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By Ottey M. Bishop, William G. Peryam, Fred E. Johnson

THE Lepanto Consolidated Mining Company is the largest copper producer in the Philippines, and the only one that makes a concentrate valuable principally for its copper; also, it has the only productive copper mine situated at considerable distance from the sea, and is the only one in the islands operating its own smelter. The Lepanto mine is in the Municipal District of Mankayan, sub-province of Benguet, near the heart of the Mountain Province of Northern Luzon. It is 165 km. from its shipping point at San Fernando, Province of La Union, on the shore of the China Sea. Elevations at the property range from 3200 to 4500 ft. The climate is very mild; temperatures are seldom below 50° or above 80°F. Annual rainfall approaches 170 in. and is mainly confined to a rainy season lasting from May to October. The months from December to April, inclusive, are usually extremely dry. This climatic pecularity entails the problems of landslides on the roads during the rainy season and water shortage during the dry season. The Mountain Trail, an improved rocksurfaced toll road maintained by the Commonwealth Government, gives access to the property. The 105 km. over this road may be traveled in about 4 ½ hr. during the dry season. Very few sections of the road are straight for more than 100 meters, and about one third of it is a one-way road controlled by gates. All freight for the property is delivered by the Manila Railroad Company to Bauang, La Union, 45 km. west of Baguio and at sea level, where it is picked up by freight trucks and hauled via Baguio to Lepanto. Granulated matte is hauled in bulk from Lepanto in four-ton lots on freight trucks to the storage bins at San Fernando. Freight rates from Bauang to the property amount to [P]8.oo per ton, and from the property to San Fernando the rate is [P]16.00 per ton. The company pays the road toll, [P] 1.00 per truck, each way. THE CAMP The company maintains a modern camp, well separated from the mine and reduction plant. Comfortable and sanitary living quarters, water, and light, as well as free medical service are provided all employees. A hospital staffed by a doctor and two nurses takes care of all medical treatment. Considering recreational facilities of great importance, the company has provided two tennis courts, two basketball courts, and badminton courts for employees. Bowling alleys and a motion picture theater are operated by the company, the profits being expended for other recreational purposes. A moderate sized recreation hall serves for barrio dances, meetings,

Jan 1, 1942

So commonplace that they are seldom noticed, mining-machine bits have a defi-nite and important bearing on the cost of coal production. At the average mine many thousands of bits are used during the year. The actual cost represented by the pur-chase of the bits used, as well as that of sharpening and handling them, represents a considerable sum of money. From the point of view of indirect costs they are im-portant, as the lack of good bits at a mining machine can seriously impair production. Good bits tend to ensure an adequate supply of coal.

Jan 1, 1940

By N. R. Shoko, J. Chirasha

Refractory design remains the most fundamental factor in furnace construction. Refractory design details and proven technology consideration is of paramount importance to come up with an optimum furnace life and to maintain productivity in the life span of the furnace lining. The failure to produce a technically or operationally durable refractory design lining could give rise to pre-mature deterioration of the refractory lining and furnace shell. The premature failure of the furnace lining will lead to extensive heat losses, furnace bath shift, change in taphole orientation and alteration of the Pitch Circle Diameter. A combination of these were experienced at Zimbabwe Alloys? new high carbon ferrochrome furnace. The Zimbabwe Alloys experience has shown an excellent furnace performance in the first two years of operation although signs of an anomaly showed within the first six months of the new furnace. Production slowed down due to induced problems from refractory failure causing furnace distortions impacting on the availability of the furnace and smelting capacity. This paper presents the lessons learnt, measures taken to deal with the premature failure and constraints within which the situation was managed.

Jan 1, 2007

By Jerry Bennett

A recant Bureau of Mines analysis has shown that failure of blast area security systems is the mayor cause of mine blasting accidents. Accidents occur during scheduled blasting because of failure to clear the blast zone, inadequate guarding, and failure of personnel to follow instructions, retreat to a safe location and/or take adequate cover. The high incidence of blastslte security-related accidents could be considerably reduced by increased attention to improving minesite blast-guarding practices.

