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By Michael J. Shulman

Outcrops of the Nubian Sandstone Series cover approximately 180,000 km2 in southern Egypt. Within the series, oolitic iron ore beds occur. The only comprehensive information available on stratigraphy of the iron beds is for the area east of Aswan, otherwise information is exiguous, sparse or unreliable. Based on this low level of information, the iron potential of the Nubian Sandstone Series was assessed and an exploration strategy formulated specifically tailored to the assessment. The area covered by the Nubian was divided into five regions, each comprised of 100 cells. A spatial distribution, i.e. negative binomial, was assumed adequate to describe the number of targets per cell and was indirectly calculated using a compound poisson distribution. Estimate of the only unknown parameter - the average number of targets per cell - implicitly/explicitly incorporated available geologic and economic information into the assessment. A probability distribution for the number of targets per region was then derived from the cell probability distribution. An allocation model based on the regional probability distribution assessment as well as on an estimate of the exploration effectiveness and on the exploration budget determines the optimal time to be spent in each region.

Jan 1, 1986

By Ethan Steward, Kyle Perry

The study investigates the effects of high-velocity impacts of common mine materials on a reinforced mine seal rated to 120 psi. It found that materials propelled during an underground explosion could generate enough stress to crack or damage seals, even with little visible damage. This highlights the need for careful evaluation of mine seals after any impact or high-pressure event.

Aug 1, 2023

By Ching L. Wu, Bolek Chytrowski, Peter Frobenius, Dale Roberts

During the past few years, the first stage of the Waste Isolation Pilot Plant, (WIPP) which consists of an exploratory shaft, a ventilation shaft, shaft stations, access drifts and test rooms, has been under construction. Construction of the first stage is scheduled to be completed in the summer of 1983. The U.S. Department of Energy (DOE) is constructing the WIPP facility to demonstrate the feasibility of disposing of defense-related nuclear waste in the bedded salt deposits of the Delaware Basin near Carlsbad, N.M. The project promises to be a proving ground for underground nuclear waste storage facility design and construction. The completed underground plant will extend over an area of 647,500 m2 (160 acres), and 1,360,500 metric tons (1,500,000 tons) of salt will be excavated. The first stage of the project, the Site and Preliminary Design Validation (SPDV) Program, provides for full-scale construction of the major components of the underground facility. Shaft construction and underground development are described. Rock bolt installation is performed as required for roof control. Geotechnical instrumentation is installed to monitor the behavior of underground openings. Direct observation of the constructed shafts, shaft stations, and underground openings is expected to confirm the adequacy of the underground design and allow full-scale construction of the first U.S. underground nuclear waste storage facility to proceed.

Jan 1, 1983

By JA Vallejos

High stress underground mining poses a significant challenge to rock mechanics and rock engineering. To overcome theses challenges significative improvements in solutions and best practices of the design and operation of mines under high stress have been developed and implemented. This paper presents certain topics related to the management of high stress for sustainable underground mining. The topics include; the effect of preconditioning techniques (destress blasting and hydraulic fracturing) in the seismic rock mass response to underground mining and the dynamic behaviour of rock support systems. The opportunities associated with research in rock mechanics and practical rock engineering are discussed.

Apr 26, 2022

By Kristin Hemlein

Mining project development, permitting, environmental regulatory and compliance issues in Uzbekistan and the CIS are every bit as complex as those in the western world. The vast array of environmental permitting, monitoring and reporting regulations for mine project development and operation in the CIS are based on existing Soviet environmental regulations and policies which have remained in place after these countries gained independence from the former Soviet Union. The approach to mine project permitting in the CIS differs from the western world. Similar pre- feasibility, baseline data collection, and environmental monitoring requirements allow the project proponent to coordinate preparation and submission of documentation to support project permitting for Uzbek regulatory requirements with environmental requirements imposed by financial institutions and western environmental compliance structures. Implementation of generally accepted western environmental best management controls and monitoring into mine design, construction, and operation will not, however, ensure automatic compliance with Uzbek environmental regulations. Uzbek environmental compliance requirements that differ from western requirements include: 1) development and maintenance of an environmental database constructed specifically to address annual, biannual and quarterly statistical reporting requirements for emissions of "environmental pollutants" from the facility into air, surface water, ground water and soil; 2) preparation and submittal of specific permits for water utilization, hazardous waste storage and disposal, landfill construction and operation, and stack emissions inventories; and 3) procurement of approvals from the Uzbekistan State Committee for Nature Protection (generally analogous to the US Environmental Protection Agency). This paper outlines and summarizes the regulatory requirements for mine site permitting and the procedures for environmental monitoring and reporting during mining operation in Uzbekistan and the CIS.

