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By E. De Souza

Rockbursts and rockfalls cause very large safety and productivity losses in underground mines. One of the major unsolved problems of safe, economical rock support in underground mining has been that of maintaining anchorage during dynamic rock loading conditions or seismic related occurrences. It is recognized that the large displacements and high strain rates in excavation walls and underground structures cannot be countered by increasing the strength of stiff rock-reinforcing systems but must be accommodated by introducing yieldability into the support elements. This paper introduces a low cost yieldable support system which provides viable solutions to dynamic support loading. Such system should not only provide a feasible and more effective rock mass stabilization strategy but improve mine safety and reduce losses.

Jan 1, 1998

By A. G. Nitschke, I. Ossenbühl, W. Dolsak, J. Dase

"The authors have successfully developed an innovative rehabilitation concept, which meets actual technical standards and minimizes the impact on the operation of a key conveyor tunnel. A flexible and stepwise ground support rehabilitation program utilized a combination of yielding steel arch sections with grout filled fabric hoses, which represents a fast and safe backfilling support system. The system was developed and successfully installed at Bingham Canyon Mine, the world’s largest open pit copper mine, which also includes numerous underground structures. The mine is owned and operated by Kennecott Utah Copper (RTKC) a fully owned subsidiary of Rio Tinto. The system was implemented at a conveyance tunnel, which was originally designed as a railroad tunnel, but was re-commissioned and is currently used as a conveyor belt tunnel to transport ore from the open pit to processing facilities outside the mine. The existing structure showed signs of overstressing due to movements in the surrounding rock mass, which had to be addressed with a yielding support system in order to provide safe access into the tunnel. However, the impact on the conveyor belt operation due to support installation was to be limited to the bare minimum. Keywords: rehabilitation, yielding support, mining, stabilization, and grout filled fabric hose.PROJECT DESCRIPTION The C6 Tunnel is considered a critical asset for the operation of the Bingham Canyon mine as it comprises the standard route for transporting crushed ore from the open pit to the processing facility on a continuous conveyor belt system. The C6 tunnel was originally built as a railroad tunnel. Construction was completed in 1959. The original horse-shoe shaped cross section of the tunnel was 18 feet wide and 24-1/2 feet high [8]. The tunnel length was approximately 18,000 feet. During its service life, the railroad tunnel has undergone several transformations. The length of the tunnel towards the Bingham Canyon pit was shortened over the course of mining operations and the railroad tracks in the tunnel were removed. The invert was partially backfilled (3 feet typical) and a 72 inches belt conveyor was installed. Currently, the C6 Tunnel is nominally only approximately 21 feet high and 15,000 feet long. Ground Support and Rehabilitation Measures prior to 2014 The C6 tunnel was mined mainly with conventional mining methods, using drill & blast as the typical one. However, the weak geological sections, such as those encountered in the Fortuna fault, were excavated by shaping and chipping with machine-held moils [8]."

Jan 1, 2015

By Layton C. Binon

Exploration budgets are commonly determined by "rules of thumb" such as a percentage of earnings or other fiscal measure. An appropriate exploration budget is the amount needed to achieve the goals of the company. It can be determined by discounting the income expected from achieved goals. Budgets for individual projects are determined in a similar manner except that risk of failure is included in the computation.

Jan 1, 1981

By Rénard Chaigneau

Quality during induration Drying ??40% of energy ??Drying velocity = f(1/radius2) ??Size versus risk of condensation ??Flow is important (minimise fines)Oxidation ??IOC Fe2+ typically 0.04% ??Important to minimise Fe2+forLow Temperature Disintegration ??Tight size distribution is key13

May 1, 2011

By A. Jakobsson

Studies of the rate of interdissolution in oxide systems in the solid state are of importance in materials processing through the powder-metallurgical route. As there is a need for following the rate of the such reactions continuously, a new method based on high temperature X-ray diffraction was developed. Mechanical mixtures of the oxides were placed in a high-temperature X-ray diffraction unit and the changes in the intensity and position of the peaks with highest intensity for both the components were followed as functions of time. A suitable theoretical model has been developed in order to interpret the experimental data and evaluate the diffusion coefficients. The method was applied in the case of the system MgO-NiO. The results obtained are compared with those obtained by another new method, based on solid-state galvanic cell technique with calcia stabilized zirconia electrolyte, developed in the Department of Theoretical Metallurgy. The advantage of the present techniques to monitor the progress of the reaction continuously make them suitable for computer control of such processes.

