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By Weibai Hu

The flotation separation of wolframite from fluorite and quartz is investigated with chelating agents and neutral oil as synergic collectors. Test results indicated that a-nitroso-ß-naphthol has a strong collectivity for wolframite and selectivity against fluorite and quartz. The 8-hydroxyquinoline has collectivity and selectivity also. They both have a better activity than sodium oleate. However, the cupferron is slightly inferior. The synergism of chelating agents and neutral oil looks promising, especially for fine wolframite particles. The activation effect of Fe2+ and Ca2+ ions on separation of wolframite from fluorite and quartz is slight. The UV absorb-spectra measurements showed that the adsorption of chelating agent on wolframite is multilayer, and flotation behavior is related to chemisorption. The chelating agent which bonds to Fe and Mn sits on the wolframite surface, and the reaction between Mn2+ ion with collector is more significant. The essentials affecting reagent activities are the bonding factor and the hydrophobic factor. These factors are discussed by structure-activity relationship theory. The synergism of neutral oil is a secondary collector likely to lengthen the hydrocarbon chain of chelating agents.

Jan 1, 1985

By Douglas B. Silver

Study Parameters (Status as of February 1993) Time Period: 1989 -1991 151 North American Public Metal Mining Companies Fiscal not calendar year basis 85+% of Canadian and U.S. Metal Production Au, Ag, Cu, Pb, Zn, Mo, Ni, W Results are Preliminary and Research Continues Chicken Little is Alive and Well

Jan 1, 1993

By R. M. Powers

The Florida Institute of Phosphate Research (FIPR) has funded a four-year research project to develop a computer model 'which will predict the hydrologic impacts of phosphate mining on surface and groundwater systems. The core of the model is an analytical geographic information system (SPANS) which integrates EPA's Hydrology Simulation Program Fortran (HSPF) surface water model with the McDonald-Harbaugh groundwater model (MODFLOW). The hydrologic model conducts both event and continuous annual Simulations driven by variable precipitation and temperature data. The model is currently being calibrated and will be ready for distribution to the user community in mid-1991.

Jan 1, 1990

By Kunzo Amano

Fully-bonded rock bolts have been widely used in construction sites and mines in recent years. The purpose of this investigation is to prove the effectiveness of rock bolt supports in unstable ground through in-situ tests and numerical analysis. 2. MEASUREMENTS AND PROCEDURES OF IN-SITU TESTS The fully-bonded rock bolts as the mine road¬way supports were tested in the Fukasawa mine which is located in the northeast district of Japan (Fig. 1). The Fukasawa mine (one of the Kuroko mines) started the production in 1973, and the present monthly production is slightly less than 20,000 tons. The ore deposit which exsists at about 400 m depth is divided into several small lenticular shaped bodies. They are distributed apporiximately 1500 m in NW-SE direction and 700 m in NE-SW direction. The hanging wall is basaltic lava and the footwall is tuff. The rocks surrounding the ore bodies are soft but relatively intact, so the trackless mining system has been adopted from the beginning of the development.

Jan 1, 1982

By M. T. Ityokumbul

Concentrate flowrates have been measured for the flotation of -100 mesh Lower Kittaning coal in a computer controlled 0.076 m x 3.5 m pilot flotation column. The variables studied were recovery zone height), air flow rate, and solid feed concentration. The size distribution of concentrate and tailings samples were determined. The results obtained show that the concentrate flow rate was independent of collection zone height, but dependent on the gas flow rate, solid loading and particle size. New correlations for column carrying capacity and yield are provided as a function of these fundamental operational parameters.

Jan 1, 1997

By Erica McGlynn, Brian Negrea, Lance Jackson

There was no need for the people of Cleveland to ask “Where does the raw sewage go? We want to know!” because it was clear. The raw sewage was being discharged into Lake Erie during heavy rainfall events due to the outdated design of the combined sewer system. In efforts to resolve this ongoing issue for the City of Cleveland, the Northeast Ohio Regional Sewer District developed Project Clean Lake in collaboration with the US EPA. Project Clean Lake is a 25-year, $3 billion program consisting of seven large-diameter CSO storage tunnels to be constructed beneath the city’s existing infrastructure. The first four tunnels have been completed using traditional hard rock TBM excavation methods. The fifth tunnel, the Shoreline Storage Tunnel Project, presents unique challenges and complexities as it will be the first large-diameter EPB TBM to dig under the City of Cleveland. The project itself consists of one tunnel drive 14,100' (2.7 miles) in length, two pipe jacking tunnels, three large slurry wall shafts, two diversion structures, and three regulator reconstructions. Upon completion of the project, 12 permitted CSO locations along Lake Erie will be taken offline, reducing overflow volumes by approximately 350 million gallons per year. This paper will discuss the current status of construction and the chosen means and methods, including the myriad of nuanced differences between hard rock and EPB TBM tunneling methods. Particular attention will be given to the site preparation, setup, and organization; TBM assembly; and TBM launching practices.

