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With the coming of the month of 'October the various sections are beginning active work for the winter. The Colorado, Washington, Montana, and New York Sections are all doing good work in raising funds for the hospital bed at Rheims which is to be a memorial to the members of the A. I. M. E. who gave their lives in the great war. We hope that all the other sections will begin to work with this object in view and will make even a better record than they did with the Belgian Relief Fund. It was with much regret that the President, Mrs. James F. Kemp, and the Secretary, Mrs. Sidney J. Jennings, were obliged to forego the pleasure of attending the Chicago meeting in September. They were, however, ably represented by Mrs. Arthur S. Dwight who gave an informal talk after which was formed the Illinois Section, which has our best wishes for all success-" Over the top and the best of luck!"

Jan 11, 1919

By J. E. Korski

Quebec Cartier Mining Co. operates a low-grade iron ore deposit at Lac Jeannine, Que., which is located at the extreme southwestern end of the Quebec-Labrador Trough (Fig. 1). The facilities there include one of the world's largest concentrators, a hydroelectric plant of 60,000 hp, and the modern town of Gagnon. A 191-mile railway connects the mine to the seaport situated at Port Cartier on the St. Lawrence River. The harbor in Port Cartier can accommodate both lake and large ocean- going vessels and is also the site of a major grain terminal. The concentrator in Lac Jeannine is designed to produce some 8 million tpy (tons per year) of specular hematite concentrate, containing 66% Fe, from approximately 20 million tons of crude ore. An annual stripping program of 5 to 8 million cu yd of waste rock uncovers the required ore. Approximately 100,000 tons of ore and waste are removed daily on a year-round, 24-hr-per-day basis. The open pit covers an area with maximum dimensions of 8,000 x 2,600 ft (Fig. 2). Present mining plans call for an ultimate depth of approximately 1,000 ft below original ground level. The rocks in the pit area are typical of this portion of the Grenville geological province. They consist largely of marble, quartz rock, pegmatite, iron formation, and stratigraphically older gneisses. The iron-ore formation consists of medium to coarse-grained specular hematite in a quartz host rock. The formation occurs locally in a plunging, anticlinal form. The topography in the vicinity of the mine is rolling, with maximum variations in elevation of about 400 ft. The hills are thickly wooded with birch, black spruce, and some tamarack. Lakes and muskeg areas are plentiful. Precipitation and temperature records have been kept since 1959. The annual rainfall has ranged between a low of 23 in. and a high of 42 in.

Jan 1, 1969

By A. E. J. Gallagher, W. D. Charles

The chapter is a review of published and unpublished data concerning energy usage and material wear in commercial crushing and grinding operations. Examples are given from practice and factors influencing power and wear are discussed.

Jan 1, 1982

By Walter Harvey Weed

The Republic of Mexico is traversed by many mountain ranges, and presents a great diversity of climates, soils and geographical features, yet its grander geographic provinces are few and peculiarly well defined. The Gulf plain, the Cen tral plateau, the Sierra Madre, and the lowland or Tierra Cali ente of the western coast are the main features of the geogra phy of the Republic, and in the northern half these provinces are particularly well defined. The Sierra Madre separates the Republic into eastern and western parts, and from the City of Mexico north to the Texas line presents an almost impassable barrier to east and west travel. On the north, the first wagon road pass from east to west is at El Paso del Norte, the site of the Texan city of El Paso. Southward for many hundreds of miles the Sierra Madre, traversed by well-worn trails, over which all travel from the west coast to the interior must pass, is a stupendous barrier to social and commercial intercourse. The Sierra Madre is commonly described as a range or con geries of mountain ranges. In fact, it is, in Chihuahua at least, a great plateau, fringed by mountains on the east, trenched by deep canons in its center, and bordered by a wild and rugged complex of mountains carved out of the plateau on the west. Professional duties took me across this region from Parral westward to the Gulf of California via Guadalupe y Calvo. As it includes some of the great ore-deposits of Mexico, and its geological features have never, so far as I am aware, been described, I have prepared a diagrammatic section made from my observations on a horseback trip across the Sierra, and added such notes as seem to be of general interest.