Jan 1, 1997

By Julian Glasser

Starting with rutile, containing more than 55% TiO2 and of the proper particle size, the commercial production of titanium tetrachloride via fluidized bed chlorination is relatively very simple and economical. As compared to shaft chlorination, it operates at a much higher capacity for given sizing of equipment, and appears more foolproof, requiring less attention. Operating data were obtained on a 53" diameter fluidized bed chlorinator using Australian rutile and petroleum coke of controlled particle size. Production rates varied from 20 to 50 tons of crude TIC14 per day for a campaign extending over one month. Close to theoretical yields and efficiencies were obtained from the viewpoint of chlorine and/or rutile consumption. Details of important equipment design, critical operating conditions and pertinent results are described.

Jan 1, 1962

By J. A. Marshall

"INTRODUCTION The purpose of this paper is to investigate the potential for use of UAVs in underground mines and present a prototype design for a novel autorotating UAV platform for underground 3D data collection. The mining industry has recently shown increased interest in the use of unmanned aerial vehicles (UAVs) to assist in everyday operations [20, 11, 4]. Above ground, small UAVs are in some cases a more efficient, inexpensive, and safer alternative to manned aircrafts currently used for photography, inspection and security [6, 10]. For example, attaching camera, infrared and LiDAR payloads, UAVs can provide a low-cost method of obtaining highly accurate 3D photogrammetric data and aerial photography. UAVs are now commonly used in open pit mining operations for applications that include stockpile surveying, 3D pit modelling, facilities management, accident reporting, progress monitoring, and environmental assessment [11]. There are numerous companies offering UAV services for mining applications; e.g., UAV Geomatics, Leica Geosystems, Sky Futures, SenseFly and FlyTerra, to name just a few. Common services include stockpile and open pit volume computations, environmental assessment, aerial mapping and photogrammetry. Although the aforementioned services are thosemost commonly provided by UAV surveying companies, they may also add value to other daily mining operations. For instance, SenseFly offers pre and post-blast monitoring in order to identify the presence of misfires and wall damage. This data can also be used to reconcile the blast results with expected results. GEM Systems offers a UAV equipped with a magnetometer for mineral exploration surveys. Companies such as Barrick have even used UAVs for solids modelling at tailings dams and stability monitoring [11]. UAVs in mining have so far been mostly limited to surface applications. Harsh underground environments pose many obstacles for flying UAVs. The confined space, dampness, reduced visibility, air movement, and lack of control signal propagation hinders most operators from being able to fly a drone underground. It may be that truly practical uses for UAVs underground will require either autonomous or semi-autonomous flight capabilities. Although there are many difficulties with flying underground, the potential benefits from a working system could greatly improve mining operations. The potential benefits of deploying UAV platforms underground include access to unreachable and dangerous locations and removing personnel from unsafe situations. These benefits have the potential to greatly improve mine monitoring and mine safety. Research has shown that current UAV technologies exist that allow for autonomous indoor flight. Extensive research has been done to develop UAV systems that are capable of performing on-board simultaneous localization and mapping (SLAM), which can allow them to navigate and map a foreign environment autonomously [5, 7, 1, 13]. Grzonka [7] successfully used an open hardware quadrotor to autonomously navigate and map an office building. The research outlines the localization, mapping, path planning, height estimation and control of the autonomous quadrotor. Other research has been done that exploits autonomous UAVs for search and rescue. Kassecker [9] proposed a software and hardware framework for a quadrotor capable of indoor and outdoor urban search and rescue and Rudol [19] developed a system for human body detection and geolocalization using an autonomous UAV.The use of autonomous UAVs in search and rescue has the potential to improve situational awareness and surveillance for a rescue team. Similar research has been done that uses autonomous UAVs for indoor exploration. Pravitra [15] outlined a strategy for autonomous exploration of miniature air vehicles (MAVs) within indoor environments and Rudol [19] developed a method for using an unmanned ground vehicle (UGV) and a UAV for cooperative indoor exploration. These studies show that aut"

