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By Pierre Mousset-Jones, Felipe Calizaya, Malcolm J. McPherson

The objective of this study is to provide potential users of booster fans in coal mines with the necessary information on monitoring and control of fans and environmental factors. The guide-lines listed in this paper were formulated based on the current practice of mine monitoring, the U.S. Code of Federal Regulations on environmental monitoring, and the United Kingdom's National Coal Board recommendations on the use of booster fans. The principles involved in the design of booster fans as well as the provisions needed to guarantee a safe operation of these units, are illustrated by means of an example problem. The example includes a summary of costs for two ventilation systems: a conventional surface fan system and a fully automated booster fan alternative. A comparison of these costs showed that significant gains may be attained by selecting a combined surface-booster fan strategy over a conventional surface fan alternative.

Jan 1, 1989

By Thomas V. Falkie

The title of this talk has brought some interesting responses - even before it was written - from different parts of the country. A geologist from the Western U. S, was deeply concerned with recent layoffs in his profession and the employment situation in general and wondered why "the AIME wasn't doing anything for the benefit of its members." A petroleum engineer in Texas said that a group in his field were studying "professionalism" and their professional status and wondered if there were any words of wisdom for him. A mining engineering professor from the East pointed out that the National Science Foundation did not include mining engineering as one of its recognized fields in one of its equipment funding programs. These are just a few examples of reactions received to date, but they serve to illustrate the broad image that the title has meant to various people. Actually the term profession is defined by Webster as "a calling requiring specialized knowledge and often long and intensive academic preparation." The word encroach means "to enter by gradual steps or by stealth into the possessions or rights of another", or "to advance beyond desirable or normal limits." The intention of this paper, as originally conceived and requested by the program chairman, was to combine those two words literally and talk about how the professional standing of mineral engineers is being eroded from people outside the profession. But the amazing preliminary response suggests that it may be timely to broaden the discussion by including some comments about professionalism in general. In the paper the terms "mineral engineer" or "mining engineering" are used frequently, but it should be clearly understood that much of what is said is valid and is intended for all fields covered by SME and perhaps for AIME in general.

Jan 1, 1972

By Bruno C. Boik

INTRODUCTION Cost Management is the evaluation and control of project scope, budgets, and costs with the objective to minimize costs and maximize the benefits to be derived from the use of project resources in conformance with Criteria stipulated or approved by the Owner. In order of importance, Cost Management is one of the most prominent Project Management functions because of its impact on the financial success of the venture. Cost Control and Cost Accounting are essential parts of Cost Management. The principal objectives of Cost Control are to monitor project commitments and expenditures, and measure performance for the detection of variances from acceptable standards and from control budgets so that timely action can be initiated to minimize costs. Cost Control is evaluation of current costs and projection of future costs, rather than the reporting of actual costs. Cost Control is not Cost Accounting. The primary objectives of Cost Accounting are the determination, classification, analysis and reporting in useful detail of actual costs. Following are some considerations on Cost Management and Cost Control as practiced by Owners and Contractors of industrial projects, Mining and Metallurgical projects in particular. COST MANAGEMENT Functions Conforming with the requirements of Owner's Criteria, the principal Cost Management functions are to • evaluate estimates of project costs and establish budgets for a scope of work and schedule; conversely, evaluate the scope of work that can be executed most effectively within a budget and schedule. • promote investigations and comparative evaluations of alternate designs and plans to find the most cost effective way to execute a project and minimize its operating costs. • based on Cost Control and Cost Accounting input, evaluate and initiate appropriate actions to correct deviations from approved budgets. assess project economics, the effect of changes on project economics and, if necessary, revise Project Criteria to modify their impact on costs.

Jan 1, 1986

By Vernon R. Degner

The past two decades has seen the application of the mechanical flotation machine, originally developed primarily for metal1iferous ore beneficiation, increasingly applied to cleaning coal in the 28x0 T. Mesh size range. Internal cell hydrodynamic studies of mechanical flotation machines of all sizes, as well as computer aided modeling studies of flotation kinetics has, within the last five years, established a basis for optimizing coal flotation circuit design and machine operation, and has a1 so pointed a way toward improvements in mechanical flotation machine design for the future. Consideration of the trend toward increased fines produced by current mining techniques, as well as the environmental need for a progressively cleaner product, lends support to basing the design of the mechanical coal flotation machine of the future on finer feed; below 100 microns in size. Future types of mechanical flotation machines, which may satisfy the fine coal cleaning requirements for a significant improvement in product grade while maintaining the combustible recovery levels of current technology, are discussed.