Jun 13, 2023

By L. Alan Weakly

The U.S. Department of Energy (DOE) has entered into a $l.5 million Cooperative Agreement with Alpine Equipment Corporation/Astro International Corporation ("Alpine") of State College, Pennsylvania, for the evaluation of water-jet-assisted (WJA) mechanical cutting of oil shale under actual mining conditions. A commercial-sized, heavy WJA mechanical miner is being assembled based upon the successful "factory testing" of a smaller prototype miner utilizing standard tungsten-carbide and Polycrystalline Diamond Composite (POC) bits in large oil shale boulders. Actual field testing of the machine will be conducted in an oil shale mine located in the Piceance Basin of Western Colorado. In-mine logistical support is being provided by several oil shale companies through the Colorado Mining Association (CMA) and the U.S. Bureau of Mines (USBM).

Jan 1, 1990

By Paul D. Bybee

The Freeport Sulphur Company operates four sulphur mines in the coastal marsh area-03 South Louisiana. Employing the Frasch process of mining, approximately 13-million gallons of water per day is heated to a mining temperature of 325°F and is injected into the sulphur bearing formations of the four mines. A volume of cold waste water, roughly equal to the Input, is removed from the formations and presents a disposal problem. Two additional mines are currently being developed and will increase the disposal volume by an additional 5-million gallons per day. Although these properties are in a relatively small area, geographically speaking, as shown in Figure 1, they each represent a separate disposal problem with the treatment methods designed for the individual mine.

Jan 1, 1959

By W. C. Meyer

A physical model of flotation, derived from viewing froth as a kinetic species since it constitutes the carrier of ore particles, not only agrees with and is simulated by engineering math models, but is statistically verified by actual laboratory flotation data. The model couples the mechanical removal of froth using paddles with the more rapid chemical interactions taking place in the bath. It clearly shows that the kinetics of mass removal is dictated by flotation cell dimensions, paddle speed, and, more importantly, froth characteristics. Some conclusions and predictions of the model are presented.

Jan 1, 1982

By Vaughn E. Livingston

Washington State has a variety of industrial minerals and although not many are produced currently (1982) most have a history of production (table 1). The value of industrial minerals produced in the state exceeds by several times the production value of metallic minerals. In 1981, 15 minerals - cement, limestone, clay, gemstone, pumice, sand and gravel, stone, diatomite, gypsum, olivine, peat, talc, garnet, silica, and dolomite - were produced. Combined value of nonmetallic production for 1981 is estimated at $218,999,000. Cement had the largest estimated value at $102 million, followed by sand and gravel at $47 million, and crushed stone at $29 million. These figures are from the US. Bureau of Mines preliminary production figures for 1981.

Jan 1, 1982

In this paper, response surface methodology was applied to optimize the experimental conditions for the wet grinding of synthetic rutile. The effects of parameters such as rotation speed, solids concentration and duration of grinding on grinding efficiency were systematically investigated and the process conditions were optimized, using a nonlinear regression model based on central composite design. The statistical analysis of the results showed that in the range studied, the grinding efficiency of synthetic rutile was significantly affected by the rotation speed of the conical ball mill. According to results from analysis of variance, the value of the determination coefficient (R2=0.9989) indicates that the predicted values are found to be in good agreement with experimental values. The optimized experimental conditions were as follows: a rotation speed of 350 rpm, a solids concentration of 27.31% and a grinding time of 50.31 min, respectively. Under optimum conditions, the predicted grinding efficiency of 94.79% is obtained. The experimental values from the validation experiments were well within the predicted value of the model.

Jan 1, 2011

By Julián Ortiz C., Clayton V. Deutsch

Indicator simulation allows specification of different continuity of high and low values through the use of grade thresholds. The sequential implementation of indicator simulation has been widely used, but the problem of order relation deviations remains a significant drawback. A new procedure for "Hierarchical Indicator Simulation" is introduced that avoids order relations and offers greater flexibility than the conventional sequential approach. The new implementation simulates all locations at the largest threshold and then considers decreasing thresholds in turn. All nodes with grades that are above the previous threshold are excluded from the domain of the current threshold and therefore, they are not used as conditioning data. The probability of being above or below the threshold is calculated using simple indicator kriging using all conditioning data in the domain, thus the covariance structure is preserved. The theoretical framework of this new approach is fully developed. Practical implementation details are discussed. Application to a copper deposit shows the advantages and drawbacks of the method. Finally, the possibility of incorporating multiple-point statistics is discussed.

