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By T. Sterry Hunt

IN my address on the " Geognostical Relations of the Metals," delivered before the Institute on the 20th of February last (Vol. I Transactions, p. 331), I spoke of the rocks in the vicinity of Thunder Bay, Lake Superior, where I indicated two series of uncrystalline rocks resting upon the Huronian schists, the lower one consisting of dark-colored argillites and sandstones overlaid, apparently in slight discordance, by nearly horizontal red and white sandstone and marls, which were compared with those of Sault Ste. Marie, and those of the Portage Lake district, on the south shore. These latter sand-stones, according to Brooks and Pumpelly, overlie unconformably the Keweenaw series of copper-bearing amygdaloids, sandstones, and conglomerates, and are in turn overlaid by the Trenton limestone. I then proposed to call this lower series of Thunder Bay, that is to say, the dark-colored argillites and sandstones which are traversed by the silver-bearing lodes of that region, the Animikie group. Shortly after the publication of that address I received an abstract of a paper on the geology of that region by Professor Robert Bell, read before the Montreal Natural History Society, February 24th. He there confirms the statement made in my address that the gold of Lake Shebandowan occurs in the Huronian, which is also seen to be cut by the silver-bearing lodes just mentioned. Professor Bell, in this paper, proposes to designate both what I have called the Animikie group, and the overlying red and white sandstones, by the name of the Nepigon group, for the reason that the upper series is best displayed about Lake Nepigon. This latter series is by Logan supposed to be overlaid by the copper-bearing amygdaloids with conglomerates and sandstones of the north shore (apparently identical with those of Keweenaw) ; and the whole together, including the Animikie group, constitute his Upper Copper-bearing group. These copper-bearing strata are by him supposed to be overlaid by the red and white sandstones of St. Mary, which are apparently the same with those sandstones which, according to Brooks and Pumpelly, overlie unconformably the similar cupriferous rocks of Portage Lake, and are, in their turn, overlaid by the Trenton limestone. Thus the sandstones which at Thunder Cape overlie the Animikie group are by Logan placed in the midst of the Upper Copper-bear-

Jan 1, 1874

By Norberto Dominguez

In the year 1820 a commission, assisted by Sr. C. Fernando de Ainada, was appointed by Sr. Jose Ramon Mila de la Roca to report on the condition of the mining region of Parral, in the State of Chihuahua, Mexico, where in recent years the mines of Batopilas have reached an important development under American management. The object of the inquiry was to provide Sr. De la Roca with facts to support a project for reopening mines that two centuries before had produced a large amount of silver. Although this plan failed, many facts of interest in the history of the mines were presented.. Much of the report dealt with questions that had only local application or were restricted to the conditions of labor and equipment in the opening of the nineteenth century. The historical part is presented in the following paragraphs: Abstract of the Report. Notwithstanding the difficulty of forming a just estimate of the system of mines in this mineral group in the valley of Senor Sail Jose del Parral without an examination of each of them, that which we shall say in a general way will suffice to convey an idea of their value and of the urgent necessity of reopening them. If this is undertaken, we believe the results will be of the highest consequence to the Republic, as well as to this immediate locality. The group of the Villa del Parral covers the mineral territory in which the village of that name was located. Its moantains contain large metallic veins, from which, as from the trunk of a tree, depend others much more slender, locally called ,fibras, crossing and interlacing each other in many directions. The first and oldest of these very rich deposits of gold

Jan 1, 1902

By Richard Bosustow, Van Dyne Howbert

The Presidio mine of The American Metal Co. is situated in the "Big Bend" region, some 45 miles over state highway south of Marfa, a station on the Southern Pacific R.R. It lies 20 miles by road north of the Mexican border, in semidesert surroundings typical of this general section of the United States and the adjoining part of Mexico. All supplies are hauled in by truck from Marfa under contract. The concentrates and precipitates produced by the mill are carried by the same trucks to Marfa, from whence they are shipped, respectively, to the El Paso and Selby plants. History The mine was discovered about the year 1880 and was soon thereafter taken over for development by some army officers stationed at Fort Davis, Texas. It was later operated by the Presidio Mining Co., which treated the ore in a small pan-amalgamation mill from 1883 until 1913, when a cyanide plant was erected which has been in continuous operation ever since. When the present company, a subsidiary of The American Metal Co., Ltd., took over the mine in April, 1926, the ore-bearing zone had been worked for about 2200 ft. to the east of I the outcrops down the dip of the formation, at which point it is at a I vertical depth of 500 ft. below the surface. Up to that time the mine had produced some 1,150,000 tons of ore averaging about 17 oz. silver. After a development campaign the company started milling again in February, 1927. Since then the production has been approximately 4700 tons per month of ore; of which the yearly average grade has varied from 19.7 to 23.2 oz. silver, $0.20 to $0.50 gold, and 2.0 to 2.5 per cent. lead. No other property in this district has ever produced tonnage of any importance.

