Search Documents

By A. Moharana

A massive slide at Bingham Canyon wiped out a side of the pit and covered the main haul road in and out of the pit. All pre-slide mine designs and schedules were no longer valid. New designs and schedules needed to be developed quickly to provide management with information regarding the immediate post-slide production potential and the time needed to ramp back up to full production. At the time of the slide, an effort was already underway to convert Bingham?s in-house Medium Term Scheduling Process to MineSight®?s Schedule Optimizer (MSSO). One of the main reasons for doing this was to reduce the time needed to produce Medium Term Schedules at Bingham, which involves a complex shovel-based scheduling approach with shovel productivities based on shovel type and the types of mining cuts to which the shovel is assigned over each planning period. The objective of the schedule was to maximize shovel usage, satisfy mill feed requirements of four SAG mills with variable milling rates, and have flexibility in setting truck constraints. This paper will describe how the new MSSO-based mine scheduling process met the challenge of producing new schedules for Bingham in a minimal amount of time.

Feb 23, 2014

By Jake Beale, Joe Wickline, M. Van Dyke, Ted M. Klemetti

A longwall coal mine in southwestern Virginia mining the Pocahontas #3 Coal Seam experienced a history of mining-related seismic events. The events were never large enough to cause concern until three major events occurred recording 3.4, 4.3, and 3.4 ML in 2005, 2006, and 2007 respectively. Two of the seismic events generated an air blast which damaged stoppings which fueled a mine fire in 2005 and 2007. The mine responded to the events by narrowing the longwall widths, changing ventilation controls, installing a 7-sensor seismic system around the active panel, and creating a mining hazard map to avoid similar geology in the future. All of the actions taken have prevented seismic activity from impacting mining operations, but it did not prevent other large seismic events from occurring (Van Dyke et al., 2018). In 2016, another large seismic event, measured at 3.7 ML, occurred in the gob that was reported by the local media and recorded by the United States Geological Survey (USGS). While the event did not directly impact mining operations, mine management wanted to know where and under what conditions could large seismic events occur in the future. The National Institute for Occupational Safety and Health (NIOSH) became involved to help understand what conditions precipitated these events so that future mine design could more accurately assess seismic hazards and reduce the risk to mine worker safety. Researchers at NIOSH and mine management created a seismic forecasting map that combined three factors: (1) overburden thickness, (2) sandstone thickness, and (3) the expected caving height of the gob. The criteria were developed based on the geologic data the mine collected from core drilling, e-log analysis, and fiberscope observations. The forecast map was able to provide an accuracy of 72%–85% of events 1.5 ML or greater and 100% accuracy of events that were 3.0 ML or greater based on historical data. The seismic forecasting map was applied to the entire future mining area to show areas where seismic potential could be the greatest based on current mine design planning, ultimately improving the ability of the mine operator to assess the seismic hazards surrounding active and future mining areas (Van Dyke et al. 2018). Following this research, the seismic forecasting map was implemented into the mine’s hazard recognition program and is continuously updated and evaluated prior to mining each longwall panel. This paper will cover in more detail how the seismic and lithologic data was processed and how the mine implemented a new seismic mitigation program based on the forecasting results.

Apr 26, 2022

By Eileen Ashworth

Computer-assisted instruct ion is now being used in areas as diversified as training handicapped children to preflight simulation for airline pilots. This paper reports on two courses that have been developed at SDSM&T on the PLATO system for miner safety training. Advantages of computer-assisted instruct ion for this type of training is discussed. (Figures show examples of actual use.) A discussion will be given on other applications such as maintenance troubleshooting, training of engineers and managers at remote sites and training of local people for working in the mine.

Jan 1, 1983

By W. J. Kennedy

Energy management in industry has recently achieved notice as a way to reduce costs without decreasing production. The same approach used in industry can be used in mining, even though the processes are different. This approach is based upon a three phase system of data collection, implementation, and monitoring, all aimed at gathering and evaluating information in such a way as to have a maximum impact on energy costs. This approach has these advantages: (1) attention is directed toward the part of each mining system where the most energy is used, (2) input is collected systematically from all persons involved in the operation of each system, and (3) a means of monitoring the progress toward established goals is created. The mining systems considered are truck haulage, conveyor haulage, blasting and crushing, and lighting. After describing the general procedure, the authors have described a specific method for improving the efficiency (and hence the energy consumption) of round-trip truck haul age systems.

