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By Joseph G. Wargo

A meteoric rise in selling price has revived gold exploration activity throughout the world. In the United States the effort is, in large measure, channeled toward discovery of disseminated gold deposits such as the Carlin-type, i.e., with size and grade characteristics similar to Newmont's Carlin mine in Nevada. The subtle surface indications characteristic of Carlin-type gold mineralization have been examined by a number of geologists, and the more obvious prospects have been tested by surface sampling and drilling. It is likely that most of these readily recognizable deposits have already been found and, as a consequence, prospectors are now entering a new, second stage of exploration for Carlin-type and related disseminated gold deposits.

Jan 9, 1979

The 114th (New York) Meeting of the Institute will be held in the third week of February, 1917. The Committee on Papers and Publications has set Dec: 1, 1916; as the closing date for the receipt of manuscripts intended for this meeting. Manuscripts must be received by the Secretary on or before this date. If they are sent through members of the technical committee they must be sent to those committees enough in advance of the time to be forwarded and in the hands of the Secretary by the time specified. While Dec. 1, 1916, is the final closing date, it is a great advantage to get papers in as much before that time as possible as it enables them to be submitted in proof form to their authors. Papers received on or before Nov. 1, 1916, will, as far as possible, be published in the January Bulletin or earlier, thus giving good distribution among the members in advance of tile meeting. The Institute's records show that the discussion of papers is very rnuch better when they are distributed somewhat in advance of the meeting instead of in the Bulletin which goes out immediately preceding the meeting.

Jan 9, 1916

By C. T. Bischoff

DURING the past few years geochemical testing for traces of heavy metals in water, soil, rock, and vegetation has aroused increasing interest. Various techniques for field and laboratory determinations have been described in the literature, as have some of the results of application. However, little information has been published regarding application to glacial terrain. Over 90 pct of the Canadian Shield is overburdened, resulting in high costs for mineral exploration once the outcropping ore deposits have been found. This has been largely responsible for the widespread application of mining geophysics in Canada, permitting concentration of effort on area or zones considered most favorable. However, geophysical interpretation has its limitations, since at least 90 pct of the structures indicated thereby contain no valuable minerals. A more direct approach is therefore highly desirable. If underlying base metal mineralization can be detected by sampling soil or vegetation at moderate cost this should prove of great help in locating new discoveries or extending known ones. A large proportion of Canadian ore deposits contain appreciable copper or zinc, even where these are not the principal economic metals. Consequently the field of application is a broad one.

Jan 1, 1954

[ ] (17) WORTHINGTON: Cartoonist-author Don Herold recently took a look at the Worthington Corp., putting the results into a compact booklet called "A lot of things beside pumps." The story is aimed to better acquaint you with Worthington and how they came to produce a diversified industrial equipment. (18) SPEED REDUCERS: Now available is Cleveland Worm & Gear Co.'s new general catalog. In its 180 pages are the illustrations and description of the complete Cleveland line, together with full engineering data, dimensions, weights and horsepower capacities of the various drives. (19) METAL PRODUCTS: Armco Drainage and Metal Products, Inc. has just published a condensed 6-page catalog of its products designed for mining use. It describes and illustrates such products as Flex-Beam guardrails, corrugated metal pipe, liner plates, retaining walls, Steelox buildings, and welded pipe. (20) RECORDS: Pre-scheduled, controlled, preventive maintenance reduces costly downtime to a minimum and eliminates the need for large emergency crews. A new folder describes how such a program can be accomplished by using Remington Rand Inc., Kardex visible records. Another Remington Rand Inc. bulletin is the certified case history of how Kardex visible purchasing records help maintain a smooth running purchasing department.