Jan 1, 2017

By Carl Heising

Longwall workings in the Federal Republic of Germany are situated in deep depths. Coal deposits are characterized by a sequence of many seams and manifold geological disturbances. Hence result special requirements on the layout of workings, the methods of coal getting, supports, mine ventilation and dust control. As for the application of dust control the large quantities of fresh air and, this, the high air velocity and the limited water contents in the run-of--mine coal must be taken into consideration. The principle of our methods of dust control is to avoid, if at all possible, the development of dust and, if this is not possible, to suppress the dust even during its development. In nearly all coal faces, the method of water infusion prescribed by our Mines Inspectorates is applied. Continuous water in- fusion is preferred. For water infusion in the coal face, intensive developments as to the process and as to the tools and apparates to be applied were done. The German coal mining industry differs between cutting coal getting and stripping coal getting. Water spraying to the tracks of coal ploughs as well as internal and external water feed to the loader required special activities of further development in past years. There are possibilities to still improve such methods in future. A new important field of applying dust control developed from the application of powered supports. In this field, water spraying prevails. Wet methods of dust control are prefered also in the conveying and loading of coal and at through-flow crushers, however, as far as possible, combined with a covering of the working points where dust develops. Devices for the collection and sedimentation of dust, so-called dust exhausters, are used also with crushers In advanced headings, dust control is performed solely by water. Gateroads kept on or behind the coal face line call for new methods of dust control which are at present under development.

Jan 1, 1980

By Stefan Lorenz, Robert Galler

"The technical lifetime of underground structures does not only depend on the long-term behavior of individual support elements and material characteristics, but also on various boundary conditions, which influence the entire long-term system behavior of the structure. Thanks to the construction of second tunnel tubes and the corresponding cross passages sampling of support materials such as shotcrete, concrete of the inner lining and rock bolts including sheet membranes is possible. To evaluate the stresses and the supporting effects of the tunnel shells, flat-jack tests and different simulations were performed. With these simulations the percentage of the load bearing behavior of the shotcrete shell can be determined. From the results, conclusions for new design approaches for tunnel construction should be generated. New concepts, in which the outer lining is part of the permanent support elements can be considered. This approach would be applicable for conventional as well as mechanical tunneling. INTRODUCTION Tunnels are an indispensable part of modern transport infrastructure. As multi-generation structures their long-term preservation as well as their technical service life is of central importance. The current state of research in the field of durability of structural elements must be considered separately. In almost all areas a prediction of materials and structural components towards lifetime exists. System-wide investigations were rarely performed, so that there is no technical lifetime consideration of the outer lining in systems included. In this study the mechanical behavior of the interface connection in a double shell lining (DSL) tunnel was investigated in laboratory tests. Objective The target of this work is, at first, to create a large database with the lifetime of different structural elements and materials, which may be the basis of durability considerations of tunnels. Secondly, the goal of these investigations is to optimize tunnel designs and their dimensioning regarding to the technical lifetime. For that matter, it is necessary to analyze the selected approaches of the loss of strength and stiffness of the outer lining."

Jan 1, 2016

In spite of our deep conviction that it would be wrong for the United States to enter World War II, when, after Pearl Harbor, we were actually in it, I felt that I must do all I could to help. The country had been so good to me that I could not decently stay on the sidelines. My first thought was that I might help with supply and administration in the Air Force, as in World War I. So on the evening of Pearl Harbor I wired the chief of our Air Force in Washington saying that I had been on Gen. William Mitchell's staff in World War I and was offering my services again. I received a noncommital answer, but after a couple of weeks was told to take my physical examination. I passed it, but nothing further happened. After helping to make plans for the wartime operations of Summit King and Desert Silver, Dorothy and I went to New York to spend Christmas with Molly and Peter, both of whom were in college in the East. I had to complete a report on the Argonaut mine in California first, though the war made my recommendations of dubious validity. Before Christmas I received wires from Temple Bridgeman, Phil Wilson, and other friends who had taken positions with government agencies responsible for securing mineral products needed for war use. They urged me to join them. It was evidently a case of not whether but how I could be most useful. After six uncertain days with the family in New York I took the night train to Washington on the 28th of December. I had a hectic day there. First I saw Arthur Bunker and Phil Wilson at what became the Aluminum and Magnesium Division of the War Production Board. Their office was in an old converted barracks. They asked me to examine magnesium deposits in Nevada at once, and then to look at other magnesium and aluminum properties. After leaving