Jan 1, 1984

By Waldo Valderrama, Luis Magne, Paola Grandela

The effect of liner shape on power consumption was studied in a small laboratory mill under various operating conditions. It was found that the angle subtended between the lifter front face and the face in contact with the mill case has the most significant influence. The increasing height of lifter reduced power consumption, whereas the lifter spacing did not show any influence. The effect of height is less relevant at lower front angles. Highest power consumption is achieved with a 45" front angle. A comparison of cylinders and balls under identical conditions gives higher power consumption for ball charges. The data does suggest that, for maximum power draw, slip in the outer layers of the charge and the early recirculation of energy to the mill case should be avoided. Both factors prevent an efficient energy transfer to the mill charge.

Jan 1, 1995

By Peter Moser, G. Reihholf

Holcim, one of the world's leading suppliers of cement, aggregates and concrete, has set up a few years ago a working group “Quarry” in order to optimize the performance of its central European quarry operations in terms of work safety, environmental standards and economic performance. One of the activities of this working group "Quarry" addresses the subject of blast fragmentation in the quarries. A benchmark study of the blast work in all quarries has shown substantial differences for the various operations in terms of drill& blast costs. Especially big differences were found with respect to the drilling patterns as a function of the borehole diameters and with respect to the utilization of the borehole volume for charging the explosives.

Jan 1, 2006

B. F. TILLSON,* Franklin Furnace, N. J.-I would like to ask Major Yerkes if he will not give us more examples of the tests than are contained in the printed pamphlet. It would be of great interest to study them more carefully. ROBERT M. YERKES, Washington, D. C.-The reason for not reproducing the methods in any public print is that it lessens their value and necessitates the preparation of new test materials. BRADLEY STOUGHTON, New York, N. Y.-I hope that this matter will be of so much interest to the members of the Institute that the Directors will decide to appoint a committee which can bring further results of this practice before us. I understand that Columbia University, at least in some departments, has already adopted the B and A tests and is using them. I understand that some industries have considered seriously the question of grading their employees in accordance with

Jan 4, 1919

By R Verreet

In April 2000 Mount Isa Mines installed hoist ropes of a new design on the double-drum winder at their P49 shaft. The ropes, CASAR Duroplast, were about three times as expensive as the previously used triangular strand ropes. The P49 shaft is situated at Mount Isa MinesÆ George Fisher Mine, located some 30 km north of Mt Isa. This shaft used the tried and proven 6 x 33 triangular strand style ropes. The rope life attained by these ropes at the time was acceptable due to many years of satisfactory performance. The following study indicates the improvement of service life using CASAR Duroplast rope in P 49 shaft, which depends on shaft and winder parameters of that particular shaft and cannot necessarily be generalised to other shafts.

Jan 1, 2005

By H. D. Jacobs

The Bureau of Mines undertook a research program to insure an adequate supply of iron raw materials for future iron and steel making needs. A sample was obtained of oxidized taconite from the western Mesabi Range in Minnesota, and the metallurgical response of the taconite to beneficiation by a process that included selective flocculation-desliming-cationic flotation was evaluated. The sample contained 35.3 pct iron and represented approximately 2 billion tons of crude material. Selective flocculation and flotation were evaluated in a pilot plant with a feed rate of 900 Ib/hr. Concentrates averaging 61.7 pet iron and 5.1 pet silica were obtained, with an accompanying iron recovery of 67.2 pet. About 83 pct of the process water requirements were reclaimed from the slime and froth tailing and then recycled.

Jan 1, 1980

With the continued implementation of stricter limitations on the discharge of excess process water from all existing and future mining and metallurgical operations, the design and operation of the entire process water circuit must form an integral part of any total operational package. It is far better to æanticipate and circumvent the problemÆ rather than be forced into an expensive remediation program after the event. By far the greatest problem relates to the treatment and disposal of what is generically known as acid drainage. In simple terms, an acidic metal sulfate solution is generated by a series of chemical and biological reactions as soon as most sulfide minerals are exposed to air and water. Treatment of this solution by one or more of a wide range of chemical and physical options can involve substantial capital and operating costs, although there are recent processing options that yield saleable by-products, thereby reducing the financial liability of what is effectively a waste stream. This presentation provides an overview of the Australian situation compared with the rest of the world and outlines the basic features of a number of the more advanced passive and active acid drainage options.

