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By Robert L. Anderson

A shaft or slope bottom is that portion of a mine that is contiguous to the bottom of the main hoisting shaft or slope. It includes the terminal tracks for loaded-and empty-car storage, locomotive run-arounds, locomotive shops, charging stalls, supply rooms, pump rooms, waiting rooms, and offices for dispatcher, weighmen, and foremen. This paper will deal principally with the arrangement of tracks and the handling of cars on the bottom, but includes other data that may be affected, directly or indirectly, by the bottom lay-out. All of the mines discussed are being operated in comparatively level coal seams.

Jan 1, 1937

By E. Oshima

In May 1991, a New Mitsubishi Continuous Copper Smelter Line started operation at Naoshima. Recently, it has been continuing steady operation and one and a half year campaign life has been achieved. In 1996, new records of on line time, the amount of copper concentrate treated and copper anode production were achieved. 1t proves the superiority of the process with respect to pollution control, energy efficiency, flexibility and easiness of the operation and over all economy including off gas handling cost. Furthermore, .plans are underway to prolong the campaign life for two years and to improve the process efficiency. This paper describes recent operation, improvements, and a future capability study.

Jan 1, 1998

It is proposed to consider a new access, mining and hoisting system for underground deposits, as an alternative to the commonly used decline or vertical shaft access. The proposed system offers fundamental improvements in gathering of exploration data, reduction of capital expenditure and significant savings in mine operating costs. The cost reductions are achieved through:superior orebody definition by Supersucker winzing on ore prior to the commencement of capital development; considerable reduction of capital development in waste; full capitalisation on all benefits of a raisebored excavation; introduction of rubber tyred skip and rubber tyred Mine Rapid Response Vehicle; introduction of simplified ore handling system and reduction of underground mobile diesel fleet; and introduction of minimum maintenance shaft concept. The system is applicable to deposits ranging from shallow, low dip angle, narrow vein, high-grade to bigger, massive type vertical mineralisations accessed from the surface, preferably from the bottom of an open pit; it is also suitable as a down dip extension of an existing underground mine. The system is highly conducive to mine automation and emerging trend aimed to increase the ratio of mined metal/mineral to mined waste. It offers substantial reduction in diesel exhaust gas emissions to the mine atmosphere.

Jan 1, 2000

By Hamed Layssi, Farid Moradi, Thomas Tingson

This paper describes the feasibility and pilot study of of using existing non-destructive testing solutions for evaluating structural integrity and mechanical performance of mass concrete foundations. This paper includes two pilot studies using well-known NDT methods (i.e., Crosshole Sonic Logging and seismic tomography) for new applications (i.e., NDT inspection of mass concrete foundations). In the first case, we will examine an existing mass concrete foundation block with internal cracking, which has negatively impacted the strength and stiffness of the foundation block. A combination of pulse velocity and 2D tomography was used to evaluate the structural integrity in the foundation block. In the second case, the quality and integrity of newly built mass foundations were evaluated using Crosshole Sonic Logging (CSL). The methods are combined to locate potential sub-surface defects such as large voids and discontinuities. This paper aims to study the effectiveness of the NDT methods of Deep Foundations to assess the quality and structural integrity of new and existing mass foundations and explore the opportunity to extend the capabilities of these tests beyond their conventional use.

