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By William F. Ward

One often reads of the rich placer gravels in many of the citnoe-trav-elqd rivers of South America. The apparent richness of these gold-bearing gravels impresses the traveler, and in fact he may see batea after batea showing enough colors to figure over a dollar per cubic yard. These workings are called "playas" from the Spanish word playa, meaning shore or beach. Many workings have been reported in tropical rivers, but to my knowledge no dredge has made a success in such deposits. Investigation generally shows that the area of richness is limited and especially that the depth of the rich concentration is hardly ever more than a few inches. The Cauca river in Colombia, South America, is noted for its many rich playas. This river rises near .Popayan in the southern part of Colombia, flows north through a narrow valley between parallel mountain ranges and empties into the Magdalena river near Maganque. , The airline distance between source and mouth of this river is only about 500 miles. The rainfall is large and the lower Cauca appears to be about the size of the Missouri river in the United States. From its mouth up to Valdivia, in the State of Antioqua, it is navigable. Above Valdivia is a narrow gorge, above which the river is again navigable for some distance. The part of the Cauca where the play a panning is most noticeable is from Valdivia down to where the Nechi river enters the Cauca, a distance along the river of about 100 miles. The current in this part is swift, so that the stern-wheel river steamers make the trip with some difficulty. In the course of my work in this section of Colombia I have had the opportunity to make a study of several of these play a workings and will give in detail the conditions observed. The Island"Playa" The richest of the island playas is about 40 miles below Valdivia and a little below the old town of Caceres. The shape of the river and the location of the deposit are shown in Fig. 1, which indicates the condition at low water. The river at this place is about 600 ft. wide and the island about 75 ft. wide by 300 ft. long. The island is made up of coarse pebbles, some of which are as big as a man's head. In times of high water this island is under several feet of water and in a swift current. When the river lowers the current is still fast enough to prevent sand or silt from covering the coarse pebbles.

Jan 1, 1915

By C. E. Shoenfelt

The most important development in an otherwise colorless year in Colorado oil fields was the completion, late in 1933, of a well on Iles dome on the western slope of Colorado, with an initial production of 1100 bbl. of oil. No great amount of activity beyond the drilling of necessary offset wells is to be expected as a result of the completion of a well of this size because the acreage on Iles dome is closely held; there is no pipe line outlet other than to the Texas Company's small refinery at Craig, 24 miles distant; and the market for the oil is limited to the demands of sparsely settled communities in the high mountains. The Iles field is located on a large dome developed in Mancos shale of Cretaceous age, and having a closure of approximately 400 ft. The structure is highly faulted on the southern end. The first commercial oil well on this dome was completed by the Midwest Refining Co. on the south side of sec. 22-4N.-92W. Oil of 37" gravity was developed in Nancos shale at 2560 ft. and water in the Dakota sandstone at 2630 ft., but a considerable amount of additional oil was found in the shale immediately overlying the Dakota. From 2630 ft., the well produced in 16 hr. 750 bbl. of fluid, 33 per cent of which was water. Production in the Sundance sand of Jurassic age was found in the Midwest Refining Company's No. 4 Parkinson, in the NE.-SW.-SE. of sec. 22-4N.-92W., and completed on the last day of the year 1926, for an initial production of 450 bbl. of oil at a total depth of 3242 ft. The well completed in 1933 is also a Sundance sand producer and was finished at a depth of 3447 ft. It extends the productive area of the field about a quarter of a mile cast. The Iles field is said to have a potential production of 5000 bbl. of oil a day from its present wells, but for the past year has been held at about 600 bbl. a day. The most important test, stratigraphically, ever drilled on the western slope of Colorado is the California Company's No. 1 Raven, NW.-SE. of sec. 30-2N.-102W., which had an initial production of 138 bbl. of oil of 32" gravity, in the Weber formation (Pennsylvanian) between 5750 to 6315 ft. It mas drilled to 7137 ft., probably near the base of the Weber, and then plugged back to 6315 ft. It was shot quite heavily with nitro-glycerin, but failed to respond. While the well can hardly be classified

