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By R. Kramer

The Process Mineralogy review arrived too late to appear in the May issue. The Process Mineralogy Committee scheduled programs with both SME and The Metallurgical Society. At the 1991 SME Annual Meeting in Denver, CO the committee sponsored five sessions containing 31 papers. Four process mineralogy sessions were sponsored at the 1992 annual TMS meeting in San Diego, CA. Process mineralogy is used to understand and evaluate mineral behaviors during mineral beneficiation, phase reactions during metallurgy, recoveries and reactions of precious metals during processing and mineral and phase behaviors with respect to environmental problems. The most recent refinement in mineralogical studies with respect to mineral beneficiation has been the wider use of image analysis and combined materials balancing techniques of image analysis data. Image analyzers that can perform analysis with respect to mineral beneficiation are expensive. They are used only for solving major processing problems. Nevertheless, the methodology of analysis continues to be refined. Much better data are collected, and methods of evaluating the data continue to improve. One interesting development involves modifying the ultrasound unit used in medical studies to perform a three-dimensional analysis of ore particles.

Jan 1, 1992

By W. L. Dare

This information circular is one of a series published by the Federal Bureau of Mines in which the methods and costs of producing uranium ore on the Colorado Plateau are discussed. This report describes the three largest company-operated uranium mines of Climax Uranium Co. - the G-1, the Mineral Joe, and the Frank No. 1. Climax Uranium Co., a subsidiary of American Metal Climax, Inc., was [corporated] May 11, 1950, just 2 years after establishment of the domestic uranium program by the Atomic Energy Commission. Twenty-five years earlier Arthur H. Bunker, now chairman of the board, American Metal Climax, Inc., organized and operated the U. S. Vanadium Co. at Rifle, Colo.3/ Soon after Climax Uranium Co. was organized, it entered into a contract with the Federal Government to build a uranium-vanadium processing mill in Grand Junction, Colo. Under the contract Climax leased from the Federal Government certain uranium-bearing lands that had been withdrawn from public entry in 1948. From Minerals, Engineering Co. on June 12, 1950, Climax acquired other uranium-vanadium properties on Calamity, Outlaw, and Monogram Mesas in Colorado and on Polar Mesa and in the Yellow Cat area of Utah. To house the milling equipment, Climax leased the old Grand Junction sugarmill building of the Holly Sugar Co. Milling facilities, based on a then new process developed for treating both uranium and vanadium, were completed, and the plant went into production in 1951.

Jan 1, 1959

By Diego Quiroz, Francisco Cuellar

Existen tareas esenciales como la exploración, inspección, y digitalización de galerías subterráneas que pueden presentar un alto riesgo para los trabajadores ya que se pueden producir accidentes. En este contexto, se hace necesario buscar soluciones más eficientes y seguras para la exploración, inspección, y digitalización de galerías subterráneas en la industria minera. Se propone como solución el uso de un robot terrestre no tripulado capaz de desplazarse en superficies irregulares para la digitalización, inspección, y diagnóstico recurrente y seguro de la infraestructura de galerías subterráneas en minería.

Sep 29, 2023

By Charles Legrand

The problem of mine pumping is so much affected by local conditions, and those conditions are so liable to changes during the life of a mine, that the best system to use is difficult to determine. The experience of the writer has been that, in general, for copper mines, electric pumping is most satisfactory unless the quantity of water to be pumped is great or the mine does not use electric power for any other purpose. As a rule, however, figuring on the cost of necessary power plant, the total cost of installation is greater with electric pumps than steam pumps. As the water is liable to be gritty, outside-packed plunger pumps are to be recommended, and if the water is not acid, or only slightly so, chilled cast-iron plungers pay for their extra cost very quickly in diminished cost of packing. With chilled plungers it is possible to use metallic packing instead of soft packing, if the water is not too gritty or the lift too high. In vertical pumps this packing is satisfactory for lifts up to 400 ft., in the experience of the writer, and may be found satisfactory for higher lifts. For water slightly acid, cement-lined pump bodies have given good satisfaction. For acid water, both plungers and puhp bodies should be made of acid-resisting bronze. For high lifts, especially with gritty water, a satisfactory pump valve is difficult to find. To reduce the unbalanced pressure on the valve at time of opening it is advisable to have narrow seats; this, however, brings high pressures on the seats when the valve is closed. On large valves for lifts of 600 to 1,000 ft. we have used leather, hard rubber, vulcanized fiber, and soft brass; for clear water the latter has given best satisfaction. The difficulties due to grit make it advisable to have large sumps where water can settle, and if possible, to have two of them so that they can be cleaned alternately. At the mines of the Old Dominion Copper Mining & Smelting Co., Globe, it was found that a small air ejector discharging into a mine car provides a very convenient way to clean mud and sand from a sump.

