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By S. Rukhaiyar, M. Ramulu, G. Pradeep, P. K. Singh, P. B. Choudhury

The drill and blast method is the most prominent rock excavation method used in mining and civil engineering projects. The ground vibration is the most undesirable effect of the blasting and needs to be controlled. The blasts are designed so that ground vibration at nearby structures must remain under the prescribed limit. Various empirical blast vibration attenuation models have been presented to estimate the ground vibration for designing purposes. These models assume ground vibration as a function of distance and maximum charge per delay. United States Bureau of Mines (USBM) model is most commonly used for the blast design. However, the uncertainty associated with these models is seldom characterized, thus diminishing its reliability. The probabilistic Bayesian approach associated with the Monte Carlo method can easily quantify uncertainties associated with the model and its parameters. Thirty-three blast vibration observation data from a granite quarry in Kerala, India, is used to estimate the probability distribution of model parameters. Markov Chain Monte Carlo (MCMC) approach is used for sampling 12,000 samples for obtaining the posterior distribution of parameters. The uncertainty associated with model parameters is quantified from the posterior distribution, and this is further used to estimate the credible and prediction limits of the model. The point estimate of the most optimum value of the parameter is estimated using maximum-aposteriori or MAP estimate. The model parameters are also obtained using the commonly used least-square error method, which is a maximum likelihood estimation or MLE approach. It has been observed that the accuracy of the model obtained using both MAP and MLE approach is almost equal. However, the MAP estimate as per Bayesian probabilistic analysis has the added advantage that it can estimate the uncertainty of parameters as well as the model, which is not possible using the MLE approach.

Sep 27, 2021

By Luis de la Pe[n]a Porth

The present process refers to a method for efficiently obtaining high purity metallic copper from copper ammonium sulfite. Essentially, this process consists of submitting the copper ammonium sulfite to the action of heat and pressure with the object of obtaining by the decomposition of it, metallic copper, ammonium sulfate, sulfur dioxide, and sulfuric acid.

Jan 1, 1974

By Ping Zhang, Shahram Mozaffari, Andreas Ylmefors

The risk associated with mining induced seismicity and the related rock bursts has become one of the major threats to the safety and sustainability of mining at the Kiirunavaara mine. The causes of mining induced seismicity at the Kiirunavaara mine are very complex and have affected our understanding on the source mechanisms of seismicity and further the mitigation of the seismic risk. Detailed analysis of historical mining induced seismicity at the Kiirunavaara mine was conducted. The focus of this analysis was placed on the classification of large seismic events and the evaluation of the influential factors on the classified seismic events. 145 events with local magnitude larger than 1.5 that occurred between January 1, 2011 and March 31, 2021 were analyzed. For this analysis, seismic events located in the hanging wall were not included, as these have not been observed to cause large damages to the mine itself. It was found that the magnitude of the events had good correlation with the stress change in relation to the production location. The seismic events were classified as mining-front associated, ore-pass associated, mining-front and ore-pass associated and others, according to their hypocenter location. Most of the mining-front associated events, concentrated around the production levels and slightly above and below them, generally correlated with shear cracks, and most of them occurred when the ore flow between two production levels started. The numerical modelling showed that slip of the geological discontinuity, due to unclamping between hanging wall and footwall, could be the major causative mechanisms, which further supports this finding. The ore-pass associated events are located close to the ore passes. Large seismic events located between ore passes have the source mechanism of both fault-slip and non-shear, but events located at the outer side of ore passes were all fault-slip type. By checking with the ore pass scanning data, it was concluded that the most of the events located between ore passes could be pillar bursts. An elastic core concept has been then used to define a critical pillar width. The paper is not intended to be prescriptive but rather to initiate discussion of the possible classification of seismic events at the Kiirunavaara mine and to present new perspectives of the causes of the seismicity for improving the present seismic risk management.