Jan 1, 1934

Manganese Resources in Relation to Domestic Consumption Discussion of paper by JOHN V. W. REYNDERS, presented at the Cleveland Meeting and issued, as Pamphlet No. 1656-C, with MINING AND METALLURGY, May, 1927. A. G. BETTS, Kinderhook, N. Y. (written discussion).-When a business concern hires an office boy, it takes on the first bright-appearing young chap to apply and pays him the prevailing rate of wages. One of the chief tasks the .office boy is supposed to be competent to perform, is to clean out the office. The manager of the business is highly competent in many lines, but for some reason lacks the ability to keep the office clean. To the steel man, it would seem that manganese is the office boy, and it is purchased just as found and offered to the purchasing agent. The steel mill is competent to perform many functions on a grand scale and with wonderful efficiency, but it is unable to make real steel. It is the function of the office boy, manganese, to do this. It is open to serious doubt if steel mill operators have ever taken seriously the metallurgy of the preparation of crude manganese. It has merely been found that some usable crude manganese may be obtained by running certain manganese ores through an iron furnace when not busy on anything else, or remote from iron ore, or with a lining that is about gone. It is, however, an entirely unwarranted assumption that the metallurgy of manganese has been worked out, or that the supplies of usable raw ore must be limited to materials of some specified analysis. There was a time when ores of copper, lead and zinc, for example, had to be rich and of specified analysis, to be usable, but the commercial raw materials of today bear little resemblance to such ores of the past. The discussions of manganese that I have seen are based on the assumption that the metallurgy of manganese is fully established and that the only usable manganese raw materials are of the kind used today. These discussions contain another error, not so much of statement, but of implication-that the tonnages of manganese materials in the United States are so much in this state and so much in that. When it requires a period of years and the expenditure of millions of dollars for a competent mining company to explore thoroughly a few acres of mining ground, is it not absurd to say that there are so many hundred tons of manganese ore in a certain state? This fact is not apt to be known fully in 10,000, years. I do not charge the mining engineers. who are on record, of making misstatements, because they merely say that so much

Jan 5, 1927

By A. Faison Dixon

In India the production of mica, which in other countries is of very minor importance, is one of the staple, long established industries, and ranks high in the statistics of mineral products. Nearly two-thirds of the mica of commerce comes from India. The Indians have used mica for glazing and decorative purposes through many centuries. About 14,000 men are employed in and about the mines, and the indigenous and primitive mode of mining is still followed; but, by reason of the exhaustion of the surface supply hitherto won without intelligence or capital, it will not be many years before the present interesting and casual methods will be replaced by a less archaic and more profitable system. India on the whole has little mineral wealth, but the unique resources of its mica-fields, cheap labor, and favorable natural conditions render it unlikely that any other country can ever more than temporarily contest her leadership in the production of this one minor but essential mineral. Mica plays a small but indispensable rôle in a variety of fields of dissimilar application. Its use and value depend upon characteristics which different kinds of mica have in varying degrees, each kind being adapted to its own special purpose. Its well-known characteristics of transparency, flexibility, elasticity, toughness, high dialectric strength, perfect flatness, ease of splitting into thin films, ability to stand high heat and sudden changes in temperature, give it value in many industries. No other substance, natural or artificial, has the same combination of qualities. The oldest use of mica is in glazing. By reason of the improvements in annealing glass, this is not now of great importance, but mica is still employed for the covers of ikon images in Russian churches, the windows of anthracite stoves, compass

Jan 1, 1914

By F. C. Blickensderfer

During 1914 and 1915, extensive experiments were conducted at the concentrator of The Detroit Copper Mining Co. of Arizona, at Morenci, Ariz., in order to test the relative grinding efficiencies of the Marathon, the Chilean and the Hardinge Mills. The Marathon mill used in the experiments was the first one ever built by the manufacturers; and since this was the first time that it was given a thorough tryout, with such remarkable results, the data have been assembled in the following paper and submitted in the interests of the milling profession. Description of the Flow Sheet The concentrator flow sheet, as it existed at the time of these tests, is shown in Fig. 1. The total mill feed, as delivered from the crushing plant, had as its maximum size 1-in. material. This material was screened dry on Cole Zig-Zag screens fitted with 4-mesh openings; the oversize going to one pair of coarse rolls, the undersize to five Wilfley tables fitted with Butchart National riffles. The coarse-roll product was elevated and screened wet on Zig-Zag screens fitted with 4-mesh openings, the undersize going to the five tables mentioned above and the oversize to one pair of fine rolls. The fine-roll product was elevated and screened together with the coarse-roll product; so that, before any concentrating operations took place, the total mill feed was reduced to pass a 4-mesh screen. After concentration on Butchart-riffled tables, the tailings from these tables passed to de-sliming hoppers, where two products were formed, viz., an overflow and a discharge. The discharge constituted the feed for the Chilean mills. It contained 16 per cent. slime (—200 mesh) and 3 parts of water to 1 of solids. The concentrator was equipped regularly with four Chilean mills (Monadnock type) to the unit; but, in order to

