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By Majid Ataeepour, Ernest Y. Baafi

High level programming languages such ass C, FORTRAN and BASIC have been used in the mining industry to simulate truck-shovel systems. In addition, some special languages for simulation such as GASP, GPSS, SLAM, PROOF and SIMAN are commonly used. The most recent simulation system ARENA uses graphical modelling approach as well as animation notion. In this paper, the main elements of ARENA required to perform a truck- shovel simulation and to view the simulation results by means of the model animation are presented. The layout of the haulage system including shovels, trucks and dump sites was generated using draw tool in ARENA. All the components of the haulage system were represented by graphical modules. Animation tool was used to depict the performance of the haulage system as the simulation progressed.

Jan 1, 1996

By R. Simon

Strain-burst phenomena are generally characterised by sudden releases of energy in a volume of highly stressed rock. Strain bursts are encountered in situations such as crown pillar bursts during cut-and-fill mining, face bursts at development headings cord floor bursts in deep shaft sinking. This paper describes a simple two-dimensional linear elastic FE modeling approach that leads to the calculation of the energy-release rate (ERR) and the total energy storage rate (TESR) in the rock-mass around the openings. The merits of using such energy parameters in the analysis of strain-burst problems for identifying areas of high energy release/storage are discussed through a case stud v. However, much site-specific back analyses are needed to better understand how strain bursts and energy parameters are interrelated.

Jan 1, 1999

By J. C. Emerick

Preliminary investigations have shown that wetland-based treatment systems can be an effective and relatively inexpensive control strategy for mine drainage pollution in eastern coal mining regions. This strategy also has potential for western mining regions, although too few systems have been installed in the west to permit general evaluation of the concept for western climates. The construction of prototype systems is encouraged for some situations. Wet-land environments have the capability of removing metals by natural geochemical and biological processes, including precipitation, filtration, ion absorption, and biological uptake and accumulation. Data presented for natural wetlands receiving mine drainage show removal of iron and other metals, and high accumulation of metals in soils and plants.

Jan 1, 1988

By L. B. Rothfeld, R. L. Dolzani

This paper presents preliminary results of a US Bureau of Mines (USBM) study of potential costs of compliance with possible federal regulations for copper heap and dump leaching. The regulations could arise under amendments to the Resource Conservation and Recovery Act (RCRA) and/or the General Mining Law. Estimates are given for the cost of compliance with possible technology standards that would require the use of liners and closure caps regardless of terrain and underlying geology and hydrology. This cost is compared to the cost of compliance with 1992 state requirements for terrains typical of those found at existing copper leach sites in the southwestern United States. Incremental compliance costs are found to widely exceed screening criteria used by the US Environmental Protection Agency (EPA) to denote significant economic impact.

Jan 1, 1995

By L. F. Nicolai, W. J. Schlitt

Lateral migration of leach solution in heaps and dumps is attributed to two phenomena. One is site-specific anisotropic conditions that exist on a macroscopic scale on the surface or within the rock piles. The second is associated with a random walk phenomenon that causes dispersion of solution, especially at gradients in flow or hydrostatic pressure. The latter phenomenon is a general condition that will occur in any leaching operation. Its effects are modeled by computer analysis and are compared with available field data on heap leaching. Under appropriate assumptions, the observed 58° angle of solution dispersion can be reproduced by the model. The combined effects of both anisotropy and random walk are also discussed. Finally, the impact of lateral solution flow on actual leaching operations is considered.

Jan 1, 1988

By Robert J. Timko, R. Lincoln Derick

This report presents a Bureau of Mines evaluation which examined the extent of gas leakage from sealed areas in underground coal mines and measured the effectiveness of commonly used structures for controlling the quantity of gas exchange from these areas. Evaluations were performed on five abandoned areas in two operating underground mines within the same coal seam. Methane and oxygen levels inby the seals were monitored to determine if the gas leakage was unidirectional or bidirectional. Results from this and prior work dealing with minimizing gas leakage were then applied to a newly abandoned area. Also discussed are bulkhead site preparation, construction plans, techniques for monitoring the status of the atmosphere within the sealed volume, and a modified European method for controlling gas migration from the sealed volume to the active mine.