Jan 1, 1916

By William Paxton Hewitt

Mineral deposits of western Utah and eastern and central Nevada have produced in excess of $8,500,000,000 since 1871. Through 1965, Bingham Canyon had produced over $4,600,000,000 and seven other camps over $100,000,000 each, principally from base metals. In addition, they yield iron and uranium ores; contain the world's largest beryllium reserves; and have produced the United States' most important gold discovery in 25 years. The area is famous for its silver production and its bonanza-type precious metal deposits, but such production has become unimportant. The area's greatest producers of metallic wealth are base-metal deposits in limestones and porphyry-type copper ores. In contrast to silver's decline, gold production has been rising-the result of by-product operations at Bingham Canyon. The area also contains gold deposits in which the gold is so finely disseminated it is not recoverable by panning. The area's gold ores frequently are associated with realgar, cinnabar, and carbon. The ore deposits generally are attributed to Tertiary intrusives,* but, at Mountain City, they may be related to Paleozoic volcanism. Mountain City has yielded rich chalcocite from quartz-pyrite-chalcopyrite bodies in siliceous sediments. Regional stratigraphy and structure are difficult to interpret, 69 per cent of the area being obscured by alluvium or volcanics. In general, central Nevada consists of chert, shale, silty sandstones, lavas, and pyroclastics; eastern Nevada and western Utah of many alternations of limestone, shale, and sandstone. Central Nevada has been structurally active since late Devonian. Although granitic stocks may have intruded eastern Nevada and western Utah prior to the Cretaceous, these areas remained quite stable until affected by the Laramide Revolution. Precambrian exposures, occupying 3 per cent of the area, have not been important hosts. However, the question is raised as to whether Precambrian carbonates, properly situated with respect to invading mineralizers, might yet prove to be important. This paper describes 16 precious metal camps, 6 limestone replacement districts, 2 silver-base metal vein deposits, and 9 miscellaneous types and discusses briefly the 11 * Some ores, as at Ely, are associated with intrusives of. Cretaceous age. major camps that are described in detail in this Volume.

Jan 1, 1968

By Keith Whitworth

The USSR, over the last 20 years, has continued to increase its out-put year by year and it is now almost four times what it was at the end of the Second World War. In 1975, it exceeded 700 million tons of run-oi-mine coal (all ranks) which amounts to over 20 percent of world output. This rapid progress has been due to modernization of the industry, by means of increased mechanization and automation and the development of new machines and systems for underground workings and by the expansion of open-pit workings and the development and implementation of larger earthmoving machines.

Jan 1, 1977

Air pollution control regulation$ already implemented or being considered for implementation require substantial investment of capital to remove the sulfur oxides from copper, lead, and zinc smelter gases. There will be an attendant increase in production costs and possibly an associated increase in the price of these metals to the consumer. The total investment and any resultant metal price increase will depend upon the control regulations that ultimately will be adopted by the individual States. Controversy has arisen between the metals industry and governmental control agencies regarding the status of stack gas desulfurization technology and the ability of industry to control sulfur oxide emissions to the degree proposed by some of the more stringent regulations currently under consideration. This paper evaluates the problems involved in achieving various degrees of control over smelter sulfur oxide emissions and the technology available to accomplish the task of assuring clean air. The estimated cost of compliance is reviewed for the copper, zinc, and lead industries, but principal at tent ion is given to the copper situation.

Jan 1, 1971

By W. W. Adams

Coal mining in the United States established a good safety record in 1939. The death and injury rates per man-hour of exposure to risk were favorable compared with most previous years, and the number of persons killed or injured in proportion to the quantity of coal mined was also lower than in any other year for which figures are available. Moreover, productivity per man-hour was higher than ever before. The number of man-hours of work performed increased 9 percent over 1938, but there was a slight decrease in the number of men employed. Reports from operating companies showed 539,375 men employed during the year, and the period of operation averaged 179 workdays per man. Man-hours of work numbered more than 678 million. Accidents to the workers resulted in 1,078 fatalities and 54,015 nonfatal disabling injuries, causing disability of the employee for more than the remainder of the clay on which the accident occurred. For each million man-hours of exposure of the employees to mining hazards the fatality rate was 1.59 compared with 1.78 for 1938, and the injury rate was 79.65 compared with 82.61 for 1938. Production of coal averaged 0.661 ton per man-hour compared with 0.637 ton in 1938. The weighted average length of the workday was 7.03 hours or virtually the same as the previous year's average of 7.04 hours. Measured in man-hours, the average period of employment per man was 1,257 hours in 1939 and 1,147 hours in 1938.