Jan 1, 1917

By C. V. Corless

We are living at a period of the world's history in which social phenomena are on so vast a scale, are of so profoundly soul-searching a nature, and are occurring in such rapid succession in the great world drama in which we are both actors and spectators, that, in our efforts to obtain a rational point of view in relation to them, our minds may fail to discern the simple in the complex and our understanding is liable to become confused or even overwhelmed. To the social student whose: scientific training has convinced him of the truth of the evolutionary law, Natura non facit salium, it is neither the vast scale of the events, their deeply soul-stirring nature, nor their rapid succession that matters so much, as the discovery of the underlying principle or law in accordance with which the disintegration and reintegration, which are the two aspects of social evolution, or indeed of evolution everywhere, are occurring. He is most deeply concerned in seeking an answer to the question: Have we in the present great and perplexing upheavals in human society, whether regarded in Central Europe, in Russia, in Great Britain, or in America, a really new cause at work, or, have we, though on a very large scale, merely new manifestations of the working out of an old principle? When we think of the appalling struggle in Europe, into which the world's greatest exemplar of democracy was finally drawn, no one has any hesitation in admitting that the great conflict was fundamentally a life-and-death struggle for self-preservation and self-propagation on the part of autocracy. The variations we meet with in the statement of the cause of the war arise mainly from differing distances of perspective; but in the last analysis all agree that the autocratic system of political gov ernment, which found its very soul and center in Prussian despotism, was consciously arrayed in a final "world-power-or-downf all" struggle against a love of freedom which was steadily widening and deepening throughout the world, and particularly throughout those parts of the world where this love of freedom and justice hasfound expressionin democratic institutions. It is not irrelevant to our discussion to recall in passing that this most imposing structure ever conceived by the human mind as an instrument of tyranny is lying today an irretrievable mass of ruins, completely over-

Jan 1, 1920

By A. P. Boller

In the victories of peace as well as of war, the science of engineering has played a prominent, if, indeed, not the leading part. While it might be interesting, and food for profitable thought, to trace the development of engineering from early times in its bearings upon the social betterment of mankind, it will be sufficient on the present occasion to suggest a few thoughts that it is hoped will aid the unprofessional listener to an appreciative consideration of the subject-matter laid down for to-day's discussion, and possibly lead the professional brother to a higher conception of the profession to which he belongs. Since the advent of the railway era, it is difficult to grasp the sequence of historic events that have led to the wondrous derelopment of mechanical science, making possible the civilization that is our daily boast, and opening up a vista of future intellectual and moral advancement among the nations of the earth, 'before which the imagination becomes hopelessly lost. Even now, looking back over a period of only half a century, we often fail to realize the vast change in the relations of individuals and nations to each other., brought about by the results of those mechanical discoveries which, having made the whole world kin, exercise a resistless levelling influence that bears fruit politically in the spread of republican ideas, and morally in the elevation of the individual through the facilities given to the dissemination of Christian ideas and general intelligence. In this view, it seems almost like a work of supererogation for a body of representative men of one department of that science to which the whole world owe. so much, to meet here at the centre of our national life to plead not only for a practical recognition of the national importance of the work to which their lives are devoted, but also for national aid, on a scale beyond that of private effort, to the end that mechanical science may be carried to a higher plane than ever yet attained, each step on the way being of material benefit to every man, woman, and child in the community. Possibly this is strong language, but none too strong when we consider that the work for which we plead is one affecting not only vast scientific and commercial interests, but also human life, to a degree little ap

Jan 1, 1882

By Nicholas J. Grant, Klaus M. Zwilsky

EVER since the unusual high temperature creep resistance and structure stability of SAP (Sintered Aluminum Powder) and similar aluminum-alumina alloys were reported,'," there has been a need to determine whether other metal-metal oxide (or other hard stable particle) alloys, not so ideal as the Al-Al 2 O 3 system, would show similar high temperature strength and stability. Of the many possible methods of obtaining a metal-metal oxide alloy,a one that offers many practical and theoretical advantages is the simple mechanical blending of metal powders with hard stable particles, followed by pressing, sintering, and hot extruding. With this purpose in mind copper powder and silica and alumina were selected for experimentation because these materials are readily available, cheap, reliable, and lend themseives te the simplest processing and testing. Starting Materials—Two sizes of electrolytically deposited copper powders were used, a —200 mesh powder referred to as A powder in this investigation and a —325 mesh powder referred to as C powder. Silica was added in the form of pure Potter's flint from which a —10µ fraction had been separated. Alumina of the a variety was used in two size ranges. The first was a —10µ fraction separated from a coarser aggregate, the second a commercial product of 0.3µ average diam manufactured by Linde Air Products. Preparation of Powders—Five-hundred gram batches of A copper with 1, 3, and 10 volume pct of each of the three oxides mentioned above were prepared, as well as C copper containing 1, 3, and 10 volume pct of —lop silica. Powders were weighed out carefully and blended by ball milling in air for 24 hr. Since this treatment resulted in surface oxidation of the copper, the charge was hydrogen reduced at 260°C for 5 hr. The next step consisted of hydrostatically compacting the powder into a shape suitable for the required hot working. For this purpose a slug about 11/2 in. in diam and 31/2 in. in length was produced by placing the mixed powders into a rubber sleeve, holding in a perforated steel canister, and rubber stoppering at the ends; the assembly was then subjected to a hydrostatic pressure of 50,000 psi. The air was evacuated from the assembly prior to pressing in order to prevent