Jan 1, 1952

By Howard E. Parkinson, John N. Murphy

The past five years have seen communications techniques and hardware developed by the Bureau of Mines and its contractors increasingly brought into use in U.S. mines. The Bureau philosophy has been to help develop and introduce new hardware that goes as far as possible toward meeting the mining industry's needs. The Bureau programs are also designed to provide continuous fallout of new communications capabilities which are introduced to the mine operators as they occur. As more progress is made in meeting mine communications needs, it is hoped that the mining industry will readily adopt the equipment and techniques that it finds most useful in meeting its individual needs. This paper reports on recent advances achieved in the development of improved mine communications systems. In May 1975 the U.S. Bureau of Mines (USBM) conducted a mine communications technology meeting to provide a brief overview of the USBM communications technology developments in the past 5 yr. This meeting lasted for 1 1/2 days. Therefore, I have elected to narrow this paper to a brief review of recent underground mine communication developments. The following will be discussed: 1) Ultra-high frequency (UHF) radio for fan hole drill operators;

Jan 1, 1978

By Robert Bakish

VARIOUS aspects of structure-sensitive corrosion of single crystals and polycrystalline aggregates of Cu,Au have been presented in papers by the author, in association with W. D. Robertson. Prompted by some observations in the course of these studies, a new approach to the problem was undertaken. Results of these new experiments are reported here. Thin slices, less than 2 mm thick, were prepared from single crystals 3.5 mm in diam grown by the Bridgman technique. The crystals were homogen- ized for 300 hr at 850°C. Crystals with no deformation, crystals deformed in tension to the yield point, and crystals deformed 20 pct in excess of the yield point were used. Crystals of several different orientations were studied. Slices were immersed for one month in 2 pct aqueous solution of FeCl3 and, subsequent to this immersion, were subjected to bending. Immersion and bending were carried out at room temperature. The size and geometry of the crystals did not permit accurate data on the loads involved. A most unexpected result was obtained in the process of bending these slices of Cu3Au crystals normal to the (110) plane. Completely brittle be-

Jan 1, 1958

Carlisle: This is April 19, 1961. My good friend Dave Irwin is sitting on the other side of the tape recorder. We are at Rose Dhu Island, Savannah, Ga. Now, let's begin with your first job, where and what was that? Irwin: I started out to Arizona, looking for a job and wound up in Morenci. The next morning I applied at the mine office and was put on as a sampler. I worked as a sampler and as an assistant to Frank Pelton, the geologist, for a year, after which I went back to New Haven to take my last year of postgraduate work. After getting my degree, I went back to the Southwest with W. Rowland Cox and Staff, supposedly as a geologist. Q: But that was not when he was with Spurr? Irwin: That was after he had left Spurr. Henry Smith was with the Spurr end of the outfit and I happened to drop into the W. Rowland Cox end. My first job with him was to do some work on a prospect above Metcalf, Ariz., and from there I would go out on short reconnaissance trips in Arizona, New Mexico and old Mexico.

Jan 6, 1964

By Rudolf Bernhard

STATIC soil investigations with more or less heavy loads and extensive borings do not always have efficient results; also, they are very expensive. The new geophysical method of dynamic tests described herein is simple and cheap and avoids several disadvantages of the routine investigation, thus forming a useful supplement to the older methods and even at times replacing various static tests. The fundamental principle of dynamic soil tests consists in the appli-cation of artificial vibration. The technique employed is essentially geophysical in nature and in some respects is akin to seismic studies. Artificial vibration may be excited by centrifugal forces resulting from eccentrically supported rotating masses. The reactions of soil and structures caused by these vibrations may be measured. Their dynamic constants, such as amplitudes, phase speeds, damping, reflection, and interference effects, can be investigated. This geophysical method has been used for several years with increasing success. The results of these tests, summarized at the end of the paper, indicate that this method opens a new field for the practical engineer in investigating soils (capacity and formation), foundations, dams and structures, and especially buildings that must withstand earthquakes.

Jan 1, 1938

By Marvin P. Barnes

Definition The term mineral inventory is a relatively new designation, born of the computer age and grown to common usage with the development of computer techniques for extending drill-hole sample values to regularly gridded data blocks representing in situ mineral values. The term has been generally accepted by geologists and engineers because it has a precise meaning which avoids many of the ambiguities of ore reserve. A mineral inventory is an estimated inventory of mineral in place and is usually achieved by dividing the deposit into regularly spaced gridded blocks to which are assigned estimated values using various extension techniques. A mineral Inventory makes no presumptions about the minability of the blocks or their cutoff grade. A mineral inventory estimate may be good or poor according to how much is known about the deposit, how extensively it has been sampled, and what techniques have been employed to assign estimated grade to the blocks Such an inventory, however, does not change with time, economic conditions, or mining technology, but only with new and better data and methods. Thus, the mineral Inventory is an excellent designation for describing mineral value distributron within a deposit's geological setting

Jan 1, 1979

By H. D. Dahl, P. C. Thakur

This paper presents an analysis of a new tool for improved productivity in coal mining: the horizontal drilling system developed by Conoco/Consol. The analysis includes a brief description of the system; discussion of the three categories of advance exploration application of horizontal boreholes; and a survey of other special mining methods planned around long horizontal boreholes.