Jan 1, 1902

By R. F. Burdyn

The inadequate use of centrifugation to economically recover solids from weighted drilling fluids reflects the need for better equipment and techniques for this putpose. Laboratory studies in the development of an improved separator are described in which an operating equation is derived and tested. Results show that the concentric cylinder geometry employed effectively separates bnrite from a suspension and that the operating equation provides a good approxinmtion for scale-up. INTRODUCTION Our current drilling technology frequently requires a high-density drilling fluid obtained by addition of barite. In the course of drilling, formation solids which are too fine to be removed either by screening or settling become suspended in the drilling fluid and gradually the volume of solids in the mud increases. The volume fraction of solids must be limited (if a satisfactory set of rheological parameters are to be maintained). A centrifugal separatorprovidesan economical way of accomplishing this. The barite recovery process can be considered as a separation of two solids. One, the light solids, composed of formation and added solids, has a specific gravity of 2.6 to 2.7; the other, barite, has a specific gravity of 4.2 to 4.3. This density difference, plus the fact that the average light-solids particle size is much smaller than the average barite particle size, permits separation by a centrifuge. In drilling fluids some of the coarse particles of the light-solids-range will settle faster than fine particles of the barite-particle range. As a result a complete separation of the two species is not possible. since the object of the process is not merely recovering the maximum amount of barite but includes as well removing the maximum amount of light solids, an optimum barite recovery efficiency exists. From a practical standpoint this optimum cannot be determined in the field for each drilling fluid system, and in practice the separation is less than optimum, with some sacrifice of barite. Drilling technology has included centrifugal separators for barite recovery for more than a decade. Results have been reported by a number of investigators indicating that the process is practical and economica1. l-4 The decision to use a centrifuge is based on economics in which direct cost savings and the indirect benefits in rig time derived from improvement of the drilling fluid are important factors. One would expect that centrifugal separation of barite from drilling fluids would significantly affect barite consumption; however, this is not the case. The Minerals Yearbook shows an annual domestic barite consumption in the drilling industry of nearly 1 million tons.5 By rough estimate there are perhaps 80 separators presently in field use. Assuming half of these in use at any one time, operating an average of four hours per day, at recovery rates averaging 3,000 Ib of barite per hour, total annual recovery is about 90,000 tons. This is less than 10 per cent of he total barite used. I conservatively estimate that barite consumption in drilling operations can be reduced by 30 per cent through greater utilization of centrifugal separators. To encourage more widespread acceptance of centrifugal separators in the drilling industry, improved equipment and techniques would be very desirable. The present paper, covering theory and results obtained from a laboratory model, is the first in a series on he development of an improved mud separator for field use. THE CONCENTRIC CYLINDER GEOMETRY AS A SEPARATING DEVICE Consider the geometry shown in Fig. 1, consisting of two concentric cylinders separated by an annular space. These are arranged so that the outer cylinder is fixed and the inner one can be rotated about its axis on shafts sealed against the ends of the outer cylinder. If the outer cylinder is fitted with openings at either end, the inner

Jan 1, 1966

By E. Gregory, C. G. Goetzel

The outstanding elevated temperature properties of materials made from sintered aluminum powder have been well established in recent years.1,2 and considerable investigation has been carried out on the structures which appear to be responsible for this type of strengthening.2,3 The maximum operating temperature of such materials is severely limited, however, by the low melting point of the aluminum matrix; and, therefore, considerable interest was aroused in methods of introducing the

