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By L. A. Bakhvalov

According to the practice of mining management in the system of industrial complexes, the Kazakhstan gold mines are part of the mine processing industrial concerns providing ore-mining and ore-dressing. The cycle technology of winning operations used at the mining of vein deposits in the mines of the industrial concern is mainly provided by the systems of scrapping, scipping and electric locomotion. At present the information and computer system, elaborated on the basis of the Maikain underground mine is intended for creation of the system of automatic operation for the industrial complex mines. The information and computer system includes: - parametres characterising the accepted technology of works; - the main parametres characterising the technical devices of operation and control ; - information about the material, technical and personnel resources available at the mine; - mining and geological conditions of the deposit; - the facilities of the subsidiary units, of the mine; - the direct parametres and technico-economical indices in which the mine efficacy and activity is estimated. The suggested structure of the automatic operation system can be sensibly realized with the application of the microprocessor on the first level, the personal computer IBM PC/XT or PC/AT on the second level. For the complete realization of the project each mine will need 4-5 computers (as PC/XT), one IBM PC/AT and each mine complex - one super IBM for creation of the distributed information bank and its including in the integral world communication system.

Jan 1, 1992

By Charles A. Gargano

The current state of the mass transit industry in America will be examined. How and why this important urban activity shifted entirely, or almost entirely, from the private sector to the public sector. Who pays for transit? For day to day operating costs? For capital investment? The prospects for transit's future will be the next major issue addressed. In a word, they are rather good. Over the past decade there have been major new transit investments made in Atlanta, Baltimore, Washington, D.C. and Miami, as well as constant re-investment in such cities as New York, Boston, Philadelphia and Chicago. While the current administration has put a temporary halt on the initiation of any major new rail transit projects using Federal funds, there are several mechanisms localities have for using other resources for such projects. These will be explored.

Jan 1, 1983

By Jack Magtoto, Lysa Voight, Tom Martin, John Forero

SUMMARY Commitment by all parties to partnering goals established early in the contract aided Affholder, Inc. in constructing 2,360m (7,700') of soft ground tunnel in Rancho Cordova, CA. Despite two zones of known contamination, encountering a zone of loose cobbles and boulders in a matrix of flowing sand, some perched water tables and a flooded tunnel after 2 upstream safety plugs failed, the Contractor finished the work 33 days early and only 1.91% over his original bid.

Jan 1, 2007

The inquiry into the explosion at the Moura No. 2 Mine in August 1994 recommended -?Emergency procedures should be exercised at each mine on a systematic basis, the minimum requirement being on an annual basis for each mine.? (Windridge et al. 1996). In December 1996 the ?Approved Standard for the Conduct of Emergency Procedures Exercises? was published and has been subsequently revised (Queensland Department of Mines and Energy Safety and Health Division 1999). This document provided guidelines for conducting mine site emergency exercises as well as the requirement for a test of state-wide emergency response by holding a Level 1 Mine Emergency Exercise at one mine on an annual basis. From 1998 to date (January 2008) ten Level 1 Mine Emergency Exercises have been held in Queensland, Australia. This paper discusses each of the exercises conducted to date as well as the logistics, scenario preparation, planning and organising required to conduct emergency exercises at this level.

Jan 1, 2009

By W. Dziurzynski

The present article sets forward the results of field tests that made it possible to validate the mathematical model used in the VENTGRAPH ventilation engineer programmes. The case considered relates to the introduction of a new heading to the ventilation network of the mine. The utilisation of computer programmes in practice is justified by the necessity of ensuring expected performance and secure conditions in the network of mine headings, where - for example - plans are being made to utilise the transport dip-heading, taking into consideration fire and methane hazards. In the article we have presented the methodology of preparation of a database for computer programmes of the VENTGRAPH system, obtained on the basis of ventilation measurements. The next step consists in the execution of a design of the modified network and prediction, this on the basis of heading geometries, of parameters characterising the flow of air for the designed headings. Due to the fact that the heading was in the final stage of driving, following its introduction to normal operation and the stabilisation of flow values it was possible to retake ventilation measurements, which validated the results obtained through computer simulations. In order to execute measurements of the volume flow in the dip-heading, we employed a new wireless multipoint measurement system to determine the velocity field of air in the mine heading; the results are characterised by a high accuracy of measurement. As a part of fire prevention and incident management planning, a series of underground fire case studies for the a validated network flow model has been made. Results of simulations show the capabilities of the FIRE module of the mentioned software, including assessment of stability of flow directions and hints on counter and preventive measures for particular locations of fire.

