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By N. A. Abdel-Khalek

Laboratory flotation tests were carried out on six Polish samples of different rank. Each coal sample was screened into 7 size fractions. The floatability of size -by- size for various size ranges for different samples was investigated as: well as the original samples. The results showed that in flotation of size -by -size, the intermediate size had the maximum floatability. The range of this intermediate sizes varied with the rank of the coal. Entrainment was shown to be an important mechanism to the recovery of fine particles in flotation of the original samples".

Jan 1, 1989

By A. A. Odunaike, E. G. Okafor, M. H. Mokwe

Microscopic Studies were performed on ore samples from the Muro banded iron ore deposit in Nigeria and the Marampa iron ore deposit in Sierra Leone. Ore characteristics that affect processing of both ores were compared with a view toward assisting mineral processing engineers in choosing the most suitable methods for upgrading the ore. The Nigerian ore contains 30% to 37% (by weight) Fe and the Sierra Leonean ore contains 34% to 51% (by weight) Fe. Hematite is the main iron mineral in both ores. The Sierra Leonean ore is relatively coarse grained (typically around 250 µm) and can be upgraded by conventional gravitational methods. In contrast, the Nigerian iron ore is fine grained and must be ground to -74 µm to liberate the hematite for recovery by flotation. Both ores contain high percentages of phosphorus and sulfur, which are above the required specifications for direct reduction and blast-furnace practice. These deleterious elements can be rejected by grinding and flotation.

Jan 1, 1999

By Erik Marsh, Frederick C. Harris Jr., Javad Sattarvand, Joshua Dahl, Alireza Kamran Pishhesari

Based on the mine safety and health administration (MSHA)reports, mining truck accidents are among the significant causes of fatalities in the mining industry. The major causes of haulage accidents can be divided into non-driving and driving factors, such as truck-related sudden failures and operator performance. Numerous parameters affect trucks' safe operation, but situational awareness plays a significant role. Due to the distinct structure of mining trucks, making them efficient for mining purposes, the operator has a very limited field of view (FOV), making them prone to accidents resulting in losing lives. The cabin's position blocks the truck's right and rear sides, creating several blind points around it. Aiming to test/train the operator's awareness of the surrounding, a proximity detection system is developed through a multiplayer virtual reality (VR) application to investigate the human factor in equipment collisions. The operators were examined and monitored when asked to conduct what exactly happened in the Marigold mine truck accident without being aware of the scenario. After receiving sound, vibration, and visual alarm warnings, their reaction and performance were analyzed. The platform is developed using the Unity game engine for HTC VIVE virtual reality goggles. An Omni-direction treadmill and a motion simulator platform are utilized for the player and dump truck operators. Fifteen students were monitored when driving the dump truck receiving/not receiving proximity detection alarms. None of them repeated the accident when receiving proximity alarms. Also, they found the visual alarm the most comfortable while driving the truck.

Jun 25, 2023

By Frederick K. A1lgaier

The Bureau of Mines' Denver Research Center initiated a subsidence research program in 1978. The short ten goals of the program were to determine practical methods and equipment for measuring subsidence and demonstrate these methods by monitoring subsidence at several mines having mining, geologic and topographic variables typical of those encountered in the western United States. Data from the monitoring program would be supplied to cooperating mining companies and used by the Bureau to accomplish the long term objective of developing and validating subsidence prediction techniques applicable to mines in the West. Subsidence monitoring is being conducted at five mines in Colorado and Utah with substantially different mine plans, mining methods, depths of cover, and topography. The monitoring procedures used at each site are similar and include designing the monitoring network layout, installing the subsidence monuments, initial and periodic surveying of the monuments, and processing the survey data. The network layout, surveying methods, and types of monuments vary according to the conditions at the individual sites and the type of data being collected.

Jan 1, 1982

By K. N. Santini

Natural zeolites are gaining recognition as an important commodity with an increasing number of industrial and consumer applications. This potential has prompted the Anaconda Minerals Company and other firms to investigate occurrences and markets for zeolites. The deposits of mordenite-rich tuff at Rome are of interest for their economic potential and for the excellent opportunity they provide to study a zeolite deposit formed in a hydrologically closed basin. Location The Rome property is located approximately 9 km west of Rome, Oregon, in Townships 31S. and 32S., Range 41E., Malheur County. It lies within the Owyhee Uplands of the northern Basin and Range physiographic province (Figure 1). The area discussed here includes a major portion of the depositional basin in which the zeolitic tuffs occur.