Jan 1, 1959

We have seen that the first coal development in Pennsylvania was in the Pittsburgh bed in the southwestern corner of the state. The next mining, in point of time, was done in Clearfield County along the West Branch of the Susquehanna River, but the amount of mining done was quite small for a number of years and was soon exceeded by that from the area north of the Susquehanna River in Tioga, Bradford and Lycoming Counties, which will be considered now. It is claimed that coal was first noticed in Tioga County, in 1792, by Robert and Benjamin Patterson who were leading a party of settlers from Williamsport to southern New York, and while clearing a road near the site of Blossburg, found coal, which was said to be good. About 1815 David Clemons made an arrangement with Aaron Bloss, owner of the land, to work some of the coal and hauled the first load down the river to Painted Post, N. Y., as there were no available markets in his own state. Smiths found it an excellent fuel and apparently he found a ready market for the small amount he could transport by wagons and sleighs. As wood began to become scarce around the towns in New York State, the knowledge of the coal deposits in the mountains at the head of the Tioga River attracted attention to the field and the necessity, for means of transportation from it. Some coal had been floated down the river, but navigation was uncertain and dangerous. In 1827 an iron plant was built, and to ship its product and coal, it was proposed to build a canal along the river to reach Corning, N. Y. A company had been chartered in 1826 in Pennsylvania to "make a navigable canal or slack-water navigation" to the state line and coal was shipped on rafts of logs, both being sold, during highwater. In 1828 the company was authorized to build a railroad instead of a canal, and in September 1840, the railroad was completed from Corning to Blossburg.1 That some coal from Pennsylvania had been reaching southern New York towns prior to the improved means of transport is shown by the report of a committee to the New York Assembly: "the bituminous coal has been brought to us either from Great Britain or from that part of our own country which borders on, and lies west and south of the Susquehan-

Jan 1, 1942

By AIME AIME

AMONG the recent mining and metallurgical developments in England great interest has been shown in the development of an iron-ore field covering 26,0.00 acres in Northamptonshire, containing 500,¬000,000 long tons of ore; and the erection at Corby, by Stewarts & Lloyds, of a modern basic bessemer steel plant and tube works. The entire project was planned to cost about £3,300,000. Many improvements have been made in the varied equipment that is being installed, some of which has set mew records for massiveness. There is, for instance, a new roll crusher, which has been manufactured by Hadfields, Limited, of Sheffield, the largest ever built in England, and weighing 130 tons. This machine, shown in Fig. 1, as erected at the Hadfields shops, is primarily designed to take blocks of iron ore as they come from the steam shovel. The maximum size is 54 by 48 by 36 in., hut occasional pieces slightly larger than this may be accommodated. The capacity is upwards of 500 tons per hour, the product passing to a secon-

Jan 1, 1934

By David R. Mitchell

Many of the difficult operating problems of the preparation of coal for market, of sampling coal shipments and in the utilization of coal are caused by segregation in the coal mass. Segregation may be of two kinds: i.e., "size segregation," in which particles of the same size in a mass of coal containing a range of sizes collect together and "density segregation," in which particles of the same density or specific gravity in a mass of particles of varying density gather together. Mechanics of Segregation Size segregation cannot take place with closely sized coal. As the size range increases, the tendency for size segregation increases. Similarly, cleaned coal with particles of approximately the same specific gravity have very little tendency for density segregation. The wider the density range of particles and the more particles of different density, the greater the chances are for density segregation. The following discussion deals primarily with coal of a wide size range as screenings and of wide density differences as uncleaned or run-of-mine screenings. If a mass of coal containing particles of a wide size range is subject to the stream action of a moving current of water, the small particles are transported farther than the coarser. Particles of different density in a stream of moving water are subject to the laws of classification, the heavier settling out first. The familiar sluice box of the gold miner and the action of rivers and other streams in classifying material according to

Jan 1, 1938

By David R. Mitchell

Many of the difficult operating problems of the preparation of coal for market, of sampling coal shipments and in the utilization of coal are caused by segregation in the coal mass. Segregation may be of two kinds: i.e., "size segregation," in which particles of the same size in a mass of coal containing a range of sizes collect together and "density segregation," in which particles of the same density or specific gravity in a mass of particles of varying density gather together. Mechanics of Segregation Size segregation cannot take place with closely sized coal. As the size range increases, the tendency for size segregation increases. Similarly, cleaned coal with particles of approximately the same specific gravity have very little tendency for density segregation. The wider the density range of particles and the more particles of different density, the greater the chances are for density segregation. The following discussion deals primarily with coal of a wide size range as screenings and of wide density differences as uncleaned or run-of-mine screenings. If a mass of coal containing particles of a wide size range is subject to the stream action of a moving current of water, the small particles are transported farther than the coarser. Particles of different density in a stream of moving water are subject to the laws of classification, the heavier settling out first. The familiar sluice box of the gold miner and the action of rivers and other streams in classifying material according to