Jan 1, 1931

By Persifor Frazer

(Read at the Wilkes-Barre Meeting, May, 1877.) A CLASSIFICATION of natural objects is usually based either upon some fundamental and permanent attribute of the thing itself (as in the case of scientific classifications), or it embraces one or more generalizations convenient for use in ordinary life. Thus, it suffices for the statistician to, know that so many tons of fish are annually taken by our fishermen, and that they realize so many thousands of dollars, whereas to the student of natural history the anatomy, habits, and relationships of the animals are of chief interest, as settling their respective places in the scale of animate nature. Many different classifications of coals have been attempted, as one would naturally anticipate from the immense extent of the coal trade, and the different localities whence the supply was derived. The English divisions were prevalent up to the date of the publication of the last geological survey of the State, except so far as they were modified by local designations. Indeed, Rogers' classifications made very little alteration in the English nomenclature, as may be seen by comparing. the tables given below. To commence with the different kinds mentioned in Ure's Dictionary of Arts, Manufactures and Mines of 1845 " 1. Cubical Coal.-Black, shining, compact, moderately hard and easily frangible. Comes out in rectangular masses, of which the

Jan 1, 1878

By E. H. Griswold, W. J. Wilkins

Pressure control of oil wells may be defined as the adjustment of pressures within a well to obtain the most efficient and economic utilization of the natural gas energy with a minimum of sand troubles or irregular water encroachment. The purpose of this paper is to present the methods used by the writers in applying pressure control and a discussion of the various effects occurring within the wells affected. The benefits to be derived from the conservation of natural gas energy have been so adequately discussed and demonstrated in prior papers by various engineers that the effects on ultimate production will not be discussed other than to mention a few representative cases. The detrimental effects of irregular edge-water encroachment and of sanding up arc of general knowledge to the industry. Effect on Ultimate Production One of the strongest objections voiced against pressure control is that of the danger or inadvisability of deferring oil production by cutting the rate of production. It has been our experience that such deferred product'ion is returned within a few weeks or months rather than years and that an increased cumulative oil production is obtained in the early life of the well by conserving the natural energy. In many cases the rate of production is increased rather than decreased by the adjustment of pressures to obtain the minimum gas factor. Fig. 1 shows the history of a Wilcox sand well in northern Oklahoma, which was pressure-controlled from completion. It is noted that during the early months while flowing naturally through the casing the gas factor was decreased rather than allowed to follow its natural tendency to increase. A string of 21/2-in. tubing was run to restrict the flow and resulted in a decreased gas factor with a more sustained rate of production. When first placed on gas-lift the gas factor again tended to increase, but after the proper pressure adjustments were made, remained approximately steady. It was necessary to defer 100 bbl. per day of oil production in order to maintain this low gas factor. In March serious

Jan 1, 1929

A special meeting of the Alaska Mining and Engineering society, held at Perseverance Mine of the Alaska Gastineau Mining Co. on Mar. 17, 1017, was attended by 46 members and about 80 guests, among whom were members of the Alaska Territorial Legislature. After an interesting trip through the mine in the afternoon, the members and guests assembled for dinner at the Perseverance Dining Room. After the dinner G. T. Jackson, assistant manager of the company, as president of the society, called the meeting to order. After the reading of the minutes, he welcomed the guests and then gave a short history of Perseverance Mine. B. L. Thane, manager of the company, briefly out-lined its general organization. The following papers were read-by members of the society and members of the staff of the Perseverance Mine: "The Organization of the Mine Staff and the Methods of Mining," by B. B. Nieding, Mine Supt.; "Tramming Equipment and Costs," by R. R. Van Valkenburgh; "The Surveying of the Mine," by R. L. Healey, Mine Engineer; "The Electrical Equipment of the Mine," by W. S. Pullen, Supt., of Power Supply; "The System of Mine Accounting, "by E. J. Doherty, Mine Accountant; and "The Mine Buildings," by D: J. Argall, Asst: Mine Supt. M. T. Tolch, Transportation Supt., described briefly the general transportation of the ore to the mill and the equipment used.