Apr 26, 2022

By K. Chief

American Indian lands contain a vast amount of renewable and non-renewable resources that have consequently been mined (Smith and Frehner). Therefore, it is understandable that tribes are concerned about environmental impacts from mining and their ability to minimize and mitigate these impacts. This has created a need to better understand mining and its environmental impacts. The University of Arizona Superfund Research Program Mining educational modules developed educational modules for tribal colleges focusing on environmental impacts of mining, remediation of mining wastes, and sociocultural impacts of mining. Educational modules are independently packaged units of study designed to enhance the learning process and can be modified and adapted to different learning scenarios and objectives. In addition to providing specialized knowledge, the modules feature hands-on activities, incorporation of technology, student involvement, discussion, and exchange of ideas. Modules will aim incorporate traditional ecological knowledge and approaches that promote effective science learning for native students. Modules are designed to augment existing associates of science programs (e.g. biology, chemistry) currently offered at tribal colleges and can be modified for use in K-12 education and for non-tribal audiences.

Feb 23, 2014

By K. T. Stafford, N. A. Iverson, V. T. McLemore

Laramide porphyry copper deposits are large, low grade (<0.8% Cu) deposits that contain disseminated copper minerals, breccias, and stockwork veinlets of copper and molybdenum sulfides associated with porphyritic intrusions in Southwestern New Mexico. Critical minerals, such as PGEs, tellurium, indium, germanium, and gallium are recovered from the anode slimes remaining after copper is refined. Detailed age dating, mineralogy, geochemistry, along with geologic mapping could refine the location of critical minerals within specific systems and could identify porphyry systems with elevated critical minerals that could become economic, in addition to the already produced copper, gold and molybdenum.

Feb 1, 2023

By Gordon Kidd

Inflation and burgeoning costs are two among many factors which have generated a new surge of interest in "fringe benefits" (sometimes referred to as "supplementary remuneration" or "supplementary compensation"). Other specialized forms of compensation ("perks", in the vernacular) such as company cars, windowed offices, etc., which also are the subjects of current study, are outside the scope of this paper. For businesses, interest in fringe benefits is based on concern for employees? welfare, compliance with government requirements, and an increasingly burdensome impact on bottom lines. In 1980, according to Fred D. Lindsey in the October 1980 issue of Nation&apos;s Business, employee benefits will cost American employers an estimated $420 billion. To paraphrase Winston Churchill, "some fringes!" Indeed, few if any administrators consider employee benefits as fringes. Employee benefits impact other major areas of a company&apos;s operations as well. As listed by Beadle (1980), these areas include employee relations, collective bargaining, short-term costs, long-range funding, manpower planning, compliance with legislation, taxation for the company and for the employee, corporate image in the community, competitiveness for staff, communications, administration, claims cost containment, etc., etc.

Jan 1, 1980

By Robert Burgess, Dale Gill, Jaco Steyn, Bill Kyslinger

"With mining, especially coal extraction, comes the necessity of supporting the roof. Since the 1950s, the primary method for roof support has been the use of roof bolts. Roof bolting is considered one of the most hazardous jobs in underground coal mining. In 2004, there were 3,405 injuries reported to the U.S. Mine Safety and Health Administration (MSHA). Of those injuries, 17 percent were associated with bolting machines (593 injuries). The majority of the injuries resulted from rock falling from supported roof. However, injuries involving a part of the body being struck by, or caught between, during bolting and drilling occurred with relatively high frequency (Burgess and Steiner, 2007).Roof drilling and bolt installation is labor-intensive and repetitive. These labor-intensive and repetitive requirements can lead to cumulative trauma. Operators are expected to perform a considerable amount of lifting, carrying, bending, reaching and stretching. Back and shoulders become sore from bending and twisting to install bolts or lift and position drill steels, wrenches and bolts. Confined operator spaces also contribute to difficult and awkward working positions for the operators (Cornelius and Turin, 1998).In South Africa, the majority of the roof bolting machines used are “man-in-position” style machines (Fig. 1). This puts the operator in close proximity to where the drilling and bolting process is performed. When proper operation procedures are followed, it has been proven to be a very effective, productive and safe system. The MSHA-certified automatic temporary roof support (ATRS), canopies and dust collection system of Fletcher bolters all provide the operator with unparalleled protection. However, there are some occupational hazards inherent to the zone located next to the drilling and bolting zone. This has led some customers to request relocating the operator away from this zone. The idea being that the operators will no longer be located in the face area, greatly reducing their exposure to dust, noise, machine and geological hazards."