Jan 1, 1958

By W. L. Freyberger, R. B. Booth

Froth flotation is a chemically induced method for beneficiating or up- grading an ore, which utilizes a layer or column of froth as a separating medium to segregate and remove the valuable minerals from the worthless gangue components of a finely ground ore suspended in water. The object of this chapter is to discuss the theoretical aspects of froth formation, the various frothing agents employed in flotation, and the effect of chemical structure on froth formation, and to correlate these factors with flotation technology. The flotation method of separation is conducted in three main steps: 1) selective chemical modification of the surface of specific mineral particles to effect floatability or nonfloatability; 2) contact between air bubbles and mineral particles, the selective adherence of floatable minerals to these bubbles, and the rejection of nonfloatable minerals; and 3) separation of the floatable minerals from the nonfloatable minerals. As indicated above, these three operations are achieved by the use of chemicals. Frothers play their most important role in the second and third steps by influencing particle- bubble contact and by affecting the degree of separation obtained in the froth column. Frothers, as defined by flotation operators, are compounds that are used specifically for the purpose of creating a froth in a flotation separation. How- ever, some collectors produce froths that are adequate for some flotation operations. Although this chapter is chiefly concerned with the specific frothers used in flotation, some discussion of frothing collectors is included. Otherwise, collectors (or promoters) and modifiersare not discussed at length; for information on these types of flotation chemicals, the reader is referred to other sections of this book or to other sources.l HISTORICAL DEVELOPMENT OF FROTHING AGENTS Historically, there are two distinct phases in the development of frothing agents and other flotation chemicals: 1) 1860 to 1920-oil flotation, and 1921 to date-chemical flotati0n.2~3 Early in the first period, large quantities of fatty and oily materials, up to 10 to 20% of the weight of the ore, were used as a means of separating the sulfide and oxide components from the gangue minerals in ore pulps. Later, various gases replaced these large quantities of oil as a buoyant and separating medium, decreasing oil requirements to less than 1% of the weight of the ore. With this reduction in oil

Jan 1, 1962

By E. L. Bruce

The district of Patricia, in the province of Ontario, lies northwest of the Albany River and extends northward to Hudson Bay. Formerly this was the unorganized district of Keewatin, the southern part of which was divided in 1912 between the provinces of Manitoba and Ontario. The interprovincial boundary now runs north from Lake of the Woods for 275 miles and thence northeast 375 miles to Hudson Bay. This district is comparable in size to all the older part of Ontario south of the Canadian Pacific Railway east of Lake Huron—thus it is roughly one-third of the whole of the present provincial area. The central part of this great triangle is one of the least accessible parts of Canada. From it streams flow southward to the English River, southeastward to the Albany, northward to Hudson Bay and the Hayes River, and westward to Lake Winnipeg. None of the streams is large and canoe travel is not easy. The only industry it has ever had is the trade in furs. Until the development of the airplane on a commercial basis, the only means of travel was by canoe or dog-train. There is not a mile of railway in the whole district. The two areas to be dealt with lie in the southwestern part of Patricia. Red Lake is 50 miles east of the Manitoba boundary and 75 miles north of the transcontinental railway from Cochrane to Winnipeg. Woman Lake is 50 miles farther east and slightly farther north. The late Dr. D. B. Dowling, of the Geological Survey of Canada, visited Red Lake and spent some time there during his exploration survey from Lac Seul to Berens River in 1893. He also visited the Woman Lake basin during the same journey, but his examination of it was much less detailed, the great area covered by him during the one field season making it impossible to make more than a hurried reconnaissance. Some prospecting in the Red Lake district followed Dowling's exploration, but the distance from railway was too great for any systematic work to be done. In 1922, following the usual plan, the Ontario Department of Mines made a geological reconnaissance of the English River, following :in instrumental survey of that river and its lakes by the Department of Lands. A side trip was taken to examine the rocks of Red Lake described