Jan 1, 1976

By H. Dho

Two aromatic-type chelating agents, 1,10 phenanthroline (phen) and 8-quinolinol (quin), were tested as specific depressants for magnetite in the cationic silica flotation of magnetic taconite concentrates. Micro and batch flotation tests, along with zeta potential and adsorption measurements were used. In the presence of a cationic collector, dodecylammonium chloride (DAC), the Fe/phen surface chelate electro-statically repelled DAC, and magnetite was depressed. The negatively charged Fe(quin)2(OH)2-on the magnetite surface attracted the cationic collector and made magnetite floatable.

Jan 1, 1995

By N. Demirel

Estimating productivity of a walking dragline is of paramount concern to mining engineers and mine planners. Risk based evaluation of the dragline productivity is a valuable tool to estimate the dragline?s long-term performances and availabilities, to develop preventive maintenance plans, and to make future projections about the machine?s performance. This paper aims to provide mining professionals with an overview of risk assessment methodology for productivity of two walking draglines, PAGE 736 and MARION 7820, which have been operating in Tunçbilek open cast coal mine of Turkish Coal Enterprises (TKI) in Turkey. The study encompasses three main stages as: (i) acquiring of monthly maintenance records, operating hours, mechanical and electrical failure hours between 1998 and 2009; (ii) reliability modeling using mean time between failure data; (iii) determining hazard rate and consequences to compute risk associated with dragline productivity. The results showed that that Page 736 (20 yd3) is seemed to be more reliable and less likely to fail when compared with Marion 7820 (40 yd3). The operating hours without failure range from 41 to 51 hours with 50 percent reliability.

Jan 1, 2011

By Huayang Luo, Hui Li, Wei Zhou, Gang Chen, Scott Huang

The beach and offshore gold resources demonstrated at Nome, Alaska are some of the richest found in Alaska. They contain potentially significant resources that may be exploited in the future. Several companies have contributed to the exploration and reserve estimation in Nome offshore gold deposits. More than 3,000 holes were drilled and over 10,000 offshore samples were analyzed in the Nome offshore areas of approximately 40 km2. Those 3,000 plus drill hole logs were converted into digital formats comparable with ArcGIS software. Considerable amounts of mineral resources data were processed and visualized using ArcGIS 8.3 and its geostatistic, 3D analysis, and spatial analysis components. In this study, based on the data processing and visualization results of ArcGIS, a user-friendly website for mineral resource management and utilization is developed using ArcIMS 4.0.1. ArcIMS is a GIS solution to build and deliver maps, data, and tools over the Internet. The Nome offshore mineral resources website presents the geostatistic and GIS analysis information. This site allows clients to access the information and perform ArcGIS analysis, such as interactive data query, and map layers display of the gold resource distribution, average grade, gold reserve, and relative mineral resource estimation via remote computers. With linkage to other related mining web sites, this web site allows users to search for related publications and more flexibly manage the information. A few other appropriate customized tools are also being developed to assist interactions between the server and clients for data analysis and management.

