged the trial of new systems of face mining, all of which have for their object the rapid advance of the faces. Although the latter has certain economic advantages, in gassy mines the rate at which gas is given off is generally found to increase in proportion to the speed of advance into new territory, which in turn increases the difficulties of efficient ventilation of the face workings. Some of the systems of advance mining being tried in connection with new mechanizing methods practically compel the use of blower fans and tubing, as single narrow places are now driven, 300 ft. or more without crosscuts. In some instances a series of parallel headings are driven without crosscuts pre-

Jan 1, 1928

By H. P. Greenwald, H. C. Howarth

The rapidly increasing use in coal mines of portable auxiliary fans, which are generally 'blowers" employed in connection with canvas tubing, raises questions concerning the hazards of such equipment, especially where the practices are opposed to established methods of ventilating face workings. Half a dozen or more coal-mine explosions and some fires have been attributed to the use of auxiliary fans; moreover, competent mining engineers have found many dangerous installations and methods of use-for example, intermittent running of the fans in gassy mines with consequent accumulations of firedamp at the faces. These facts have led the U. S. Bureau of Mines to issue this recommendation: "In the interest of safety, the Bureau of Mines, Department of Commerce, recommends that auxiliary fans or blowers should not be used in coal mines as a substitute for methods of regular and continuous coursing of the air to every face in the mine." The comparatively recent introduction of new types of mining machines, mechanical loaders, face conveyors, and slabbing machines has encouraged the trial of new systems of face mining, all of which have for their object the rapid advance of the faces. Although the latter has certain economic advantages, in gassy mines the rate at which gas is given off is generally found to increase in proportion to the speed of advance into new territory, which in turn increases the difficulties of efficient ventilation of the face workings. Some of the systems of advance mining being tried in connection with new mechanizing methods practically compel the use of blower fans and tubing, as single narrow places arc now driven 300 ft. or more without crosscuts. In some instances a series of parallel headings are driven without crosscuts pre-

Jan 1, 1928

By F. L. Wolf

THERE is a tendency on the part of practical foundrymen to accept with reluctance the results of tests on sands, binders, and. such materials made in the chemical laboratory alone. They feel that such tests frequently emphasize and measure properties that are of minor importance and fail to take account of characteristics that are important in determining the value of the material in actual practice. Experience seems to indicate that the most thorough and conclusive, test for any new foundry material is an actual run in the foundry alongside of a standard material of known value. Such a test, however, involves certain difficulties and necessitates certain precautions. It is not always easy to obtain a fair trial for a new material. We all have certain prejudices, which unconsciously affect our judgment to a marked degree. A practical test frequently involves so many workmen, each of whom reacts in a different manner to the test, that; the personal equation becomes very, complex and the true results of the test are obscured. There are times, too, when a thorough experimental trial of a material would interfere too much with the rush of work in a department or would hazard the quality, of the product to such an extent as to make it inadvisable. Under such conditions a laboratory test is advisable before the material is sent into the foundry. These tests should be made as practical as possible and so closely related to foundry practice as to give a true index to the value of a, product for the purpose desired. Core sands and molding sands are as numerous "as the sands of the sea" and vary as much in quality. Old sources of supply are continually failing and new ones must be opened, so that we must continually search for new and better grades of sand. During the past year, the Ohio Brass Co. has developed tests for sands', cores, and binders which bear a close relation to the particular use to which these materials are put in

Jan 9, 1920

By Benjamin Talbot

(New York Meeting, February 1913.) THE problem of segregation and cavities in steel ingots is a subject which has given and is still giving metallurgists, en¬gineers, and operators matter for serious consideration.. This question has come more into prominence lately in the United States, clue largely to the desire of railroad engineers to secure a better rail than they have obtained in the past, as the service they demand is increasing in severity; and no doubt manufacturers will be able to meet what is required of them. The rails here are as good as those made in other countries, but the conditions of service and the extremes of climate are more severe and consequently more breakages occur. Various reasons have been advanced to explain why rails may not be as good in quality to-clay as in the past. Some engineers consider that modern methods of manufacturing, designed chiefly to obtain large output, tend to reduce the standard of excellence of more deliberate methods. Others think that 4-ton ingots are worse than those of 2 tons. Again, it is .stated that the 100-ton heat in one ladle is too large, and is a :step in the wrong direction in casting. My experience upon the question of the size of the ingot is that in rolling rails of from 85-to 100-lb. sections, the range of ingot is only practically such that the difference in the size does not help in the question of segregation, cavities, or blow-holes.