Jan 1, 1995

By A. F. Baker

Laboratory flotation of synthetic coal-pyrite mixtures and high-pyritic-sulfur coal indicated that ferric chloride (FeCl3), aluminum chloride (AIC13), chromium chloride (CrCl3), and cupric sulfate (CuSO4) are potential pyrite depressants. For each metal salt there appeared to be a range of pH values and optimum concentration for selectively depressing pyrite in coal flotation. Pyrite was depressed in the pH range from 4.5 to 7.0 with ferric chloride, from 5.8 to 7.0 with aluminum chloride, from 6.4 to 7.1 with chromium chloride, and from 6.4 to 7.4 with cupric sulfate. Best separation of pyrite from coal was achieved in flotation solutions containing from 2 X 10-5 to 5 x 10-5 mole/ liter of each salt. In solutions containing excess salt concentrations, coal was also depressed. These Bureau of Mines tests demonstrated on a laboratory scale that, in solutions containing 4 X 10-5 mole/liter ferric chloride and from 1 x 10-4 to 2 x 10-4 mole/liter sodium hydroxide, the pyritic sulfur content of a Lower Freeport bed coal sample could be reduced from about 2.51 percent to less than 0.60 percent with recoveries of over 83 percent. The depression of pyrite appears to be due to the adsorption of positively charged colloidal metal hydroxide at the pyrite-solution interface. This hypothesis is supported by zeta potential determinations which showed that suspended coal and pyrite particles in solutions containing metal salts are positively charged in the pH range where depression occurs.

Jan 1, 1971

By B Harvey

Achieving community and stakeholder endorsement during life-of-mine planning and implementation requires a business-connected approach, as opposed to charitable giving, disconnected offsets and environmental adventurism.CITATION:Harvey, B, 2014. Extractive companies, development and environmental agendas, in Proceedings Life-of-Mine 2014 , pp 19–22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Patrick R. Taylor

Glass is used for immobilization of radioactive and hazardous wastes due to its durability and ability to accept a variety of waste constituents into its network structure. Alternative high temperature vitrification techniques have the advantage of increased throughput, increased waste loading and being applicable to variable and heterogeneous waste streams. However, the increased processing temperature places further concerns on the increased volatilization of contaminants, and increased corrosion and erosion of me Iter components. A database of melt properties at higher temperatures, such as partitioning, viscosity, density and electrical conductivity, in the temperature range of 1400-20000 K are being developed.

Jan 1, 2000

By D. M. Richards

"IntroductionThe Highland Valley Copper partnership was formed in July 1986 as a logical result of a mine with a large ore reserve but a small mill, and a mine with a large, modern mill but dwindling ore reserves. The original partnership of Cominco and Rio Algom was expanded in January 1988 to include Highmont Mining Company. During 1988/89 the Highmont mill was moved 7.5 km to adjoin the Lornex mill, becoming the Highland mill in the process, with a nominal capacity of 130 000 tonnes per day.The mine is located near the town of Logan Lake, 220 km northeast of Vancouver, British Columbia and 55 km southwest of Kamloops. The map in Figure 1 shows the general area. Kamloops is a major service centre and is served by two railways, two major roads and a regional airport. The mine site is situated between 1200 m and 1600 m above sea level on the Thompson Plateau. Principle activities in the area, in addition to mining, are cattle ranching and forestry. Ore reserves at the beginning of 1996 totaled 533 million tonnes at a grade of 0.42% copper and 0.008% molybdenum. Ore is mined from two pits — Valley, 3 km northwest of the mill; and Lornex, 1 km southwest of the mill. With 78% of the reserves, the Valley pit is the focus of activity.In order for Highland Valley Copper to remain competitive with a very low grade ore reserve, it has been necessary throughout the mine’s life for new technologies to be embraced as they become available. These have included such diverse technologies as in-pit crushing and conveying, large mechanical drive trucks, computerized truck dispatch and oneman survey instruments. During the next few years, it is planned to introduce two further technologies that are relatively new to both the world at large and the mining industry in particular. These are namely Global Positioning Systems (GPS) and Geographical Information Systems (GIS), both of which are expected to have a major impact on the way mining is carried out in the years to come."

Jan 1, 1997

By G. R. Smith

This report describes research carried out by the Bureau of Mines to develop new technology for electrorefining metals at much higher current densities than those normally used in commercial practice, preliminary studies using rotating-ring and cylinder electrodes to increase the mass transport of copper are discussed. Following this work, single- and multichannel cells were developed that utilized a high electrolyte flow in the channels formed by the anode-cathode pairs. Using these cells, copper was successfully refined at current densities in the range of 70 to 300 amp/ft2. The effects of flow rate, electrolyte composition, and grain-refining and leveling agents on the morphology and purity of electrodeposited copper were determined.