Jan 1, 2005

By Daniele Martinelli, Rodrigo Winderholler, Daniele Peila

"This paper presents a technical description of an experimental procedure developed for the geotechnical characterization of granular soils conditioned for EPB tunneling using a modified direct shear box. As the main concerning parameters of the conditioned soil mass were their undrained properties, in order to preserve its pseudo-fluid characteristics, a watertight direct shear apparatus was constructed. A comparison between the results obtained under dry, saturated and conditioned conditions is presented. INTRODUCTION EPB shield machines have been used for tunneling excavation in many different types of soils thanks to the use of soil conditioning agents. These modify the properties of the soil into that of a plastic paste, thus permitting the homogeneous flow of the excavated soil from the tunnel face through the bulk chamber, the screw conveyor and finally the conveyor belt. Moreover this technique allows controlling the face pressure and its regulation in the bulk chamber, preventing water inflow when tunneling below the water table. Further advantages are a drop of the cutter head and screw conveyor torque and reduction of the friction between metallic parts and the soil, consequently reducing wear phenomena (Merritt & Mair, 2006; Vinai et al., 2007; Borio et al., 2010; Thewes & Budach, 2010; Herrenknecht et al., 2011; Barbero et al., 2012; Peila, 2014). Several studies have investigated the possibility of conditioning and the chemical materials to be used in different types of soils, mainly subdivided into three groups: cohesionless soils (sand and gravel), silts and clays, and rock masses. This various researches have set up several laboratory procedures for these achievements before and after soil conditioning, as stated in Thewes & Budach (2010) and Peila (2014) (for cohesionless soils), in Thewes & Burger (2005), Hollmann & Thewes (2013), Zumsteg et al.(2012) (for clay), in Peila et al. (2013) and Martinelli et al. (2015a) (for rock mass). Such tests should be simple to execute, reliable and easy to interpret at the in-situ excavation step. The reduction of shear strength is necessary in EPB operations, since it allows an effective transmission of the pressure from the material itself to the front. In some cases the slump is not sufficient to return a reliable result on the shear strength reduction, as in some cases some materials are behaving differently. Therefore this research is aimed to study this aspect more in detail, in order to show the effectiveness of the soil conditioning process on the material to be excavated."

Jan 1, 2016

By M. A. S. Martins, H. Medeiros, B. Y. B. Dos Santos

This paper contains the geometallurgical studies, performed for Mineração Rio do Norte bauxites, applied to a selected area belonging to Plateau Saracá III, referring to an exploitation period of one year and three months, approximately. It is worth mentioning that Mineração Rio do Norte has the biggest bauxite operation in Brazil producing 8,500,000 tons of concentrate per year. The studies included wide investigations directed to the final objective of establishing a precise mining and production planning, based on the different behavior of the distinct bauxite ores, when submitted to industrial processes. Geometallurgy can be defined as the study of the regionalization (space distribution) of the metallurgical variables of a mineral deposit. This study involves and integrates all process engineering, geology, geostatistics and mining planning, among others. The development and application of the geometallugical studies to Mineração Rio do Norte were motivated by several reasons and necessities, among them: 1. Improving the forecast of the amount of concentrate (metallurgical mass yield) produced; 2. Improving the equipment operational efficiency, providing a more homogeneous feed; 3. Conducting a more precise material balance that permits a better daily, monthly and yearly production control; 4. Improving the forecasts for the final products generated by each ore type; 5. Obtaining better knowledge of the behavior of several ore types, submitted to the different process unit operations; 6. Promoting adequate ore blending, producing an homogeneous feed during mining operation.

Jan 1, 1998

By D. R. Buist

The Taharoa plant of New Zealand Steel Mining Limited extracts a 57% Fe titano-magnetite concentrate from a large mineral sand deposit 90 miles south of Auckland on the west coast of New Zealand's North Island. The plant consists of an 18-inch suction cutter dredge which feeds a 750 TPH floating separation plant. An initial gravity/ size separation is obtained using cone concentrators. Finished concentrate is produced by a combination of conventional drum magnetic separators and top fed wet Mortsell magnetic separators. Concentrate is stockpiled by cyclone, and reclaimed by a bull- dozer and tunnel system. Repulped concentrate is pumped by sub- marine pipeline to slurry tankers anchored at a single buoy one mile offshore. Current concentrate production rate is in excess of one million metric tons per year.

Jan 1, 1973

By Ingo Ossenbühl, Wolfgang Dolsak, Vojtech Gall, Axel G. Nitschke

"Yielding support systems for application in underground construction have a long history, primarily in mining. Typical examples are tunnels subject to loading conditions that lead to overstressing of the newly installed support or existing tunnel structures in active fault zones. Recent applications for tunnel rehabilitation projects unveiled the capabilities and flexibility of combined yielding support systems presented in this paper. Frequently, the main requirements for tunnel rehabilitation applications are a fast, safe, and simple installation along with the need for flexibility with regards to existing tunnel geometries. A combined support system consisting of steel sets with yielding connections and special groutable hoses has proven to be an efficient support measure providing a multitude of advantages compared to conventional rehabilitation approaches. The presented yielding support system provides an immediate and active support, while it allows for controlled yielding upon experiencing loads beyond its support capacity. INTRODUCTION The excavation of underground spaces leads to redistribution in the existing stress regime. This load redistribution goes along with deformations in the surrounding rock mass. Magnitude and duration of these deformations depend on the tunnel’s depth and geological conditions, but also on the installed support system. Modern civil tunneling infrastructure has generally an envisioned service life of about 120 years. Conventional tunneling provides typically a dual support system, split into the initial (or primary) and final (or secondary) lining. A typical design principle in civil tunneling is to let the vast majority of deformations acting on the initial lining cease, before the final lining is installed. Based on this approach, the loading on the final lining is significantly reduced and signs of overstressing, such as cracking of the lining, are typically limited to the initial lining. However, special cases in swelling and squeezing ground require different approaches, including yielding support systems."