Jan 1, 1928

By Walter Miller

Although confident of its ability to meet any demands that may be made, the petroleum-refining industry is not complacent about the situation and realizes that the quantities of petroleum products to be furnished are so enormous and so far beyond what was previously estimated that the full cooperative effort of the industry must be exerted. Establishment by the President in May of the Office of Petroleum Coordinator for Defense with Secretary of the Interior Ickes at its head, plus the formation of the Petroleum Industry Council for Defense, in November, provide the channels for united endeavor within the industry and the means for gearing that endeavor in full harmony with the nation's needs. Great strides have been made and a rapid understanding of the situation and the magnitude of the task is being attained by all concerned. Refining, by constant study and development, by willingness to experiment and install new processes, and to replace older plants with more efficient equipment, had kept on a high plane of efficiency and progress. Working under the free competitive system, it built up its establishments until, as expressed in last year's report, it was easily able to supply any domestic demand that might be placed on it. Turning the United States into the arsenal not only of itself but of the united nations resisting aggression, however, in- creased the call for practically all petroleum products and in particular 100-octane aviation gasoline and high-viscosity aviation lubricating oils. Refining Capacity With over four million barrels a day of crude oil being charged to stills at the year's end, oil refining had broken all records and faced the necessity of further increasing its size to supply the ever-increasing demand for products, some of which, like 100-octane aviation gasoline, were research laboratory curiosities a few years ago. Although the refining capacity of the United States is listed at 4,860,000 bbl., about 800,000 bbl. of this is economically unavailable because of plant location or type. To meet the increasing needs, additional capacity of another half million barrels may have to be built in suitable locations and designed with an eye toward maximum production of aviation gasoline but with inherent flexibility to make it possible to vary and interchange with production of motor gasoline, furnace oils, and other products as necessity dictates. An interesting side light on this refining capacity question was an enquiry from official Washington for knowledge as to any idle refineries of something of the order of 10,000-bbl. daily crude capacity that might be purchased for bodily removal to Russia. 100-Octane Aviation Gasoline Largest of the tasks confronting refiners at the year's end was that of raising

Jan 1, 1942

TO THE BOARD OF DIRECTORS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS Gentlemen -The Institute was founded 54 years ago "with the object of promoting the arts and sciences connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained" At least once a year it is well to take stock of our assets, review our performance and determine how well we are now carrying out the purposes of our Founders There can be no question as to the work the Institute has done and is doing in promoting the arts and sciences in the fields of mining and metallurgy One needs only to contiast the methods, the labor and the costs of a half century ago with those now to visualize how far we have gone in the development of accurate technology and sound economics in mineral and metal production The great mines, mills and smelters of the present, handling individually thousands of tons per day, would have been impossible except for the accumulation of knowledge, the development of theory, and the improvement in practice that has charac¬terized the period since the foundation of the Institute The United States has prospered in the last half century greatly, and this has been due not merely to the possession of great natural resources, but to these resources being reduced to possession and put to work The absence of customs barriers and the freedom of trade across the whole width of this great continent has been an important factor in the growth of our wealth Unrestricted interchange of goods has permitted each citizen to draw on the resources of the whole country However, these are but subsidiary causes of prosperity The free interchange of scientific and technical data, by making the whole body of facts and theory available to each worker, has made this quick and unrivaled development possible In promoting this free trade in knowledge the Institute may claim a large place without fear of denial The 72 volumes of TRANSACTIONS, the special volumes, the bulletins and the other pub¬lications that have been issued, include a store of knowledge of the arts and sciences related to the pioduction and use of metals and minerals not duplicated elsewhere The large list of foreign members-1746 in number-few of whom ever have opportunity to attend meetings and all of whom derive their main benefits from membership through the pub-

Jan 1, 1923

By Walter Miller

Although confident of its ability to meet any demands that may be made, the petroleum-refining industry is not complacent about the situation and realizes that the quantities of petroleum products to be furnished are so enormous and so far beyond what was previously estimated that the full cooperative effort of the industry must be exerted. Establishment by the President in May of the Office of Petroleum Coordinator for Defense with Secretary of the Interior Ickes at its head, plus the formation of the Petroleum Industry Council for Defense, in November, provide the channels for united endeavor within the industry and the means for gearing that endeavor in full harmony with the nation's needs. Great strides have been made and a rapid understanding of the situation and the magnitude of the task is being attained by all concerned. Refining, by constant study and development, by willingness to experiment and install new processes, and to replace older plants with more efficient equipment, had kept on a high plane of efficiency and progress. Working under the free competitive system, it built up its establishments until, as expressed in last year's report, it was easily able to supply any domestic demand that might be placed on it. Turning the United States into the arsenal not only of itself but of the united nations resisting aggression, however, in- creased the call for practically all petroleum products and in particular 100-octane aviation gasoline and high-viscosity aviation lubricating oils. Refining Capacity With over four million barrels a day of crude oil being charged to stills at the year's end, oil refining had broken all records and faced the necessity of further increasing its size to supply the ever-increasing demand for products, some of which, like 100-octane aviation gasoline, were research laboratory curiosities a few years ago. Although the refining capacity of the United States is listed at 4,860,000 bbl., about 800,000 bbl. of this is economically unavailable because of plant location or type. To meet the increasing needs, additional capacity of another half million barrels may have to be built in suitable locations and designed with an eye toward maximum production of aviation gasoline but with inherent flexibility to make it possible to vary and interchange with production of motor gasoline, furnace oils, and other products as necessity dictates. An interesting side light on this refining capacity question was an enquiry from official Washington for knowledge as to any idle refineries of something of the order of 10,000-bbl. daily crude capacity that might be purchased for bodily removal to Russia. 100-Octane Aviation Gasoline Largest of the tasks confronting refiners at the year's end was that of raising