Jan 1, 2004

By Gerald Sherman

MINING asbestos ore by caving at Thetford Mines, Quebec, has been described in the Transactions of the Canadian Institute of Mining and Metallurgy in papers presented by the staffs of The Asbestos Corp. Ltd., in 1934, and Johnson's Co. Ltd., in 1941. The production by caving prior to 1949, in round figures, has been 14,500,000 tons of ore by The Asbestos Corp. and 5,500,000 by Johnson's Co. They are the only caving operations in asbestos at the present time. The Jeffrey mine of the Canadian Johns-Manville Co. at Asbestos, 40 miles southwest of Thetford, is well along in preparations for caving, and The Bell Asbestos Mines Ltd. at Thetford Mines, will follow their examples later. GERALD SHERMAN, Member AIME, is Consulting Engineer, Johnson's Co. and Canadian Johns-Manville Co., New York, N. Y. AIME San Francisco Meeting, Feb. 1949, and New York Meeting, Feb. 1950. TP 2828 A. Discussion (2 copies) may be sent to Transactions AIME before May 31, 1950. Manuscript received Nov. 2, 1949. Nearly all of the asbestos produced by the western hemisphere is mined in those districts of Canada. Since it has been the subject of a number of technical papers, this contribution is offered as a review of progress. Some introductory information seems appropriate, for few members of the American Institute of Mining and Metallurgical Engineers are familiar with the mineral, or how asbestos deposits differ from others in caving characteristics. Asbestos is found in peridotite, a basic intrusive rock irregularly altered to serpentine and erratically fractured, well enough to cave in bulk, but leaving many blocks of solid ore of all sizes scattered through the deposit. Chrysotile is the variety of asbestos produced in Canada. Its fibers are the most valuable commercially, having a good proportion of long fibers, strong, silky, flexible, and suitable for spinning. The fibers occur in all lengths, from the microscopic to 3 in., or more, the shorter are more abundant. Their values depend on length combined with other qualities noted above. They occur as veinlets filling fissures in the peridotite, with crystals compactly arranged in parallel across the cracks. They are sometimes lightly frozen to the walls but the partings are distinct, often marked by particles of magnetite adhering to the fiber ends. Sometimes they break away from the rock in slabs an inch or more in thickness. In wide fissures the fibers are not always continuous, the "broken fibers" being separated by lines of parting with occasional scattered grains of magnetite, which is an injurious mineral to be elirninated when possible. In addition to the chrysotile ''Cross fiber," some "slip fiber" is found in fault fractures in limited quantities of less valuable character. With the exception of the Asbestos Corp, ore, in which the content is said to be more uniform, asbestos is eccentrically distributed through the peridotite. It is the general impression that the higher grades are more often found in hard rock. There are rich pockets and leaner areas which range down through various grades to minor barren sections. Wholesale mining is necessary to make sure of recovering all the high grade for there are no reliable indications of its existence. Ore selection only appears in constructing assay-grade limits for caving. The mill yield of the Thetford ore body in 1934 was 6 to 10 pct of the ore milled, made up of all classes, with occasional runs up to 15 pct or so. Quotations for Canadian asbestos* are as follows: Per Ton No. 1 Crude (% in. and longer) $896 @ $960 No. 2 Crude (Y8 to % in.) 350 @ 545 Spinning (less than % in.) 204 @ 378 Other classes, price diminishing with length. Shorts or "refuse" 24 @ 46 • From Eng. and Min. Jnl., Nov. 1948. Asbestos of even superior quality for electric insulation is found in Arizona limestone. It is white, containing very little combined iron, but occurs only in small quantities.

Jan 1, 1951

By Carroll W. DeKock

Thermodynamic data for selected metal sulfates were critically evaluated and compiled as part of the Bureau of Mines program to provide a scientific base for use in developing new technology and predicting the feasibility of new processes. Values for Cp°, S°, H° - H°298, -(G° - H°298)/T, ?Hf°, ?Gf°, and log Kf as a function of temperature are given in tabular form. Thermodynamic data were compiled for VOSO4, Cr2(SO4)3, MnSO4, FeSO4, Fe2(SO4)3, CoSO4, NiSO4, Cu2SO4, CuSO4, CuO-CuSO4, ZnSO4, and ZnO-2ZnSO4, together with their stable hydrates.