Jan 1, 1938

Jan 1, 1952

By D. S. G. Hanson

The Flin Flon Mine has been in production for over fifty years, and current mining is dependent on pillar and remnant recovery. One of the last major blocks of ore, and an important economic entity to the Mine, is the North Main Shaft Pillar. A rock mechanics program was initiated through under' ground instrumentation and other subsequent analyses, to establish the degree of instability as min¬ing progressed. Several studies have been and will be undertaken to evaluate the general stability, and possibly improve the chances of stability during pillar recovery. The North Main Shaft Pillar is immediately bounded by cemented cut and fill supporting rib stopes which inturn are bounded by slag and waste filled stopes. The min¬ing method involves a modified longhole open stoping and slag fil¬ling sequence for each mining block in a general mining upwards scheme.

Jan 1, 1983

By Dorsey Lyon

INTRODUCTION THE electric furnace has always been found to be especially adapted to melting, refining, and finishing processes throughout its gradual acceptance by metallurgists, as a practical apparatus for conducting metallurgical operations. In the steel industry, the electric furnace is firmly established in the manufacture of steel of the highest grade, equal to crucible steel. For the production of the cheaper grades of steel in large tonnage, the electric furnace gives a higher-grade product than the open-hearth or converter, but due to the high cost of power prevailing in steel centers, considered from the electric furnace standpoint, it is not economical to produce tonnage steel in the electric furnace. As a refining and finishing agent for open-hearth or Bessemer steel, the electric furnace has had some degree of success in the production of tonnage steel. After a study of the use of the electric furnace in the steel industry, it appears that there may be a possibility of its use to advantage for the melting of cathode copper. In the case of copper the problem is not one of actual refining, because the copper if refined properly y the electrolytic method needs no further refining; it needs simply to be cast into a marketable shape. The name" refining". is applied to the present finishing process, because in the operation oxygen and other impurities are removed, which the electrolytic copper absorbs in being melted in the reverberatory furnace. Considering that processes may be positive, negative, and neutral; the electrolytic method would be positive; reverberatory melting of cathode copper, negative; and electric furnace melting, neutral. The electrolytic method produces about as pure a copper as is possible, if operated properly and the anodes are not too impure. The final reverberatory melting of this cathode copper lowers the grade of the final product, due to the absorption of gases and impurities.

