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By E. M. Frizzell

It is unlikely that improvement in truck efficiency and capacity can fully offset the effects of inflation, fuel cost/shortages, and increasing haul distances as in the past. Therefore, investigations of haulage systems less sensitive to these problems are warranted. Thus, this Bureau of Mines contract research study on alternative continuous haulage systems was prepared. This study identifies the physical, economic, and technological parameters in the application of continuous haulage systems with special attention to under pit slope conveyors and skip hoisting systems. The evaluation data were gathered from extensive literature searches, European/North American mine visits, and industry comments. The study concludes that continuous underground haulage is a viable method within the proper geometric configurations.

Jan 1, 1979

By Donald R. Simon

Money... not many subjects are as personal or as emotional. Hessiod said it well in 700 B.C. "Money is life to us wretched mortals". Are you getting paid enough? Does your company reward its top people? Does coal or copper pay more? Production or engineering? How is the synfuels industry going to influence mining salaries? Do high salaries attract and retain the best people? Do modern compensation systems ensure fairness or destroy entrepreneurial spirit? With our tax system and high standard of living why are we so salary conscious? Salary is not only important for what it can purchase but it is also a yardstick, measuring how well we are doing. We all need money to pay the bills and maintain our standard-of-living, but once we reach a certain point the psychological ramifications become more important than the purely practical side. Even necessary payments like the mortgage and the car are a function of our egos. Are our choices of cars and homes based on simple transportation and shelter?

Jan 1, 1980

By J. Philip Bromberg

Any effectuation of a viable program of air pollution control will' require a basic understanding of the chemistry of atmospheric processes, the fate and migration of SO2, and the ultimate health effects of the sulfur oxides themselves. The migration and ultimate fate of Sop discharged into the atmosphere will be discussed with particular emphasis on the various conflicting views and how these relate to our present emission control regulations. Our present lack of knowledge is a severe detriment, and consideration will be given to those particular areas where future research may best be directed to provide the answers to a number of perplexing questions.

Jan 1, 1976

By Rosario Lunar, Jesús Martínez-Frías, Egidio Marino, Trinidad Torres, Jose E. Ortiz, Juan A. Martín-Rubí, Luis Somoza, Ricardo León, Teresa Medialdea, Javier González

Seamounts, submarine banks, volcanoes and undercurrent channels are prominent geomorphic features that have become an important target for minerals research and exploration with the goal of future exploitation. Polymetallic ferromanganese deposits are common types of mineralization on these settings. Co-rich ferromanganese crusts are important as potential resources of Mn and Co, but also Ti, Ni, Tl, REEs, PGEs, and other metals. Many seamounts and channels along the Atlantic Spanish continental margin are known to hold mineral deposits but are poorly studied. This work presents and briefly describes the most recent activities of the Spanish Geological Survey (IGME) on exploration and investigation of ferromanganese deposits along the Atlantic Spanish continental margin. Different submarine areas from the northwestern margin of the Iberian Peninsula to the west off Canary Islands have been surveyed by geophysical, sampling and underwater observations from 89 to 4000 m water depth. The mineral deposits cover a large diversity of submarine geological and geomorphical features: mud volcanoes and diapirs related to hydrocarbon seeps, seamounts associated with hot spot volcanism, hydrothermal vents in active magmatic volcanoes, structural basement highs and banks or contourite channels. Considering the collected dataset, we present the preliminary results of the study of these mineral deposits, including ferromanganese nodules and crusts and phosphate pavements and nodules, which can be considered as potential sources of raw materials.

Sep 1, 2014

By L. Valentik

Many attempts have been made during the last forty years to evaluate the performance of gravity separation equipment, that is, the effectiveness with which light and heavy particles are separated. The most comprehensive treatment of the subject was made at the 1st International Conference on Coal Preparation held in Paris (1950) by Cerchar. The methods suggested by the Conference were accepted and very widely used in the last 25 years. This paper discusses an improved method of evaluation in the light of the now accepted standard presentation. The float and sink analysis of the product is presented on a Gaussian distribution curve, resulting in an easier visualization of the inherent difficulties of separation. The ogives of the distribution curve are then plotted, giving a quantitative measure of the deviation from perfect separation as an error distance instead of an error area. Illustrations of the new method are given both for gravel and for coal preparation, but the concept is valid and applicable to other types of minerals which are separated by gravity methods.