Jan 1, 1988

By J. Pang, S. Chander

The results of an investigation to characterize the chalcopyrite/solution interface are presented. Several techniques were used, including galvanostatic and steady-state polarization, cyclic voltammetry and impedance spectroscopy. The results show that the dissolution of chalcopyrite was incongruent. Initially, at low potentials (< 0.12 V), iron species were released that led to the growth of an iron-deficient sulfide (IDS) layer (referred to as the "reacted layer" in this paper). Depending on the solution&apos;s composition, the dissolved iron might reprecipitate as a hydroxide layer. In the potential range of 0.12 V < E < 0.23 V, the IDS layer was passivating. In comparison, development of a passivating IDS layer under galvanostatic conditions led to a jump in potential to 0.48 V. The IDS layer began to dissolve at potentials greater than 0.24 V. The dissolved species precipitated to form a product layer in alkaline solutions. Continued oxidation involved diffusion of species through the reacted and product layers. At higher potentials (> 0.48 V), further oxidation led to the dissolution of the copper and sulfur species, with a resultant breakdown of the IDS layer. The changes in surface-coating properties, resulting from various electrochemical treatments, are discussed.

Jan 1, 1993

By Heinz Distelmeier

Short Historical Review Tunnelling in Germany is as old as it is in other industrial countries. Until the middle of this century German contractors had no chance to work continuously in this business except if they were operating internationally. Since 1960, however, tunnelling has been a growing market domestically. The reasons for this growth have been both in the growing demand of traffic routes and also in an increasing environmental consciousness, which tries to transfer any cause of disturbance underground. Tunnelling engineers of course don&apos;t complain about this trend. As almost every German city is built upon water-bearing soft ground, shields have been used soon after they were first successfully utilized in Great Britain and the United States. Until the seventies lining systems for shield tunnels were predominantly either cast iron segments or concrete segments for primary support combined with different sealing systems and a secondary concrete lining cast-in-place. Steel ribs and timber lagging for primary support has not been utilized in Germany, since the owners don&apos;t accept timber to be left in the ground. In 1973, for the first time, permanent linings were constructed with watertight segment rings of precast concrete (Fig. 1). This lining was developed as an economical solution for use with slurry shields in noncohesive, water-bearing soils that required an immediately watertight lining. Extruded linings have a similar effect, although these still need a secondary lining

Jan 1, 1987

By Y. C. Kim, M Nataraja, J. T. Buckley, D. H. Tiktinsk

The Nuclear Waste Policy Act of 1982 (NWPA) assigns the U.S. Department of Energy (DOE) the responsibi1it.y of locating, constructing. operating, closing and decommissioning a nuclear waste repository. Prior to submittal of a licensee application to the U. S. Nuclear Regulatory Commission, the DOE is required by 10 CFR part 60 to conduct a program of site characterization for the site to be described in such application. Site characterization includes an exploration and research program in the field and laboratory to determine the geologic conditions and ranges of those parameters which are necessary for determining the suitabi1it.y of the site as a geologic repository. The information thus collected should be able to establish with reasonable assurance that the public and environment will be adequately protected from the hazards associated with a repository at the site. This paper demonstrates by example a geostatistical approach which, on the basis of the existing limited data base, can be used to evaluate (1) whether existing information on a certain parameter is adequate to be considered representative. (2) if additional information is required, where should the additional sampling or testing be performed, and (3) whether the new1.y acquired data along with the existing information constitute representative data.

Jan 1, 1986

By G. H. Roybal, J. M. Barker

Humate mining in New Mexico is a small industry [455 m3 (16,079 cu yd) valued at $395,894 for 1983] with three mines active in 1985. Either humate (carbonaceous claystones rich in organic matter) or weathered coal ("leonardite") high in humic acid are mined. The humic acid content needed to meet consumer specifications determines which type is mined. The humate and "leonardite" now mined in New Mexico are used primarily as soil conditioners or as drilling mud additives. The potential resource for both are very extensive within the coal-bearing formations of the San Juan Basin in northwest New Mexico.