Jan 6, 1917

By A. W. Edelen, H. V. Lee

THE Teziutlan copper-zinc deposit is supposed to be of late Cambrian or early Paleozoic age. The country rocks are a series of schists or phyllites, flat lying and in the form of a plunging anticline. The ore deposit occupies a single horizon in the schist for a known horizontal extent of 1200 meters. Along its strike occur four large lenses or ore bodies. These ore bodies occupy positions along the flank and extend to the crest of the anticline. The primary mineralization is in the form of quartz, pyrite, sphalerite, chalcopyrite and galena, with a few scattered silver anti-monides. Quartz and pyrite form the mineralization between the ore lenses. In the ore lenses the sulphides appear as a massive, very he-grained intergrowth of minerals. The intergrowth suggests a contemporaneous deposition of the heavy sulphides. The grain size, usually under 0.09 mm., makes the separation difficult and fine grinding important. The ore bodies were formed at great depth by solutions probably originating in the same basic magma that gave rise to the dolerite sills that are so common in their vicinity. INTRODUCTION The Teziutlan copper-zinc deposit is distinctly different from other ore deposits of Mexico in age and type. Previously stated to be pre- Cambrian in age, it is now quite generally supposed to belong to the late Cambrian or to the early Paleozoic period. Also, in contrast to the usual shallow-vein zone type of mineralization in Mexico, there is here exemplified an intermediate vein zone deposit of copper and zinc. So far as is known, the Teziutlan vein is unique in the history of Mexican geology and in a class by itself, its closest counterpart probably being the copper veins of the pre-Cambrian of Canada. The Teziutlan district is in the extreme northwestern corner of the State of Puebla, Mexico. Teziutlan, the terminus of a branch line of the National Railways from Mexico City, is connected to the mine at Aire Libre by a 17-km. narrow-gauge railroad owned and operated by the Teziutlan Copper Co. Owing to excessive grades on this short line, Shay-geared locomotives are used for the transportation of concentrates and supplies.

Jan 1, 1937

By Dubois Eastman

BEHIND the contrasting liquid-fuel technologies of Germany and the United States lie the basic differences of scarcity and abundance. The chemists and engineers of each nation have developed processes that accommodate available raw materials. In the United States, processing is based on an abundant supply of petroleum, which is refined into a variety of fuels and lubricants. Germany has little indigenous petroleum but has a readily available supply of coal that can be converted into liquid fuels and lubricants. As a result, in Germany several basic processes have been developed for the conversion of coal into synthesis gas (carbon monoxide and hydrogen). In turn, this gas is processed into products. As a normal function of its researches into petroleum processing, the petroleum industry in the United States has made careful studies of various conversion and synthesis techniques. A number of oil companies are carrying out independent development programs with the aim of synthesizing hydro- carbon products that can be marketed at a price that will compete with the price of refined petroleum products. American oil companies hope to perfect synthesis processes that will directly benefit the consumer. A good example of progress in these terms is the synthesis plant at Brownsville, Texas, which is based on the conversion of natural gas to synthetic fuels and other valuable products. When this plant is operated at near capacity, it is expected that the products will be able to compete favorably for the consumer dollar. The complete gasification of coal is a technique well rooted in history. As a controlled process on a small scale, it goes back centuries. As a practical technique on a commercial scale, it dates back to 1839, when "producer gas" appeared in Germany for limited industrial use. By 1873, "water gas," or "city gas" as it is sometimes called, was being manufactured commercially in the United States for use in heaters and stoves. The water-gas process was the cornerstone for modern synthesis. To older methods that were concerned only with carbon and oxygen reactions, it added hydrogen by means of steam. Thus far the goal of conversion was to produce gas for heating, lighting, industrial use, and cooking. The long step forward to synthesis was made in 1927, when Germany started to make gasoline from coal by means of the revolutionary Bergius hydrogenation process. A year earIier, Franz Fischer and Hans Tropsch had announced their process, which finally reached the