Sep 8, 2021

By S. S. Dean, B. Silkes

"INTRODUCTION The metallurgical-research program of the Bureau of Mines .for the past 15 years has emphasized the production of high-purity nonferreus metals through the utilization of our available resources, ores, reducing agents, fuel, and power.Ore dressing or concentration, has always been a vitally important part of nonferrous metallurgy, and the Bureau continues to give most of its attention to it. In the field of the traditional nonferrous metals, the Bureau staff has developed natural-gas reduction of zinc, the application of glomerule technique to preparing high-grade lead concentrates for Scotch-hearth smelting, the production of electrolytic antimony from precious metal-bearing ores, and the recovery of nickel from nickel-chrome-iron ores.In the field of light metals, the Bureau staff has developed several improvements in both magnesium and aluminum production and in alloys of these metals. In the so-called ""rare-metal"" field, Bureau activities have included the production of pure ductile titanium on a larger scale than heretofore attempted, the electrolytic production of cobalt, chromium, and manganese which may now take their proper places as bases for nonferrous alloys as well -as ingredients of special steels. The Bureau staff has investigated many of these new alloys. Investigations of methods of recovering vanadium from its low-grade domestic ores have given promising results. Methods for the preparation of metallic zirconium have been improved."

May 1, 1947

By S. Dixon

The Peñasquito deposit in Mexico is one of the largest grassroots precious metal discoveries to be developed in recent years Minera Peñasquito, S.A. de C.V., a wholly owned subsidiary of Goldcorp Inc. has developed the Peñasquito property to produce an average annual production of 120 kilo tonnes of lead containing 0.5 million oz gold and 30 million oz silver and 250 kilo tonnes of zinc containing 20 thousand oz gold and 1.5 million oz silver.. The Peñasquito property covers a 39,000 hectare area in the western half of the Concepción del Oro district in the northeast corner of Zacatecas State, Mexico, approximately 24°45'N latitude/101°30'W longitude. The sulfide reserves are 1,009 million tonnes containing 3.33 million tonnes of lead, 7.26 million tonnes of zinc, 16.5 million ounces of gold and 1,000 million ounces of silver. This paper describes the work to justify the installation of HPGR to process the crushed SAG mill pebbles. The SAG mill-Ball mill and Cone crusher (SABC) grinding circuit is an accepted grinding circuit to optimize power consumption relative to throughput. The installation of a HPGR to process the Cone crusher product is the next step in optimizing the power consumption relative to throughput. The concern expressed by some on not moving on this change in grinding circuit was the capital and operating cost of a HPGR. The pebbles from the SAG mill can be the more abrasive and are the harder particles of the ore. Goldcorp investigated the wear and processing costs of installing a HPGR to treat the crushed pebbles. The conclusion was the installation would be a very positive economic factor in the operation of Peñasquito. This is the first application of the use of HPGR to process crushed pebbles. Minera Peñasquito and M3 Engineering selected Polysius to provide a Polycom 2417 with twin 3,000 kW drives. A comprehensive test program at Polysius has shown for 7% higher circuit power it is possible to get approx 23% higher tonnage. This coupled with full utilization of the SAG and Ball Mill available energies and with proper control of the transfer size from the SAG to Ball mill circuit there is the potential to achieve 65,000 mtpd per line or a 30% total capacity increase. The cost of power for this increase in grinding capacity is 4.8 kWh/tonne.

Jan 1, 2010

By P. Srinivasan

Corrosion is a major operational problem in amine-treating plants causing significant expenditures each year, Corrosion may become more severe when the amine plants contain process contaminants ? namely heat-stable salts. The heat-stable salts enter the plants with feed-gas streams and makeup-solution, and/or are produced within the plants by reactions of alkanolamine and available carboxylic-acid anions, This work investigated interaction corrosion effects that may exist in amine-treating plants containing a mixture of heat-stable salts, The investigation was experimentally carried out in a 5 kmol/m3 monoethanolamine (MEA) solution containing 0,20 mol/mol carbon dioxide (CO2) loading at 80°C under atmospheric pressure using carbon steel 1018, Six heat-stable salts, including formate, oxalate, bicine, acetate, thiosulfate and chloride, were tested with a series of salt combinations, Potentiodynamic Polarization, Tafel Extrapolation, and Cyclic Polarization were used for revealing corrosion behavior, determining corrosion rate, and examining the pitting tendency, respectively, Results show that thiosulfate induces the most corrosive environment when present either individually or in the form of salt mixtures.