Jan 1, 1982

By Galen G. Waddell

Several years of rock-burst research conducted by the Federal Bureau of Mines, in cooperation with the mining companies of the Coeur d?Alene Mining District, Idaho, in addition to progress made by others throughout the world, have led to a good understanding of the rock-burst problem. This paper describes conditions which have caused specific bursts, present capabilities of detecting stress buildup and bursts, control methods, and a suggested approach to analyzing any individual mine-burst problem.

Jan 1, 1970

By M. Z. Rashad

The intersections of numerous joint sets at the surface of tunneling region of Abu-Tartour-Project in Egypt create blocks with irregular shape and size in the rock mass. Most of these blocks are not able to move into the free space of the tunnel. Few key blocks are in a position to move and as soon as they begin so, some restrained blocks will be liberated. The aim of this work is to find the (removable) key blocks for walls, floor, roof and corners of a portion of the tunnel under jointed surface rocks; and then determine the best tunnel direction.

Jan 1, 1991

By John P. Dunford, Lewis A. Martin

Researchers from the Spokane Research Laboratory, National Institute for Occupational Safety and Health, in cooperation with engineers from the Department of Mining and Geological Engineering, Montana Tech, Butte, MT, conducted tests to evaluate the tensile strength, fiber count, and adhesion of shotcrete applied to panels at the Chief Joseph Mine, a research and training facility operated by Montana Tech. The tests were conducted in the mine ramp 45 m (150 ft) inward from the access portal at a 15.25-m- (50-ft) long test area divided into five 3-m- (10-ft) long sections. The shotcrete was applied with an Aliva 240.5 machine fitted with a predampener. Different amounts of fiber were entrained for each panel. Background data for the tests were obtained from earlier tests in Nevada, where the typical amount of fiber in the shotcrete is 6.54 kg/m3 (11 lb/yd3). All shotcrete was applied to a minimum thickness of 76 mm (3 in). Cylindrical cores were drilled at the wall-rock interface, and adhesion was tested after 28 days of curing. The goal of this research is to reduce the need to install multiple supports at the advancing face by creating a safer mining system that limits the time miners are exposed to unprotected roof.

Jan 1, 2005

By Douglas E. Hansen

A current trend in blasting of large volumes of rock is to use increasingly larger diameter shot holes. The use of large diameter holes meant; correspondingly large explosive charges will be loaded and detonated, and, if special efforts are not made, will result in more damage and vibration beyond the intended blast area. With the rising awareness of environmental factors, vibration control becomes increasingly important. Equally important is the preservation of intended lines and grades, and in some cases by blasting with care, slopes can be safely steepended. In the past, vibration control was established to prevent damage to man-made structures. The quarry or open pit itself can be regarded as a structure composed of rock. Far too little attention has been given to the effects of blasting on rock walls. The primary purpose of blasting is to break rock. If the integrity of the rock has been destroyed beyond intended lines and grades, the excavation will be more costly than originally anticipated. The increased cost will not only be from in¬creased excavation due to overbreak, but also increased maintenance due to blast induced wall instabilities

Jan 1, 1976

By A. V. Castelli

Weighting materials as we know them today were first recognized in 1922 by B. K. Stroud1. Stroud, who was supervisor or the Mineral Division of the Louisiana Department of Conservation, tested galena, cement and hematite as weighting materials and successfully used hematite to make a "heavy mud". The first use of barite was in the fall of 19222 . The process of adding heavy minerals in mud was patented in 1926 by Stroud and National Pigments and Chemical Company, a subsidiary of National Lead Company now NL Industries, Inc. The ground barite was marketed as BAROIDR barite.