Jan 1, 1983

By N. LILIENBERGS

DURING the past few years, the requirements for steel have been raised so high that soundness is more important than ever before. The old practice was to mike steel ingots of sufficiently large sections to permit a considerable reduction of area in rolling and hammering to a given size, relying on the fact that by such rolling and hammering all cavities will be squeezed together and practically eliminated. The finished sizes, if found by inspection of the surface to be faultless, were therefore pronounced to be sound. But when such steel is ?worked up,? the manufacturer is surprised and disappointed to find that it splits, or that streaks and seams make the product unmarketable. Large sections, such as rails, beams or heavy forgings, may, within certain limits, be sufficiently strong, even if the sides of the cavities are only squeezed, and not welded together. But it is well known that, in the interior of heavy articles, under certain conditions, forging may develop small streaks into large cavities. Small sections, steel for ordnance and tubes, and numberless articles in the tool-trade, always show up the defects. It may be doubted whether cavities in steel ingots can ever be completely welded. The old theory, is, that the silver-clear blow-holes, without the blue oxide, can be welded by sufficient working. They are, however, not empty, but are filled with carbonic oxide. It is admitted that the "blue" cavities, resulting from air mechanically drawn down into the mold during the casting, can never be welded, because the oxide does not melt, and there would be no escape for it if it did. The only way in which steel can be made satisfactory for the above-named particular purposes is by having it ?dead molten." But then the trouble of piping is encountered. As is well known, a pipe is the result of the contraction of

May 1, 1906

By William L. Payne, Edward E. Ives

A unique feature of Potash Co. of America's A new potash property near Saskatoon, Sask., is the use of semi-dome-shaped buildings for product storage. Four domed structures, timber-framed and corrugated-sheet covered, are being built; each designed to handle 20,000 cu yd. The relatively small capacity units, PCA believes, give flexibility not only in storing different grades and sizes of product, but also in permitting greater ease in shipping products as market demands change. The domed buildings are 150-ft diam, comprised of a 16-ft-high concrete wall base, topped with a metal sheet-covered octagonal timber frame. The dome of each unit is designed to fit very closely the angle of repose of the contained material, which results in the maximum usable volume. The entire roof is flood coated with a bitumin to provide a complete weather seal.

Jan 9, 1959

By Freeman Bishop

The first session of the 91st term of Congress became so completely snarled up in economics and politics that no one knows how things will go in 1970 including the White House. Everything from mineral depletion allowances to tax deferments kept the Republican President and the Democratic Congress from settling their differences. But as these reconcilements approach definition, a new battleground develops around the President's authority to make trade and tariff adjustments.