Jan 1, 2002

By P. M. Krishna

An example illustrates the use of ASTM Standard E901-82, Classification System for Uranium Resources. The example demonstrates the dynamic nature of the process of classification and attests to the necessity of addressing both the aggregate needs of broad-scale resource planning and the specific needs of individual property evaluation. Problems that ,remain in fixing the classification of a given uranium resource include the uncertainty in estimating the quantity of undiscovered resources and resolving the differences that may exist in deciding when the drill-hole spacing is adequate to determine the tonnage and grade of discovered resources.

Jan 1, 1983

By Jean-Michel Rendu

In most mining operations, some degree of selectivity is applied. Whether one deals with surface or underground operation, ore zones, and waste zones are defined not only on the basis of the value of the ore contained, but also taking mining constraints into account. A number of computer techniques are presented which can be used to determine the optimum location of the footwall and hanging wall of ore zones intersected by drill holes. Minimum mining width and minimum internal waste width constraints are taken into account, as well as other economic constraints. The system is presented as an integral part of a larger manumatic ore reserve and mine planning system.

Jan 1, 1982

By P. Geoffrey Feiss

The Piedmont province of the southern Appalachians is becoming the focus of interest for many exploration geologists. In the past, only those deposits with significant surface exposure have been exploited. Thus, few deposits have been found and relatively little exploration has been conducted in recent years. Modern geochemical and geophysical techniques can alleviate this problem of concentrating on exposed ore bodies by allowing us to "look through" the soil and saprolite to detect the presence of significant mineralization at depth. This paper will attempt to evaluate the feasibility and effectiveness of several geo¬chemical exploration techniques in the Piedmont, of Cabarrus and Stanly Counties, North Carolina. The area chosen for the study is shown in Figure 1, lying almost wholly within the Mt. Pleasant quadrangle, North Carolina. The area is on the eastern boundary between the Charlotte belt, a zone of plutonic and intermediate grade metamorphic rocks, and the Carolina Slate belt, a series of complexly interbedded volcanic and sedimentary rocks of predominantly low grade metamorphism. The area is now considered to be a 500 million year old active, continental margin.1 As is typical of most of the piedmont, outcrop is sparse. Figure 2 is a sketch map of the general geology of the area under study, showing the Charlotte belt rocks in the northwestern quadrant and slate belt rocks, to the east. Within the area are a number of old mines and prospects, the most famous of which are the Furniss and the Phoenix mines in Cabarrus County. All are reported to have contained Au and Cu. Ag and Pb were reported from some. A summary of the deposits is given in Table 1. Data used in this study are from three Master's theses conducted at the University of North Carolina at Chapel Hill. 3,3,6 In separate studies, well waters5, B-zone soils3, and vein and float quartz6 from the area described were sampled and analyzed. Each study concluded separately that geochemical anomalies in the vicinity of the ores justify use of that specific sample type in a geo-chemical exploration program. However, no comparative study of the methods has

Jan 1, 1977

By DIONISSIOS T. HRISTOPULOS, JUAN DIAZ, Kray Luxbacher, Steven Schafrik, Zach Agioutantis

Explosions in underground mining due to methane gas have been the leading cause of incidents and fatalities in the mining industry. The main objective of this research is to develop a forecasting methodology for methane gas emissions based on time series analysis. Methane time series data were retrieved from atmospheric monitoring systems (AMS) of three underground coal mines in the United States. The AMS data were preprocessed and statistically evaluated to explore the potential autocorrelation of methane gas. It was concluded that the autoregressive integrated moving average (ARIMA) time series model used in the one-step-ahead forecasting mode provides accurate estimates that match the increase or decrease of the methane gas emission data.

