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By G. Don Sullivan

Surface mine operators have organized a voluntary group known as the Mined-Land Conservation Conference for the specific purpose of developing and expanding reclamation programs on mined land. As a part of the Conference program, a Voluntary Industry Program was adopted and subscribed to by its membership. This program stated: "The basic approach to a sound conservation program is the restoration of mined land to its most practical and productive use within the shortest possible time . . . reclamation of mined lands, including planting to grasses or tress, should be done on a planned basis, under technical guidance by personnel trained in this field."

Jan 7, 1965

By R. B. Schluter, M. M. Fine

The Bureau of Mines' Twin Cities Metallurgy Research Center has of late concerned itself with reduction-induration of iron ore. One development provided a flowsheet for the agglomeration of green concentrate pellets in a reducing atmosphere created by a solid reductant external to the agglomerate. The product pellets were well metallized and physically competent. Maximum recommended operating temperature was 2100º F. In these studies, it was observed that unflred iron ore pellets indurated in a bed of anthracite or certain lignite chars frequently acquired exceptional crushing strength. A diagnosis of the phenomenon revealed that sulfur in the fuel was the probable cause. Accordingly, a research program was established to test this premise and to put it to practical use. Gaseous reductants were employed initially because of the ease and accuracy with which they could be metered.

Jan 10, 1969

By R. S. Dean

JUST as the mineralogical name bauxite has come to include several minerals not known at the time the name was first applied, so the concept of bauxite as the one source of alumina must be enlarged during the war period to include the production of alumina from other, low-grade sources. Speaking in a narrow mineral logical sense, there is no such thing as bauxite, and similarly there is now no one source of alumina, and no one process for its extraction.

Jan 1, 1943

Pumping coal to market may help Appalachian coal operators increase their share of the eastern seaboard fuel business. Transporting it by pipeline is already an accomplished fact, but until recently it had to be dewatered to be used in boiler furnaces. The campaign for these eastern markets was begun in earnest last November by the widely publicized announcement of successful plant-scale firing of a central station boiler with coal slurry pumped to the burners. This latest advance makes coal similar to oil and gas in convenience in handling and controlling at the consumption end of the pipeline. Slurry could be considered a new commodity for the fuel market. HUGE POTENTIAL MARKET The heaviest concentration of power plants in the U.S. is along the line Washington, Baltimore, Philadelphia, New York and Boston which makes this region the best hunting ground for selling pipelined coal brought from western Pennsylvania and northern West Virginia. Furthermore, if this region is assumed to consume 125 million tons of coal annually, on a comparable basis, the consumption of oil and gas would be about 180 million tons. Even if all of this fuel is not consumed in central stations, it is still a very big market for coal at the right price. Consolidation Coal Co. and Texas Eastern Transmission Co. are trying to line up customers in this area so that a pipeline can be built. This is not to say that there are not many other areas in the U.S. that could not be supplied advantageously by a mine-to-market pipeline.

Jan 1, 1962

By Charles P. Williams

THE successful production of zinc white or oxide on a commercial scale in this country dates from the issue of the patent of Samuel Wetherill, for the preparation of the material (November, 1855), and

Jan 1, 1877

By W. G. Pfann

The problem of forming points on wires that were from 0.002 in. to 0.010 in. in diam arose in the recent appearance of silicon and germanium point contact rectifiers as elements in microwave radar.' In these devices a pointed tungsten wire makes a delicate contact with the surface of a semiconductor. Because the quality of such rectifiers is largely determined by the nature of this contact, considerable attention has been given to the formation of the metal point. Reproducibility of contour and freedom from burrs and even microscopic irregularities are considered essential. The operations involved must be simple and rapid enough for mass production. Previously tungsten wircs had been provided with conical points by a grinding method which involved rotating a wire about its axis and causing it to bear at an oblique angle against a spinning abrasive disc. This was later complemented with an electrolytic polishing treatment which removed irregularities from the ground point and also rounded it off at the tip—a desirable feature. Finally, these operations were supplanted by the electrolytic pointing method described here. Mechanism of Point Formation The wires to be pointed are partially immersed in an electrolyte in a vertical position whereupon they are provided with smooth rounded points entirely by electrochemical action. The process is independent of the depths to which the wires penetrate the electrolyte because the points are formed at the surface level. It may be used to point a single wire or many of them simultaneously and is applicable to wires of different diameters within a limited range. Solution of the immersed portion of a tungsten wire is accomplished by making it the positive electrode in an electrolytic cell, as shown in Fig I. While the wire is maintained at constant voltage the current through the cell falls continuously, principally because of the decrease in wetted area which results from solution of the tungsten. This increase in resistance occurs in a reproducible manner and is used as a control in the process. As thc immersed portion of the wire dissolves, it remains cylindrical in shape except for the short section which is wetted by the meniscus. Here the rate of solution is lower and decreases as the top of the meniscus is approached. The result is the formation of a tapered section inside the meniscus. As solution continues, the cylindrical section either dissolves entirely or drops off just before complete solution, leaving only the taper which is now sharply pointed. Further action causes this point to become rounded and then quite blunt, until finally the end of the wire is almost plane. Fig 2 shows the stages in this development. Contour PF is most representative of those used in point contact rectifiers. Thus a variety of point