Jan 1, 1942

By D. Harrington

United States newspapers of 25 or 30 Years ago ran headlines every few weeks telling of some mine disaster. Each disaster was a first-page attraction for a day or so then was forgotten until the next sensational event, frequently another mine disaster, a few weeks later. Interspersed with the large mine disasters were the so-called ?snipping? mine accidents that caused the death of one or two mine workers. The summation of mine fatalities of all types usually exceeded 3,000 a year, and nonfatal accidents to workers in mines of the country approximated 250,000 annually. From 1906 to 1910, inclusive, there were 84 major explosion disasters (about 17 per year) in. United States coal mines. The resulting fatalities totaled 2,388 for the 5-Year period. These frightful catastrophes helped the number of fatalities in coal mines of the country to reach the enormous total of 13,288 for the 5 years, or an average of 2,658 per year.

Jan 1, 1940

By Christopher Mark

Colombia is 11th largest coal producing nation in the world, and the world?s fifth largest coal exporter. But while most of Colombia?s coal is mined at large modern surface mines located near the Caribbean coast, there are also underground mines that produce high-grade metallurgical coal. These mines employ traditional hand-loading techniques in a variety of geologic environments, and they have some of the highest accident rates of any Colombian industry. The National Institute for Occupational Safety and Health (NIOSH) has been collaborating with POSITIVA, the primary provider of worker?s compensation insurance to the Colombian underground coal industry, to reduce the economic and social cost of rock falls in these mines. The specific goals of the collaboration are to 1) document practices and conditions in Colombian underground coal mines, 2) identify relevant international best practices, and 3) provide recommendations for developing a national campaign to reduce fatalities and injuries associated with roof falls. NIOSH conducted a survey of seven underground coal mines in four separate coalfields. Five of the mines were characterized by steep dips and weak roof and floor rock. The coal was loaded by hand at all seven mines, though two employed partially mechanized longwall techniques. Wood posts were by far the most common ground support. Roof bolts were not observed in use at any of the mines, and they are unlikely to replace timbers any time soon. While long-term entries generally appeared to be adequately supported, the survey found that less attention was paid to the temporary support that is installed right after the coal is removed. This temporary support is critical for protecting the workers from rock falls, however, because with hand-loading mining methods most of the activity takes place between the permanent supports and face. The study concluded that improving the temporary support in the working faces would be the most effective way to reduce the number of rock fall injuries. The key principle should be that every worker is protected by planned roof support at all times. Ground Support Management Plans, consisting of specific rules about when, where, and what roof support is to be installed, should be the focus of the campaign. Each Plan should be tailored to a specific mine based on the geologic conditions and mining methods in use. The Plan provides miners with clear, simple rules that can be easily understood, while management can easily check to see if it is being followed. Ground Support Management Plans will also provide the campaign with a concrete focus for the necessary cultural change.

Jan 1, 2014

"Geological investigation in the Appalachian region of Canada began more than 150 years ago. The distribution of rock formations, and their ages and regional structure are today reasonably well known in most parts of the region to 1-or 2-mile scale. Most Newfoundland geology is known only to 4-mile scale. About 200 earth scientists carry out research in the region, of whom about 25 per cent are government employees, 50 per cent university staff and graduate students, and 25 per cent industry employees.Increased activity is needed toward both regional analyses and problem studies through the efforts of multi-disciplinary teams. The ultimate objectives of earth science must be the discovery and development of mineral re•-sources and the use and conservation of natural material in the environment, all for the benefit of the local in-habitants. To accomplish this, the scientific community must carry out an array of research projects ranging from the technical products of geological, geophysical and geochemical surveys through to the research products de-signed to renew theories and hypotheses bearing on natural processes. Some scientific sub-objectives are listed.Recommended is the increase and broadening of communication among Appalachian scientists, specifically those resident in the Atlantic Provinces. It is proposed that an Appalachian Division of the Geological Association of Canada be formed to provide a forum for discussion of Appalachian topics. In addition, a committee or council of university, industry and government earth scientists should be formed to examine the state of the science in the region, to identify programs of investigation and individual projects of research, and to recommend methods of approach. If the committee succeeds and the scientific community acts upon the recommendations, the quantity, quality and pertinence of research will increase, and earth science will better serve Appalachian society."