Jan 4, 1913

By A. L. Holley

THE members of the society are doubtless aware that the production of American Bessemer steel works is constantly increasing ; that the same converters and machinery are doing more work every year. This enlarged output is due to various causes, chiefly the following: 1st. Better organization-better knowledge on the part of both managers and men, of the plant and the process ; of the way to economize the more exhausting labor, and of the arrangement of the details of labor and operations so that they shall not conflict; also, more pluck-a greater willingness to take risks, or, more properly, such an intimate knowledge of the nature and capacities of the refractory tory linings in various stages of disrepair, and the probable be- . havior of the fluid metal at various stages of its treatment, that the precise nature of the risk may be better known, so that the works may be crowded to their full capacity. In the early practice, after getting four or five consecutive heats in a day, the men preferred to "let well enough alone," and to devote the remaining time to preparation for another turn. Now, thirty, and sometimes forty heats are regularly made during the twenty-four hours, day after day, without the frequent occurrence and without the fear of breakdowns or "messes," as the spilling of steel charges was graphically named in Sheffield. 2d. Although no new refractory materials have been developed, improved means of preparing such as we have, and of imbedding

Jan 1, 1874

By Reger, B. David

FOR many years, the belief that the so-called "Clinton" sand of Ohio might produce. oil and gas, if it could be reached, has been prevalent in West Virginia. To test this theory, many hundreds of thousands of dollars have been spent and several extremely deep wells, including the deepest boring of the world, have been sunk at various points. With the exception of one well now completed through the sand and the possible exception of another still in progress, all of these wells failed to reach the goal, either through failure of funds or through drilling accidents. REVIEW OF DEEP DRILLING The subject of deep-sand oil and gas in West Virginia has already been discussed by the author1 and by White.2 In these papers, it was shown that the Upper and. Middle Devonian shales, lying between the Berea oil sand (basal Mississippian) and the Oriskany sandstone (Lower Devonian), thicken steadily from eastern Ohio across northern West Virginia and Pennsylvania; but it was stated that the same rate of thickening did not occur in that part of West Virginia south of the Great Kanawha River and in the adjoining portion of Kentucky. In spite of this great eastward thickening, the fact that both the Oriskany and "Clinton" sands, the latter of which is equivalent to the White Medina of New York, exist in great thickness all along the Appalachian Mountains farther east, was held as proof of their probable presence in the deep Appalachian basin.

Jan 3, 1925

By Clemens Jones

An interesting paper by J. E. Merion and Edward Hart, in Volume I., No. 2, of the Journal of Analytical Chemistry, on the Decomposition of Blast-Furnace Cinder by Acid, describes a plan of sampling the cinder by means of a previously-heated iron bar thrust into the cinder car or into the cinder at the notch, and then allowed to cool, thus chilling the cinder which adheres to the bar, and rendering it decomposable by hydrochloric acid, of 1.12 sp. gr. A short series of results is given, from which the deduction follows that blast-furnace cinder " is decomposed perfectly when chilled." Where many silica determinations are to be made, this method, if reliable, would effect notable economy of time and reagents. The conversion of insoluble silicates by fusion with an alkaline carbonate, together with the subsequent solution, evaporation, drying, etc., is destined to remain the standard method. But all fusionmethods are time-consuming and expensive. Chilling appears to render the supplementary method available for all practical purposes, in the determination of silica in cinder. But, with a view of securing more evidence on the subject, and in view of the fact that uniform results were not obtained by employing this method, it was decided to test the method in the laboratory of the Thomas Iron Company where a large number of silica determinations are made. The experience met with may not be devoid of value, both theoretical and practical. Mr. Iles's paper, in the Chemical News, Volume L., 1881, doubtless suggested to several chemists, connected with iron metallurgical