Jan 1, 2016

By T. Eggenberg

Mechanization and automation of logistic equipment has become one of the main key factors in raising productivity and competitiveness especially for complex and larger mining or tunneling projects. The Lake Mead Intake Tunnel #3 shaft mucking installation is a good example to demonstrate the potential that is found in an overall optimized logistic. It starts with the planning and results in using customized installations which fulfill the specifically defined requirements for the project. Rowa developed a solution and supplied a shaft mucking system using a discontinuous double drum hoisting concept with shaft buckets, loading, and unloading devices. With this fully automated system a continuous muck flow of 437t/h can be achieved.

Jan 1, 2010

By Gary H. Higgins

The paper by Lewis and Braun l presents experimental and calculational evidence that primary chalcopyrite ores are rapidly oxidized by warm oxygen-bearing water. Resulting solutions contained copper sulfate products of the matrix rock decomposition such as magnesium sulfate and sulphuric acid. Iron was oxidized to insoluble hematite and hydrous iron sulfates. Oxygen injection near the base of a broken and permeable flooded ore deposit was calculated to cause circulation of oxidizing solutions to the entire permeable region. The rate of dissolution of copper and degree of oxygen saturation for given oxygen injection rates were presented. Their work suggests that in-situ recovery of deep, disseminate primary copper deposits is technically feasible. The actual feasibility depends on economics and environmental safety as well, and it is the purpose of this paper to address these two aspects.

Jan 1, 1972

By T. Rockley, B. Goertz, S. McDaniel, J. Brune, K. Bakhsh

"Researchers at the Colorado School of Mines, under a project funded by the Alpha Foundation, have developed a working prototype of a dust sample collection device designed to determine if sufficient rock dust has been placed in an underground coal mine to prevent coal dust explosions. When used in conjunction with the Coal Dust Explosibility Meter (CDEM), the device will provide near instantaneous results on the quality of rock dusting at the tested location. The sampling device applies a pulse of air to a testing surface and collect a representative sample of mine dust based on the pneumatic entrainment process during a mine explosion. The use of both physical testing and Computational Fluid Dynamics (CFD) modeling has allowed researchers to refine the design to accurately represent the particle entrainment and optimize the sample size collected for the CDEM. The prototype is being tested in a mine environment to produce information of usability and practical aspects of mine dust sampling. This paper is a progress report summarizing the current status of sampler development. Researchers expect to have a fully developed and tested sampler in early 2016. INTRODUCTION Underground coal mines face the danger of methane and coal dust explosions. The disaster at Upper Big Branch mine (2010) has demonstrated the impact of a violent coal dust explosion that fatally injured 29 miners. Reviewing the history of coal dust explosions, researchers found that that mine operators and mine inspectors do not have a reliable method of collecting dust samples to assure that sufficient amounts of rock dust have been places to inertize the coal dust. This is a problem specifically with small mines that do not have dedicated safety departments to track rock dusting work. The aim of this research is to develop a simple, portable device that can help underground mine examiners collect dust samples from workings and test the explosibility of the sample near instantaneously. Researchers determined that the current brush-and-pan sampling method required by MSHA (MSHA 2013) is flawed in several aspects: Mechanical sampling with a brush exerts forces on the mine dust that may differ significantly from those present during an explosion. Also, U.S Bureau of Mines research (Nagy 1965) has determined that only the top 0.125 inches of the mine dust layer will be entrained in a coal dust explosion. Using a handheld pan and brush, it is difficult to correctly and repeatably sample a layer of this exact thickness. The following will describe the CFD modeling and experimental testing for the development of the prototype sampler. Researchers analyze the accuracy and performance of the prototype during the course of the build process."

Jan 1, 2015