Jan 1, 1982

By TOMI GIORGIO DE, Ricardo Tichauer

Mineral exploration is a key factor for success in the mining industry. However, exploration best practices are often ignored in small-scale mining. This works presents the Tichauer-DeTomi Matrix, a methodology that measures the level of compliance of exploration programs in small-scale mining with the industry best practices. The matrix has been applied to three projects in Brazil: an artisanal gold mine in the state of Pará, a small-scale manganese project in the state of Bahia, and a small-scale manganese project in the state of São Paulo. The application of the matrix resulted in indexes that represent the level of maturity of the exploration program in each project and indicate priority actions for reduction of the geological uncertainty. Therefore, the Tichauer-DeTomi Matrix has shown potential to be a useful tool for assessment of geological uncertainty in small-scale mining. As a risk indicator, it may contribute to promoting investment in small-scale mining and development for communities that depend on this activity around the world.

By Richard B. Stein

This paper will present an overview of several hydrometallurgical processes which can be used for sea-nodule metal recovery and some simplified economics. Before going any further, here are some of the basic figures from which the economics were developed. The first is to establish a representative composition for a typical nodule feed (Slide 1). This set of chemical analysis figures can be taken as typical for a deep Pacific nodule feed and shows manganese at 30%, copper at 1.1%, cobalt at 0.2%, nickel at 13% and iron at 10% for the metals of economic interest1.

Jan 1, 1982

By R. W. Waytulonis

This paper is an update of the activities of the U.S. Bureau of Mines, other government agencies, and the automotive and truck industry concerning diesel emission control. Enacted and proposed regulations from the U.S. Mine Safety and Health Administration (MSHA) and developments in diesel emission control are presented in terms of their impact on underground coal, metal, and nonmetal mines. Mine air quality regulations proposed by MSHA may require the underground mining industry to comply with new standards. Some mines may be required to take additional actions to meet new diesel particulate and lower nitrogen dioxide exposure standards; however, the mining industry is in a position to benefit from emission controls developed for the on-highway diesel engine market. The U.S. Environmental Protection Agency (EPA) has enacted regulations to reduce emissions from on-highway diesel trucks and buses. Engine manufacturers have responded by developing cleaner burning engines. Fuel producers have responded by providing cleaner burning reformulated diesel fuel, and exhaust aftertreatment devices have been developed to provide additional emissions reductions. Bureau research and development projects seek to determine the advantages of using modern engines and fuels, and to evaluate the efficacy of new exhaust control devices on mining machines. It appears that the diesel engine will continue to be a practical power source for use in confined environments because no other available power source is as mobile and efficient.

Jan 1, 1993

By D. V. Bush

The economic application of real time computer control can be broken down into 2 broad areas of concern. The first would be in gaining the most efficient utilization of energy. The second would be in improved product quality. This paper will be primarly concerned with the first area of efficient energy utilization as that area has the greatest effect on costs and thus net profits. Most process control strategy attempt to achieve the greatest comminution with the least amount of energy thus maximizing efficiency. A more direct approach to energy control involves a total mine and mill energy management system. In most cases these systems have an ability to achieve a very short payback period with the greatest return on investment.

Jan 1, 1986

By D. G. Krige

I read the paper “The jackknife approach” with interest. There appears to be a widespread misunderstanding of the kriging variance as a measure of the error variance of the kriged grade estimate of an ore block. Virtually all mineral deposits display skew frequency distributions and are subject to the well-known proportional effect. Thus, it is usual to find in an ore body, when subdivided a really into subpopulations, that the variances of the grades (or the total sills of the variograms) for the subpopulations will be correlated with the corresponding mean grades (usually linearly with the squares of the mean grades). Thus, the variogram will be stationary.