Feb 1, 2023

By B. Pesic, J. E. Wey

Introduction One important class of manganiferrous ores is manganiferrous-silver ores. They occur in the oxidized portions of the silver deposits of the western United States. Silver is often associated with manganese oxides, which in some ore deposits are dispersed through calcite, causing the black color of the host rock, known as black calcite. Black calcites can occur in carbonate rocks (0.3 to 50 kg Ag/t) and in volcanic rocks (less than 30 g Ag/t). Silver mineralization associated with manganese oxides and black calcites can occur in veins (Hewett, 1968) or as disseminations (Graybeal, 1981). In the US, silver-bearing manganese veins are located in a broad arc that extends from southern Colorado to southwest New Mexico, southern Arizona, and southeast Califor¬nia (Hewett, 1964). Areas of disseminated silver-manganese mineralization include the Creede and Silver Cliff districts of Colorado and the Tombstone and Hardshell districts of Arizona (Graybeal, 1981). These deposits are also characterized by significant amounts of silver halides - cerargyrite (AgCl), bromargyrite (AgBr), and iodargyrite (AgI). Black calcites are also common in these deposits. Oxidized silver ores containing the higher oxides of manganese are generally refractory to hydrometallurgical methods of treatment. In the past when these ores could not be smelted, they were treated generally by cyanidation at very low efficiency. The US Bureau of Mines (USBM) studied the problem of treating silver-manganese ores in the early 1920s (Clevenger and Caron, 1925). It was found that the refractory silver in the original ore was insoluble in all the common solvents for metallic silver and its salts. The conclusion was that to obtain the highest recovery of silver, all the manganese had to be dissolved or the higher oxides of manganese reduced to manganous oxide. More recent results from treating refractory silver¬manganese ores were given by USBM (Scheiner et al., 1973). The silver ores from Candeleria District, NV, and Round Mountain District, CO, were investigated. Electrooxidation experiments recovered only 34% silver with minor amounts of manganese dissolved. Sulfurous acid pretreatment followed by cyanidation revealed that silver extracted was proportional to the amount of SO2 used. A similar approach, using sulfurous acid pretreatment followed by cyanidation, was also proposed by Rhoades et al. (1984). Hazen Research Inc. performed extensive testing on silver and manganese dissolutions from Ag-Mn ores obtained from the Candeleria and Round Mountain ore deposits. The methods examined were direct cyanidation, pretreatment with sulfurous acid followed by cyanidation, malonitrile leach, and leaching with ammonium hydroxide-sodium thiosulfate under slight oxygen pressure. The results were not satisfactory. The importance of the vast reserves of Ag-Mn ores and the lack of an efficient method to recover these metals warranted a search for new technologies. One novel method for extraction of these metals is treatment of Ag-Mn ores with acidified thiourea solutions. Preliminary results of the leaching of silver and manganese from Ag-Mn ores were very encouraging (Pesic, 1984a) ; thus, it was decided to examine the new lixiviant in more detail. Experimental Ore from the Round Mountain District was studied. It was crushed, ground, and dry sieved into monosized fractions in the range of 16 to +400 mesh. The ore composition was about 90 g Ag/t and 3% Mn, depending slightly on size. The leaching experiments were performed in apparatus described elsewhere (Pesic, 1982 and 1984b). All experiments were performed at constant temperature conditions. The leaching residues were analyzed for silver and manganese. Atomic adsorption was used to analyze the solution samples and fire assaying to analyze the leaching residues (for silver). The standard experimental conditions are given in

Jan 1, 1987

By Nathaniel White, Todd Kilduff, Justin Laviolette, Dan Laviolette, Randy Zeigler, Sean Sundermann

The Mitchell Point tunnel is a part of several ongoing efforts to connect the 12-mile-long Historic Columbia River trail between Mitchell Point Outlook to Mitchell Point Drive. The tunnel lies inside the Mitchell Spur entablature basalt geologic feature, extending 647 linear feet utilizing a typical horseshoe section with a height of 14.5 feet. The Oregon Department of Transportation (ODOT) required proper vibration control to minimize potential impacts to Interstate 84 and Union Pacific rail immediately below the tunnel excavations and sensitive, rare plants. The method of designing the vibration monitoring program and the results of its implementation show the iterative process of using monitoring to improve blast design as excavation proceeds, such as reducing air overpressure and COVID-related supply chain-constraints.