Jan 1, 1970

By Sidney A. Swensrud

MUCH discussion has occurred as to the use or uses which might be made after the war of either or both .of the large diameter (24 inch and 20 inch) War Emergency pipe lines built by y the United States Government during the war, to move crude petroleum and refined products such as gasoline and light distillate fuels. Indeed, the disposition and future use of these lines constitutes, in the minds of many people, one of the most important problems of postwar readjustment in the Oil Industry. The two lines, running from points in Texas to the New York-New Jersey-Philadelphia area, were constructed only because of the inability during the war to continue normal ocean tanker movements from the Gulf Coast to the East Coast. Physically they could continue after the war to move crude or refined products, and it appears that lines of such large diameter as these, if operated at or near capacity, could move these liquids at costs per barrel which might be considered in the same general cost range as for tanker movements.1 If, therefore, we were to look forward at the end of the war to a shortage of tankers, it is probable that the continued use of these pipe lines for petroleum movements to the East Coast would be worth considering, as against building new tankers to take over the movement, provided there were no other economic or national defense reasons for restoring tanker fleets and no other better use for the pipe lines. Because of the extensive tanker construction program which has been and still is in progress, and because of our Navy's marked success in combating the submarine problem, it appears to be quite possible, however, that instead of a shortage of tankers at the end of the war, we may have a surplus instead. If this should turn out to be the case, then there would seem to be considerable doubt that these lines would continue to be used for moving petroleum or products to the East Coast at the expense of tying up tankers. It would hardly seem probable that the owner of any such tankers would ship via one of the large lines at the expense of tying up one of its own tankers, unless the pipe line tariff rate charged was lower than the out-of-pocket cost of operating a tanker as against the out-of-pocket cost of keeping it tied up. And considering that a substantial part of the cost of operating a tanker goes on even when it is tied up, it is very difficult to figure out how any pipeline tariff could be established that would be low enough to compete with individually owned tankers that otherwise would be idle. Certainly a pipe line tariff rate high enough to cover direct costs plus even a low rate of depreciation and return on the investment would be far above the out-of-pocket tanker operating costs. In view of these considerations, it has seemed desirable to examine with some care some of the various alternatives that have been suggested as to other possible uses to which these lines might be put. One of these is for transportation of natural gas to the New York-New Jersey Philadelphia area. This Eastern area, located at the destination of these lines, contains the heaviest concentration of population in the United States, and is not now served with natural gas. At the other end of the lines lie the greatest discovered natural gas reserves in the United States, if not in the world, and many

Jan 1, 1944

By Walter English

THE four papers making up this symposum have been prepared espe-cially for those who have no knowledge of seismograph prospecting. To many people mathematics is a formidable subject, and many are discouraged from studying seismograph prospecting under the mistaken assumption that the mathematical requirements are severe. In the papers presented here there is not a single mathematical equation. We believe that considerable competence in dealing with some of the most important problems of this work can be attained without any mathe-matical training whatever. At the present time, there is a real need for interpretation of results by persons thoroughly competent to bring geologic experience and imagination to bear on data that are subject to multiple interpretation from a strictly physical viewpoint. Likewise, those charged with the responsibility of planning seismo-graph exploration campaigns would do well to become familiar with as much as possible of the technical aspects of the work. They would then be in better position to judge of its success in individual cases. It has often been said that the seismograph is a new structure-finding tool for the geologists to use. Using a tool and using its product are two different things. One does not use an automatic screw-threading machine when he buys a box of screws at the hardware store. Neither does the geologist