Jan 1, 1996

By Ralph Musick, Brian Briggs

The U1h Shaft Project is a design/build subcontract to construct one 6.1 meter(m) (20 feet [ft.]) finished diameter shaft to a depth of 321.6 meters (m) (1055 ft.) at the Nevada Test Site (NTS). Atkinson Construction was subcontracted by Bechtel Nevada(BN) to construct the U1h Shaft for the Department of Energy (DOE). The project consists of furnishing and installing the sinking plant, construction of the 321.6 m(1055 ft.) of concrete lined shaft, development of a shaft station at a depth of 297.5 m(976 ft.), and construction of a loading pocket at the station. The outfitting of the shaft and installation of a new hoist may be incorporated into the project at a later date. This paper will describe the design phase, the excavation and lining operation, shaft station construction and the contractual challenges encountered on this project.

Jan 1, 2001

By Cem Şensöğüt, Özer Ören, Yaşar Kasap

The mining sector, which has an important place in terms of raw material and energy supply, is referred as a sector with one of the highest fatal accidents in comparison with other sectors. In this century, where occupational health and safety awareness has increased, it is important to review the past accident statistics and to determine the current deficiencies by using the information in the inventory. In this study, the Malmquist total factor productivity index (MPI) has been utilized to investigate the changes in the work accidents occurring in the Western Lignite Corporation (Turkey), where underground and surface production methods are applied, and to determine the measures to be taken. According to the results obtained, both the decrease in production amount and the increase in the number of accidents caused inefficiencies during the period in concern due to the expected 10-year economic life of the mechanized system operating in the underground production panel that came to an end in 2007 and the flooding took place in early 2017. Compared with the underground operations, it has been determined that production can be carried out at the appropriate scale despite the heavy working conditions encountered due to the changing climatic conditions and the progress of production in the surface operations.

By L. W. Saperstein, M. C. Radomsky, D. L. Passmore, J. D. Bennett

About 60 small surface coal mines in Pennsylvania participated in a program designed to improve safety performance in the workplace. The method involved the use of safety sampling and observation to assess the degree of safety exhibited by workplace behavior and conditions. Data were collected through the use of on-site safety instruments covering seven major occupational positions typical of small surface mines. Workplace events observed (acts and conditions) were assigned a hazard classification. Feedback was initiated to improve safety performance in areas failing to conform to appropriate safety standards. Results suggest that the variety of unsafe acts and conditions associated with the companies observed are extensive. Further, the experiences drawn from this pilot project have proven the need to pursue this behavioral approach. Future research should concentrate on subjecting the present approach to a strict experimental design involving randomly selected “poor risk” mines.

Jan 1, 1987

By P. Zhu

The leaching behavior of copper powders recovered from waste printed circuit boards (WPCBs) was investigated using electrogenerated chlorine and aeration in a sulfuric acid solution with added NaCl and CuSO4. Various parameters were studied to understand the mechanism of the copper leaching. When the current density increased from 0 to 0.1 A/cm2, the temperature from 30 to 60° C, agitation speed from 100 to 400 rpm, and the size ranged from below 75 to 150 µm, the leaching ratios of copper powders increased. The leaching kinetics were analyzed using a shrinking core model: 1-(1-X)1/3 = kt, and the leaching process was chemically controlled with an activation energy of 14.7 kJ/mol due to Cl- ion catalysis. The ratios of [Cu+]/[Cu2+] at various temperatures (30, 40, 50, 60 and 70° C) showed a periodic variation with the increasing of the leaching time. The redox potentials of the leaching solution and copper leaching ratios in different conditions were measured. The result indicates that dissolved oxygen achieved the dissolution of coppers and electrogenerated chlorine can promote the dissolution of copper powders and improve the reaction rate of kinetics in the presence of oxygen.

By M. S. Enders

The McDonald deposit is a volcanic-hosted epithermal gold resource that is estimated to contain 251,000 kg of gold in 375 Mt of ore at an average grade of 0.7 g/t gold. Phelps Dodge exploration geologists, working for the Seven-Up Pete Joint Venture, discovered the deposit in 1989. By the end of 1992, 494 drill holes for over 113,000 m of drilling, bulk sampling, soil geochemistry, geophysics, metallurgical testing, engineering, and environmental studies had been completed to support feasibility studies. The discovery of McDonald required vision, persistence, and commitment of everyone from the geologist on the drill rig to the senior management of the company.