Jan 1, 1888

The following is an incomplete list of members and guests who called at Institute headquarters between Nov. 10 and Dec. 10, 1917. Harlan H. Bradt, Duluth, Minn. Lt. Geo. H. Morgan. Albert Burch, San Francisco, Cal. F. W. Osborn, Ajo, Ariz. J. A. Daniel, Institute of Mining & Metal- J. C. Ray, 2d Lt., 0. M. C., N. A. lurgy, London. A. E. Ring, Creede, Colo. Martin Fishback, Benson, Ariz. Geo. B. Rodgers, Dobbs Ferry, N. Y. E. L. Foucar, San Francisco, Cal. Forest Rutherford, Pueblo, Colo. I. A. L. Henderson, Institute of Mining & J. G. Scrugham, Reno, Nev. Metallurgy, London. A. F. Shurick, Forest Hills, L. I., N. Y. Jerome A. Hilbert, Santa Monica, Cal. Arthur C. Spencer, Washington, D. C. B. B. Hood, Chrome, N. J. Robert C. Sticht, Mt. Lyell, Tasmania. J. C. Hoyt, Jerome, Ariz. A. Perry Thompson, San Francisco, Cal. A. F. Kennedy, Duluth, Minn. J. B. Tyrrell, Toronto, Canada. Paul S. King, Wilmington, Del. Thor. Warner, Phoenix, Ariz. Alfred C. Levis, Golden, Colo. S. F. Wellman, Cleveland, 0. A. F. Lucas, Washington, D. C. Gardner F. Williams, San Francisco, Cal. B. E. McKechnie, Sharon, Pa. W. G. Woolf, Salt Lake City, Utah.' A. N. Mackay, Barranquilla, Colombia. C. W. Merrill, San Francisco, Cal. P. G. Beckett expects to be located in New York for some time, and may be addressed care of the Phelps, Dodge Corporation at 99 John Street. Corey C. Brayton and E. R. Richards have temporarily closed their San Francisco offices in order to give more time to their operations at Midvale, Utah.

Jan 1, 1918

By Thomas A. Wright

No symposium on die casting could be complete without consideration of the methods of formula and impurity control. No consideration of control would be complete without discussion of that new tool of the analytical chemist and inspector, the quartz spectrograph. Just as there is an increased appreciation of the possible applications of the die-casting process and of die castings, so too is there, slowly but surely, of the spectrograph. At present the role of the instrument might well be compared with that of brass or magnesium die castings. Neither is as widely understood or known as they will be. Product specifications are increasing and are getting more explicit and often more rigid. The designer, metallurgist and production engineer or superintendent will be forced to depend more and more on the chemical laboratory. Sampling, as well as analyses, testing and inspection problems will grow. The chemical laboratory must meet its increased responsibility and use of the spectrograph will become more common. Advantages of increased precision, greater speed, lessened labor and often lower costs cannot be ignored. It will be the purpose of this paper in part to outline the respective fields of chemical and spectrographic analyses and to indicate where one may overlap the other and in part to indicate certain possible sources of contamination of zinc-base die-cast alloys in particular. COMPOSITION Aluminum.-Aluminum die castings are expected to conform to the specifications of the American Society for Testing Materials1† and the Society of Automotive Engineers2. The A.S.T.M. has recognized seven

Jan 1, 1935

Article IX of the Bylaws constitutes the basic instructions to the Nominating Committee The first duty of the Nominating Committee is to select a candidate for Director and President-elect It is desirable that the successive Presidents from year to year be men of differing professional interests so selected that over a period of years each major group in the Institute will be represented in the Presidency a number of times bearing some reasonable relationship to the numerical strength of that group in the Institute In Section 2 of Article IX it is stated that "a sufficient number of Directors be selected on the basis of geographical districts so that each district will have at least one representative" These districts, as now established, are shown in the accompanying map There are ten districts including the New York metropolitan district Each of these districts is entitled to one Director, except the metropolitan district which is entitled to six Each year each district, the term of whose officially recommended Director expires, shall suggest a candidate and if desired an alternate candidate to the Nominating Committee to fill the vacancy If a candidate and an alternate are suggested they should preferably have different Divisional or Branch affiliations The Chairmen of the Sections In the district shall constitute a committee to select the candidate or candidates The Sections shall rotate the chairmanship, as shown in the Appendix to this instruction It is desirable that in filling a quota vacancy in any district, the selection be made from the name or names suggested by the district