Jan 1, 1939

By Louis P. Gignac

INTRODUCTION The selection of trackless equipment for underground mining can be a complex engineering problem due to the wide range of equipment sizes and operating modes. Computer simulation is particularly useful in estimating the performance of different systems for specific rock- handling problems. A hybrid simulator, incorporating some of the features of deterministic and stochastic simulation, was developed in order to handle not only queuing delays at loading and dumping points, but a1 so traffic interferences. Any number of vehicles can operate in any one of four basic modes (LHD, LAF, FEL, HFC) in parallel or in series. If the units use common roadways, loading and dumping points, certain operating delays will occur and be registered by the simulator and thus give a better evaluation of the marginal productivity of each additional unit. Based on a typical layout of drawpoints and ore passes for the sub-level stoping method, productivity and operating costs of different rock-handling systems will be examined. 1 . COMPUTER SIMULATION Numerous applications of computer simulations are reported in the 1iterature for various mining problems. Depending on the complexity of the system to be studied, simulation models were conceived with different degrees of sophistication. Three different types of simulators are generally recognized: stochastic, deterministic, and hybrid. Stochastic or Monte Carl o simulation randomly generates items, transactions, or events from some population defined by a frequency distribution and produces some expected future situations. Because this type of simulation is governed by the input of probability distributions, it requires a detailed knowledge of the system to be simulated; it implies expensive and time-consuming studies and reports to gene- rate this input information. A major short- coming of stochastic techniques is in new equipment evaluation, where the lack of data is unavoidable, and in new system design where the conditions are outside the range of the known historical behavior of the equipment. However, probabilistic simulation is almost essential for the study of cyclic queues and traffic problems. Deterministic simulation studies a system by generating performances on the basis of the mechanical capabilities of the vehicles and the physical limitations of the mining scheme. It is based on the engineering principle that the engine converts its energy into a rimpull at the wheels, which is in turn opposed by the rolling resistance and the grade of the ground; the machine is accelerated or decelerated until the tractive and resistive forces are in equilibrium, at which point it moves at constant speed. The information required by this technique, such as rimpull charts and equipment weight, is readily available from equipment suppliers. However, equipment performance at the mining site is also dictated by human and environmental conditions and changes with time and usage. For this reason, deterministic simulation generally overestimates the system capabilities; these must then be adjusted by efficiency factors based on observation and experience. Recently, hybrid simulation models, using both stochastic and deterministic techniques, have been built with some of the events generated stochasticly and others being deterministic. This compromising approach originated at the Pennsylvania State University. O'Nei1 (1966) designed a simulator for truck-and- shovel operations that allows for transportation from multiple faces to mu1tiple destinations. Each truck performs according to its mechanical capabilities while its loading and dumping time and its load fluctuate according to specific probability distributions. A major advance in the simulation of mining systems is due to Sanford's model (1969) of underground coal mining operations. The originality of the model is in the use of an Executive System Control which sets up the initial system, de- fines the operation conditions , and instructs continuously four sub-assemblies representing shuttle cars, trains, continuous miners , and conveyors, which in turn generate a feed-back of their movement to the Executive Control System for further instructions. The model has enough flexibility to simulate simultaneous and sequential jobs that characterize any dynamic system. Sanford's early work evolved slowly to what is known today as the Under- ground Materials Handling Simulator for coal mining (Manula, 1974).

Jan 1, 1981

By C. S. Smith

QUANTITATIVE methods were used to good effect in the earliest days of metallography1-3 but they mysteriously passed into virtual disuse until the important paper4 by Howard and Cohen in 1947. Various devices for the measurements of integrated linear intercepts have been constructed, primarily by petrographers. The hydraulically operated stage designed by the writer5 was satisfactory, but prolonged use caused air bubbles to become entrapped, which introduced back-lash. A new stage has been constructed which avoids this defect and provides better integration when measuring directional structures. This utilizes a circular traverse, and integration is achieved by counting electrical pulses produced by a photocell and a light chopper.* The stage is shown diagramatically in Fig. 1 and in photograph, Fig. 2. It is of simple construction. Mounted on a plate with clamps to fit the stage of a standard metallurgical microscope is a worm and 100-tooth worm gear, the latter supporting the specimen to be measured. The worm is manually actuated by a knob which contains inside it three