Jan 1, 1953

By R. G. Webber, F. C. Langenberg

During the course of some magnetic investigations which the authors have under way, six bars of 0.43-carbon steel were tested, a permeameter designed after the Hopkinson yoke type being used. The results obtained were of some interest and although far from complete serve at least to show the necessity for a careful investigation of the previous history of the samples under study as well as the chemical composition. A steel of given chemical composition may assume a great variety of structures, depending on its treatment. Professor Sauveur has devised a very clear and effective means of illustrating this point. The accompanying microphotographs show some of the possible structures assumed by a 0.30 carbon steel (Fig. 1). It is now a well-established fact that a structural change is accompanied by changes in the tensile strength, elastic limit, hardness, etc., and it seems reasonable to assume also, a change in the magnetic properties. Six bars of a 0.43-carbon steel were used, all the bars being taken from the same rod and treated as follows: Bar 1. Heated to 1,100° and cooled in the furnace. Bar 2. Heated to 1,000° and cooled in the furnace. Bar 3. Heated to 900° and cooled in the furnace. Bar 4. Heated to 1,000° and cooled in air. Bar 5. Heated to 900° and cooled in air. Bar 6. Untreated. The bars were then turned to 13 mm. diameter and tested by the Hopkinson yoke method. After testing, three specimens were taken from each bar, one from each end and one from the middle. The homogeneity of the bars was tested in this manner and in no instance could any difference in structure in the three specimens1 be detected. Bars 1 to 3 inclusive are pearlitic in structure. The white areas are ferrite (iron with certain impurities in solution) and the dark areas pearl-

Jan 1, 1915

By Frank C. Greene

Missouri has had one of the best years in history in the development of gas, the 49 completed gas wells having an average of nearly 1,000,000 cu. ft. initial open flow. Altogether 101 wells were drilled in the western part of the state, from Andrew County on the north to Vernon County on the south. Of these 49 were gas wells (including four old wells drilled deeper) with an initial open flow of 48,850,295 cu. ft., eight were oil wells (including one old well drilled deeper) with an initial capacity of 125 bbl. per day and 44 were dry holes (including five old wells drilled deeper). All the oil wells were in previously discovered pools in Jackson and Cass Counties. The outstanding discovery was a "shoestring" of a sand that is termed the Bartlesville, trending northwest and southeast across townships 48 and 49 N., R. 32 W., in central Jackson County. The sand is believed to be a narrow channel or bar, probably not over 800 ft. wide, lying at a higher horizon than the Bluejacket or true Bartlesville sand. A total of 32 wells with 47,453,080 cu. ft. initial open flow has been completed along the 6 miles of the shoestring. The largest individual well had an open flow of 4,500,000 cu. ft. The depth of these wells ranges from 350 to 635 ft., depending on surface elevation. The rock pressure ranges from 145 to 169 pounds. The Missouri Valley Gas and Oil Co. and Panhandle Eastern Pipe Line Co. have laid pipe lines into the area and most of the wells are now connected. In other parts of Jackson County and in other counties of the state there was very little activity during 1937. Of the 101 completions, 88 were in Jackson County. Cass County had five oil wells and three dry holes, Bates County one dry hole and Vernon County two dry holes. In the northern counties, Andrew and Clinton were represented by one dry hole each. At the end of 1937 drilling and leasing operations were very active and wildcatting promises to feature the coming year.

Jan 1, 1938

By N. W. Wickersham, Ward B. Blodget, Roberts R. Boyd

The year 1926 has seen few radical changes or developments in methods of drilling and handling oil wells, but it has been a year of steady progress and development in deep drilling and production methods. Probably the outstanding development of the year was recognition by the directors of the American Petroleum Institute of the importance of natural gas in the production of oil, and the Institute directors' resolutions in December, 1926, regarding regulation of gas production with oil by state legislation. This matter is extremely important and will receive the attention of the industry in 1927. Advances in Drilling Equipment The history of the progress of deep well drilling is the solution of problems as they have confronted the operator. As the prospects for deeper production have become apparent, methods of penetrating the earth to greater depths have been devised. Rotary Equipment Improvements in the construction and in the methods of operation of rotary drilling equipment have practically caused elimination of cable tools in California for all but shallow work. The rotary drill, from 1910 when it began to be a practical factor in California, has been making steady advances, first displacing cable tools for drilling to the oil sands in proved fields and later displacing the cable-tool outfit entirely. With the perfection of machinery for taking core samples of the formation penetrated, the rotary drill has become generally used for wildcat work, continuous coring being practiced when desirable. Deep Holes The use of the rotary drill has made commercially feasible the opening of oil fields at greater depths than was considered possible with cable tools. Heavier equipment has been promptly supplied as occasion has