Jan 1, 1991

By Nick Barton, Khosrow Bakhtar

Two plate load tests of 1 m2 area were per- formed in a pressure tunnel at the Rocky Mountain Pumped Hydro Project. Reaction for the 250 tons loading in this 10.5 meter diameter tunnel was provided by deeply anchored, diverging rock bolts, eight per load frame. Pressure build up to 2.5 MPa was provided by circular flatjacks. Rock deformation was recorded at depths of approximately 0.3, 0.9, 1.2, 1.8 and 3.3 meters using axially located multiple position borehole extensometers. The tests were performed in representative units of massive shale and thin to medium bedded siltstone. Stress was built up in four equal steps to 2.5 MPa, held constant for one week for creep monitoring, then unloaded, reloaded and unloaded over a period of one day. The most deformable unit was the massive shale which exhibited 1.3 mm of permanent deformation at the surface after the first loading and unloading cycle, which included 0.36 mm of creep. After the second loading-unloading cycle, the permanent deformation had increased to 2.6 mm, following a maximum deformation at the surface of approximately 3.6 mm. At the maximum stress of 2.5 MPa, the tangent modulus averaged 0.4 GPa when loading, and 0.3 GPa when unloading. The thin to medium bedded siltstone exhibited only 0.17 mm of permanent deformation at the surface after the first loading-unloading cycle, which included only 0.05 mm of creep. After the second loading-unloading cycle, the permanent deformation had increased to 0.27 mm, following a maximum deformation at the surface of approximately 0.53 mm. At the maximum stress of 2.5 MPa, the tangent modulus averaged 6.2 GPa when loading and 21.9 GPa when unloading.

Jan 1, 1986

By S. Dereski, G. Chancellor

"INTRODUCTION Barrick Goldstrike underground mine is located in Northern Nevada on the Carlin trend. The underground mine produces approximately 1.5 to 1.8 million tons a year and approximately 400,000 ounces of gold a year. The mine is comprised of two main mining methods, underhand drift and fill and long hole stopeing. The mass blast project stated in 2012 as Value in Use project between Barrick, Southwest Energy and Orica, the goal of this project is to be able to blast an entire drilled stope in one blasting event instead of taking multiple blasts. This will improve productivity by eliminating intermediate blasts, reducing additional blast time, eliminate drill hole cleaning due to the previous blast. Project implantation started in the fourth quarter of 2013 and mass blasting has been common practice throughout all of 2014. STOPPING PRACTICE AT GOLDSTRIKE BEFORE MASS BLAST PROJECT The production from the Goldstrike mine is approximately 70% from stopes. The timely completion of all stoping blocks is imperative to maintaining the plan, delays in the execution of any particular block can have detrimental ripple down effects as neighbouring stoping blocks become delayed. Before the implementation of this project the standard practice for Goldstrike was to: 1. Drill the entire stope 2. Blast a bottom shot, normally between 10 feet and 20 feet off the bottom of the slot rings. This would be mucked out before the next shot 3. Blast a pull through shot, this included the raise and one or two production rings. Again mucking this out before the next shot 4. Blast production rings, one or two more blasts depending on stope size. In most cases between each of these blasts the holes in the other rings of the stope would have to be cleaned. This meant either cleaning manually using air and water, or mechanically cleaning with a bench drill. In many cases this resulted in delays in completing the stoping block."

Jan 1, 2015

By Eduardo Velasco, Paz Navarro, Alfonso Navarro, Claudio Cimiotti, Alejandro Sanz, Nick Karlin

The LA Effluent Outfall tunnel is a 7-mile long, 18' internal diameter, secondary treated effluent discharge tunnel currently under construction by Dragados USA for the Los Angeles County Sanitation District No. 2 (LACSD). The purpose of this tunnel is to add redundancy and increased capacity for discharge of secondary treated effluent from the LACSD’s Joint Water Pollution Control Plant, located in Wilmington, California within Southern Los Angeles County. Current discharge from this facility flows through two existing tunnels of 8' and 12' horseshoe profile, constructed in 1937 and 1958, respectively. When the new tunnel is complete, it will add an additional capacity of 670MGD in peak wet weather flow conditions. Geology of the roughly 7 mile long tunnel was divided into six reaches by the contract documents. Tunnel Reaches (TR) 1 to 3, comprising 19,550' will be excavated in alluvial sands of the San Pedro and Lakewood formations, with cover ranging from 45 to 90 feet. In this reach the tunnel intersects the seismically active Palos Verdes fault Zone. TR 4 is a 1,600' transitional zone between alluvium and the rock formations of the Palos Verdes (PV) Hills, comprised mostly of Malaga Mudstone. TR’s 5 and 6 total 15,591', and are within the rock formations of the PV Hills with overburden ranging from 315' to 475'. The primary constituent of the PV Hills is Altamira

Jun 13, 2021

By Terry I. Mudder, Michael M. Botz

Discharge regulations for mine waters require relatively low concentrations for cyanide and metals, and the trend is for discharge limits to be lowered. In the event conventional treatment practices are not sufficient to meet discharge limitations, advanced treatment technologies such as ion exchange and reverse osmosis may be considered. Though these technologies will provide discharge quality waters, they also require the disposal of a concentrated brine and are relatively complex and costly to operate. Many mine sites currently using activated carbon in precious metals recovery present the opportunity to economically operate an activated carbon water treatment plant for polishing of effluents. This paper presents summaries of six ( 6) mining operations which have evaluated or use activated carbon for treatment of water and which also use carbon in precious metals recovery processes.