Jan 1, 1983

By Virginia T. McLemore

The Black Hawk district in New Mexico hosts an unusual type of deposit: arsenide five-element veins. These deposits are Ag-Co-Ni-Bi-As-bearing carbonate veins with local concentrations of U, Pb, Zn, Sb, and other elements. They are high-grade silver deposits (1000s g/t Ag), but low tonnage (<1 Mt) and difficult to find. By 1881, claims were staked and a town developed. It is estimated that >$1,500,000 was produced in 1883–1893, when Ag prices dropped due to the 1893 Ag panic. Solid Silver Mining Co. produced $600,000 from the Black Hawk mine; one car load contained $28,000 worth of silver! The town of Black Hawk grew to 125 population by November 1883. By the end of 1893, the town was vacant; nothing remains. The district was idle until 1916, and the mines operated sporadically since because of lack of available capital, water issues, and difficulty in finding ore shoots. The area is a favorite for mineral collectors. Tungsten was found in the district in 1935 in quartz veins associated with pegmatites. Metal production from 1881–1960 is estimated as 3,000 lbs Cu, 1,000 oz Au, 1,286,000 oz Ag, and 4,000 lbs Pb. In addition, 10,542 short tons of 2.7–71% WO ore and 615 short tons of fluorspar ore have been produced from the district.

Feb 1, 2025

By Z. J. Hladysz

The Hladysz Rock Tester was developed at the South Dakota School of Mines as a portable rock strength tester. The hand held device is placed against a rock surface and struck by a hammer. The impacted force causes a steel ball in the device nose piece to indent the rock and simultaneously indent a standard steel bar also contained in the nose piece. By comparing the two indented diameters the compressive strength of the rock can be calculated using laboratory determined correlation coefficients.

Jan 1, 1984

By Ali Keneti, Xavier Ryan, Gerardo Sanchez, Shannon Goff

In this study, FLAC3D modeling was conducted for ground-structure stability assessment for a pilot tunnel passing under a large shaft excavated in the vicinity of existing structures at Karangahape Station for the City Rail Link Project in Auckland, New Zealand. The analysis involved generation of the geometries and construction sequences in Rhinoceros®, modeling the existing ground condition, calibration of the simulated in situ conditions with the observed behavior of the ground, and excavation of the shaft and the pilot tunnel. A comprehensive interpretation of the results was then performed accompanied by comparison of the predicted behavior with the observed response of the ground during construction.

Dec 1, 2022

By Dennis Asmussen

The peatlands of the U.S. and Canadian parts of the Upper Great Lakes region have a long history of modest utilization in agriculture, forestry, horticulture, and as natural undisturbed areas. Only recently have they been assessed as potential sources of non-renewable or renewable energy. This new interest in peatlands, should current proposals be realized, might mean the commitment of millions of acres to energy production purposes. The magnitude alone of this potential utilization of peatland signals the possibility of substantial environmental disturbance, local resource shortages, resource use conflicts, and social and economic change. Peat- land resource managers in the region are just beginning to weigh the advantages and disadvantages of large-scale peatland utilization. The Minnesota Department of Natural Resources has made a considerable effort to study peat resource management issues and will shortly make recommendations to the state legislature regarding utilization alternatives. What follows is a general discussion of peatland utilization and management trends in the region with a focus on Minnesota and its peatland management efforts.

Jan 1, 1980

By G. Balletto

Increasing environmental awareness leads to a reflection on the consequences of a non-appropriate use of mining resources. In this sense the determination of the mining requirements for the building industry is the necessary prerequisite to activate planning in mining according to the principles of environmental sustainability. Experience shows that there is a relationship between the production of buildings in relation to the shape of the city and the resulting demand for minerals. The increasingly urgent demand for maintenance and restructuring by existing buildings will stretch further the demand for minerals with an excessive, no longer sustainable withdrawal, which will lead to focussing greater attention on environmental policies oriented to the use of alternative materials including materials from recycling. It is pointed out moreover that the joint action of land use planning and mining planning leads to interesting applications that have significant repercussions on the environment.

Jan 1, 2005

By T. E. Walsh

I will address two important alternative energy resources, solar and geothermal, with emphasis on their potential application in electric power generation. As a result of this presentation, I hope to leave you with a realistic view of the principal technology options that are being developed or that are available. Solar Types of Collection In terrestrial solar applications, the biggest challenge is to find ways of collecting the sun’s relatively low intensity energy so it can be converted economically to useful thermal or electric energy. Fig. 1 shows that there are both natural and technological ways of collecting solar energy. In nature we find that solar energy aids in the production of biological growth, rainfall, and wind, all of which can, in one form or another, be put to use in the production of heat or electric power. The sun’s rays also are collected and stored naturally in the form of heat in the upper layers of the ocean which can be put to use in the production of electric energy by means of ocean thermal energy conversion (OTEC) approaches. On the technological side, the sun’s rays can be intercepted by materials that directly absorb and convert its energy to low-grade heat, or by mirrors or lenses that focus the rays onto a material to produce high-temperature heat. The higher temperature systems can be used to drive efficient heat engines in the production of electricityy. The sun’s rays also can be collected on photosensitive materials, in either a direct or concentrated form to generate DC electricity directly. The systems I will discuss employ all of these means of collection and conversion, excluding biological and hydroelectric. The former is too exi