Jan 1, 1968

By L. E. Mercando

The proposed Flambeau Mining Project is based on a high grade copper deposit located approximately one mile southwest of Ladysmith, Wisconsin. The project involves only the mining, crushing, and shipping of ore to facilities outside of Wisconsin for processing. The Wisconsin environmental regulations include provisions for identifying wetlands, the requirements for minimizing the disturbance of wetlands, and the need to establish new wet-lands to replace any wetlands which have to be disturbed.

Jan 1, 1991

By Enrique Levy

Central America is graduating this year into large scale mining with the start up of Inco's multi-million dollar nickel laterite processing plant in Guatemala. In the other extreme of the Isthmus in Panama Texas Gulf Sulphur is doing check diamond drilling and foundation test drilling at the Cerro Colorado copper porphyry. The higher price of gold and silver has spurred development and exploration of several small precious metal mines. The purpose of this presentation is to make a brief resumé of the most important mines operating in the area and a list of significant exploration projects. Also, tables will be shown to compare mining codes and taxes. Unfortunately these tables lack information on Panama. Before starting I like to express my appreciation to Kennecott Copper who permitted the use of some of the data compiled by the author on their behalf during the year 1975. Other persons which did not want to be named also have my gratitude.

Jan 1, 1977

By Michael Edesess

The salt gradient solar pond has been the focal point of accelerating international attention and interest in recent months. Only recently have most investigators in the renewable energy field come to realize the versatility of the solar pond, and its ability to overcome certain problems usually associated with solar technologies. These realizations, together with clear demonstrations in Israel and elsewhere of its technical feasibility, have combined to bring the solar pond to the forefront of renewable energy technologies. The solar pond is a natural or site-built pond, about one to five meters or more in depth, which has been altered to retard the loss of absorbed solar energy. The absorbed solar energy is usually lost through upward buoyancy of the warmed water, followed by the loss of its heat to the atmosphere. The chief solar pond technology -the salt gradient, or "nonconvective" solar pond-prevents this upward buoyancy by means of a vertical density gradient achieved with dissolved salt. The deep waters in the solar pond reach high temperatures, up to and even above the boiling point of pure water.

Jan 1, 1981

By Robert H. Merrill

7.1-STABILITY OF SLOPES IN SOIL AND ROCK ROBERT H. MERRILL 7.1.1-DESIGN ANALYSIS APPROACHES The analyses of slopes in soil or rock can be made through application of soil- or rock-mechanics principles. In most cases, the material in the slope wall can easily be identified as either a soil or a rock. However, there will be instances where, because of unique characteristics, the soil may behave as a rock structure, or vice versa. By necessity, these unique cases must be identified through experience or critical observation by the engineer, because there are no definitive rules clearly establishing the differences. The most important step in a solution to a slope problem is to define it. Normally, once the problem is identified, a solution usually can be found or a reasonable estimate obtained. The design analysis of a slope wall implies an evaluation of the stresses or forces in the wall, and of the ability of the material in the wall to withstand them. Therefore, the factors influencing a design analysis can be divided into two categories: those which influence stresses, and those which influence the ability of the wall to withstand stress. For simplification, the latter is termed the strength of the soil or rock. Perhaps the basic difference between analyses for soils and those for rock is in the identification of the failure surface. Soils generally do not have an identifiable failure plane. However, some soil layers in a slope wall may have different strengths. A soil slope wall may consist of a thin layer of topsoil overlying a thick, uniform clay, or a topsoil over a gravel or other materials. Therefore, the soil generally does not have a potential plane of weakness that can be identified through observation. On the other hand, rocks normally contain planes of weakness in the form of fractures, faults, joints, bedding planes or other discontinuities weaker than the intact rock, which can be found through observation and/or tests upon rock samples. If the failure surface cannot be identified, the principles of soil mechanics should apply because, in soil mechanics, the failure surface usually is assumed. If it can be identified, then the principles of rock mechanics should apply. 7.1.2-ANALYSES OF STRESSES OR FORCES IN SLOPES All existing methods of soil-slope analysis are based upon interpetations of the Coulomb and Coulomb-Navier failure criteria, commonly termed the total-stress 2nd the effective-stress criteria (Sec. 6.1). The total-stress criterion may be illustrated by the diagram in Fig. 7-lA, which relates the total stress, S, to the cohesion, c: the normal stress, u, and the angle of internal friction, 9, by the expression