Jan 1, 2009

By Z. J. Hladysz

A Deep Underground Science and Engineering Laboratory (DUSEL) is being planned at the site of the former Homestake Gold Mine in Lead, South Dakota, under the sponsorship of the National Science Foundation (NSF) in cooperation with the Department of Energy (DOE). This national facility will host a variety of multi-disciplinary science and engineering experiments including physics experiments that require shielding from cosmogenic radiation. Current plans include construction of large rooms (up to 55 m in width) at depths of 1.48 km (4850 ft) and 2.25 km (7400 ft) below the surface. Preparation of the preliminary design required the development of a geotechnical characterization program including: preliminary drilling and coring, core logging, drill hole mapping with a televiewer, drift mapping of the geology and rock structure, in-situ stress measurements, and laboratory testing of the mechanical properties of the rocks and discontinuities. Overall rock quality is very good to excellent. Site investigations were followed by geotechnical assessments for the construction of caverns and laboratory modules. The results are favorable and reaffirm selection of the Homestake site for establishment of a Deep Underground Engineering and Science Laboratory.

Jan 1, 2011

By K. N. Han, N. S. Kim, H. Yoon, J. S. Sohn

The leaching behavior of silver and silver oxides in ammonical solutions has been studied. The current study is concerned with an effective recovery of silver from secondary sources such as spent silver batteries. Silver associated with these batteries appears in various forms including metallic silver, argentous oxide, Ag2O and argentic oxide, AgO. The leaching behavior of metallic silver in ammoniacal solution has been studied using an electrochemical mehtod. Oxidants used in this study include hyperchlorite, hydrogen peroxide, bromine and iodine. Results on cyclic polarization and Tafel plots on the silver anode in ammoniacal solutions are presented and the results are discussed. The dissolution rate of metallic silver in ammoniacal solutions is also compared with those of silver oxides.

Jan 1, 2002

By Calvin J. Konya

An investigation was performed to determine conditions which optimize fracture formation between blastholes used for purposes of pre-splitting. Experiments-involved high-speed photography in Plexiglas models and radiographs in sandstone models. Additionail data was obtained from full-scale pre-split blasts. Pre-split fractures between blastholes were found to form as a result of gas pressure and were affected little, if any, by stress wave interactions. Pre-splitting was effective with short period delays of 25 milliseconds or less, and did not require instantaneous initiation of blastholes. Significant reduction of ground vibration resulted with the use of delays

Jan 1, 1980

By Wei Victor Liu, Omer Faruk Ugurlu, Chengkai Fan, Bei Jiang

The accurate prediction of truck productivity plays a pivotal role in improving the efficiency and profitability of open-pit mining operations. However, predicting truck productivity is challenging owing to the complex nature of the working conditions of the mine site. This paper proposes a deep neural network model to overcome the challenge of predicting truck productivity in open-pit mines. The prediction model was built using eight variables and was optimized by considering different train-test split ratios, numbers of hidden layers and neurons, and activation functions. The proposed model's performance was evaluated using various metrics and was compared with other commonly used machine learning algorithms. According to the results, the proposed model outperformed traditional machine learning algorithms by achieving higher accuracy and lower error rates, with the best-performing model having four hidden layers with 70 neurons per layer and a scaled exponential linear unit activation function, resulting in a coefficient of determination value of 0.89. This demonstrates the potential of deep neural network models for predicting truck productivity in open-pit mine sites. Moreover, a single variable sensitivity analysis was conducted to investigate the impact of input variables on truck productivity. The results show that haul distance is the most influential variable for the prediction of truck productivity.