Jan 1, 1997

By D. Duvris

The main objective of this work was to quantitatively investigate exhaust emission levels relative to maintenance (service) intervals during the operation of diesel-powered equipment at an underground bauxite mine in Greece. Such emissions depend on a great number of parameters, including the type of engine (technology) and its tuning, the type of work performed (as related to the engine workload), the suggested maintenance intervals, the altitude, the temperature and humidity of the atmosphere in the underground mine, the properties of the fuel and the operator's training and experience levels. The necessary ventilation quantities were calculated based on exhaust gas-concentration measurements and site-specific relationships between pollutants and adjusted air-quality indices. Diagrams comparing the necessary and recommended airflow for several equipment groups, featuring two engine types and different maintenance intervals, are presented.

Jan 1, 2000

By C. Y. Kao, Roger Y. Cheng, C. S. Hsieh

The mushroom-shaped Minghu power cavern located in central Taiwan is 21.2 m (W) by 40.5 m (H) by 127.2 m (L) and is designed to house 4 units of power generating-pumping equipment with a total capacity of 1,000 MW. This paper presents an introduction to the geological conditions at the cavern site; the rock mechanical tests undertaken; the design approach adopted; the construction method and sequence followed; and the instrumentation provided in the roof arch to monitor the behavior of the surrounding rocks. The measured data collected from the embedded instruments will be compared with those obtained from theoretical analyses and presented in this paper. Several technical problems encountered during the construction stage are covered and the solutions of these problems are also described therein.

Jan 1, 1983

By G. Zandt, H. R. Pratt, W. A. Hustrulid, M. Bouchon, D. E. Stephenson

PREFACE The National Waste Terminal Storage Program was initiated to conduct the research to select a site for the disposal of high level radioactive waste in deep geologic formations. As part of this program, the Savannah River Laboratory at Aiken, South Carolina, is conducting geologic research of generic applicability on the potential subsurface damage to a repository from an earthquake. Part of this study involved the collection of data on subsurface damage due to an earthquake, and another part involved the calculation of displacement fields as a result of an earthquake. Both of these studies were conducted at Terra Tek of Salt Lake City. This report is an abridged and combined version of both studies which was presented at the Rapid Excavation and Tunneling Conference in Atlanta, GA, on June 19, 1979.

Jan 1, 1979

By Nathaniel Arbiter

The development of flotation machines since the first industrial use of the process can be divided into three stages. The first, up to about 1930, was marked by diversity in the means for contacting floatable mineral with the air/ water interface and for generating the interface, as well as in cell design. By 1927 Taggart (1) could list 170 patents covering flotation cells, and he mentioned dozens which were or had been in operation. He divided cells into eight categories according to design, type of separating interface, and where in the cell and how separation took place. These were: (1) Film or skin flotation with wet or dry oiling of surfaces; (2) pulp body process with bubbles generated chemically by pressure reduction, by vacuum or by boiling; (3) agitation-froth processes involving local supersaturation with air; (4) bubble column; (5) pneumatic; (6) cascade; (7) subaeration; and (8) combination and miscellaneous types and processes. Most widely used then were the agitation-froth, sub- aeration, pneumatic types. By 1943 a significant reduction in categories had occurred to the two main divisions of mechanical and pneumatic cells according to whether agitation and aeration were (a) by an impeller with or without compressed air, or (b) by compressed air alone. Cells at that time were still relatively small; the Morenci Concentrator completed in 1942 used 432 1.7m3 (60 cu ft) Fagergrens for roughing 45,000 and later up to 55,000 t/d.

Jan 1, 1979

By Brian Hays, Victor Mwaba

Optimization of water use has become a top priority for virtually every mining operation. The mineral extraction process typically requires vast quantities of water, which can be particularly challenging when a mine is located in an arid location. Most mining permits have very strict limits on water usage, so tight control of water utilization and extensive recycling are critical to regulatory compliance and profitability. Water management is not only dependent for selecting the right flowmeter for different applications.