Jan 1, 1942

By G. D. Van Arsdale

THE paper of Mr. Posnjak presents a laboratory confirmation of the well known facts that air ox-idation of pure solutions of ferrous sulfate is slow and difficult and that, like many other similar reactions, the speed, may be greatly accelerated by the presence of other substances, often in very small amounts, the effect of the presence of copper being determined ex-perimentally in this case. However, it should not be. overlooked that copper is always present in heap leach-ing solutions in amounts equal to or greater than those in the experiments described; therefore the paper may be considered as an explanation of present results rather than a possible improve-ment to be added to present practice. It is not practicable and it does not pay to precipitate copper by ce-mentation below a point about 5 lb. per 1000 gal., equivalent to about 0.0005 mol. Cu. per liter, compar-ing with the approxi-mately 0.0009 mol. per liter of curve 2 in the diagrams given of course, also, in the heaps local concentrations are usually very much higher than this, which is also true of the effluent li-quors, so that I feel that it is safe to say that copper is already present in amount sufficient to realize, as large an accelerating effect as is practicable. Too much im-provement or refinement cannot be expected in a method of this kind, due to commercial limitations. It should be remembered that chemically and physically there is no sharp dividing line between leaching in place, heap leaching, and the usual tank leaching practice, practi-cally the same reagents being used in all three. From the viewpoint of extractions, etc., it is not common sense to apply leaching in place to an orebody carrying enough copper to pay for mining; and the same is true of heap leaching, for an ore carrying enough to pay for the crushing, handling, etc., of ordinary leaching. That is to say, leaching in place should properly be consid-ered only for an ore too low-grade to pay for mining, and heap leaching for the next higher grade, still how-ever too low-grade to pay for crushing and other re-finements. There is no advantage in leaching without mining or in heap leaching except lower cost of in-stallation and handling; on the other hand there are very distinct disadvantages which are inherent and which should prohibit their use except where necessity requires. The object of metallurgy is to make money out of the handling of ore, and it is purely a question of money as to how far we can go in "improving" or

Jan 7, 1927

"The richest hill on earth" had its start as a placer gold camp in 1864. The gold was quickly worked out but then silver was discovered in the copper ores in Butte Hill. After ten years as a silver camp, rich copper ore was found in 1881 and the future of Butte was assured. In the early 1960's, the Anaconda Company began the shift from underground mining at Butte to open pit mining of the enormous, low-grade copper deposit surrounding the old high-grade veins which had been worked for over eighty years. Their first primary crusher was a 66 in. by 84 in. (168 m by 2. 13 m) jaw crusher. The pit was expanded at such a rate, however, that its location became endangered. Additionally, the new Clyde Weed concentrator had been built at Butte; and in 1969 construction of a new gyratory installation was started. The primary crusher at the Clyde Weed concentrator is one of the most unusual primary crushers ever put into operation. At times, the ore from the Berkeley pit contains large amounts of timber, pipe, rails, and so forth left in the ore body from the old underground mining operations; and the crusher installation had to be designed so this tramp material could be readily removed ahead of the crusher. Ore is delivered by 100- and 150-ton trucks to two side-by-side dump pockets, each with a capacity of 400 tons. Originally, a hydraulic grapple was installed on the dividing wall between the dump pockets; but it was found that oversize boulders large enough to block the discharge opening at the bottom of each hopper were rapidly covered with other material, and the grapple was unable to reach and remove the large boulders causing the blockage. In addition, the grapple was located in a quite vulnerable position; and it sustained damage from being struck by rock dumped from the trucks. Oversize boulders are now blasted. Underneath each pocket is a vibrating grizzly feeder with the grizzly bars set at 4 in. (102 mm). These feeder-grizzlies are 84 in. (2. 13 m) wide and 32 .ft (9. 75 m) long, with grizzly sections 16 ft (4. 88 m) long. Approximately 75% of the ore passes through the grizzlies and grizzly oversize then drops onto two parallel 6 ft (1. 83 m) wide picking belts. The belts are 3 in. (76 mm) thick and rest on idlers supported by air- filled rubber shock absorbers. At the side of each picking belt is a hydraulic grapple which is used to remove timbers too large to be removed by hand. At times, four men are used to remove timber and tramp iron. Timbers are dropped onto a transverse belt conveyor which discharges into a truck stationed outside the primary crusher building,