Jan 1, 1982

By Stephen Northey, Nawshad Haque, Terry Norgate

"Life cycle assessment (LCA) is a recognized tool to evaluate various processing routes for metal production. Declining ore grades and higher specific energy requirements for primary metal production put greater emphasis on recycling. Greenhouse gas (GHG) emissions of steel and aluminium metal production were quantified with recycling scenarios using material recovery facility (MRF) data from the database of SimaPro LCA software. The GHG footprint of the MRF is relatively minor compared with that of associated transport during collection (i.e. 10 times more than MRF) of curbside recyclable material. Additionally, if the bulk recyclable material is sent overseas (i.e. Australia to China) from the MRF for further processing, the GHG footprint of shipping can significantly be larger compared with the sum of the collection and MRF (assuming electricity is from same source). Thus opportunities exist for reducing GHG emissions from secondary metal production if it is processed close to the MRF.IntroductionIt is a challenge to recycle metals significantly, although theoretically infinite recycling is possible due to their elemental nature. Leaks from the metal stocks in society occur through corrosion, wear and dispersive uses, or via land filling or similar activities that return metals to the earth. In order to provide a technically sound and transparent assessment of metal recycling, a methodology such as life cycle assessment (LCA) should be used. By taking a life cycle perspective, the beneficial recycling properties of metals can be evaluated in a manner that enables appropriate comparisons with other materials or product systems that do not have recycling loops. In practice, mixtures of primary and secondary metals are often used in new products, and also at the end-of-life various processing methods are used for recycling.The difficulty of introducing recycling into LCA is to set the right boundaries for the different flows ending in different product systems. It is a question of which observed material flow belongs to the first product system and which one to the second or subsequent systems. Recycling can be part of any product LCA. However, it is often a complex issue which requires specific considerations. As pointed out by Yellishetty et al. and Birat et al. [l, 2], LCA practitioners are left with much freedom in allocation of environmental burdens to account for recycling, thus making subjective judgments on recycling and allocation of credits to recycling. This often makes it difficult to compare the results of LCA studies conducted by two different practitioners even on the same processes. As LCA is often used to define policy in government, business and society circles, it should be based on a sound, objective and unbiased description of recycling."

Jan 1, 2014

By E. P. Bucklen

Simulation is a tool useful in the evaluation of the probable effect which various changes may have on the performance of time-dependent systems. This is especially true as far as rail transportation in mining is concerned. The VPI-OCR RAILSIM program is a computer program designed specifically for solving a broad range of problems encountered in the design of haulage systems of new mines as well as in the operation of haulage systems in existing mines. This program is one of several computer applications for evaluating mining systems developed at the Virginia Polytechnic Institute and State University under contract with the Office o f Coal Research of the U.S. Dept. of the Interior. The RAILSIM program uses Monte Carlo techniques to introduce variability in the occurrence of events such as would be observed in real systems. Data are required to describe the haulage network, locomotives, stationary facilities, and other miscellaneous parameters. Output from the program lists measures of performance that are useful in assessing the capabilities and limitations of given system configurations. The output information may cover many shifts of operation to indicate the broad range of variation and interaction which can occur as the system responds to varying levels of demand for service. The RAILSIM program was tested extensively in mining operations. The results of some of these tests are used to illustrate the usefulness of this program.

Jan 1, 1972

The detailed engineering of a coal preparation plant is important from the point of view of optimum constructibility, operational security, ease of maintenance, operating costs, meeting environmental goals, safety, plant housekeeping and reduced corrosion and erosion. This paper reviews the several large coking coal preparation plants engineered by Fluor Australia in the past 10 years, and changes and trends apparent for detailed engineering of future plants. Areas of engineering to be covered are coal feed preparation, conveyor design, plant layout, electrics and instrumentation, noise attenuation, erosion and corrosion protection, magnetite handling, rejects and tailings disposal and coal stockpiling and blending.

Jan 1, 1982

By Robert A. Clifton

This Bureau of Mines report discusses the mineralogy of zeolites, the properties that make them commercially valuable, the conditions of formation of both natural and synthetic zeolites, and present and potential markets.

Jan 1, 1987

By J. M. Stuve

A novel calorimetric solution technique, recently developed at the Bureau of Mines, was tested using synthetic samples of chalcocite (CU2S) and covellite (CuS). The solution of these refractory sulfides was accomplished by oxidation with bromine in a moderately acidic, aqueous solution. The resulting values for the standard enthalpies of formation (?Hf°, 298.15) for CU2S(c) and CuS(c) were -18.1 ±1.1 kcal/mol and -13.3 ±1.1 kcal/mol, respectively. These values are in good agreement with published formation values derived from other methods of physicochemical measurement.