Feb 12, 2024

By Peter T. Chiang

A brief literature review on metal separations by ion exchange and solvent extraction of their thiocyanate complexes which are practiced in analytical chemistry as well as in industries was performed. Owing to the poor stability of free thiocyanic acid in acidic aqueous and organic media, technical and environmental problems which cause high thiocyanate consumptions often arise during the practice of the separation processes. This prompted the conducting of a second and more thorough literature review on the chemistry of thiocyanic acid. The objectives of this undertaking are to compile and interpret literature data on the physical properties and chemical reactions of thiocyanic acid, thus providing a clearer understanding of the causes of these problems and giving options as to how to minimize them. The best answer found for carrying out the separation processes is to keep the temperature, thiocyanic acid concentration and total acidity as low as practical.

Jan 1, 1984

There is wide agreement that sustainability has multiple dimensions, but substantially less agreement on the appropriate balance among those dimensions. This occurs because peoples’ vision of a sustainable future, their goals for sustainable development, and their objectives for resource management are reflections of their values, culture, and life experiences. Even assuming agreement about the objectives of sustainable resource management can be reached; there is still a need for policy and decision makers to choose from among alternative courses of action, each of which has its own set of impacts and outcomes. One of several tools used to compare the consequences of alternative actions is the Computable General Equilibrium (CGE) model. This paper uses CGE modeling to demonstrate how policy decisions do not take place in a vacuum and how policy-makers must be aware that there are trade-offs involved in any decision.

Jan 1, 2005

By G. T. Swanby

Members of AIME, I read to you now a portion of a very fine business letter which we received several years ago. This letter originated in Rangoon, Burma, and reads in part: "Rest assured, if your goodselves see with us eye to eye, sure as certain we should get the business". I don't plan to give anybody "the business" today, but you can rest assured that if some of "you goodselves see with me eye to eye" on what I am about to discuss, I would be most pleased. My talk with you today will discuss the Federal Corporate income tax and its effect on our lives as engineers. In the-engineering-construction business we are faced with all the usual form of taxation which includes such items as sales tax, use tax, school tax, contractor; gross receipt tax, import duties and excise taxes, severance taxes, etc, adinfinutum.

Jan 1, 1965

By L. Frederick

Measurement of gamma radiation occurring in nature to characterize geological formations has been widely recognized in mineral exploration. Different methods and apparatuses have been developed for drill hole logging purposes. Geological formations vary in amount of naturally emitted gamma radiation. A gamma signature from a geological formation is captured by utilizing different types of gamma detectors. A natural gamma radiation detector (NGRD) can be used to control mining whenever there is a significant difference between the radiation levels in the mineral or ore being mined and the waste materials surrounding the ore. Surface miners, such as the one shown in Figure 1, can precisely control the elevation of the cutter as the machine moves over the surface of the formation. This type of machine is predominantly used in selective mining operations, e.g. surface coal mining. If there is a means to know the position of the cutter relative to the interface between the ore and waste, the miner can recover all or most all of the valuable mineral with very little out-of-seam dilution. This paper discusses the results of a successful application of gamma detectors to control a surface miner at one of North American Coal Corporations? locations - Red Hills Mine. The mine has nine coal seams in total with thicknesses ranging from 12? to 60?. The bottom six seams (Figure 2) are minable. The mine has complex geology and a significant amount of annual rainfall (4.7 ft). The mine produces approximately 3.5 million tons of coal and about 40 bcy of overburden per year. The operation utilizes diverse mining equipment including Dragline Marion 8200, electric shovel P&H 2800, Caterpillar end dump trucks CAT 785 and 789; bulldozers CAT D11, D10, D8, and D6. Coal is mainly extracted by utilizing a Wirtgen SM 4200 surface miner that is loading CAT 785 trucks with high volume coal bodies and payload of 150 t. Operational cutting depth is 24 inches with maximum cutting depth of 36 inches. Surface miner operators determine a cutting depth based on multiple cues, the most important being visual observations of a coal seam being cleaned or mined. The cleaning process involves removal of the last foot of waste material covering the coal seam. This is one of two critical phases in the coal extraction process. If, during the cleaning process, an operator sets a cutting head too deep, valuable product is wasted. If it is set too shallow, waste material is left to be mined with the coal. The second critical phase occurs in the last cut on the interface between the coal and waste material at the bottom of the coal seam. If the cutting head goes deeper than favorable, then waste material is delivered to a power plant.