Jan 1, 1995

By John H. Canterford

The adsorption of uranium onto Wyoming bentonite was measured in carbonate media over the range pH 8-11. Uranium was removed from solution onto the solids by a rapid reaction, proposed to be adsorption of the anionic uranyl tricarbonato complex onto edges of the clay platelets, and a slow reaction which may be precipitation of a hydroxide. The changes in uranium content of the aqueous and solid phases of a uranium ore carbonate leach slurry were also measured as the slurry was progressively diluted. There was an increase in the uranium content of the solids as the pH of the suspension was lowered, as was observed with the Wyoming bentonite. The results indicate the conditions that should be met with respect to pH control in order to prevent the problem of excessive uranium adsorption in the counter-current decantation washing circuit of a conventional leaching process, as well as in the leaching and restoration phases of carbonate solution mining.

Jan 1, 1983

By Dolf Vos

The balling section of the pelletizing plant at Hoogovens IJmuiden consists of 7 balling drums. Each with an average capacity of 100 tons of green pellets per hour. The balling drums are equipped with rotating scrapers and water-spraying systems. The scrapers are installed in order to restrict the growth of the race to a certain thickness. The spraying system is used to adjust the desired value of the moisture-content of the rewetted ground ore, the pellets and the race. The desired value is the value by which the balling- process is stable, good pellets are formed and surge occurs within certain limits. In October 1980 the construction of one of the balling drums has been modified. The rotating scraper was removed and the inner wall of the drum was supplied with a rubber-lining. In 1982 a second balling drum has been rubber- lined. At the same time the Tyler vibrating screen of this balling circuit has been replaced by a roller(bed)screen. By the end of 1983 all 7 balling circuits will be equipped with rubber-lined drums in combination with roller(bed)screens. The combination of these two modifications will improve the quality and the screen analysis of the green pellets, moreover resulting in savings on energy- and maintenance costs. This paper describes the influence of a rubber- lining on the balling process and the green pellet quality by carrying out in-plant testruns in November/December 1980. The testrun results have been compared with the results of a not modified balling drum.

Jan 1, 1983

By W. Nazarewicz

The introduction of continuous papermaking in the early 1800's was the beginning of the industry as we know it today. Since that time, the majority of the paper produced has employed an acid process. However, in the mid 1960?s, European producers began a transition to an alkaline papermaking process. Early European mill conversions to alkaline papermaking begun in the 601s, accelerated during the 1970's influenced by the dramatically higher cost for OPEC energy as well as the high cost of fiber and imported filler clay.

Jan 1, 1986

By R. G. Reddy, A. E. Torma

Bio-treatment of uranium contaminated soils from Fernald using the bacterium Thiobacillus ferrooxidans was investigated. The experimental results showed that extraction of uranium upto 99 percent from soils were obtained with 10 percent pulp density suspension and with addition of iron (3000 mg/l) after bio-remediation time of seven days. Application of the results to industrial practices is discussed.

Jan 1, 1995

By Hamid Maleki

Mine seismicity is influenced by the mechanical properties of both near-seam rocks and overburden and the prudent selection of mining methods and mine layout designs. Using finite-difference modeling, experience in many U.S. mines and measurements of the pressure arch width, the author has reviewed the engineering design factors that control seismicity in room-and-pillar retreat operations for stiff stratigraphic conditions in deep western U.S. mines. By back analyzing the overburden response in now understood to have been inadequately designed historic room-and-pillar mine, the overburden collapse mechanism is addressed as well as the need for improvements in designs including panel and barrier pillar widths, and sequence of retreat.

Jan 1, 2009

By Judson H. Whitman

To evaluate intelligently and to market a source of rare earth raw material, it is necessary that the producer understand the requirements of the processor and the manner in which these requirements effect the value and salability of his product. This paper will be an attempt to aid in such an understanding. The majority of rare earth processors are primarily chemical companies, not mining or metallurgical companies, as the complexities of the processing procedures are' much more chemical in nature than metallurgical. The rare earths and the rare earth industry are normally divided into two groups - the ?light? or cerium group and the ?heavy? or yttrium group. They are so named because cerium and yttrium are the most common elements in 'heir respective groups and are so divided on the basis of mineralogical and chemical characteristics. The dividing line of the two groups is not rigidly fixed but usually is considered as being between samarium (atomic number 62) and europium (atomic number 63). Although the two groups are quite similar, processing procedures differ significantly, hence most processors tend to specialize in one group or the other. There is, however, a growing tendency toward participation in both groups.

Jan 1, 1960