Jan 1, 1970

By Shankar Narasimhan

Data Reconciliation is a technique that has been developed more than fifty years ago and has been refined over the past few decades and is now being deployed routinely in several process industries such as refining, petrochemicals, mineral processing and hydro-metallurgy. The main aim of data reconciliation is to obtain accurate estimates of all process variables and parameters using plant measurements that are invariably corrupted by random errors and may also contain biases and other gross errors. These reconciled estimates are subsequently used either in offline exercises such as simulation, retrofitting, and de-bottlenecking or in online optimization and control applications. In this presentation, a brief history of data reconciliation, its assumptions, and uses are reviewed. New developments in this area are highlighted such as robust data reconciliation to handle model uncertainties, and reconciliation using identified models derived purely from operating data. Several case studies in the mineral processing industries reported in the literature are also highlighted to indicate the potential benefits of this technique.

Sep 1, 2012

By D. M. Abbott

The requirements of the International Mineral Property Valuation Standards Template (IMVAL Template) (includes Petroleum), 4th edition of April 14, 2021, are based on six principles: 2.1.1 competence, 2.1.2 materiality, 2.1.3 transparency, 2.1.4 objectivity, 2.1.5 independence, and 2.1.6 reasonableness. The IMVAL Template describes “reasonableness” as, “The Valuer must ensure the Reasonableness of the Valuation. Any Valuation, assumptions applied, and any method relied upon should be reasonable within the context of the purpose of the Valuation and the Basis of Value. A method applied to the subject Mineral Property should be within the expected capability and consideration of an assumed likely buyer or lessee of the property.” The IMVAL Template’s Guidance 3.6 on Reasonableness states, “The test of Reasonableness is to consider what appropriately qualified and experienced Valuers, acting reasonably, would conclude in the circumstances. The Valuer must form an opinion that is reasonable in the circumstances, that is, what a Valuer believes is rational and plausible in the circumstances and would be viewed as such if considered by other appropriately qualified and experienced Valuers with the same information and at the same time.” Finally, the IMVAL Template’s Definition 4.26 states Reasonableness “[m]eans that other qualified and experienced Valuers with access to the same information for the same Valuation Date and Basis of Value would consider the Valuer's estimate of Value to be within a reasonable range.”

Mar 2, 2022

By Keith L. Harris

Recent data indicate a marginal decline in overall growth in world economic output from 3.1% in 1985 to 2.9% in 1986 (table 1),2, 3 Many nations experienced slower economic growth because of the huge trade imbalances existing between the United [ ] States and Japan and the Federal Republic of Germany, the U.S. budget deficit, and the growing Third World debt. Some developing nations, however, experienced booming growth. Declining prices for energy and nonenergy commodities and the fall of the dollar against the currencies of major industrial countries benefited several developing countries--energy importers and exporters of manufactured goods with currencies tied to the U.S. dollar, which were able to expand markets in the industrialized nations. The drop in commodity prices increased demand in industrial countries and depressed it in developing countries. Lower demand in the developing countries contributed to a decline in the real net exports from industrial countries. As a result, output growth in industrial countries declined from 3.0% in 1985 to 2.4% in 1986, despite growing internal demand, Average output growth of developing countries increased from 3.296 to 3.596 during the same period, however, primarily because of the low prices of their products and the strength of demand in industrial countries for those products. Developed country output growth was extremely uneven, however. For example, the economic output of nonfuel exporters grew 5.4% in 1986, while that of fuel exporters dropped 0.7%.

Jan 1, 1987

By Steve Dillingham

A blast site incident has just occurred. Tensions are high, and, as the blaster, you’re in charge of the crisis at hand. Your mind is reeling, your thoughts frantic. The main areas of concern for you at the scene are to deal with immediate problems...aid the injured, take a head count, assess the damage, call emergency response, contact company headquarters, calm the neighbors, update your customer, and respond to the press on site. You feel as if all the bases have been covered...but, then again, have they? One of the biggest mistakes blasters and their companies can make is not including their Insurance carrier in the critical on-site accident procedures and emergency call list. Unfortunately, many companies believe that they are immune to the perils that can often, within a matter of minutes, create chaos that only happens to someone else.

Jan 1, 2002

By L. L. Lien

In this economic age of high interest rates and softening mineral commodity markets, the mining industry is taking a hard look at how it conducts its business and where economies can be effected. The capital investment to build a new metallurgical facility or open a new property has traditionally attracted substantial investigation, analysis and management attention. The areas of mineral exploitation, financial feasibility, engineering and construction have been studied extensively and their management, although still difficult, have become refined disciplines.