Jan 1, 1961

By W. R. Webb, M. O. Peterson

WHEN men drive haulage equipment ranging up to 22 tons in an open pit operation, they must live with the realization that their safety is dependent upon the machines they drive and how well they operate them. The hazards inherent in their jobs must be recognized, met, and defeated. It comprises a never ending struggle toward perfection-an almost un- obtainable goal. The Jones & Laughlin Benson Mines, at Adirondack State Park in New York, created a safety program which resulted in only one three day lost time accident from April 1948 to April 1952. At the very start of the program, management of the open-pit operation recognized the hazards existing at Benson. The program was designed to meet each danger. With a knowledge of the problem faced, the process of minimizing each facet was planned along lines of maintenance of equipment and training of personnel. Its success is evident. In the ever-present struggle, care and maintenance of machines and application of experience to new equipment design are mainstays. Truck Haulage Benson produced 2.9 million tons of crude iron ore and 1.6 million tons of waste in 1951. To do the job, truck mileage reached 500,000 miles. The tremendous mileage emphasized to safety planners, the fact that the more work done, the greater the possibility of risk in haulage operations. Instrumenting the aim of the safest equipment possible is a methodical servicing program. Like other segments of the drive, the servicing program is based on greater production with fewer accidents. Every truck is serviced at least once per eight-hr shift. Examination includes inspecting and tightening wheel studs, checking tires, steering apparatus, lights, brakes, wipers, heaters, fire extinguishers, and refueling. A running history of the equipment's operating life is kept in the form of service and maintenance records. Machine operators are constantly on the alert for malfunctioning of units. At the first sign of trouble the truck is returned to the garage for exchange. No truck functioning incorrectly is kept on the line, regardless of its shift check schedule. The program resulted in a reduction of the number of costly overhauls and cut down the number of haulage accidents. Miscellaneous Mobile Equipment Auxiliary units, operating within the pit, have presented definite safety problems. The highest accident rate in the pit occurred on trucks carrying water and bits to the churn mills. The weight and awkwardness of bits and drill stems, combined with remote delivery points were direct causes of numerous accidents. Here, the problem has been one of equipment handling, rather than haulage. All air compressors for secondary drilling are truck mounted, facilitating mobility. In addition to making it easier to move the equipment, truck mounting has eliminated many of the hazards connected with relocating machinery. By making air compressors independent of other units, drilling operations have been speeded up considerably. Unseen rocks in the path of moving vehicles are a constant source of tire damage. At Benson the problem has been met by supplying each loading crew with a bulldozer for cleanup operations. The pitman directs the dozer operation, and when truck drivers back into loading areas, he serves as an extra set of eyes. Modern Truck Garage Provides Drive-Through Service Simplicity is the essence of any preventative maintenance program. At Benson, a modern garage, with a drive-through service bay simplifies servicing. Shift inspection of the 22-ton haulage units is accomplished with minimum delay and maximum thoroughness. Major repair work and periodic overhauls are done in the repair section of the truck garage. Crane facilities for handling heavy assemblies ease the job and add to the safety factor. Other mobile machinery,

Jan 1, 1952

By John Tyssowski

IN 1925, Harry Howard Stout, then metallurgist for Phelps Dodge Corporation, while investigating the cleaning of cathode copper by various gases at elevated temper-atures below the melting point of the metal, observed in the laboratory that particles of pure copper heated in a closed tube filled with hydrogen seemingly "stuck together." By further investigation he found that there was actual crystal growth across the boundaries of the particles of pure metal; in other words, there was a complete new crystal realignment and growth throughout the newly formed copper mass. It was coalescence, not adhesion; the several parti-cles had become one unit. From this dis-covery has been developed the coalescence process, whereby copper of cathode purity is squirted out in semifabricated form from an extrusion press, by the appli-cation of about 30c0 tons pressure on a 10-in. piston. Stout decided that cathode copper pro-duced by electrolytic deposition was the logical source of the pure copper required for the coalescence process, but as there was no way of reducing the ordinary tough commercial cathodes to the small particles required he was confronted by a serious problem at the outset. Under his direction, this problem was solved by William H, Osborn and Harry Howard Stout, Jr. They developed the process and technique for producing cathode copper in brittle, friable form, and to them must be given the greater part of the credit for this phase of the development program as well as for that relating to the gas cleaning of the cathode particles.

Jan 1, 1940

By Clemens Jones

A FORM of apparatus for volumetric determinations which shall possess the features requisite for the constant use of potassium permanganate, is a very desirable fixture in a well-appointed laboratory. Expedients to economize time and insure accuracy are generously employed for various other reagents, while the permanganate seems to have been consigned to the use of an ordinary burette, and a black bottle of the standardized solution. But the introduction of new, methods dependent on the permanganate, and the urgency of technical requirements where it has long been indispensable, require a revision of practice more scientific and convenient. The apparatus designed by the writer for the laboratory of the Thomas Iron Company at Hokendauqua, Pa., is so simply contrived and works with such entire satisfaction that a description of it may be of use. It may be prefaced that the characteristics of a suitable device offer some mechanical difficulties when combined in a continuous appliance. The burette, B (50 C.C. to 1/10 c.c.), shown in Fig. 1, consists of the graduated tube proper and an arm, E, fused to it below the 50 c.c. mark. At its top are rubber connections with the blast-aspirator, shown in the cut (Fig. 2) of the front view. By means of an extra stopcock, D, connection through E is established with the reservoir F. The burette is clamped Securely to a slide, C, which is counterpoised and moves freely on guides between two parallel sides, L, suitably

Jan 1, 1887