Jan 1, 1973

By Donald J. Hill

To be successful, every organization within the mining industry must involve itself in researching and evaluating methods of loss control. The appraisal and evaluation of accidents and injuries is required to determine the costs of loss producing practices and conditions. This involves all of an organizations disciplines that concern themselves with a more efficient and cost effective organization. To come to know the cost of your safety program or how much is expended yearly for each employee on safety; to know what your safety costs are per man-hour or per ton-produced; to know what the health, medical and compensation costs are for any given incident are just a few of the important facts and figures that the safety management of a given organization needs to know to operate in the mining industry today.

Jan 1, 1984

Machine breakdowns and maintenance delays are large contributors to lost production and increased operating costs in the mining industry. The U.S. Bureau of Mines is investigating the applications of expert system technology to diagnostic and predictive maintenance tor mining equipment. This will help increase mining productivity and decrease operating costs, by reducing the frequency of equipment failures and repair times. The Bureau has begun this effort by applying expert system techniques to the diagnosis of hydraulic system problems on a continuous mining machine. This paper discusses the development of the hydraulic diagnostic expert system.

Jan 1, 1990

Coal-derived flue gases contain CO2/SO2 and these contaminants preferably have to be captured by cheap sorbents. This remediation approach is from the standpoint of addressing issues such as global warming, acid rain and development of Advanced Power Generation Systems and to realize the economic gain as well. Conventional and existing dry scrubbing technologies use regenerable sorbents which are pollutant specific and require expensive stabilizers in order to attain versatility. This paper discusses the use a novel class of sorbents prepared from the heavy metal contaminated Berkeley Pit water (Butte, Montana) by a proprietary process developed at The University of Nevada, Reno. These sorbents are activated mixed spinel ferrite (MxFe,_X04)' Preliminary experimental results show that the sorbents have good desulfurization and CO2 decomposition capacities. The decomposition effectiveness of these mixed spinel ferrites was studied at 300°C and compared against the synthetic magnetite obtained from ferrous sulfate solution in our laboratory. The results indicated that the mixed spinel ferrite had good affinity for the adsorption and decomposition. The CO2 decomposition data of both sorbents fitted the first order reaction kinetics. Even though the surface area of the magnetite was higher than that of mixed spinel ferrite, the CO2 decomposition rate of the mixed spinel ferrite was estimated to be 2.5 times higher than that of magnetite under identical conditions. The carbon analysis deposited on the sample indicated that the CO2 was 100% decomposed into carbon and other carbon! hydrogen compounds by the mixed spinel ferrite whereas the conversion was 43% by the magnetite. In terms of specific adsorption of carbon, ferrite was 3-5 times more efficient than magnetite.

Jan 1, 1996

By Jieliang Wang, Shiwen Yi, Zhao Cao, Peng Zu

Bayan Obo ore contains mainly bastnaesite, monazite and associated iron, fluorite, calcite, dolomite, barite, and trace amount of columbite. Due to its complex mineral compositions and similar mineral properties, it is difficult to separate and obtain rare earth and fluorite concentrates with high purity by conventional magnetic separation and flotation. In this paper, a stepwise magnetic separation process comprised of wet permanent magnetic separation (PMS), wet electromagnetic separation (EMS), and superconducting magnetic separation (SCMS) was proposed to pre-concentrate iron, rare earth, and fluorite minerals from Bayan Obo ore. The results showed that iron, rare earth, and fluorite preconcentrates with high purity and low impurity content could be achieved, which might be helpful to shorten the technological process and improve the separation efficiency for the subsequent flotation of iron, rare earth, and fluorite minerals.