Jan 1, 1949

By Louis C. Just, Robert L. Sandefur, Carl E. Williams

In 1981 Ertec Rocky Mountain, Inc. completed a significant development in contemporary planning support; MINEPAK was completed, tested on various properties and offered for license. MINEPAK was one of the first computer systems for ore body analysis and mine planning that - Was designed as an interactive and completely integrated system - Was portable so that it can run on many hardware systems - Was really user friendly - Can run on minicomputers and on some microprocessors - Was built around a data base management system MINEPAK was designed to be a completely general block modeller and it achieved that goal. Since it contained a gridded file type, surfaces could be easily modelled but the system needed extensions to allow layered deposits to be modelled with the same ease as block models. So COALPAK was designed. COALPAK is an extension as well as a modification of MINEPAK. A 'layer' file type was defined and retrofitted into the existing system, new software tools were developed for modelling layered deposits, and tools for strip mining were written.

Jan 1, 1983

By Joseph Domenico

AMONG others, one of the most important duties of the accounting department is to disclose to the management the cost of production accurately and as quickly as possible after the ore has been produced and treated. A report is issued daily showing man shifts and the cost of labor, supplies, power, and miscellaneous charges to each department of the operation: mining, crushing, milling, packing and loading, and general expense. Mining costs are broken down into stoping, handling, development, exploration, and miscellaneous, and each of these subdepartmental costs are further broken down into the branches making up the subdepartment. Costs of crushing, milling, packing and loading, and general expense are detailed in the same manner. With such a detailed daily report as this, the management is able to keep in close touch with the efficiency of the entire operation. Because no expense items are deferred or spread over a period, and so that the report does not lose its comparative valve, appearances of unusual charges are explained.

Jan 1, 1946

By R. W. Raymond

In connection with the paper of Mr. Locke on Gilsonite or Uintahite (Trans., xvi., 162) read at the Salt Lake session of the Utah and Montana meeting, in July, 1887, the following data may be of interest and value. In December, 1887, I received from Mr. William Wagner, Seeretary of the Denver & Rio Grande Railway Co., a box of specimens of an asphaltic mineral from Utah. In the course of the correspondence which followed, I learned that the box had been forwarded by Mr. J. A. McMurtrie, of the firm of McMurtrie & Streeter, railroad contractors, Denver, Col. Mr. McMurtrie was, in 1883, chief engineer of the Denver $ Rio Grande Railway, and the mineral mas first brought to his attention in that year by Mr. Thomas H. Wigglesworth, who was then employed in making preliminary reconnaissances for wagon-roads to be used in constructing the Utah extension (now the Denver, Rio Grande $ Western) of the railway. Mr. Wigglesworth, I understand, was subsequently chief engineer of the Colorado & Utah Midland, and is now again employed by the Rio Grande. He writes substantially as follows concerning this mineral:

Jan 1, 1889

By H. Foster Bain

This is the third volume of the collective index of the Transactions Each volume is indexed and the indices of Volumes I to XXXV have been collected into a single index volume, similarly the indices of Volumes XXXVI to LV are collected in a single volume This index covers Vol¬umes LVI to LXXII, and the three index volumes together cover all the volumes of Transactions published from the organization of the American Institute of Mining and Metallurgical Engineers in 1871 until the end of 1925.