Jan 1, 1978

By Donald M. Liddell

From a commercial standpoint, the only beryllium mineral warranting attention is beryl, 3Be.Al2O3.6SiO2, which is of fairly widespread occurrence. The chief deposits are in Brazil, Argentina, India, Canada and Portugal. When pure this contains about 14 per cent of beryllium oxide. The mineral richest in beryllium is phenacite, (BeO)2SiO2, or beryllium orth-osilicate, which contains 45.55 per cent beryllium oxide when pure, and if anyone is ever fortunate enough to discover a large deposit of it, it will revolutionize beryllium metallurgy. Gadoljnite, zBe0.Fe0.2Yz0~.zSi0~, is also often referred to as a beryllium mineral, though the occurrences are comparatively scant and it is of more interest as a source of yttrium than it is of beryllium. There has been a good deal of talk recently regarding some occurrences of helvite in the United States. Helvite is a complex manganese-iron beryllium silicate and, apart from difficulties that would arise in its treatment because of its compo-sition, the beryllium content of the known deposits is not high. Early Metallurgy The elemcnt beryllium was first isolated by L. N. Vauquelin in 1797.~ He crushed and heated beryl, having the idea that this heating made it more readily amenable to attack by chemicals, and then mixed the mineral with three times its weight of caustic potash and fused the mixture. The melt after cooling was dissolved in hydrochloric acid: dehydrated, and again taken up with hydrochloric acid and filtered to separate the silica. The filtrate was treated with an excess of potassium carbonate and the precipitate after draining was leached with a solution of caustic potash, which dissolved the alumina. The undissolved material was, in Vauquelin's own words, "une terre nouvelle." He dissolved the precipitate with nitric acid and evaporated it to dryness, took up with hydrochloric acid and threw the iron out with potassium hydrosulphide, though he found that to make a complete separation of the iron involved a second treatment. The solution, after throwing out of the iron, had a pronounced sweet taste, and though Vauquelin always speaks of working on "terre du beril" he suggests that the new element should be known as "glucine" (glucinum) from the Greek word for sweet, because of this outstanding property. Vauquelin did considerable work on the comparison of aluminum and beryllium, working out a separation of most of the aluminum based on its precipitation as alum. His work is reviewed at some length, since ordinarily his procedure is incorrectly stated. It will also be recognized by those who have studied beryllium metallurgy that a good many technicians have followed his ideas since, including preheating the beryl before treatment. The fusion with

Jan 1, 1944

By Lester C. Uren

Tars paper reviews the industrial trends and changes in educational concepts that have led to the development of the modern petroleum engineering curriculum. A trend toward emphasis on engineering fundamentals is noted. While most universities are committed to the traditional four-year engineering program, it is agreed that more than four years is necessary for academic preparation of the petroleum engineer in all phases of his profession. The author proposes a coordinated program of undergraduate and graduate training that will permit of adherence to the general pattern of the present four-year engineering course, with provision for extension of the program into specialized graduate courses of professional character. In the latter, emphasis may vary with the interests and objectives of the individual student. A specific undergraduate curriculum is proposed in which upward of 80 per cent of the available time is devoted to engineering fundamentals. A broad survey of the professional field is afforded in courses grouped in the third and fourth undergraduate years, but detailed treatment of the professional aspects of petroleum engineering is reserved for the graduate program. INTRODUCTION Of necessity, engineering curricula must ever be changing to reflect the new techniques, the changing concepts that are presented as the engineering industries develop and unfold. Particularly is this true of the younger engineering curricula representing comparatively new and rapidly changing industries such as the petroleum industry. Institutions that planned their petroleum engineering curricula a decade or two ago now find that the petroleum industry has become vastly more technical in its requirements. En¬tirely new methods and techniques have come into vogue and must be given place in the curriculum, and some of these are of a character that demands changing emphasis in the fundamental preparatory subjects. College and university faculties cannot complacently assume that curricula in this field that were considered appropriate 10 or 20 years ago still reflect the needs of the industry that they are designed to serve. If they do, their graduates will be poorly equipped to meet the requirements imposed upon them by a rapidly changing industry. Perhaps it is not too much to expect academic authorities to anticipate the trends of industry and equip their graduates with what they will need to attain leadership 10 or 20 years after graduation. Whether or not this desirable objective is possible, there is no excuse for allowing curricula to fall behind the current needs of industry. DURATION OF CURRICULUM The majority of our engineering schools and colleges still adhere to the four-year curricula and there appears to be a definite sentiment among many engineers engaged in industry that work should be so planned that the engineering student may secure the essential academic preparation for his profession in a terminal four-year program. Yet, in recent years, it has become increasingly apparent that four years of