Jan 1, 1982

By G. Jalkanen

Dealing with a trend in inverse distance estimation, IWD, is presented. A measurement is proposed to be consisted of a portion due to a mean and a portion due to a residual. The procedure consists of de-trending the measurement via a linear or nonlinear regression. Residuals are computed, and IWD parameter estimation is conducted on the residuals. Estimation at un-sampled points is then computed by estimating the mean and adding on the estimate of the IWD on the residual. A possible BOXCOX transform is also proposed.

Jan 1, 2010

By James Douglas

In discussing the waste upon which hinges, or is supposed to hinge, so largely the preservation of our national resources, the conclusions reached would be more reliable if actual experience were consulted, and fewer deductions were drawn from general statements, which are often the product of the imagination. It cannot be questioned that the value of by-products has .not been sufficiently appreciated by us, and that our tardiness in recovering the useful ingredients of the escaping gas of our coke-ovens is one of the most glaring instances of shortcoming in that direction. And yet even for that sin there is some palliation in the immature condition of affiliated industries. I presume that it is admitted, without argument, that, except under very exceptional conditions, all the elements cannot be recovered from most of the ores or natural products which we treat. While it is a shame that the by-products from our coke-ovens should be dissipated, Edward W. Parker's report to the U. S. Geological Survey for 19061 supplies a fairly good excuse in justification of this appalling waste. He says (pp. 773 to 774.): " What has been already commented on in previous reports about the slowness of manufacturers to change from the better known but wasteful beehive practice to the by-product recovery method of coke manufacture is particularly emphasized in the statistics presented in this chapter. For it would appear from the table following that the construction of by-product ovens had about come to a standstill, especially when the records for the preceding five years are taken into consideration. At the close of 1901, when there were only 1,165 by-product ovens completed in the United States, there were 1,533 in course of construction, 498 of which were completed during the following year. At the close of 1902, 1,346 retort ovens were building, 293 of which were added to the completed plants in 1903. At the close of 1903, 1,335 new ovens were building and 954 of these

Jan 1, 1910

By M. W. Clegg

The application of the Laplace transformation to problems in the flow of compressible fluids in porous media has provided a large number of exact solutions. For plane radial flow, however, these solutions are either complex integrals or infinite series and are of little value to the field engineer. In the case of production at constant well pressure, the available approximate solutions me valid for large times only. In this paper it is shown that an approximate inversion formula for the Laplace transform, developed for the solution of viscoelastic problems, is applicable to radial flow problems and provides simple analytical solutions to constant terminal pressure problems. The method may be used to obtain approximate solutions to many problems, including media with radial permeability discontinuities, multi-layer formations and pressure buildup in wells after shut-in. The results are compared with the few available computer solutions as well as the large time solutions, and it is shown that this approximate method greatly extends the time interval over which a simple analytical solution is acceptable. INTRODUCTION The study of transient problems in the flow of fluids through porous media has benefited greatly from the application of transform methods. The use of the Laplace transformation for solving parabolic equations has been widely discussed in the field of heat conduction and diffusion as well as in the petroleum literature. Removal of the time variable with the Laplace transformation generally reduces the problem to a boundary value problem which may be solved by standard techniques. A much more formidable problem then faces the engineer, however, for frequently the transform does not possess a simple inverse. The result is that the general inversion integral must be used and this leads to either an infinite integral or an infinite series, both of which are difficult to handle from a computational standpoint. Asymptotic approximations for the inverse have been known for some time and these yield approximate inverse functions that are valid for very large or very small times — but frequently the times of interest lie somewhere between these two extremes. Therefore, some acceptable approximation valid over a larger interval of time is desirable. During the past few years a number of methods for achieving this have been developed and some of these are discussed briefly in this paper. The relative merits of the various methods are not evaluated here, but some general conclusions reached by other authors are given. One of these methods has been applied to problems associated with the radial flow of compressible liquids to producing wells. In the case of production at constant well pressure, the method leads to simple analytical solutions for a number of standard problems; e.g., homogeneous formation, permeability discontinuities, pressure buildup. These solutions greatly extend the range of validity of the asymptotic ones (valid for large times only) and should be of value in studying the behavior of wells producing under constant pressure conditions. METHOD FOR THE APPROXIMATE INVERSION OF LAPLACE TRANSFORMS Much of the work that has been done on the approximate inversion of Laplace transforms has originated in viscoelastic problems. Apart from the asymptotic approximations,1 one of the first approximate methods was due to Alfrey.2 If (s) is the Laplace transform of f(t) defined by