Dec 1, 2022

By Aurel Goodwin

MSHA is the regulatory Agency which administers the Federal Mine Safety and Health Act. Although MSHA's principles largely derive from this Act, they do not exculsively derive from it. One might expect that our principles are contained in the regulations we have published to implement the Act. To a degree, this is true; but the regulations we have now were developed and published before the current Act became effective. For this reason, as well as others, there are some principles that we support which are not evident in our regulations, or in the Act. One of these is the ALARA principle. This principle requires that all unnecessary exposure be avoided; that is, all exposures should be kept "As Low As Reasonably Achievable." Almost all professionals in radiation control can agree with this broad principle; but it would be difficult to get agreement on a regulation which would translate the principle into industry practice. Rather, our regulations specify a limit to exposure for any individual. For radon daughters the current limit is four working level months per year. By having an explicit limit such as this, the ALARA principle often becomes lost and the limit becomes the goal. The principles contained in the Act are equally broad in scope. The principles apply not only for radiation protection, but also for toxic substances and harmful physical agents. The Act states that standards for such substances or agents shall most adequately assure on the basis of the best available evidence that no miner will suffer material impairment of health or functional capacity, even if such miner has regular exposure to the hazards dealt with for the period of his working life. The Act also provides that, although protection of health must be our foremost concern, other considerations shall be the latest scientific data in the field and the feasibility of the standards. Our regulations reflected similar principles when they were developed and promulgated. From experience with other health and safety laws, Congress realized that setting and meeting an exposure limit may not be sufficient to prevent disease. The Act, therefore, contains a detailed description of additional provisions to be included, where appropriate, in mandatory safety and health standards. One of these additional provisions requires that miners be informed about the nature of the hazards associated with their job and about the means for their own protection. Another provision requires the use of labels and other forms of warning to inform miners about the hazards, about proper precautions for safe use or exposure, about relevant symptoms of overexposure, and about emergency treatment. We have partially implemented these provisions through regulation. The Act requires also that standards shall prescribe protective equipment and control of technological procedures and that they shall provide for the monitoring of miners' exposures. We have implemented this provision to a degree also through regulation. Finally, the Act specifies that, where appropriate, a mandatory standard must prescribe the type and frequency of medical examinations in order to most effectively determine whether the health of miners is adversely affected by exposure. Additionally, when a determination is made that a miner may suffer material impairment of health or functional capacity by reason of exposure, that miner must be removed from such exposure and reassigned. In order to encourage miners to take the medical examination, the Act also provides that the miner shall not suffer loss of pay as a result of being reassigned. This additional provision on medical examinations has not been implemented by regulation for radiation hazards, nor for most other toxic substances or hazardous physical agents. We believe that this conference will provide us with valuable information on medical examinations for radiation exposure, as well as on other considerations to be used in future regulations. We still question whether our basic exposure standard of four working level months per year is adequate to protect a miner's health. This conference is indeed timely because both MSHA and NIOSH have been reviewing this issue for some time. I would like to reemphasize MSHA's commitment to education and training. MSHA strongly believes that miners should be informed fully about the real and potential hazards associated with their work. They should know the nature of the hazard and the means for protecting themselves from the hazard. The Act also emphasizes the need for training miners by requiring that new miners receive 40 hours of training before working underground and 24 hours of training before working on the surface. The Act also requires eight hours of refresher training annually. This training must include information on the relevant health hazards and the potential consequences of overexposure. Before I close, I would like to mention briefly another source of principles that MSHA often consults to obtain guidance for both the development and enforcement of regulations. These are the various court decisions that are handed down from time to time. Two in particular that I want to stress are the recent Supreme Court Decisions on benzene and cotton dust. Although neither of the decisions has a direct impact on mining or radiation, they do clarify some general principles and directions for regulatory agencies, such as the role of cost-benefit analysis and the need for risk assessment. In closing, I wish us all an open exchange of information for a productive and useful conference.

Jan 1, 1981

Caterpillar recently held two, two-day demonstration programs for its mining customers. The event, billed as MineDemo by Caterpillar, consisted of two sessions held on consecutive weeks at the company's Tinaja Hills proving ground south of Tucson, AZ. The program included several classroom sessions that focused on Caterpillar equipment applications, including the VIMS (vital information management system) and the CAES (computer-aided earthmoving system). Also included were field demonstrations and the opportunity to test drive mining-related heavy equipment, including dozers, trucks, graders, shovels and loaders. Featured at the event were the recently upgraded 785, 789 and 793 C-Series trucks. Caterpillar recently announced the availability of the 136-t (150-st) 785C and the 177-t (195-st) 789C. The upgraded haulers have replaced the respective B-Series models. The 218-t (240-st) 793C was introduced in 1996. It, too, has been upgraded but retains the C-Series designation. While attending the press event, the author had the opportunity to test drive the 793C at the Tinaja Hills test site. It was amazing how well the machine handled. The operation was smooth and the braking system was precise. The cab was extremely comfortable. To see a C-Series truck in action, the author also visited Newmont Mining's Mesquite Mine, located in Cali¬fornia, across the border from Yuma, AZ. The Mesquite Mine operates a new model 785C truck. At the mine, temperatures have been measured as high as 58° C (138° F) in the pit. Needless to say, the ability to operate dependably in extreme heat is an important consideration for the mine operators. An interview with the driver and later with management confirmed that the 785C has worked out well. The driver praised the comfort of the cab and the ease of operation. Management reported significant fuel savings and was impressed by the truck's maintenance features.

Jan 1, 1999