Feb 27, 2013

By Duane L. Abata

This paper discusses recent technology dealing with the use of computer graphics in the mining industry and presents a newly developed computer software package specifically designed for use in underground mining operations. This software package, developed under a United States Bureau of Mines contract, 1) displays mine ventilation schematics and other representative illustrations for a real time data acquisition system and 2) utilizes the Bureau-owned Minefire and Ventilation Code for display of ventilation and contamination predictions on the microprocessor system. The package utilizes a unique system of display indexing that provides a simple yet efficient method of recalling a series of mine schematics detailing an underground operation and an alarm acknowledgement scheme that provides an effective method of identifying problem areas which may exist in the mine network. The package was written in Fortran for a 64 kilobyte, Z80-based microprocessor-computer.

Jan 1, 1984

By S. C. Chelgani

The Thor lake deposit is a world class resource of rare earth (REE) metals and minerals in Canada. Development work to optimize a REE mineral recovery process flow sheet is underway, however, given the ore mineralogy; the developed reagent scheme is relatively complex. As part of a research project, micro flotation tests were conducted on a feed sample in order to examine factors affecting stream partitioning. SEM-EDX was performed to evaluate variability in grain composition between streams (concentrate and tails) and TOF-SIMS surface analysis was used to determine statistically significant differences in surface species particularly related to potential activation (or depression) of the examined mineral phases. SEM-EDX analysis reveal that the concentrate has a significantly higher proportion of REE bearing grains (carbonates and phosphates) relative to the tail (almost none were identified). Spectral fingerprinting by TOF-SIMS has allowed for the identification of all reagent species investigated. Reagent signal intensity discrimination on test stream mineral surfaces was observed by the TOF-SIMS analysis using reagents at plant concentration levels. TOF-SIMS analysis confirmed that REE bearing grains reporting to the concentrate are doing so in response to collector attachment whereas grains reporting to the tail are doing so in response to a lack of collector and/or in combination with the presence of the depressant. The surface analysis of gangue phases reveal a similar reagent discrimination; the signal intensity of collector species was significantly higher on the concentrate samples relative to the tails while depressant species were significantly enriched on the surface of the gangue phases in the tail samples. A detailed evaluation of the surface species representing the various reagents used in flotation scheme revealed a distinct competitive relationship between two of the reagents. The surface analysis identified that when used in concurrently, there appears to be a negative feedback resulting in a significant reduction in loading for several of the collectors on grains reporting to the concentrate. An evaluation of the effect of reagents on REE mineral in pilot plant is currently under way. Key words: Rare earth minerals, Flotation, Surface chemistry, TOF-SIMS, SEM-EDX

Feb 27, 2013

By Steven G. Vick

Effects of the August 1995 failure of the Omai tailings dam in Guyana continue to be felt throughout the mining industry. This article is taken from the final report of the independent body of experts commissioned by the government of Guyana to establish the cause of the failure. It explains what happened, why and how to avoid it in the future. Despite environmental, health and safety effects that were negligible by any objective measure, the failure has received wide international attention. Coming on the heels of the shift in exploration targets and development opportunities to developing countries, it has intensified interest in tailings dam safety and environmental management issues. An informed understanding of the nature of the failure and its effects is key to responding to these concerns.