Jan 1, 2005

By Peter McKenna

Different reefs being extracted from a mine will, in all likelihood, have significantly different semi-variogram models - and these will probably vary from geozone to geozone. As errors of estimation are dependent on the semi- variogram parameters, it follows, if a mine samples all reefs in all sections using the same sampling grid pattern, that estimation errors (or limits of confidence) will not be the same throughout the mine. This may be an undesirable situation! A geostatistical study of the relative merits of alternative sampling arrangements has been carried out by considering different reefs in different sections of a South African gold mine.

Jan 1, 1989

By John R. Bradley

The object of this paper is to survey and analyze the bearing of economic nationalism, competitive sources of energy, and technologic developments on international trade in coal with especial reference to the competitive position of the leading coal-exporting countries in the Italian market, the largest in the Mediterranean region, and the Brazilian market, the second largest in Latin America. The political, economic, and financial disturbances caused mainly by the World War have resulted in an amazing situation. Especially since 1930 have conditions been complicated.

Jan 1, 1936

Discussion of the paper of Robert H. Richards, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 81, September, 1913, pp. 2299 to 2303. C. D. DEMOND, Anaconda, Mont. (communication to the Secretary*) :-Any one who has observed the increased efficiency of the Wilfley tables in a mill when fed from a reasonably good hydraulic classifier, as compared with tables fed from a spitzkasten., which is a very poor classifier, will agree to the advantage of ? better classification." It must be gratifying to Dr. Richards to know that, directly or indirectly, maim mill men are responding to his persistent advocacy of correct principles of ore dressing and are accepting the results of his investigations. As he says, these principles mean much for both the conservation of resources and the profit of operators. When Dr. Richards gives us accurate figures as to the maximum size of free mineral grains in the tailings of the Wilfley table and of the vanner, they will be of a good deal of practical value in delimiting the proper fields for the Wilfley, the vanner, and the round table. He has coined the terms ? free settling" and "hindered settling."' The series may be completed by adding "crowded settling," the main principle of action on both the vanner and the Wilfley table, which is the principle of separation in a mass of grains crowded as closely together as they can be and yet continue free to move between one another; and the occurrence of larger mineral particles in the Wilfley tailing than in that from the vanner is apparently caused by the more violent agitation, due chiefly to the purposely sudden reversal of the stroke. It seems likely that the agitation caused by the wash water dropping directly upon the concentrate on the vanner is more harmful than that due to the shake. For the very finest material that can be concentrated by usual methods, the round table is superior to the vanner because it does not, have even, the gentle agitation of the latter. The action on round tables is, not crowded settling," but "film sizing," 2 but agitation is harmful in the latter action. George Gates proved this harm 20 years ago : in slaking the first successful large-scale application of canvas tables in California gold mills he abandoned all shaking motion, although he had patented canvas tables to which such motion was applied.

Jan 11, 1913

By Nelson Reátegui

El presente trabajo describe los sistemas computarizados utilizados en el centro de operaciones, explotación y beneficio de Hierro Perú, compañía minera localizada en el departamento de Ica. Inicialmente, la función de un sistema computarizado se limitaba a la reducción de costos en la mano de obra y a realizar operaciones básicas en los negocios. Posteriormente, esta situación cambió ya que estos sistemas se utilizan en los niveles de la gestión empresarial.l. Asimismo se explica las aplicaciones de este sistema al comercio, al tipo técnico-científico, así como el cálculo de reservas y el desarrollo del sistema computarizado de performance de equipo.

Nov 20, 1978

By Robert McIvor

The following is a summary of the Robert H. Richards Lecture on “Learning and Good Fortune on the Road to Discovery” presented at the Mineral & Metallurgical Processing Division (MPD) Awards Plenary Session on Feb. 23, 2026 during the MINEXCHANGE 2026 SME Annual Conference & Expo in Salt Lake City, UT.