Sep 15, 2020

The mining industry is an important economical factor in Vietnam. Mining is presently being conducted at about 60 locations and at over 1000 mines. Petroleum extraction and coal mining are the most important parts of industry though metals such as zinc, tin, chromites, iron are also extracted. Last year the sector produced 20 million tons of crude oil, 26 million tons of coal and 500,000 tons of apatite. In particular, Vietnam is one of the world?s largest producers of anthracite, and it is one of the top producers of ilmenite and zircon in the Asia-Pacific region. The government intends to increase the mining production on all levels, however, at present one can observe adverse impacts of the mining activities on the natural environment such as insufficient waste dump rehabilitation, occurrence of acid mine drainage, mining subsidence and emissions as well as lack of appropriate water treatment facilities. This paper describes the current mining situation, future perspectives, the major environmental challenges of the country and approaches to solve these problems. Particular emphasis will be given to the research project ?RAME ? Research Association on Mining and Environment in Vietnam?, a venture carried out by universities, research centres and industry. This project is worked out in collaboration with the national Vietnamese coal and industrial minerals company VINACOMIN.

Jan 1, 2006

By Jr. Smith

Borates have been mined in the desert areas of California and Nevada for more than 100 years. To about 1890, playa surface mining provided the chief sources of boron minerals. Underground mining of colemanite and later of borax and kernite was predominate until about twenty years ago. Open pit mining of the large deposits of borax and kernite near Boron, California has been most significant for the past twenty years. Mining of colemanite in the Ryan, California area, near Death Valley, began in 1907. Following the discovery of the large deposits in the Boron area (about 1957), mining in the Death Valley area became nearly nonexistent. Only small tonnages were mined for special uses. Little mining was done in the Boraxo area near Ryan. The first claim was made in about 1915 In 1960 the area became the property of the Kern County Land Company, which was acquired by Tenneco Oil Company in 1967. In 1976 the various borate properties and claims in this region were acquired by American Borate Corporation. The open pit mine is now approximately 400 feet (121.9 m) deep, 3000 feet (914.4 m) long and 1000 feet (304.8 m) wide. The borates in the Boraxo pit consist primarily of three minerals. These are about 50% coiemanite (C2B6O11' 5H2O), about 40% probertite (NaCaB5O9.5H2O), and 10% ulexite (NaCaBcO9.8H2O). The colemanite, along with boric acid and high-grade coiemanite ore from Turkey provide the only sodium-free borates for production of textile grade fiberglas. When heated to its decomposition temperature, colemanite decrepitates to a fine powder. This provides the basis for the concentration process. The gangue minerals in this deposit are primarily calcite and clays, including bentonite. The ore body has a very low arsenic content.which is a desirable feature. Test work had been done with samples prior to the results discussed herein. This paper will discuss results of test work which were the basis for erection of a plant, and the subsequent plant operations.

Jan 1, 1978

By P. James

"INTRODUCTION Control of target stream pH is very important in leach mining and treatment of MIW (mining influenced water). On the production side, solution acidity can impact SX (solvent extraction) effectiveness through PLS (pregnant leach solution) and raffinate pH. Many older operations and legacy mining sites generate ARD (acid rock drainage) that is too weak for profitable metal production by conventional means and faces costly wastewater treatment for mitigation and disposal. For wastewater and environmental treatment, neutralization to precipitate and remove metal contaminants to clean the wastewater is the dominant approach. Traditional lime neutralization and precipitation is most often used but results in large amounts of mixed metal sludge requiring costly disposal. Blue Planet Strategies (BPS); which focuses on improved resource utilization targeting electrolytic treatment and waste conversion into resources, has developed a new “reagentless” neutralization process. Electricity is utilized in its proprietary DEMET™ (Dynamic Electrolytic Metal Effluent Treatment) platform capability to controllably raise target stream pH. The method offers a simple, low-cost approach yielding cleaner treatment chemistry. It can result in less sludge generation and enables possibilities to selectively recover contaminants as potentially saleable products for new revenue generation to offset further offset treatment costs. DEMET Overview BPS’s patented electrolytic DEMET platform leverages solid scientific and chemistry foundations through its advanced design to achieve capabilities and performance not previously realized. DEMET technology combines separated compartment electrolytic cell functionality with proprietary advanced dynamic electrodes and cell configurations to achieve a variety of chemistries and processing targets.[1-6] DEMET‘s unique elements can yield higher processing rates at practical efficiencies, lower energy consumption, plus improved processing stability and lower maintenance requirements due to enhanced resistance to cell fouling and shorting; while also thwarting cross stream (catholyte vs. anolyte) contamination. Consequently, DEMET can provide a superior, extremely versatile, and more cost-effective electrolytic treatment option where a multitude of FEED and PRODUCT stream combinations might be employed in comparison to traditional tankhouse electrolytic cells."