Jan 1, 1952

By Haim Chiswik

IN recent years considerable attention has been devoted to the devel-opment of new commercial uses for silver, chiefly because of lowered prices and large stocks of the metal. This has led to increased interest in the phase diagrams of silver alloys. The silver-lead diagram is reported' to be of the simple eutectic type, but no measurements of the solubility of lead in silver have been made. The solubility of silver in lead has been estimated2 from diffusion experiments and resistance measurements to vary with temperature from 0.09 to 0.18 atomic per cent (0.05 to 0.10 weight per cent). Silver-rich silver-lead alloys have recently been recommended as high-strength bearing metals.3 The silver-bismuth diagram is similar.' The solubility of bismuth in silver has been estimated to be about 5.5 weight per cent on the basis of X-ray work.4 Matthiessen5 found a solubility of silver in bismuth from 0.25 to 0.50 per cent by conductivity measurements. Silver and thallium form the same type of diagram,1 with no data on their mutual miscibilities. We have studied the first two of these diagrams by X-ray methods, verifying their main features and determining the solubilities of lead and bismuth in silver at several temperatures. We also determined the solubility of thallium in silver at one temperature. The solubilities of silver in lead and in bismuth were found to be too low to be detectable.

Jan 1, 1940

By C. S. Corbett

There is much comment at present in the ranks of the oil industry regarding unit operation of oil fields and the benefit that would accrue if it could be extensively applied. It seems certain that, as an immediate corrective of the present situation, overproduction could be effectively curtailed with all the advantages of proper conservation of petroleum resources and with no important loss to anyone connected with the industry. Unit Operation in Certain Foreign Fields Many an oil operator in America would doubtless like to have exclusive control of one or more oil-bearing structures for development in accordance with the economic position of the industry and especially in accordance with the best production practice known. A few operators now have this privilege, particularly in certain foreign fields, and are following lines of procedure which show that they are aware of the great opportunity that is theirs. We find in an article by Professor Strigeoff,1 and in a paper read by Captain Comins2 before the American Petroleum Institute, the outlines of procedure adopted, respectively, by the Soviet Government for the nationalized Russian oil fields and by the Anglo-Persian Oil Co. for its fields in Persia. Comprehensive plans for the unit operation of other oil fields may have been described publicly but no such descriptions have come to the attention of the writer. New fields are coming more and more into the hands of single operators or of a few who control large activities and who appreciate fully the need for cooperative action and are willing to forego the lure of a large quick profit from high flush production in order to secure the advantage of better stabilization in the industry and a larger though more deferred profit by operating the field as a unit. Much can be done toward efficient development of an oil field controlled by a few operators who are willing to cooperate for that purpose, but the best result can be obtained only by pooling their interests in the field

Jan 1, 1930

By John V. Beall

As recently as 1964, the situation in the Australian iron ore industry was chiefly one of potential. The only producer was the Broken Hill Pty. (BHP). That company mined about 5 million tpy from deposits in the Middleback Range in South Australia and at Yampi Sound in Western Australia. No ore was exported from Australia. Now, just five years later, and after expenditures amounting to approximately one half billion dollars, BHP and seven new companies exported about 15 million tons (long tons) of iron ore and pellets as well as meeting Australia's own annual requirements of approximately 8.5 million tons of ore. Early this year, the volume of iron ore on order stood at 328 mil- lion tons to be delivered over a period of 15 years, but Cliffs Western negotiations for sale of Robe River iron ore have boosted the volume to the new high of 466 million tons. All of this has meant a great deal to Australia in terms of new income. In fiscal year 1967 (ending June 30, 1967) exports of iron ore amounted to $52 million; in 1968, $128 million and by 1'972 the Bureau of Mineral Resources expects the value of exports from iron ore to reach $242 million. In achieving the position of major- supplier of iron ore to the Japanese steelmakers, it was necessary to build a great many new facilities, mostly in Western Australia. Three railroads, 70 miles long, 182 miles and 265 miles were constructed. A new port was created at Dampier; Port Hedland was deepened and otherwise improved; both of these ports are in Western Australia. In Tasmania, Savage River developers built an offshore shiploading station that has received the recognition of engineers internationally. At least a half dozen new communities have been founded. The narrow gage railroad from Kalgoorlie to Perth and Freemantle was replaced with a standard gage line.