Mar 1, 2026

By W. E. Roscoe

"Mineral exploration properties are those on which an economically viable mineral deposit has not yet been discovered. Such properties are bought, sold, optioned and joint ventured on the basis of their perceived potential for the existence and discovery of a viable mineral deposit. The intrinsic value of an exploration property is therefore based on the exploration potential. One measure of the exploration potential is the amount that can be justified to spend on exploration for a viable deposit.The appraised value method uses a cost approach to value exploration properties. It is based on the premise that an exploration property is worth the meaningful past exploration expenditures plus warranted future costs to test remaining exploration potential. Results of past exploration work are analyzed in order to retain only those past expenditures that are productive in terms of identifying remaining potential. Warranted future costs comprise a reasonable exploration budget to test that potential."

Jan 1, 2002

By George A. Page, Hewitt Wilson, Vance S. Cartwright

"Purpose of InvestigationThe process of removing solid material from liquid suspensions has been studied at the Northwest Experiment Station, United States Bureau of Mines, in cooperation with the University of Washington, as part of a general program to investigate the dewatering of Pacific Northwest plastic kaolins, which is difficult by ordinary filter-pressing methods. The present paper is a progress report of the work began by Vance S. Cartwright in 1928 and continued in 1931 and 1932. Spray evaporation is believed to be valuable for the following classes or grades of clay and clay mixtures:(1) Highly colloidal, plastic-type clays, which release their mechanically attached water with difficulty; (2) clays prepared for shipment in pulverized or powdered condition; and (3) synthetic, ceramic, porcelain, and tile mixtures prepared as aqueons suspension, dried and pulverized before molding. Dilute suspensions can be dewatered by spray evaporation to produce concen-trated casting slip or plastic clay with a lower water content.The most common dewatering method used in preparing powdered kaolin for the market comprises the following steps: Reduction of the water content by filter-pressing from approximately 75 percent in the thick ""slip"" condition to about 30 percent in the condition; further reduction of the water in the filter-press cakes by heat to about 5 percent; and pulverization of the dried cakes in hammer or dust. These three steps can be simplified to a single process by spray evaporation."

Jan 1, 1935

By J. Nielen van der Merwe

During the process of pillar extraction at the Welgedacht Colliery, an unexpected pillar collapse resulted in the entrapment of equipment. The area was visited soon after the event to evaluate the stability of the area for the purposes of extracting the equipment. It was found that the area had stabilised sufficiently to allow work without undue risk to the safety of workers. The equipment was reclaimed successfully. A subsequent investigation into the reasons for the collapse was conducted. It entailed detailed underground and surface subsidence observations and numerical modeling. It was found that none of the perceived negative factors that were present at the time could result in pillar loads that were sufficient to cause the collapse. It was concluded that the local pillar strengths were less than the nationally used value and that they were possibly further reduced by aging.

Jan 1, 1999

By K. L. Williams

The Bureau of Mines tested a prototype tapered-element oscillating microbalance (TEOM) dust monitor for measuring respirable coal mine dust. The monitor uses the inertial behavior of a vibrating element to measure the mass of sampled dust. Tests were performed to determine variability, drift, the effect of humidity, placement of collection filter, and element orientation during analysis, and comparability with gravimetric measurements of respirable coal dust. Variability was about 1.6 µg. Over about 26 h at 46 pct relative humidity, drift was very slightly negative. When the relative humidity was increased to 78 pct, all units showed a total positive change less then 40 µg over about 70h. Filter placement variation on the tapered element resulting from in- consistent sizing of the filter mounting bases caused significant error (up to 0.2 mg). In practice, calibration of the system for each new filter will eliminate that error. Orientation of the element during analysis did not introduce significant error, but care is necessary when mounting the canister that houses the element to avoid damping oscillation of the element. Dust tests were performed in an aerosol chamber using coal dust. Measurements made by the TEOM dust monitor agreed to within 10 pct of simultaneous measurements by gravimetric personal samplers.