Mar 1, 2017

By J. Kretschmann, R. Amiri

"The Sangan iron-ore mines (SIOM) in Iran are located in a remote area, near the Afghanistan border. The deposit of SIOM is containing a geological resource of 1.2 billion tons of mostly magnetite with a Fe grade ranging from 27 to 61 %. The Iranian government plans a stepwise development of SIOM in cooperation with private companies to satisfy the growing demand of the Iranian steel industry. Sustainable development (SD) is an influential ethical concept in mining all around the world. However, a successful realization of a SD is not possible without a foundation on the core values and regarding the specific circumstances of the individual mining country. This paper introduces SIOM and describes SD activities undertaken during its development. From the early stages, these activities have been realized to secure the acceptance of the stakeholders in the region. To evaluate their effects, indicators could be filtered as the ones with the highest priority for the stakeholders. Moreover Islamic values and Iranian regulations and their influences on SIOM have been analyzed. Keywords: Iran, Sustainable Mining, SIOM, Evaluation, Islamic Values INTRODUCTION Mining Industry in Iran The Islamic Republic of Iran holds 68 types of minerals, including salt, sand and gravel, gypsum, chrome, lead, zinc, copper, coal, gold, iron etc., with 37 billion tons of proven reserves and more than 57 billion tons of potential reservoirs. Iran is ranked among the 15 major mineral rich countries (1). In accordance with the statistics published by Statistical Center of Iran (SCI), there were 5.316 active mines and 84.922 employees in the whole country in 2012-13 (2) and according to the statistics published by Central Bank of Iran (CBI) in 2011 the share of this sector in the Gross Domestic Product (GDP) of the country was 1.2 per cent (3). Sangan Iron Ore Mines (SIOM) The deposit of SIOM is one of the largest iron-ore deposits in Iran, also considered to be one of the Middle East’s richest deposits, which contains a total geological resource of 1.2 billion tons of mostly magnetite with a Fe grade ranging from 27 to 61%. It is located 300 km southeast from Mashhad, the capital of Khorasan-e-Razavi Province, and 18 km northeast of Sangan town, in Khaf County, at latitude N34°24’, longitude E60°16’ in the north-eastern Khorasan-e-Razavi Province, 30 km west of the Afghanistan border (4) (Figure 1). SIOM is owned by the Iranian Mines and Mining Industries Development & Renovation Organization (IMIDRO). IMIDRO intends to develop an open pit mine complex and supporting facilities in SIOM for the production of about 20 Mtpy of iron oxide concentrate and pellets in four developing phases (5)."

Jan 1, 2016

By Carl Rampacek

Laboratory and small-scale continuous pilot-plant investigations made at the Tucson Metallurgy Research Laboratory of the Bureau of Mines have demonstrated that the copper segregation process is applicable to the treatment of oxidized and mixed oxide-sulfide copper ores regardless of the gangue constituents. The process comprises heating the ore to a temperature of 750° C. with small quantities- of sodim chloride and coke to produce metallic copper, which then is recovered by flotation. Tests were made on&apos; 23 copper ores of different types containing 0.8 to 5 percent Cu, .The copper recoveries ranged from 73 to 96 percent in concentrates assaying 10 to 62 percent Cu, depending on the grade and type of ore, The direct operating cost for a 1,000-ton-per-day furnace and flotation plant is estimated at about- $3 per ton of ore.