Jan 1, 2015

By Diler Katircioglu-Bayel

This study aims to investigate the effect of combined mechanical and ultrasonic milling on the size reduction of talc. Firstly, the talc sample was wet ground in a stirred media mill for five different times (30, 60, 90, 120, and 150 min), and the optimum result was subsequently achieved with treatment by ultrasonication. The effects of amplitude (20, 35, and 50 μm), solid content (2.5, 5, 7.5, and 10%), and sonication time (60, 120, and 240 min) on the sizes of the final product were investigated. The pre-milling by wet grinding caused a decrease in the grinding resistance of talc. Sequential ultrasonic treatment, which was applied to the talc sample, generated smaller particles in comparison to those acquired by stirred media milling alone. Experimental results were assessed based on the product particle size (d10, d50), reduction ratio, and specific energy consumption. Submicron particles prepared by ultrasonic treatment were perfectly stable compared to stirred media milling alone as investigated in terms of particle size. In addition, the effects of mechanical and ultrasonic milling on structural properties of talc particles were characterized by XRD analysis.

By N. J. Keys

This paper concerns the development and application of a high throughput multi-stream photometric sorting machine developed for the South African gold mines. It is now believed that this sorter and its progeny may be found suitable for a large proportion of all possible sorting applications. A laser light source and sensitive photomultiplier are employed in a scanning system to detect light reflected from the surfaces of rocks passing through the sorting zone. Electronic circuitry then analyzes the photomultiplier signal, which represents the varying intensity of the reflected light, and produces control signals to actuate the appropriate valves of an array of air blast rejection devices to remove from the feed certain particles selected by the analyzing process. Typical throughput per machine ranges from 50 tons/hour for a-2 ½? + 1 ¼? feed to 200 tons/hour for -6" +2 ¾ " material.

Jan 1, 1974

This paper presents the results of an experimental study undertaken to demonstrate the feasibility of using silica sand as a grinding media in stirred ball mills for ultra-fine coal grinding. Laboratory batch as well as bench scale continuous tests indicate that the use of silica sand can reduce the energy consumption by 50% and more over its steel media counter-part. Moreover, this approach has been found to eliminate the disadvantages observed with grinding using steel media such as high replacement cost, contamination of coal through media wear, greater degree of coal oxidation due to higher slurry temperature and greater level of noise dissipation. Additionally, coal-sand attrition system reduces the manpower time required which is often spent towards cleaning and storing of steel media in inert atmosphere to avoid rust and corrosion problems.

Jan 1, 1991

By Frederick B. Brien

For many years tin mining in Bolivia has been very important to the economy of the country. In recent years the tin content of the ore reserves has been steadily declining. An improvement in concentration efficiency is highly desirable in order to increase productivity from the present-low-grade mine ores and to allow retreatment of the many millions of tons of tailings from past operations, some of which equal the present ores in tin content. A number of investigators have been or at present are working on various phases or approaches to the problem. Gravity concentration is used in Bolivia today as it has been in the past to recover tin minerals from the mine ores. An objective of the work reported in this paper was to examine the possibility of treating present low-grade ores and sink-float tailings products, at a relatively coarse grind, in order to produce a higher grade feed material to the present gravity concentration plants. The possibility of using heavy liquids in cyclones to treat large tonnages with a minimum of outlay presented itself and is of particular interest since appropriate heavy liquids are available and with physical properties which lend themselves to simple recovery methods. Tests were carried out using a closed circuit laboratory cyclone assembly. It was desirable to determine the value of using the SG50 concept and Tromp curves for analyzing the cyclone concentration test results. The effects of entrained water on the behavior of ore particles in the cyclone were examined.

Jan 1, 1964