Jan 1, 1986

By N. C. J. Dempers, J. A. L. Parker, R. A. Wildenboer

More than half of global cobalt reserves are located in the Southern African Copperbelt, stretching over the northern tip of Zambia and southern area of the Democratic Republic of Congo. In these areas, cobalt is not typically produced as a primary product but as a byproduct of copper production. Ores from this region often contain uranium, which is readily leached under typical copper leach conditions and enters the process. Uranium does not pose a challenge to copper production, but it becomes a significant problem when it follows cobalt to the cobalt precipitation process and results in unacceptably high levels of U in the final Co product. This paper evaluates the existing process technologies that can be used to remove uranium from cobalt-bearing process streams, including phosphate precipitation and ion exchange. Advantages and disadvantages of the uranium removal processes are discussed, and important design considerations are highlighted.

Jan 1, 2023

By E. Don Dilling, Wm. F. Hergert, J. W. Pennington, C. E. Wood, M. J. Slendlove, H. A. Doerner

"INTRODUCTION The Bureau of Mines began a study of various methods for producing magnesium metal from magnesite ores in 1936 at Pullman, Wash., with the cooperation of Washington State College. This work included a study of the basic principles involved in the reduction of magnesium oxide by carbon, which soon led to the development of a continuous process. In May 1939, a small pilot plant was operated, which included a small single-phase arc furnace with a hydraulic feed mechanism and an oil-spray device for shock cooling the metal vapor. 5/Subsequently, the Ford Motor. Co., Dearborn, Michigan, began a study of this process on a larger scale. A pilot plant with a nominal capacity of 10 pounds of magnesium metal per hour was constructed and operated intermittently. A larger unit with a nominal capacity of 100 pounds of magnesium per hour was partly constructed when war activities prevented experimental work.In the meantime, the process was greatly improved through continued investigation by the Bureau of Mines at Pullman, and these improvements were successfully tested by continuous operation in a small pilot plant having a normal capacity of 4 pounds an hour."

Aug 1, 1945

By Forrest T. Moyer

The National Safety Competition was inaugurated in 1925 by the Bureau of Mines, U.S. Department of the Interior, in cooperation with the Explosives Engineer. In the first nationwide contest, 210 mines and quarries were enrolled. In 1962, the thirty-eighth anniversary of the competition, 910 mines and quarries were enrolled. These participating plants were worked a total of 133,292,989 man-hours. Of the enrolled plants, 415 achieved injury-free operations for the year, the largest number of perfect safety records in the history of the contest.

Jan 1, 1964

A methodology has been developed and demonstrated to be effective in reclaiming surface-mined land for a forestry post-mining land use. The forestry reclamation approach (FRA) has been applied, almost exclusively, to flat or gently rolling surfaces. One of the primary steps in the FRA is to loosely grade the top 1.22 m (4 ft) of soil or substitute root growth medium to avoid excessive compaction. Concern has been expressed by regulators and the public that loose grading on steep slopes (i.e., greater than 23°) could lead to slope failures, which is one of the issues that the Surface Mining Control and Reclamation Act of 1977 (SMCRA) sought to correct. A field investigation was conducted at a steep-slope contour operation in eastern Kentucky to test the applicability of FRA in this setting. Final grading was performed according to FRA standards. The surface consisted of two distinct substitute rooting media. One was unweathered gray sandstone and the other was a combination of gray sandstone, brown sandstone, and topsoil. A variety of native hardwoods was planted following the FRA guidelines. The slope was instrumented with 70 survey monuments to monitor for mass movement. The reclaimed spoil was also characterized using bulk density and penetrometer resistance methods. The characteristics of both spoils are similar to those observed on flat to rolling surfaces where the FRA has been used and, after one year, approximately 70% of the trees had survived. During this first phase of investigation, there has been no major mass movement of the slope and slope stability analysis indicates that the application of the FRA has little impact on the overall stability of the slope. Mining Engineering, 2011, Vol. 63, No. 12, pp. 55-62. Official publication of the Society for Mining, Metallurgy and Exploration, Inc.

Jan 1, 2011