Jan 1, 1987

By A. Wahab Khair

There are a number of factors, including mine geometry, local geology, geotechnical properties of overburden materials, surface topography, sequence of overburden strata, and extraction rate, affecting characteristics of surface subsidence imposed by large underground excavation. Among the factors, the first three have the major impact on magnitude and area of influence of final subsidence. Hence, a model has been developed, considering mine geometry and geologic and geotechnical properties of the associated area, to predict maximum possible subsidence and subsidence profile at any cross-section within the subsidence influence zone. Based on extensive field measurements and mechanics of strata behavior, under the action of overburden pressure in the vicinity of the large underground excavation, the vertical plane of influence zone has been divided into five areas: 1) excavated, 2) caved, 3) fractured, 4) highly deformed but continuous, and 5) subsided zones. In the final state of subsidence each area maintains a certain volume expansion/contraction, i.e. a factor which depends on geologic, geotechnical properties of overburden strata and state of stress within the subsidence trough. The cumulative volume expansion and contraction partially compensates for the extracted volume and the difference between the two is reflected as the subsided area in the form of the area within a curve defined by a probability function. The input parameters for the model are mine geometry (i.e. length and width of the panel), depth of cover, and geologic and geotechnical properties of overburden strata (i.e. percentage of hardrock, sandstone and limestone, and soft rock, shale within the overburden strata and Rock Quality Designation). The model calculates angle of draw for the site, expansion factor for each zone utilizing empirical relationships, maximum possible subsidence and plots the subsidence profile curve. The model is developed for a longwall excavation with unique characteristics of prediction of angle of draw and maximum possible subsidence for a given geologic and mining condition at any cross-section within the influence zone of subsidence.

Jan 1, 1986

By S. Kesler

Rössing Uranium Limited has operated since 1976 a large open pit uranium mine and extraction plant at a remote site in the Namib desert, South West Africa/Namibia. The geology (Berning, I., et al. Economy Geology) and the technical aspects concerning mining, grade control and metallurgy have previously been described (Rössing Uranium, Mining Magazin and Whyllie, R.J.M. "Rössing Uranium reaches rated production", World Mining). The improvement of leach &apos;extraction has been reported in 1984 (Kesler, S.B. et. al. "Uranium extraction at Rössing") and the installation of a central process control system has been described (Kesler, S.B. et al. "The introduction of a central process system at Rössing"). At the beginning of 1983 a decision was made to develop a computer system for metallurgical plant optimisation which included mass and volumetric balances, analytical assays for up to 5 chemical elements and the costs for the major consumables. Within 10 months this computer system was developed and implemented. A large number of test runs were made and computer studies were undertaken. The metallurgical division now has a scientific tool for production; planning for actual comparison with plant results and for strategic investigations and decision making.

Jan 1, 1986

By J. Brent Hiskey

INTRODUCTION Metal electrodeposition processes are of fundamental technological importance to a number of fields. Electrorefining, electrowinning, electroplating, and electrogalvanizing have all been the subject of intense study for over a century. More recently, electrochem- ical deposition has played a critical role in advances in microelectronics and lately has been an enabling technology for the production of certain nanostructured materials. Electrometallurgists have most frequently been concerned with the structure and morphology of massive deposits. For example, in metal recovery steps such as electrorefining and electrowinning, deposits demonstrating adherent coarse-grained characteristics are most desirable. In the case of electroplating, a bright fine-grained, tenacious and strongly adherent deposit is required. The fabrication of microelectronic devices and the production of nanoscale structures such as nanoparticles, nanowires, and nanorods requires a keen understanding of early stage deposition effects. The initial stages of metal deposition, usually referred to as electroclystallization, are fundamentally linked to nucleation and growth phenomena. Early stage deposits are typically very ordered. Whereas, bulk metal deposition structures are much more ran- dom. In both cases, the discharge of a metal ion at an electrified interface is represented by simple cathodic reduction as follows: [ ] Me(H2O)xn[ ] is a hydrated metal ion residing in the bulk solution and Me is the metal atom occupying a crystallographic lattice position. A similar reduction reaction can be

Jan 1, 2005

By MATTHEW HART, THOMAS BAMFORD, Kamran Esmaeili, MICHAL KOWALCZYK, FILIP MEDINAC

Improved haul road conditions can positively impact mine operations resulting in increased safety, productivity gains, increased tire life, and lower maintenance costs. For these reasons, a monitoring program is required to ensure the operational efficiency of the haul roads. Currently, at Bald Mountain mine, monthly site severity studies, ad hoc inspections by frontline supervisors, or operator feedback reporting is used to assess road conditions. These methods are subjective and provide low temporal resolution data. This case study presents novel unmanned aerial vehicle (UAV) technologies, applied on a critical section of haul road at Bald Mountain, to showcase the potential for monitoring haul roads. The results show that orthophotos and digital elevation models can be used to assess the road smoothness condition and to check the road design compliance. Moreover, the aerial mapping allows detection of surface water, rock spillage, and potholes on the road that can be quickly repaired/removed by the dedicated road maintenance team.

Sep 15, 2020

The surface of chalcopyrite was studied in situ in aqueous solution by an atomic force microscopy (AFM). The AFM images showed that some absorbate in patches was detected on the mineral surface, after the chalcopyrite sample was soaked in 5x10-4M potassium ethyl xanthate (KEX) solution at pH 11 for 10 minutes. These patches increased in size with time elapsing. At the same time, as shown by the obtained AFM force curves, the adhesion between the AFM tip and the substrate increased greatly due to the adsorption. Rinsing with ethanol removed the absorbate from the chalcopyrite surface, as well as the big adhesion observed in KEX solution.