Jan 1, 1960

By Hans Hamrin, Bruce Kennedy

Once an ore body has been probed and outlined, and sufficient information has been collected to warrant further analysis, the important process of selecting the most appropriate method or methods for mining can begin. At this stage, the selection is preliminary only, serving as the basis for a project layout and feasibility study. Later, it may be found necessary to revise the details, but the basic principles for the ore extraction should remain a part of the final layout. With respect to the basic principles employed, relatively few mining methods are used today. For the purposes of this presentation, the principles are classified as follows: 1) For naturally supported stopes, the available methods are room-and-pillar mining and sublevel stoping. 2) For artificially supported stopes, the available methods are shrinkage stoping, cut-and-fill mining, square-set mining, and longwall mining. 3) For caving methods, the available techniques are sublevel caving and block caving. Due to the uniqueness of each ore deposit, the variations on each of these methods are nearly limitless. It is impossible to include even the major variations in this chapter; the goal of this chapter is to present the principles as a guide to the mining engineer in adapting the general methods to specific needs. The selection process described herein is intended to supply the techniques by which the candidate methods available for a given ore body can be reduced to one or two feasible approaches. The feasible approaches then can be evaluated in detail, and the particular modifications can be investigated. In describing costs and economic factors, all values herein are expressed in terms of 1978 US dollars.

Jan 1, 1982

By Robert A. Jankowski, Charles A. Babbitt, Natesa I. Jayaraman

The U. S. Bureau of Mines, through a contract research program with Foster-Miller, Inc., has identified guidelines for the selection of the most effective water spray system and water flow rates for use on continuous mining machines. Specifically, these parameters were modified to obtain maximum dust control with regard to quartz dust exposure and more stringent respirable dust standards due to quartz. A novel water spray system, consisting of flat fan spray nozzles, mounted across the top of the mining machine, along with high flow, flat fan and higher pressure hollow cone nozzles mounted under the boom has been identified and tested. The anti-rollback/underboom spray system minimizes dust rollback while increasing dust knockdown by its unique positioning of spray manifolds and orientation of spray nozzles. Respirable dust suppression characteristics of the system acted in three ways: - by wetting the surface of the broken coal material to prevent dust from becoming airborne; - by controlling the airflow pattern at and near the face to minimize dust rollback to the operator Is control location; and - by dust knockdown, i.e., airborne capture, or scrubbing of airborne dust from the air. During underground trials, the anti-rollback/ underboom spray system reduced dust levels at the operator&apos;s position and in the immediate return by 55 and 15 pct, respectively, when compared to a conventional spray system. Quartz dust levels at the operator &apos;8 position were essentially eliminated, while quartz dust levels in the immediate return were reduced by 57 pct. Applying the concepts of this technique throughout the mining industry should reduce the health hazard associated with excessive exposure to respirable quartz dust, as well as allow coal mine operators to comply with the associated, more stringent, respirable dust standards.

Jan 1, 1987

Software exhibitors at MINExpo will feature the newest, the best, the most comprehensive computer-based tools available to get minerals from the ground to the market. From the ?cloud? to the pit, the variety that will be featured is almost limitless ? a digital tool for every phase of the mining lifecycle. Blue Sky Network SkyRouter brings the Blue Sky Network to the cloud. Using its interactive Web portal, SkyRouter, with detailed mapping and integration with Google Earth, the Blue Sky Network links enterprises to personnel and assets anywhere on earth through Iridium satellites. The cloud-based solution is designed to support connectivity with remotely dispersed mobile assets, including Blue Sky?s dual-mode GSM and Iridium tracking and communications services. This enables seamless connectivity with assets in problematic cellular reception areas, where only 10 percent of the Earth is covered, and in remote locations.

Jan 1, 2012

By M. J. Farrell

Mining is a significant emitter of greenhouse gases and is the focus of increasing attention from green groups and regulators. Miners need to know their own carbon emissions and how they compare with the rest of the industry. Miners and mining companies need to know where they fit in the emissions curve. Who is in the bottom quartile? This article updates data from minecost.com which detail the specific carbon dioxide emissions for over 200 mines producing 90% or more of western world copper, zinc, lead and nickel in 2009. This data shows the potential impact on mine economics of proposed carbon taxation regimes and emissions trading schemes proposed at COP 15 in Copenhagen during December.