Jan 1, 1982

By Brian Zelenko, William H. Hansmire

"By the time the latest expansion of the Washington Metropolitan Area Transit Authority (WMATA) system, known locally as Metro and which opened in 1976, is completed in 2020, the system will serve 97 stations and operate on 188 km (117 miles) of track on six interconnecting lines. Metro provides a critical transportation link to a population of approximately six million people within a 3,900-km2 (1,500-sq-mile) Washington Metropolitan area and has allowed job growth to expand to all corners of the region. In the 1950s and 1960s, when the system was first conceived and construction began, most jobs were centered in downtown Washington, and most of the workforce commuted by bus or car. Today, transit-oriented development has increased residential, commercial and government facilities near most of the existing 91 stations increasing the importance of the Metro system as a critical transportation link for the region. According to recent American Public Transportation Association (APTA) data, Metro is the second busiest transit system in the United States (after New York City’s transit system).During the nearly 50 years of construction on the Washington Metro system, technology improvements and lessons learned from the global tunneling industry were implemented. Portions of this background and history have been adapted from other work by the authors Roach et al. (2017) and expanded for use herein. For soil tunnels, these improvements included the change from a “two-pass” tunnel lining with a typical initial lining of steel ribs with wood lagging or segmental precast lining erected within the tunnel shield followed by a final lining of cast-in-place concrete to a one-pass lining system of pre-cast concrete gasketed segmental lining. Soil tunnels were originally excavated using open-face tunnel shields, but changed over time. By the late 1980s, tunneling using closed, pressurizedface tunnel boring machines (TBMs) using a one-pass tunnel lining consisting of segmental precast concrete permitted tunneling in a wider range of soil conditions with much less risk of damaging overlying utilities or structures, greater safety for tunnel construction personnel and without the need to dewater the soils. However, due to concerns about conditioning clays with earth pressure balance (EPB) TBMs, open face machines were still favored by contractors for their better advance rates, lower cost and ability to deal with boulders that were occasionally encountered in the Coastal Plain Terrace Deposits."

Jan 6, 2018

By H. Ikeda

INTRODUCTION [Slide 1] The Role of the MMAJ Ladies & Gentlemen, it is a pleasure for me to be able to make a speech at this SME annual meeting, representing the Metal Mining Agency of Japan. [Slide 2] Today’s Topics In my presentation today, I would like to divide my topics into four parts. First of all, I would like to describe the current situation of Japanese non-ferrous metal mining and mineral processing industries in Japan. Secondly, the supply and demand of non-ferrous metals in Japan. Thirdly, I would like to spare some minutes on the overview of overseas development by Japanese mining companies. Finally, since some people may not be sure what the Metal Mining Agency is or what this Agency, I would like to briefly introduce the Metal Mining Agency of Japan.

Jan 1, 2001

By E. H. Burroughs

Persons interested in th_e study of petroleum and allied substances have long felt the need of a bibliographic index to the literature. This bibliography, which is intended to be the first elf a yearly series, has been compiled by the petroleum division of the Bureau of Mines with a view to satisfying this need. The references include only the more noteworthy writings that appeared during the year 191.5 in both ·the United States and foreign countries. Only patents plainly applicable to the industries in point have been included, although, of course, a close scrutiny of the great volume of patent literature might reveal many other patents of possible value. The references are arranged according to the subject classification on pages 3 to 11. This classification, which is to be followed in the succeeding bibliographies of this series, is offered as a guide for further study and classification of the pertinent literature.

Jan 1, 1918

By Edward B. Cook

INTRODUCTION. THE installation of the Gayley Dry-Air process appealed specially to the management of the Warwick Iron & Steel Co., for the. reason that for fifteen years records had been kept at the works of the company, showing the amount of water entering the furnace in the form of aqueous vapor, and careful observations had been made of its effect upon the working of the furnace. Some years had proved much worse in their effect than others, on account, not only of excessive moisture, but also of great variation in the moisture from day to day, and sometimes within a few hours. It had been found impossible to. make a satisfactory percentage of high-silicon foundry-iron in summer, even on high fuel; and for some years the endeavor had been made so to arrange the sales that, during July and August, only a small percentage of the iron produced would be required to carry more than 2 per cent. of silicon. Our larger furnace, running on basic iron, year after year, produced in February a tonnage 20 per cent. higher than in August, on a much lower fuel-consumption, while, at the same time, the summer months were marked by ? messes," tuyeres closed by slips, and other irregularities, constituting serious additional business losses. It will be easily understood, therefore, that the records made at the Isabella furnace after the installation of the dry blast in 1904 possessed special interest, and were closely watched by us. On the basis of our own experience, we argued that if the moisture could be kept low, and also uniform, the cost of installation would be more than justified. The subject was brought before our Board of Directors in the fall of 1905; and in the spring of 1906 it was decided to install a plant of sufficient capacity to treat 70,000 cu. ft. of air per min., an amount

Nov 1, 1908