Jan 1, 1927

By R. W. Ph. D. Raymond

PROFESSOR W. P. BLAKE, in a note to his Catalogue of California Minerals, pointed out that the mining districts of the Pacific slope are arranged in parallel zones, following the prevailing direction of the mountain ranges. This interesting generalization has been more fully illustrated and connected with the geological history of the country by Mr. Clarence King, who sums tip the observed phenomena as follows: "The Pacific coast ranges upon the west carry quicksilver, tin, and chromic iron. The next belt is that of the Sierra Nevada and Oregon Cascades, which, upon their west slope, bear two zones, a foot-hill chain of copper mines, and a middle line of gold deposits. These gold veins and the resultant placer mines extend far into Alaska, characterized by the occurrence of gold in quartz, by a small amount of that metal which is entangled in iron sulphurets, and by occupying splits in the upturned metamorphic strata of the Jurassic age. Lying to the east of this zone, along the east base of the Sierras, and stretching southward into Mexico, is a chain of silver mines, containing comparatively little base metal, and frequently included in volcanic rocks. Through Middle Mexico, Arizona, Middle Nevada, and Central Idaho is another line of silver mines, mineralized with complicated association of the base metals, and more often occurring in older rocks. Through New Mexico, Utah, and Western Montana lies another zone of argentiferous galena lodes. To the east, again, the New Mexico, Colorado, Wyoming, and Montana gold belt is an extremely well-defined and continuous chain of deposits." These seven longitudinal zones or chains of mineral deposits must

Jan 1, 1873

By S. E. Bretherton

During the year 1878-79, Anton Eilers, who was then interested in the lead smelting and refining business near Salt Lake City, Utah, made a somewhat radical departure from the regular practice at that time, which was to use but little lime in the slag, with a high percentage of iron. Lime was not only a cheaper flux than iron, but it enabled the metallurgist to make a more siliceous slag, an economical advantage in smelting where the smelting companies had to purchase either iron or lime to neutraiize the excess silica, and penalize the ore shippers accordingly. The larger amount of both lime and silica in the slag also made it of lighter specific gravity, and a better separation of the metals and mattes was secured. This change in the formation of slags for lead smelting was brought about by Anton Eilers, prior to the Leadville mining excitement of 1879.. We must also give Mr. Eilers credit for the general introduction of the hollow water-cooled cast-iron jacket for the blast furnace. Again referring to the use of more lime and less iron in the formation of slags, there is no doubt but that it prevents the formation of a great many so-called "sows" in the lead crucible, such as were made in the early history of lead smelting in the Rocky Mountains; these sows consisted of lead, iron, arsenic, sulphur, copper, and other metals, including gold and silver, mixed with unconsumed fuel, and often, after vain attempts to cut them up or melt them to a suitable size for handling, were buried in the slag dumps to get them out of sight. Another advantage derived from the adoption of high-lime slags when smelting ore containing arsenic is the production of less speiss (a byproduct heavier than matte, resulting from careless operation of the furnace, in the lead being driven out of the crucible and sows built up). This speiss, while usually not as rich in precious metals as matte made at the same time, is too valuable to be thrown away; but it is difficult to treat, and it was thrown away or piled on the slag dumps in the pioneer days of lead smelting in this country. About the time of the introduction of the lower iron and higher lime slags in lead smelting, sulphide ores were encountered in Utah and Colo-

Jan 1, 1916

By D. Swan

Industrial research may be defined as a critical and exhaustive investigation to create new and better ways of doing things. The results of industrial research are new and improved products, processes, and techniques. This broad definition, of course, covers investigation of all subjects by either individuals or groups of people, and this chapter aims to examine the purpose (what research tries to do), and methods (or how research is done) as applied in the mineral industries. Concepts and History The idea or concept of organized research probably originated in the universities of Europe. There, groups of scholars banded together for discussion and application of their particular specialty to a common problem. Publication of the conclusions drawn from such investigations gave scholars in other areas the opportunity to review and criticize the work of their colleagues, and one of the hallmarks of scientific research work is the publication and criticism of the results of the investigation. It was not until the late nineteenth century that the concept of organized research for the profit of industry was recognized. During the late nineteenth and early twentieth centuries, a large number of industrial enterprises sponsored organizations to study the application of the physical sciences with the aim of making discoveries that would result in profit to the sponsoring organization. The tangible benefits accruing from these activities were so great that they, in turn, fostered several other methods for the support of organized research activities. For the large problems involving public interest, United States Government scientific research laboratories were set up. As the demand of smaller enterprises for research activities increased, research institutes and consulting laboratories were organized. In Europe the idea of common industry sponsorship of research centers grew and many large research organizations there were sponsored by associations of manufacturers. Finally, in the United States