Jan 1, 1941

By Robert Bosworth

THE liability for damages to the surface caused by subsidence is an ever present threat in all underground mining. In ordinary lode mining, this threat rarely materializes into an action, due to the method of mining metalliferous ores, the dip of the veins, and the nature of the ground itself. In the mining of coal, however, this threat is very real. The coal frequently lies close to the surface, in beds underlying large areas of land of which the surface is suitable for agricultural or urban development. Furthermore, the coal is generally mined by the "room and pillar" method and when the pillars of coal are removed, the subjacent support is destroyed. This question of the duty of surface support has now become a very live one in Colorado. What was waste prairie land a few years ago has become valuable agricultural land dotted here and there with growing towns. Frequent references will be made here to Colorado conditions and adjudicated cases, but those conditions and cases and the conclusions to be drawn therefrom are applicable to all coal-mining states. Briefly stated, the question is "Does the owner of the substrata or underlying mineral owe any duty of surface support to the owner of the superjacent strata or surface?" There is -no absolute duty of support owed by the mineral owner and this assertion is made with full knowledge of numerous expressions to the contrary by courts of Pennsylvania, Illinois, Colorado and other coal-mining states. Whether or not any duty exists depends upon the circumstances surrounding each case, and since in the nature of things those circumstances are rarely identical, there can be no absolute rule.

Jan 1, 1928

By William Phillips

THE possible sources of potash salts in the United States have been considered from many points of view during the last several years, but it is only within the last two or three months that the situation has become acute. We import from Germany, the only source of large supply, more than $10,000,000 worth of potash salts annually, and this business has been badly crippled by the European war. If there was ever a time in our industrial existence when the necessity of providing for our own needs was more acute than it is now, we are not aware of it. One has only to study the price, lists of chemicals sent out by the large supply houses to see the change wrought within a very short time. Whether or no these prices are to maintain for a considerable time, no one can say; but it appears to be probable that we shall not see prices materially lower for a period of uncomfortable length, to say the least. It is not my purpose at this time to discuss the various sources of supply of potash salts that have been suggested or recommended. Some of them might afford a pleasing relief but all of them combined would not affect the situation seriously. If we are to have our own sources of potash salts, they will have to compare, in some efficient manner, with the sources upon which we have drawn during the last 20 or 30 years; i.e., they must exist-in minable quantities. It seems to me to be quite idle to speculate upon our domestic sources of potash if those sources are not of a character similar to those upon which we have so long depended. A few thousand or, perhaps,, a few hundred thousand dollars' worth of chemically derived 'potash may be produced under the stress of present conditions, but when we consider that each year demands more than $10,000,000 worth, we must look to underground sources; we must look to mines similar to the famous Stassfurt and Halle deposits. If we cannot mine potash salts, we shall have to do without them for a while.

Jan 2, 1915

By John J. Croston

The year 1935 witnessed one of the world's oldest industries—gold mining—attain the stature of a billion dollar business. Preliminary estimates indicate that somewhat over 30,000,000 oz. of gold was produced, the largest output ever recorded and exceeding the previous year by more than 11 per cent. Of this huge total the Witwatersrand field produced about 10,800,000 oz., compared with 10,480,000 oz. in 1934. Russia was apparently the stellar performer, and from incomplete data it appears that between five and five and a half million ounces were produced by the Soviets compared with 4,200,000 last year and 2,814,000 in 1933. The United States nosed Canada out of third place with a production of 3,546,000 oz. against 2,916,000 in 1934, while Canada increased her total from 2,965,000 to 3,291,000 oz. Similarly, gains of lesser magnitude were made in Australia, the Gold Coast and other countries. As a result of great activity in developing outlying areas on the Rand, and the great number of new companies building mills in Canada, Australia, the Gold Coast and the United States, the years 1936 and 1937 should see new high records, as these new producers will more than offset any decline in the older properties. The whole world has become "gold conscious" during the past three years. It has been the subject of innumerable articles by economists and others, but, unfortunately, because of their lack of actual mining knowledge, they have treated the production of gold as a static affair, ignoring geological and technical factors. It is hardly necessary to draw attention to the fact that the world's gold-mining industry was slowly but steadily shrinking in importance, owing to the gradual depletion of known deposits that were profitable to work at costs existing prior to 1929. The International Geological Congress at Pretoria and the League of Nations Committee drew attention to the estimates of the mining experts of the various governments predicting a steady falling off in world production. On the Rand there

Jan 1, 1937