Jan 1, 2010

By Yongsik Jeong, Kwangmin Kim

Most tailings storage facility (TSF) failures occur in active, upstream-type TSFs, often due to extreme and unexpected weather conditions—specifically, heavy rainfall and strong winds. This case study of a TSF in southern Arizona examines the use of the optimum safe beach distance (Doptimal, the optimum distance between the crest and decant pond) as a tool for monitoring geotechnical stability and reducing catastrophic failures. A digital model of the TSF was used to determine the critical beach distance (Dcritical) under normal weather conditions, and Doptimal was then determined by adding incremental distances to account for the effects of heavy rainfall (Drainfall) and strong winds (Dwind). To overcome accessibility issues, a drone was used to map the TSF geometry and create a digital model. This model served as the basis for conducting a coupled stress-seepage, finite-element (FEM) analysis with a safety factor of 2.0 to assess geotechnical stability (Dcritical). The safe beach distance increments were determined using the PMP (probable maximum precipitation) and possible maximum wind speed. Based on this analysis, the optimal safe beach distance at the study site was identified as 202.2 m. Since the current beach distance (371 m) exceeds this value, the TSF was considered to be stable and satisfied the design safety factor of 2.0. However, this distance should be reassessed periodically to account for changes in the TSF geometry and other conditions. Furthermore, it applies only TSFs that are well-managed and feature a smooth, non-undulating beach surface with a consistent slope.

By Hasan Ali Taner, Vildan Onen

One of the problems in flotation is mechanical entrainment and the other is the presence of complex gangues (especially clay minerals). In the present study, it was aimed to determine the effects of clay types (kaolinite, illite, and montmorillonite) on mechanical entrainment parameters (total flotation recovery, real recovery, mechanical entrainment recovery, and water recovery). Effects of clay types and clay amount on chalcopyrite flotation were investigated by flotation experiments. Interaction mechanisms between the clay minerals and ore were characterized using SEM–EDS analyses. Experiments were carried out with and without a collector using the mixture of clay minerals and ore under certain experimental conditions. While the clay mineral most affecting the chalcopyrite grade was montmorillonite, the highest mechanical entrainment recovery and the lowest real recovery values were obtained in the presence of illite. While illite is stated as the least problematic clay mineral in the literature, it was determined that illite among three clay minerals used in this study caused significant mechanical entrainment. In contrast, it was determined that increasing the amount of kaolinite did not have a significant effect on mechanical entrainment. This study’s findings will guide in determining of clay minerals’ effect on gangue entrainment in flotation.

Dec 29, 2023

By Robert J. Ramsey, N. Finkelstein, Robert D. Jeppson

Introduction The Utah Copper Division of Kennecott Copper Corporation will present its contribution to the A. M. Gaudin Flotation Symposium in four parts. The first two segments will discuss briefly the historical development of the Utah Copper Division and describe the ore body. The third segment will review the facilities and operating procedures for the Utah Copper Division&apos;s newest plant, the Bonneville Concentrator. The fourth segment describes flotation process circuitry, including molybdenite recovery procedures, at the Arthur and Magna concentrators. (The Bonneville concentrator is a crushing and grinding unit and does not have its own flotation plant). 1. Historical Development Progress through change has been the key to the successful operation of the Utah Copper Division for more than 70 years. As the original low-grade copper operation, the pressures to remain competitive and profitable have dictated the timing and extent of each change. Much of the change has occurred through technological and economic advancements in the area of ore concentration. The Utah Copper Division of Kennecott Copper Corporation had its origin June 4, 1903, when the Utah Copper Company was organized. The initial mill of 300 tpd (tons per day) capacity was built at Copperton a few miles below the present Bingham Canyon mine site. From 1904 to 1910, the Copperton mill was expanded to a capacity of 1,000 tpd, and all of the known apparatus for gravity concentration were evaluated.