Jan 1, 1979

By Ben E. Lindsly

The study of "bottom-hole' samples follow,-is in natural sequence the study of samples3 obtained under high pressures at the well heads of flowing wells. The principal object of this phase of gas-solubility research, started actively in January, 1530, was to gain a more accurate knowledge of the physical and chemical characteristics of the oil-gas mixtures that exist in natural reservoirs. In possession of actual data regarding the condition of the oil; the quantity of gas liberated from solution upon dimunition of pressure; and the relative volumetric proportions of gas to oil at various pressures throughout the flow string in a well, it should be possible to predict, with a fair degree of accuracy, what physical changes these mixtures would undergo throughout the life of a pool. Such information not only is important in designing flow strings in flowing wells but is important also in solving problems relating to pumping efficiency and the power required for pumping. Although certain fundamental rata Mere obtained in the stud of samples taken at the well head, "bottom-hole" samples are more representative of subsurface mixtures of oil and gas because they are obtained at reservoir temperatures, and before the oil has had the opportunity of intermingling with extraneous gas; that is, gas which either was not in solution originally, or which was liberated from solution at some higher pressure, and later became mired with the original undissolved gas.

Jan 1, 1933

By Jay F. Colinet

Coal workers’ pneumoconiosis (CWP), commonly known as black lung, is caused by the inhalation of respirable coal mine dust and is a disabling and potentially fatal lung disease with no cure. Historically, CWP has taken a tremendous human and financial toll in the US coal mining industry. Recent health surveillance data indicates that CWP continues to occur at elevated levels. Respirable coal dust exposure must be controlled to prevent the development of CWP. The Pittsburgh Mining Research Division of the National Institute for Occupational Safety and Health (NIOSH) conducts laboratory and mine-site research to identify control technologies that can be used to successfully reduce respirable dust levels. Various technologies, using multiple methods of control, can be applied in order to reduce dust levels. An overview ofCWP’s impact and a general methodology for controlling respirable dust in underground coal mines are discussed in this paper.

Jul 30, 2020

By J D. McDonald

This paper outlines the function of the Safety and Compensation Division of the Mining Association of British Columbia. After a general discussion of safety and the safety program now being followed in B.C., the author goes on to describe the wide-ranging aspects of compensation payments and company assessment rates. Special attention is also given to the problem of silicosis in mining operations. In appendices to the paper, the experience rating plan of the mining industry is compared to that recently adopted for the construction industry. Introduction The Mining Association of British Columbia consists of fifty-five member companies, including virtually all the producing mines as well as the larger exploration, contracting and development companies. On completion of an extensive study of safety and compensation in the mining industry, the Mining Association of British Columbia instituted a Safety and Compensation Division in 1954. The director of the Safety and Compensation Division reports to the Executive Committee of the Association. There are two main functions of this Division. First is the prevenion of accidents by encouraging

Jan 1, 1965

By Gennaro G. Ph. D Marino

In order to improve handling of subsidence damages the Illinois Mine Subsidence Insurance Fund supported the development of novel cost-effective methods of repair. The research in developing the repairs was directed towards the most common and costly damages that had been observed. As a result repair techniques were designed for structurally cracked foundations in the tension zone; structurally cracked foundations in the compression zone; and damaged or undamaged tilted foundations. When appropriate, the postulated methods would result in: 1. significant cost savings (over conventional procedures); 2. a structural capacity greater than when the foundation was untracked; and 3. an aesthetic appeal. All the postulated repair methodologies were laboratory and/or field tested. The paper will summarize the essentials of each technique developed and the test results.

Jan 1, 1986

By Sean Warren, JOSEF BOURGEOIS

The potential of rockfall at open-pit mines presents a continuous hazard to mine workers and is typically mitigated by designing catch benches at empirically determined widths. The National Institute for Occupational Safety and Health (NIOSH) is working in conjunction with industry and academia to revisit and update current catch bench guidelines to better match acceptable risk tolerances for modern mining practices. To begin this process, a rockfall testing program was designed to gather empirical runout and bench catchment data at partnering mine sites in the Western United States. This paper presents a detailed description of each component of the rockfall testing program, including scouting and safety plan development, equipment requirements, synthetic rock development for uniform testing across varying bench configurations, local rock collection for testing of mine-specific geology, data acquisition during testing, and data processing. Additionally, this paper describes how the program has been updated over time according to lessons learned during initial rockfall testing.