Jan 1, 1996

By António Fiúza, Anthony Danko, Patrícia Leitão, Aurora Futuro, Cristina Vila, Lurdes Dinis

The average global recovery rates for processing scheelite ores by physical methods are normally in the range 50 to 70%, and it is problematic to attain a minimum grade of 60% WO3 in the concentrates without penalizing further this yield. Direct hydrometallurgical processing of low-grade concentrates or medium- to high-grade ores may become an interesting global economic alternative as it allows increasing the recovery rate, avoiding major penalizations due to the grade of the concentrate and increasing the added value of the final product. Leaching of scheelite by sodium carbonate presents several advantages such as its selectivity regarding the dissolution of troubling metals like iron and aluminium, allowing for a simple and flexible process diagram. However, it has the disadvantage that it is performed at high temperature and pressure with a high consumption of reagents. The feasibility of leaching is appraised by the extraction yield and selectivity, but also by the operating cost. Considering these aspects, a relevant objective of the research was to transform alkaline pressure leaching into a feasible processing alternative directly applicable to both medium- and high-grade ores and simultaneously to low- and high-grade concentrates produced by physical methods. The research used ore samples and low-grade concentrates from a typical skarn orebody as well as high-grade concentrates from a chalcopyrite-scheelite orebody. Different operating conditions were tested. Temperature, pressure and reagent concentration showed to be fundamental, but not exclusive, in determining the leaching behaviour. The operating conditions are milder than the ones generally proposed in the literature or currently in use in industry, but with higher carbonate consumptions. The research was oriented towards potential industrial implementation allowing for the application of optimization methods and straight scale-up to pilot-plan design and project.

By A. L. Anderson, J. T. Rybock

Lime, soda ash and similar precipitants have been the industry standard for treatment of acid rock drainage (ARD) because of their proven ability and low per-gallon operational cost. However, these methods carry serious environmental drawbacks and high life-cycle costs. KEECO’s Silica Micro Encapsulation (SME) technology has all the positive characteristics of conventional ARD-treatment systems but none of the drawbacks. SME achieves highly effective treatment in a single step, provides options for ARD prevention and recovery of metals, requires lower capital expenditures, generates smaller volumes of higher-density sludge, consistently passes leach tests, and eliminates long-term liabilities associated with potential metal remobilization and hazardous waste landfilling.

Jan 1, 2000

By Xie Junjie, Li Shina, Ma Ruixin, Min Changli, Yin Zichen, Li Kang, Shi Zhuonan

Cesium and rubidium were effectively separated by zinc ferrocyanide coprecipitation method, and the effect of precipitant addition amount on the separation of cesium and rubidium was studied. Under the conditions of Zn/Cs molar ratio of 0.45 and Zn/Fe molar ratio of 1, the precipitation rate of cesium is 84.01% and the separation factor of Cs/Rb is 164.65. The thermogravimetric curves of the sediment were measured, and the effects of roasting temperature, roasting time, and leaching liquid/ solid ratio on the extraction of cesium were studied. Almost all of the cesium was extracted under optimal conditions: roasting temperature of 600 °C, roasting time of 3 h, leaching temperature of 25 °C, leaching time of 0.5 h, and liquid/solid ratio of 5:1 mL/g. After the leaching process, the leach liquor with high concentration of cesium of 80.17 g/L was obtained. Finally, the leach liquor was further purified by solvent extraction, and the purity of the cesium chloride product reached 99.66%.

Mar 17, 2024

Floor heave events in underground mining often happen suddenly and cause risk to workers and equipment. Reducing the risk of floor heave must be addressed in mining layout design. To improve that design one must understand the significant parameters that are correlated to the occurrence of floor heave. To accomplish that goal, researchers from the National Institute for Occupational Safety and Health (NIOSH) completed a numerical study using FLAC3D, taking advantage of its strain softening and ubiquitous joint capabilities to better simulate the floor heave and caving mechanisms involved at an actual mine site.

Jan 7, 2020