Jan 6, 1969

By G. R. Fitterer

NonmEtallic inclusions in steel have received much attention by metallurgists during the past few years. Many investigators have been emphatic in stating their belief that these impurities are the chief causes of steel failures, while others think that their effects are negligible. One of the main reasons that definite information on the effects of these impurities is lacking is that no reliable method has been developed for the exact determination of the amounts of these different impurities in steel. Some valuable new information has been brought out by a reliable method for nonmetallic inclusions which has been developed at the Pittsburgh Experiment Station of the U. S. Bureau of Mines, in cooperation with the Carnegie Institute of Technology and the Metallurgical Advisory Board. This procedure satisfactorily extracts some of the more common inclusions from steels, thus enabling the investigator to correlate steel failures with inclusion content. Although the data given herein are the first to be published on the subject of the electrolytic extraction method, the interest in the subject is evidenced by the fact that it is already being used by some 20 to 30 steel companies for their various purposes. Some of the comments received from these laboratories indicate that the method is highly satisfactory: the unfavorable comments, when traced to their sources, have been found to be based on some small mistake made in either installation or operation. The chief discrepancy seems to have occurred in attempts to apply the method to the extraction of inclusions from alloy steels. The procedure can be used only for the plain carbon steels and for such low alloy steels as those containing the usual amount of copper (0.2 to 0.3 per cent). Steels containing the carbide-forming alloys such as chromium, tungsten, etc., present far too many difficulties for the accurate determination of inclusions. Luckily, the iron and manganese carbides do not offer any difficulties and no contamination of the oxide-sulfide residue results, It is highly probable that some modification of the following

Jan 1, 1931

By O. G. Bell

Development and exploratory work continued vigorously during 1933 in Southwest Texas and, from a standpoint of new production discovered, the new discoveries probably equal or may even exceed any previous year in the history of this area. While exploratory work has been general over the area much of it has been confined to two localities; namely, northern Duval-southern McMullen counties and Starr County. A persistent effort has been made to open new productive areas in northern Duval County and the adjacent part of McMullen County, occasioned primarily by the fact that the Government Wells group of fields in northern Duval County have been by far the best fields so far developed in this part of the state, and the possibility of being able to find new fields in the same general area under similar geologic conditions. This has resulted in the discovery of three new fields, Northwest Government Wells, Moca and Eagle Hill. In addition encouraging shows have been found in North Kohler, Hoffman, Smith-Hunter and the Ignacio areas with the prospect that continued exploratory work will develop some of these prospects into fields. Wildcatting in Starr County was the continued result of an effort to find a trend of production through the county southwestward from the older Reynosa Escarpment fields in Webb, Jim Hogg and Zapata counties. This same impulse has caused most of the wildcatting in Zapata County. New Fields Cuevitas.—During the early part of the year the Sun Oil Co. began some core-drill work on a block of leases in northern Starr County, then in June drilled a test which found production in the McElroy member of the Jackson at 2200 ft. Drilling in this field has continued but the productive area has not as yet been clearly defined. Seven oil wells and three gas wells have been completed. There is as yet no pipe line outlet for this production, hence no productive history of the wells has been

Jan 1, 1934

By J. D. Price, W. M. Bertholf

Making maximum possible use of available equipment and material, CF&I placed a high-efficiency, high-capacity washery unit in the existing buildings to gain simplified operation, reduced manpower requirements, raised efficiency, and boosted production. THE central washing plant of the Colorado Fuel & Iron Corp. was first operated in 1918 to furnish coal for two 60-oven batteries of Koppers design. Prior to that time the coke for the blast furnaces had been secured from a number of beehive operations, some with their own washeries. The original washery had four Elmore jigs, which did not do as well as had been expected. In 1923 the jigs were taken out and replaced by Deister Plat-O tables, with various changes in auxiliary equipment. In 1936 the throughput of the plant was considerably increased by the installation of vibrating filters for recovery and drying of fine coal, thereby reducing a large recirculating load of fine coal which passed through the screens of the Carpenter driers. In the late 1940's it became evident that something would have to be done to keep the washery abreast of progress at Pueblo and other washeries. Coal requirements were nearly two and one-half times the original requirements of the 120 small ovens, as additional ovens had been built in 1930, 1938, and 1945, whereas no additional coal washing capacity had been added since the 1936 modifications. Much of the equipment, moreover, had seen better days. One answer to the problem was to build a new and completely up-to-the-minute plant, with sep- arate sections for coarse, medium fine, fine, and very fine coal. On the other hand, it might be financially more profitable to place a high-efficiency, high-capacity unit in the existing buildings. The washing problem at Pueblo is not unique, but it is approached differently. There are no established specifications for coke ash and sulphur. The plant is operated on the principle that if it is more economical to wash it out than to slag it out, wash it out; otherwise, send it on to the blast furnaces. With coals at the Pueblo plant costing what they do, the benefits of washing at a low gravity are questionable. Hence the primary problem is to eliminate the high-ash components and retain all the low and medium-ash components. Sulphur is no problem at all, averaging 0.6 pct in the coke. Since a good proportion of the free impurity in the coals is as large as the coal or bone or larger, it appeared that it would be safe to go to jig washing and discontinue crushing the coal before washing, as had been the practice with the tables. This would boost the throughput. It might also decrease manpower requirements and washing costs considerably. It was assumed at the start and has been demonstrated in the first year of operation that a jig will do as well on the fines as the tables had been doing. It would not be necessary to discount any gains due to increased efficiency in washing the coarse material because of incapacity to wash the fines. By washing at —2+0 mesh it would be possible to dewater, by screening, a considerable tonnage satisfactorily, for example, at —2 + % or —2 + l/4, and then crush it in a hammer mill. The —?+20 could be dewatered in centrifugal driers and the remain-