Jan 1, 1926

By M. E. Shank, J. Wulff

In view of the current interest in magnetic materials having rectangular hysteresis loops, as for example those obtained with the grain oriented 50 nickel 50 iron alloys,t we wish to call attention again to the results obtainable with the perminvar (Co-Ni-Fe) alloys heat treated in a magnetic field. Data taken from direct current measurements made prior to and during World War II give the typical values shown below for two of the perrninvar alloys. Fig 1 and 2 show- the hysteresis loops for these samples. The first sample above consisted of small rings punched from 0.014 in. sheet stock. These rings were heat treated at 1000°C for one hour in a hydrogen atmosphere and then cooled with the furnace to 750°C at which point they were subjected to a magnetic field of 15 oersteds maintained during cooling to room telmperature. The molybdenum perminvar sample consisted of a spirally wound core of 0.001 in. tape. The heat treatment was the same except that box annealing methods were used and no hydrogen atmosphere was employed. Even better properties might be expected using hydrogen. The heat treating temperatures and cooling rates are not critical. Rectangular hysteresis loops produced in other perminvar alloys by heat treatment in a magnetic field were described earlier.',? Properties similar to those described above are realized in perminvars manufactured by conventional methods. Drastic cold working which in practice limits the final thickness and is gen- erally expensive may thus be avoided. This information may be of interest to those concerned with magnetic alloys and the development of contact rectifiers, magnetic amplifiers and so on.

Jan 1, 1950

By R. L. Stone, T. D. Tiemann

Jan 1, 1964

By H. I. Ashby

INITIAL development of the south orebody at San Manuel is being carried out from the No. 1 and No. 2 shafts. The haulage and grizzly levels are being driven to develop the upper one third of the massive hydrothermally altered and fractured monzonite orebody. This first haulage level has been placed at the 1475-ft level with a grizzly level 60 ft above. The grizzly level will be connected to all service shafts so that men and supplies can come down to the grizzly level and go to working places without congesting the haulage level. These connections are also a vital part of the ventilation plan. The haulage level is being advanced along the north and south fringes of the orebody and connections are being driven to the three shafts now under construction. The No. 1 and No. 2 shafts will serve the development work with supplies, skip hoisting, and ventilation at each shaft and the two shafts are connected on both the grizzly and haulage level.

Jan 7, 1954

Jan 1, 1936

RESOLUTION ADOPTED BY "THE BOARD OF DIRECTORS AT ITS MEETING ON APRIL 17, 1936 Recognizing the fact that the problems of the committee named by the Board to prepare the "official ticket" for officers and Directors of the Institute are various and difficult; and desiring to assist this committee by setting forth some of the principles that should guide the committee and some of the qualifications that should be required of candidates, the following instructions are formulated and the Secretary is directed to publish them in MINING AND METALLURGY concurrently with the publication of the names of each newly appointed Nominating Committee and to send a copy to each member of the Committee.

Jan 1, 1942

By A. C. Losekamp, R. M. Fincel, J. B. Conway

HIGH-TEMPERATURE thermal-expansion data for tungsten, rhenium, molybdenum, Mo-50Re, and W-25Re were obtained recently by means of a paired

Jan 1, 1965

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 W. J. Tait, A. E. Craig, E. P. McCurdy

The Circuitron herein described applies current from the classifier motor circuit and energy from the sound of grinding media to move an oscillating disc. The disc through a photoelectric cell controls the speed of the ore feeder and consequently the amount of ore delivered to the mill. THE Telluride Mines, Inc. at Telluride, Colo., is operating a flotation concentrator recovering lead, zinc, and copper with some gold and silver. The nominal capacity is 500 tons per 24 hr. The ore, which comes from several different mines, is characteristic of the district, changing from extremely tough rhodonite to soft gouge. The ore is crushed and washed, recrushed, and delivered to the mill bin at about % in. to serve as ball mill feed. Details of Grinding Circuit The material from the fine-ore bin is carried over a belt feeder driven by a Reeves vari-speed device. The belt discharges to a No. 86 Marcy ball mill, which operates in closed circuit, with jigs and a 6-ft Dorr classifier. A Massco density controller holds the density of the classifier overflow at a predetermined point. The overflow, which contains about 5 pct + 48 mesh, goes to the flotation section. Manual Operation Before the adoption of automatic control for the grinding circuit, this work was all done manually by the operator. The bin gate was set to deliver 40 to 50 lb of ore per lineal foot of belt, and the speed of the belt was adjusted by the operator to deliver at the rate of about 500 tons per 24 hr. As the ore changed in hardness, specific gravity, or in the amount of moisture, or, as the size of the feed changed due to bin segregation, crusher setting, or other causes, the operator made corresponding changes in the rate of feed by manipulation of the Reeves control. Sometimes these changes occurred so rapidly that they caused sharp, pronounced surges, which created very considerable unbalance from normal conditions in the grinding circuit and, more critically, in the flotation section. Since it is not possible for the operator to anticipate or follow such changes closely, a very considerable unbalance from normal conditions may occur, which will require a drastic change in the rate of feed. These surges upset the fineness of grind and interfere radically with the balance between tonnage and reagent control. All of this tends to reduce the grade of concentrates, increase the loss in the tailing, and thus decrease the recovery of values. The Circuitron Some years ago, The Mine and Smelter Supply Co., in conjunction with the operators at the Telluride Mill, undertook to build a device that would give close control of the rate of feed from the ore bin and to coordinate with this a related device that would regulate the amount of sand load on the classifier rakes. Emphasis was strongly laid on the fact that such a control must apply to the entire grinding circuit and must include the feed to the ball mill, the classifier sand return, and the density of the classifier overflow. If this could be done successfully, we felt that the circuit could be operated under best possible conditions, with compensations