Jan 9, 1980

By T. E. Walsh

Introduction I will address two important alternative energy resources, solar and geothermal, with emphasis on their potential application in electric power generation. As a result of this presentation, I hope to leave you with a realistic view of the principal technology options that are being developed or that are available. Solar Types of Collection In terrestrial solar applications, the biggest challenge is to find ways of collecting the sun’s relatively low intensity energy so it can be converted economically to useful thermal or electric energy. Fig. 1 shows that there are both natural and technological ways of collecting solar energy. In nature we find that solar energy aids in the production of biological growth, rainfall, and wind, all of which can, in one form or another, be put to use in the production of heat or electric power. The sun’s rays also are collected and stored naturally in the form of heat in the upper layers of the ocean which can be put to use in the production of electric energy by means of ocean thermal energy conversion (OTEC) approaches. On the technological side, the sun’s rays can be intercepted by materials that directly absorb and convert its energy to low-grade heat, or by mirrors or lenses that focus the rays onto a material to produce high-temperature heat. The higher temperature systems can be used to drive efficient heat engines in the production of electricityy. The sun’s rays also can be collected on photosensitive materials, in either a direct or concentrated form to generate DC electricity directly. The systems I will discuss employ all of these means of collection and conversion, excluding biological and hydroelectric. The former is too ex

Jan 1, 1980

By K. Luxbacher, D. T. Hristopulos, S. Schafrik, J. Diaz, Z. Agioutantis

Big data is generated from both surface and underground mining operations. Such data contain a wealth of information concerning safety and health in the workplace and production parameters. This paper will discuss the progress towards developing an accurate forecasting model for methane gas concentration based on the analysis of data collected from Atmospheric Monitoring Systems in underground coal mines employing time series models. Several procedures need to be applied to raw data, such as data cleaning and filtering for outlier removal, data homogenization and segmentation, and exploratory statistical analysis. The data analyzed were retrieved from two coal operations in the Eastern US. A negative correlation between barometric pressure and methane gas concentration was established, at least for certain data segments. Such correlations raise the possibility that barometric pressure data can predict variations of gas concentration in the mine. The datasets will be further investigated to establish the robustness of barometric pressure and gas concentration correlation and explore the dependence of gas concentration on other factors related to mine design and operations

Mar 2, 2022

By Charles K. Presley

This paper deals with drilling large diameter shafts for the mining and construction industry with diameters in excess of 3 feet to more than 20 feet in diameter. It discusses appropriate applications of the rotary drill method, linings for large diameter shafts, circulation systems,, and the limitations of the method. Each specific rotary drill method is determined by the geology of the area, the depth to be drilled and the formation fluids encountered. Shaft lining or casing must be improved to result in lighter weight, higher strength and lower cost. All phases of rotary drilling equipment must be improved to drill shafts in excess of 10 feet in diameter. As these goals are reached, more shafts of large diameter will be drilled by the rotary method for the mining and construction industry.

Jan 1, 1967

By J. Groff

The Getchell and Twin Creeks mines are located along a north-northeast trending structural zone in Humboldt county, Nevada approximately 40 miles northeast of the town of Winnemucca. Gold mineralization at the Getchell mine is represented principally by sulfide-rich ores, which contain significant amounts of realgar and\ orpiment, with the gold being recovered through processes which involve pressure oxidation. In contrast, oxide ores are currently being mined and processed at the Twin Creeks mine although large reserves of sulfide ores, some of which contain orpiment-realgar-stibnite, have been defined (Bloomstein et al., 1990). The Getchell and Twin Creeks mines represent major gold orebodies but very little has been published pertaining to mineral paragenesis and the characteristics of ore-forming fluids for these deposits.

Jan 1, 1994