Jan 1, 1955

By D. K. Bose, C. K. Gupta, K. U. Nair

A new approach to processing an indigenously available low grade molysulfide concentrate by chlorination with elemental chlorine in presence of oxygen is reported. Recovery of nickel and copper values associated with the sulfide concentrate by suitably treating the residue obtained after chlorination is also reported. In the chlorination process, a gaseous mixture of chlorine and oxygen in the volume ratio bf 2:5 has been passed at 1.66 x 10- 5 m3/s for 1800 s over a 0.01 kg batch of molysulfide concentrate at a temperature of 573°K. Most of the molybdenum has been volatilized as molybdenum oxychloride which has subsequently been extracted in water. The molybdenum value from the aqueous solution has been recovered in the form of calcium molybdate (CaO.MoO3) by treatment with calcium chloride (CaCI2). In an alternative processing scheme, the molybdenum rich solution has been treated with an oxidizing agent (K2S20f.J) and allowed to boil to recover a major portion of the molybdenum value in the form of molybdic oxide (MOOS). The spent charge obtained after molysulfide chlorination has been mixed with about 1 wt % sodium chloride and heated at 773K under an oxygen atmosphere. The reacted mass has been water-leached to yield a nickel-copper bearing solution with limited iron. The process liquor appears to be well suited for further processing by known hydrometallurgical recovery processes for nickel and copper. In the conventional process of molybdenum extraction, the molysulfide concentrate (-59% Mo) is first subjected to roasting to produce molybdic oxide. The oxide is then further processed in sequential steps involving vacuum distillation, ammonia leaching, and calcination to higher purity prior to hydrogen reduction to metal. In India there is at present some small tonnage production of molysulfide concentrate from a byproduct recovery plant of the M/s. Uranium Corp. of India Ltd. (M/s UCIL), Bihar. Efforts are being made at this laboratory to process the low grade fraction of the concentrate which contains sulfides of copper, nickel, and iron; quartz; and chlorites. Here, the conventional routes involving roasting and vacuum distillation appear unsuitable to produce an acceptable quality of molybdic oxide at high recoveries. Formation during roasting molybdates of some of the impurities present in the sulfide concentrate make subsequent vacuum distillation less efficient. In view of these problems, in earlier work reported from this laboratory the low grade concentrate has been processed hydrometallurgically to P. produce calcium molybdate. Starting from this molybdenum intermediate, processes have also been developed for the production of molybdenum and ferromolybdenum. Chlorination as an alternative to roasting for metal sulfides has been drawing considerable interest. The high reactivity of chlorine, the relatively low temperature of operation, the suitability of application to low grade resources, the convenience of recovering sulfur in non-polluting form, and the purity of chlorides which are separated by distillation all favor chlorination. In recent years, considerable work has been reported on the chlorination of common metal sulfides. In the field of molybdenum extraction from its sulfide resource, use of chlorination technology has been rather limited. Senderoff and Labrie3 were the first to chlorinate molysulfide concentrate with elemental chlorine at about 823°K to molybdenum pentachloride for use in the electrolytic preparation of molybdenum. The only other reported work, by Haver, Uchida and Wong, involved reaction between molysulfide and chlorine at 673°K to recover sulfur. The reaction products were, however, identified as molybdenum pentachloride and sulfur monochloride.

Jan 1, 1979