Jan 1, 1951

By E. P. McCurdy, W. J. Tait, A. E. Craig

The Circuitron herein described applies current from the classifier motor circuit and energy from the sound of grinding media to move an oscillating disc. The disc through a photoelectric cell controls the speed of the ore feeder and consequently the amount of ore delivered to the mill. THE Telluride Mines, Inc. at Telluride, Colo., is operating a flotation concentrator recovering lead, zinc, and copper with some gold and silver. The nominal capacity is 500 tons per 24 hr. The ore, which comes from several different mines, is characteristic of the district, changing from extremely tough rhodonite to soft gouge. The ore is crushed and washed, recrushed, and delivered to the mill bin at about % in. to serve as ball mill feed. Details of Grinding Circuit The material from the fine-ore bin is carried over a belt feeder driven by a Reeves vari-speed device. The belt discharges to a No. 86 Marcy ball mill, which operates in closed circuit, with jigs and a 6-ft Dorr classifier. A Massco density controller holds the density of the classifier overflow at a predetermined point. The overflow, which contains about 5 pct + 48 mesh, goes to the flotation section. Manual Operation Before the adoption of automatic control for the grinding circuit, this work was all done manually by the operator. The bin gate was set to deliver 40 to 50 lb of ore per lineal foot of belt, and the speed of the belt was adjusted by the operator to deliver at the rate of about 500 tons per 24 hr. As the ore changed in hardness, specific gravity, or in the amount of moisture, or, as the size of the feed changed due to bin segregation, crusher setting, or other causes, the operator made corresponding changes in the rate of feed by manipulation of the Reeves control. Sometimes these changes occurred so rapidly that they caused sharp, pronounced surges, which created very considerable unbalance from normal conditions in the grinding circuit and, more critically, in the flotation section. Since it is not possible for the operator to anticipate or follow such changes closely, a very considerable unbalance from normal conditions may occur, which will require a drastic change in the rate of feed. These surges upset the fineness of grind and interfere radically with the balance between tonnage and reagent control. All of this tends to reduce the grade of concentrates, increase the loss in the tailing, and thus decrease the recovery of values. The Circuitron Some years ago, The Mine and Smelter Supply Co., in conjunction with the operators at the Telluride Mill, undertook to build a device that would give close control of the rate of feed from the ore bin and to coordinate with this a related device that would regulate the amount of sand load on the classifier rakes. Emphasis was strongly laid on the fact that such a control must apply to the entire grinding circuit and must include the feed to the ball mill, the classifier sand return, and the density of the classifier overflow. If this could be done successfully, we felt that the circuit could be operated under best possible conditions, with compensations

Jan 1, 1951

By Charles Williams

BOYLE'S law states that the volume of a gas at B constant temperature varies inversely as its pressure, PV = C, or V = C/P Therefore, the volume of a gas at any pressure is to its corresponding pressure as the volume of the same gas at atmospheric pressure is to atmospheric pressure, V, = V° Also, P1 P0 the volume of the gas at any other pressure is to its corresponding pressure as the volume of the gas at atmospheric pressure is to atmospheric. pressure, V2/P1 V0/P0 V°P VA Solving for V1 and V2, V2 = and V2 =V0P2/P0

Jan 2, 1927