Jan 1, 1964

By A. V. Pegler

As with most rheologically defined materials, rocks react differently in different environments to similar forces. Physical changes and deformations depend as much on the rate of change of stress as the magnitude of stress. In many instances the rate of change is more important. Under load, all real materials will flow if given time. If there is no time for flow, materials tend to react in a brittle manner. Particular characteristics are developed in rocks during their periods of formation and postformative geologic history. Whatever their mode of occurrence, rocks are a record of their formation and changes. Where analyses are possible, advantage should be taken of the natural inherent characteristics to help design economical functional structures. A number of techniques of measurement and analysis have been developed. The fracturing of rock by hydraulic pressure has been examined by many authorities but few within the scope of available published literature have used the actual rocks concerned in tests to examine directional characteristics or preferred strain propagation rates and directions. In a number of investigations of the properties of rocks for mine design purposes and stress analysis problems in which the writer has been associated, it has been demonstrated that there are definable preferred shear planes in most rocks. Preferred shear planes can be identified by a photoelastic method of analysis, and the information can be used to improve design of optimum drilling and breaking directions for mining purposes. Definable principal strain directions can be determined to facilitate design directions of optimum stability for permanent mine openings. In field fracturing operations the same directional characteristics as outlined above should be used to define preferred fracturing directions as in the laboratory from oriented samples. It is mainly with this aim that

Jan 1, 1968

By R. A. Deju, R. B. Bhappu

The theory of electrophoresis is briefly outlined and an apparatus which may be used for electrophoretic studies is explained. The results obtained using this apparatus are in agreement with those obtained by other investigators. How to solve some of the complications which occur in the measurement of zero charge and zeta potential is explained. It is believed that the apparatus described in this paper will allow rapid measurements of zeta potential, zero point of charge, electrophoretic mobility and zeta coefficient. For many years the phenomenon of electrophoresis has been studied, and much work has been done in designing an apparatus for better measurements of mobility, zeta potential and zero charge of minerals. Up to the present, most electrophoresis experiments have involved cumbersome equipment and tedious microscopic observation. The modified cell proposed in this paper obviates these drawbacks by using a Rayoscope together with a special system of lenses and filters. It therefore allows a faster and more accurate measurement of zero charge and particle velocity. THEORY Most authors currently regard zeta potential as the potential difference in an otherwise uniform medium between a point some large distance from the surface of the mineral and a point on the plane of shear. Fuerstenau,1 Miaw,2 and Gaudin and sun3 have performed some calculations of zeta potential using Henry's equation.4 Their results show wide discrepancies, probably due to differences in the past histories of the minerals used. The authors have also noticed this difference on determining the zero point of charge of quartz as shown on Table I.

Jan 1, 1967

By P. D. I. Honeyman

Changing trends in concentration, involving regrinding with the subsequent production of a finely divided, high-grade flotation product, presents a real problem to the modern copper smelter. In the treatment of such a material, handling difficulties are numerous and potential possible losses may be very great. In many plants, of course, preliminary roasting of the furnace charge remains an economical necessity. Under such circumstances, the operator has no alternative except to follow orthodox roaster reverberatory practice, though taking all possible precautions to avoid excessive dust losses and bad working conditions. In other plants, roasting is not only unnecessary but would be highly undesirable, and at best the charge would be merely dried before entering the reverberatory furnace. In the latter case the possibilities of raw charging loom large. The Miami plant of the International Smelting Co. handles the entire output of concentrates of the several mining companies operating in the Globe-Miami district. All of these companies produce a flotation concentrate which, at the Miami Copper Co. particularly, is all reground and is high in grade. In addition, the Inspiration Copper Co. ships a substantial tonnage of high-grade cement copper to the smelter from its leaching plant. Following the flow sheet of the original plant, all such material received was bedded, dried in Wedge furnaces and smelted in reverberatory furnaces. At times during the history of the plant it has been necessary to carry the drying operation further, to a partial roast, before reverberatory smelting. Since the charge contained over 80 per cent flotation concentrates, the handling of which in a dried condition was at best a dusty job, unusual precautions were taken to cut down dust losses. The Wedge furnace plant was equipped with a Cottrell treater and all hoppers and calcine cars were carefully designed to cut down dust loss in transferring the so-called calcine from hoppers to car and from car to furnace. In the furnace itself the dusting problem was a severe one. Arch erosion was very rapid and flues and waste-heat boilers rapidly filled up with a partly smelted flue dust.