Jan 8, 1914

By K. Sallmann

Spurred by a variety of factors, coal flotation is making headway among the preparation plants of West Germany. The author gives some statistics on German coal flotation plants and information on the properties of the feed and quality of the derived products. Types of machines and reagents used, dewatering practices, tailings disposal, and thickening operations are covered. There is special emphasis on the many-sided problems that confront German coal preparation engineers. The coal mining industry of West Germany is concentrated in three coalfields: the first on the Ruhr and the Rhein rivers, the second on the Saar river, and the third near the frontier between Germany and the Netherlands, around the towns of Aachen and Erkelenz. The total run-of-mine production of these three coalfields amounts to 736,000 tpd which come from 145 collieries. There are 121 washeries, 43 of them with a flotation plant. The total throughput of these 43 washeries is 280,000 tpd, out of which 26,000 tons (9.3 pet of the washery feed coal) are cleaned by flotation. The capacity of the individual flotation plants varies within relatively wide limits, the average being 40 tph and the capacity of the largest flotation plant being 120 tph. During the last few years, the number and size of flotation plants have been steadily increasing, although flotation must be looked upon as an expensive and rather complex cleaning process. The considerations which have led to the widespread application of flotation may be summarized as follows: 1) In making coking coal, it is seldom possible to add uncleaned fines to the coke oven charge, as their ash content is too high. If, however, the ash content of the fines is reduced to a maximum of 7 or 8 pet, they can be admixed to the washed and crushed small sizes without difficulty. This means, naturally that revenue is increased since the price of coking fines is always higher than the price for dust or uncleaned wet fines. 2) To prevent silicosis and pneumoconiosis, water infusion and spraying of the coal are practiced much more today than ever before. As a result, moisture content of run-of-mine coal has markedly increased and the washery feed coal contains more and more slurry instead of dry dust. The price of slurry, how- ever, is very low, and in many cases it is impossible to sell filtered raw slurry with a moisture content of 20 to 25 pct and, at the same time, 20 to 25 pct of ash. Reduction of the ash content of these slurries improves the possibility of dewatering them and, in this way, also enhances the marketability of this product. 3) The new severe laws and regulations against pollution of air and rivers make it necessary to de-dust coal better than in the past and to reduce the quantity of the waste water from coal preparation plants and their solids content to a minimum. 4) Even if there were no compulsory reasons to clean the fines, flotation will often lead to an increase in the overall yield. Although not the only application, it appears that the treatment of coking fines is the primary field for the flotation process in coal preparation. It must not be overlooked, however, that a series of arguments may be advanced against flotation: 1) Flotation is an expensive process because, in addition to the cleaning operation itself, the dewatering of the froth and the disposal of the tailings is very costly. 2) Operation of a flotation plant requires well trained personnel. 3) Filtered froth has about a 20 pct moisture content and, therefore, if mixed with the cleaned small coal it causes an undesirable increase in water content of the coke oven charge. For this reason it is necessary to take additional measures for dewatering washed small coal and this, of course, entails additional expense. 4) Disposal of flotation tailings involves very difficult problems, particularly in the highly industrialized regions. An investigation covering 32 flotation plants of Western Germany shows the following composition and properties of their feed:

Jan 1, 1961

By David B. Rushmore

Torches were used by the early Romans for mine-lighting, and these were followed by open lamps or earthen jars filled with tallow or oil, and later by candles. In early coal-mining, explosive gases seldom occurred, and, if they were encountered, the danger of explosion was materially diminished by the absence of any ventilating-system and the consequent insufficient circulation of air to form with the methane an explosive mixture. As the art advanced, the danger of fire-damp became more apparent, and methods for testing the air were resorted to as early as in the fifteenth century. The method of testing consisted in lowering a dog in a basket down the shaft. As soon as he encountered fire-damp he would commence to howl, after which he was withdrawn, and a leafy bush was fastened to the end of the rope and run rapidly up and down the shaft. This so disturbed the accumulation of gas as to cause it to rise out of the shaft. Later this odd method of testing was improved upon through the discovery that a light inserted in a body of fire-damp Gould produce a blue flame. Candles were used for this purpose, and, when fire-damp was thus discovered, brushing or some other primitive method of fanning was resorted to for driving out the gas. In some instances the gas was burned away, regardless of the danger thereby incurred. A man, wearing a well-moistened coat and a mask with glass spectacles, descended in the mine a few hours before each shift. With a long stick, to which was fastened a burning torch or candle, he would crawl on the floor with the stick so raised that the light would sweep the roof and ignite the gas which it encountered. In this position the flame of the explosion would pass over him, after which he would retreat from the gases resulting from the combustion. The occurrence of serious accidents resulted in

Jan 1, 1913

By Paul F. Kerr

Uranium mineralization occurs in the footwall of the Sunshine vein from the 2900 to the 3700 level. Veinlets of uraninite associated with pyrite and jasper have been so extensively divided and recemented that units more than a few feet in length are seldom observed. The wall rock is St. Regis quartzite of the Belt series. The age of the uraninite, on the basis of isotopic analyses, is 750 t- 50, which agrees with geological data suggesting that phases of the Sunshine mineralization are pre-Cambrian.