Apr 1, 2026

By E. W. Geist

This paper is presented from the viewpoint of the mill operator and maintenance supervisor. Its purpose is to highlight the things that have been accomplished by the mill designers to lighten the load for the maintenance superintendent and to reduce the overall costs for the plant operator. The complexity of plant design, the civil and structural engineering problems encountered when the satisfactory maintenance layout is accomplished are appreciated, and the writer is fully aware of the complexities of these problems. However, it is not the purpose of this particular paper to dwell upon these problems, nor to emphasize or de-emphasize the problems of the civil, mechanical and electrical engineers. It is simply that the paper will attempt to review what these people have accomplished in spite of the many technical problems. This paper then is prepared with the operator and maintenance people?s viewpoint. What is their definition of design for maintenance? It is the writer's interpretation that the various design concepts which mean improved maintenance are such items as (I) maintenance areas, (2) laydown space for maintenance materials in specific maintenance jobs, (3) the inclusion of bridge cranes in the plant and specific design of the craneways to accomplish flexibilities for the cranes, and (4) the location of the piece of equipment to allow maintenance people to work around the equipment - - - this specifically includes the orientation of the particular piece of equipment.

Jan 1, 1967

By D. Malhotra

Most primary-molybdenite producers use a selective-flotation process in which molybdenite is floated from the ore while other sulfide and non-sulfide gangue minerals are depressed in the same step (Figure 1). The process was developed at the Climax mill. Reagents used in the rougher-flotation stage include vapor oil (collector), syntex (surfactant), pine oil (frother) and occasionally sodium cyanide and Nokes reagent (depressant). Rougher concentrate is upgraded by cleaner flotation to produce market-grade molybdenite concentrates. Reagents used in the cleaner flotation stage are Dowfroth 250, vapor oil, sodium cyanide and Nokes reagent. The development of the flotation reagent scheme at Climax and the role of the reagents have been well described by Born, et al, (1976) and Malhotra, et al, (1976, 1977a, 1977b, 1977c, 1980). The hydrocarbon collector, vapor oil, accounts for approximately 50 percent of the total molybdenite-flotation reagent cost. Because vapor oil sources are limited, and the cost of vapor oil has increased significantly over the last decade, several studies have been done to evaluate alternate oil-based collectors and/or blends of collectors which would produce similar metallurgical results at a reduced cost, or increase the overall molybdenite recovery at the same cost (Smit and Bhasin, 1983; Hahn, 1969; Smith and Bhappu, 1971). The approach taken in the present study was to evaluate alternate non-oil based collectors and collector systems that are less expensive than vapor oil.

Jan 1, 1985

By III Cocanour

The line scan video photometer is a personal computer (PC) based, software-driven instrument which is used for the real time, on-line analysis of industrial process streams. The novelty of the instrument lies in the integration of its various components: (l) a true Red/Green/Blue (R/G/B) color video camera; (2) a unique, line-scan color sample and hold technique which provides a 4 to 20 mA analog signal to a commercial 12 bit analog to digital (A/D) converter; (3) software which converts data through a color absorbance algorithm to correlate elemental color to concentration; and (4) software-based control which utilizes color data, along with temperature and conductivity data to control process equipment. The photometer can be used for noninvasive analysis wherever color hues are representative of process variables such as chemical concentrations or mineralogy color reflectance. The line scan video photometer has been successfully demonstrated in solvent extraction/electrowinning (SX/EW) and ball mill circuits of copper producers.

Jan 1, 1996

By Nico Sutmoller, Rich Palladino

Underground voids present a unique geotechnical engineering challenge. This paper will address materials and transportation mediums that are typically used for backfilling underground voids with native material. After reviewing traditional backfill and transportation methods, this paper will explore the advancing technology of foam transportation and the advantages of using this technology for transporting fill materials into underground voids to backfill them with Liquid-Sand. The paper will also review the benefits that Liquid-Sand brings to these applications and highlight specific case studies in which foam transportation has proven effective and provided cost-effective, environmental benefits.

Feb 1, 2025

By D. Seneviratne

Iron transfer from the pregnant leach solution (PLS) to the electrolyte can have a major economic impact on solvent extraction (SX) operations. High iron transfer will lead to greater operational costs, due to increased reagent consumption through electrolyte bleed and make up, or increased power costs due to decreased electrowinning current efficiency. Bioleaching of low-grade copper sulfide ore from the Kennecott Utah Copper Mine was investigated in a large scale piloting program including SX and electrowinning. Plant data and lab test work conducted throughout the course of operation, show that the unique containing PLS high ferric iron with high pH can lead to lower Cu: Fe selectivity than is typically seen in traditional copper SX operations. The impact of high ferric iron on the plant operation, and methods to reduce iron transfer will be discussed. Special considerations need to be taken for plant operating conditions and selection of SX reagents (including both extractant and aromatic content of diluent) based on the feed PLS characteristics.

Feb 23, 2014