Feb 1, 2024

By L. E. Schultze

The Bureau of Mines has devised techniques to recover lithium from geothermal brines as the chloride. More than 99 pct of the lithium was precipitated from a brine containing 170 mg/L Li by adding a solution of AICl3 and increasing the pH to 7.5 with lime slurry. The Li-Al precipitate was dissolved in HCl and sparged with gaseous HCI to recover the AlCl3; this resulted in a solution containing LiCl and CaCI2. The solution was evaporated at 1000 C to obtain a mixture of the chlorides from which 97 pct of the lithium was recovered and 90 pct of the calcium was rejected by leaching with tetrahydrofuran. The LiCl recovered by evaporation of the tetrahydrofuran was purified by dissolution in water and treatment with oxalic acid. The final LiCl solution contained 89 pct of the lithium originally present in the brine and had a purity of 99.9 pet.

Jan 1, 1984

By E. Morrice

This report of the Federal Bureau of Mines presents a laboratory procedure, with the requisite equipment, for electrowinning ingot (liquid) cerium metal from a fused-fluoride bath, the metal purity being about 99.9 percent. Physicochemical studies, including bath properties and electrochemistry, are included, with a speculative model of the mechanisms involved. An historical review of the methods used for electrowinning misch metals and yttrim-group metals, as well as individual rare-earth metals, is presented. The electrolytic preparation of metal from fused salt and nonaqueous media is summarized, along with the unsuccessful attempts at depositing the metals from aqueous solutions.

Jan 1, 1961

By John Murray, Daniel Ebin, Robert Gould

The Atlanta Plane Train project at Hartsfield-Jackson Atlanta International Airport employed the progressive design-build approach. This provided opportunities for collaboration between the design-builder, design engineer, and owner and the implementation of innovative design and construction approaches. The innovations have reduced risks, allowed for adjustments during design to accommodate new challenges, and provided open-book cost and schedule evaluations. The progressive design-build approach has also allowed for pricing of work to occur in phases—capturing the design/construction challenges as the project evolves and when they are more clearly defined. While this has allowed for pricing to be performed with better project understanding and therefore less contingency, the associated time frame for approvals has required careful consideration to avoid impacts to the schedule. This paper discusses the benefits and challenges of the progressive design-build approach.

Dec 1, 2022

By Ingo Kaundinya

"INTRODUCTION Tunnels are important elements of the German federal road network which have to cope with an increasing traffic load especially of heavy goods vehicles. In order to ensure a high availability and safety level for these key infrastructures, big efforts are required by owners and operators in order to keep all infrastructures up to date. This mainly relates to current European regulations regarding tunnel safety (Directive 2004/54/EG) [1] and their national implementation, which must be fulfilled by many existing tunnels. In this context the German Federal Government spends more than 1.1 billion € for the structural and operational retrofitting of more than 120 existing road tunnels. As many of these projects have recently been finished or are still under progress, experiences and best practices could be reported. After the description of current requirements in national standards regarding structural fire protection, the paper gives an example for an upgrade of a tunnel’s fire protection by installing an additional fire protection system, which is a quite costly measure. Another possibility to fulfill current requirements regarding structural fire protection could be the numerical proof of sufficient bearing capacity of a structure. The influence of different fire loads and fire durations on the bearing capacity of typical road tunnel structures have been investigated in a research project funded by the German Federal Ministry of Transport (BMVI) and coordinated by the Federal Highway Research Institute (BASt). The results of this research project have been used to define a procedure how to investigate existing tunnels regarding structural fire protection. Finally, the research results have also been the basis for a current update of national standards for tunnel construction. REQUIREMENTS REGARDING STRUCTURAL FIRE PROTECTION The structural fire protection design of road tunnels is usually based on temperature-time curves of exposure to fire, for simplicity called ""fire curves"". The fire development after fire growth is illustrated with fire curves. Fire curves can be subdivided into a heating-up phase, a fully developed fire phase, and if applicable, into a cooling-off phase (cf. Figure 1). During the fully developed fire, the fire remains at a certain temperature level."

Jan 1, 2016

Diesel powered machines are doing some specific operations in the cyclic order required by the technical process. The dynamics of this process in certain conditions has an essential influence on environmental health conditions in the working area. The main purpose of this paper is to show, using computer simulation, how the movement (dynamic) of diesel vehicles effects environmental health standards and also how to determine the required air quantity for ventilation.

Jan 6, 1985