Jan 5, 1953

PORPHYRY mining in the Bisbee district in Arizona did not begin until 1923, though Bisbee had been the scene of profitable copper-mining operations since 1880, and during the interval had contributed roughly 2,000,000,000 lb. of copper to the world's supply. At that time it ranked third among the copper districts of the United States, first place for total production going to Butte, Montana, and second to the district centering around Calumet, Michigan. Bisbee's production had come from the so-called "limestone" mines operated principally by the Phelps Dodge Corporation and the Calumet & Arizona Mining Co. Each of these companies had a large smelting plant at Douglas, 25 miles southeast of Bisbee on the Mexican border. The town of Douglas owed its existence primarily to the copper mines of Bisbee, the particular location having been determined, first, by the fact that water in adequate supply could be obtained by sinking wells; and, second, by its position about equally distant from Bisbee and the mines in Sonora, Mexico, of the Moctezuma Copper Co., a Phelps Dodge subsidiary. Three partners, Martin, Reilly, and Ballard, conducted the first operations of consequence at Bisbee about 1880; and in 1881 a smelting plant consisting of two 36 in. water-jacketed blast furnaces was erected near by. The ore came from open-cut workings on the later-to-be-famous Queen orebody. The furnace charge is said to have averaged 23 per cent copper-twice as rich as the concentrates from the mills and four times as rich as the smelting ore shipped from Bisbee in recent years. As early as 1881, disputes arose among owners of various claims, and groups of claims, over the ownership of orebodies under the law of apex and extra-lateral rights. This law gives a miner the right to follow his vein downward on its dip, even

Jan 1, 1933

By Frederick G. Coqueron, Joseph E. Pogue

FOR a number of years, the Department of Petroleum Economics of The Chase National Bank has been conducting a study of the capital employed in the petroleum industry. The technique followed is that of combining and summarizing the available financial and operating data for a group of thirty representative oil companies, doing about two thirds of the domestic business of the entire industry. This paper presents the results of the findings for the year 1943, and supplements the survey, "Sources, Disposition, and Characteristics of the Capital Employed by Thirty Oil Companies During the Nine-Year Period, 1934-1942," presented before the Petroleum Division of the American Institute of Mining and Metallurgical Engineers on Feb. 24, 1944, and also published as a pamphlet by The Chase National Bank.

Jan 1, 1944

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members) Member, Graduate Colorado School of Mines. Four years' experience in West and Northwest. Two years with American Smelting and Refining Co. Wishes to join field party on geological work, mining or areal, where opportunity will be given to be of direct assistance to chief of party in solution of field problems. Age, 26. Unmarried. At liberty June 1. No. 342. Member, technical graduate, aged 30, with' 7 years' experience in concentrating and mining, desires a position of authority with reliable company. At present employed. No. 343. Member. Ambitious, energetic, tactful engineer, college graduate, married, aged 30, desires location with a large coal mining organization. Seven years with present employers -n middle west; has had broad experience in the past eight years on examination, development and construction; successful record in handling men. Position must carry responsible work and a future. Will go anywhere for proper opportunity. Exceptional references as to reliability, character and capacity for work. No. 344.

Jan 3, 1917

THE shipments of high-grade manganese ore, con-taining 35 per cent or more of manganese, from the mines in the United States in 1926 were slightly less than half as large as similar shipments in 1925, accord-ing to the United States Bureau of Mines, Department of Commerce. The shipments in 1926 by 45 producers amounted to 46,258 long tons as compared with 98,324 long tons by 42 producers in 1925. This decrease was due to the falling off of the shipments from Montana. The domestic production of metallurgical ore in 1926 was 26,530 tons; that of chemical ore, 19,728 tons. Montana was the largest shipper with 5713 tons of metallurgical ore and 17,904 tons of chemical ore. The largest individual shipper of metallurgical ore was the Crescent Mine in the Olympic Mountain Region, Clallam Co., Washington, from which the shipments for the year were 3162 tons. The mine was operated by lessees and reverted to the owners in July, and thereafter to the close of the year no .ore was shipped.

Jan 6, 1927