Jan 1, 1934

By Valentine R. Garflas

The Mexican oil fields, during 1921, produced in round numbers 203,000,000 bbl. of which 176,000,000 bbl., or 86 per cent., were exported, the bulk of these exports, or about 73.3 per cent., going to the United States. The Mexican exports were divided by grades as follows: Light crude, 47.0 per cent.; heavy crude, 22.0 per cent.; tops, 3.5 per cent.; fuel oil from light crude, 24.0 per cent. The balance, or 31/2 per cent., includes the bunker fuel shipments and the coastwise trade in Mexico, which is not classified as to grades. The figures show that, in importance, the light-oil fields form about 75 per cent. of the Mcxican petroleum industry. The production of the Panuco field has followed the general history of the American fields, and its gradual decline, which is at present foreshadowed, may be estimated as well as its ultimate economic life. On the other hand, the behavior of the light-oil fields to the south is unlike any in the world so far discovered, and as a result we have concentrated overproductions followed by sudden droughts, both sometimes equally unexpected. The coming in of two or three gushers within adequate pipe-line facilities will flood the market with 100,000 bbl. or more a day, while the flooding by water of a particular pool will, in a few weeks, remove from the market one-half the total production of the Mexican fields.

Jan 1, 1923

By Valentine R. Garflas

The Mexican oil fields, during 1921, produced in round numbers 203,000,000 bbl. of which 176,000,000 bbl., or 86 per cent., were exported, the bulk of these exports, or about 73.3 per cent., going to the United States. The Mexican exports were divided by grades as follows: Light crude, 47.0 per cent.; heavy crude, 22.0 per cent.; tops, 3.5 per cent.; fuel oil from light crude, 24.0 per cent. The balance, or 31/2 per cent., includes the bunker fuel shipments and the coastwise trade in Mexico, which is not classified as to grades. The figures show that, in importance, the light-oil fields form about 75 per cent. of the Mcxican petroleum industry. The production of the Panuco field has followed the general history of the American fields, and its gradual decline, which is at present foreshadowed, may be estimated as well as its ultimate economic life. On the other hand, the behavior of the light-oil fields to the south is unlike any in the world so far discovered, and as a result we have concentrated overproductions followed by sudden droughts, both sometimes equally unexpected. The coming in of two or three gushers within adequate pipe-line facilities will flood the market with 100,000 bbl. or more a day, while the flooding by water of a particular pool will, in a few weeks, remove from the market one-half the total production of the Mexican fields.

Jan 1, 1923

By Robert H. Holgers

Eveleth Taconite Co. was chartered on July 29, 1963, and is 85% owned by Ford Motor Co. and 15% by Oglebay Norton Co. The latter also serves as managing agent. The location of the company's facilities is depicted in Fig. 1. The Thunderbird mine is located midway between the cities of Eveleth and Virginia, Minn. (Fig. 2). The Fairlane plant and General Office are located approximately 10 miles south on the St. Louis River near the community of Forbes (Figs. 3 and 4). The crude ore and the finished pellets are transported by a common carrier railroad, the Duluth, Missabe & Iron Range Railway Co. The facilities are also serviced by the Duluth, Winnipeg & Pacific Railway Co. Pellets are hauled year around by the DM&IR to its docks 60 miles south in Duluth, Minn. Ford Motor Co. consumes its share of the high grade pellets at its Rouge plant in Dearborn, Mich., and Oglebay Norton Co. sells its share in the open market. HISTORY Following six months of preliminary engineering by the initial staff of Eveleth Taconite Co. and the Western Knapp Engineering Div. of Arthur G. McKee & Co., the project was approved by Eveleth's board of directors on Apr. 17, 1964. On May 1, 1964, contracts were awarded to McKee for the mine, coarse and fine crushing and concentrating facilities, and to Allis-Chalmer for the pelletizing facilities. The pre-production surface overburden stripping contract was awarded to Skubic Brothers Co., Virginia, Minn. Ground-breaking ceremonies were held at the Thunderbird mine on

Jan 1, 1969