Jan 1, 1976

By J. Brad Dalton, Sam Vance, Trude V. V. King, Roger N. Clark, Raymond F. Kokaly, Gregg A. Swayze, Dana J. Bove

Visible-wavelength and near-infrared multispectral image cubes for the Animas River Watershed from Hermosa, Colorado to the headwaters at Animas Forks, Colorado were acquired on June 18, 1996 using the Jet Propulsion Laboratory&apos;s AVIRIS (Airborne Visible and InfraRed Imaging Spectrometer) instrument (Green et al., 1998). These image cubes have been analyzed using the USGS Tetracorder V3.4 implementation (Clark et al., 1995), an expert system which utilizes a database of more than 300 laboratory spectra of endmember minerals and mineral mixtures to generate maps of mineralogy, vegetation coverage, and other material distributions. Major iron-bearing, clay, carbonate, and other minerals were identified along with several minerals associated with acid-generating hydrothermal systems including pyrite, jarosite, alunite and goethite. Additionally, distributions of alkaline minerals such as calcite and chlorite indicate a relation between acid- buffering assemblages and stream geochemistry within the watershed.

Jan 1, 2000

By Victoria Vaccarezza, Corby Anderson

The demand for rare earth elements for everyday technology and applications has initiated much research into the extraction and recovery of these rare earth elements. An otherwise unknown group of minerals, eudialyte is a zircon silicate consisting of rare earth oxides (REO), contained in a unique mineral structure and represented by a complex chemical formula. Research into extraction and recovery of rare earth elements involves various beneficiation and hydrometallurgical techniques. The goal of beneficiation being to efficiently liberate and upgrade the REO content, followed by hydrometallurgy to extract the desired elements. This overview will discuss previous research on treating eudialyte group minerals via different mineral processing and extraction techniques.

By H. Lawrence

In 1977, the Bureau of Mines awarded a grant to the State of South Carolina to explore the possibility of using Landsat multispectral scanner (MSS) data as an aid in monitoring surface mining activities in selected counties of the State. Work had been done in Aiken County prior to the grant by Bureau of Mines and State personnel at the EROS Data Center using both the GE Image 100 and ESL IDIMS systems. The initial work on the 1-100 consisted of locating and measuring the areas of various kaolin mines. The results were excellent on location, identification, and accurate area measurements of several mines as compared with aerial photos of each mine. The effort also included locating and measuring the size of all mines (including sand and gravel) within two U.S. Geological Survey (USGS) 7 ½ min quadrangle maps. Line printer overlays using the IDIMS equipment and software resulted in the location of all known mines within an estimated error less than ±91.4m (5300 feet). Mine acreage was calculated by counting each symbol (which represented one pixel) and multiplying by 1.1 (the number of acres per pixel). Figure 1 shows a portion of one quadrangle overlay. Table I gives a comparison of acreage measured for sever- al mines from the 1-100 and IDIMS systems vs. aerial photo measurements.

Jan 1, 1979

By R. E. Thill

An ultrasonic, pulse-immersion apparatus and method are described for determining the effects of moisture on the dynamic elastic properties of rock. The method provides an alternative approach for assessing the moisture sensitivity of rocks. Ultrasonic wave velocities are continuously monitored in immersed rock samples as a function of water absorption and time up to saturation. Moisture effects on compressional wave velocity vary as a function of the type of rock and the time and amount of water absorption. Regression analyses are used to curve-fit plots of the data and to derive empirical expressions for compressional wave velocity as a function of water content for different categories of rock. Results indicate that compressional wave velocity can be used to predict both the moisture content and its effect on strength and deformational properties of rock. These results have potential for detecting or monitoring bad roof conditions in situations where the mine rock exhibits strength degradation with moisture absorption.

Jan 1, 1986