Jan 1, 2010

By Kent S. Roessler

The Bureau of Mines is currently investigating the geophysical application of Tomography to monitor leachate during in-situ mining. Determining the location of the leachate is important for both economic and environmental reasons. By analyzing a sequence of tomographic images, we can determine where highly permeable/fractured regions are located and hence, major flow paths. Since BOMTOM (Bureau Of Mines TOMography - Tomographic Reconstruction Program), and BOMCRATR (Bureau Of Mines Curved RAy Tomography - Tomographic Reconstruction Program) are sensitive to user-selected ray path arrival times, we are also investigating the use of neural networks to automate the process of recognizing this feature. This paper presents a technique for detecting fracture zones and their orientations in a region between two boreholes, by using a motion analysis study of a sequence of tomographic images. It also addresses the need for an automated/unbiased method to pick crosshole seismic arrival times using a trained neural network. In exploration geophysics, the picking of first break arrivals represents a pattern recognition task. The neural net paradigm has proved to be a good method of solving this type of task. To pick the first arrival peak of a trace, the network is trained with a set of known (user selected) first arrival peaks by creating a binary image of a set of traces. Once trained, the neural net correctly picked first arrivals of the remaining traces in the set.

Jan 1, 1992

By Gordon R. Haworth

Conditions affecting minerals investments are continuing to change at an increasing rate, and in this paper we will attempt to predict the course of mine financing in the future. We will first review the situation historically and then examine the problems and constraints that are now making the financing task more difficult. Suggested solutions are discussed, and a new method of financing a group of mining projects is hypothesized.

Jan 1, 1977

By R. E. Gertsch

A mobile-modular carbon adsorption mill design and operation for small to medium sized heap leach precious metal mines is presented. In the mobile-modular strategy, charcoal columns with adsorbed metal move from small strategically located carbon adsorption loading stations to a central stripping facility and back. The design has many advantages: 1) It scales-up from pilot plant to full production. 2) It has low capital requirements. 3) Operational costs are competitive with other systems. 4) Mill production can react quickly to changes in ore grade or property area. 5) The solution circuits are simple and easy to maintain. 6) Charcoal damage is reduced.

Jan 1, 1993

By Wenhua Li, Tsuyoshi Adachi

Resource nationalism is essentially mandatory government intervention in natural resources businesses by political or economic means in order to benefit the nation and the people. It is attacking the mining industry more and more rampantly by all kinds of means since the twenty-first century. Poor countries who count on a resource-led economic growth usually find themselves trapped into “resource curse”. The harmfulness of resource nationalism for investors is that one event can quickly escalate and lead to a chain of events which make projects commercially unavailable. In spite of historical and theoretical social investigations in the causes of resource nationalism, rare studies engaged in quantification of dominant parameters of it. The objective of this study is to find significant factors that dominate the occurrence of resource nationalism for important metal and energy resources producing countries and quantify their marginal effects. The study applies binary choice logit model for panel data using pooled method. One feature of the research is that binary data set of occurrence of resource nationalism are sorted out by authors referencing U.S. Geological Survey’s reports. The results indicate that high-technology export (% manufactured export), ores and metals exports (% merchandise exports), rule of law (world governance indicator), trade (% GDP), and natural resource rent except forest (% GDP ) dominant the occurrence of resource nationalism for high and upper middle income group countries; government effectiveness (world governance indicator), policy perception index (The Fraser Institute), high-technology export (% manufactured export), and mineral rent (% GDP) dominant the occurrence of resource nationalism for lower middle and low income countries. According to our model, probability of occurrence of resource nationalism in 90 countries are predicted. Top 10 risky countries in 2012 are estimated to be North Korea, India, Honduras, Indonesia, Kazakhstan, Burkina Faso, Mongolia, Cuba, Bolivia, and Peru. The study is a primary trial of researching on resource nationalism and provides some insights for theoretical building and simulation on the issue.

Jan 1, 2017

By D. A. Swanson, G. Danziger, G. Savci, C. Barnes

Hydrologic assessments of existing and proposed waste rock stockpiles are typically required for application of operating and closure permits at mine sites. A hydrologic assessment should include an evaluation of climatic data and prediction of the net infiltration rate through the waste rock stockpile surface. In addition, hydrologic factors such as the time required to deplete available moisture storage in the stockpiles and the time required for potential seepage to migrate to the underlying aquifer should also be predicted.

Jan 1, 2000

By R. P. King

INTRODUCTION It is now 21 years since Wiegel and Li published their paper on a random version of Gaudin&apos;s model for the mineral liberation phenomenon (Wiegel and Li, 1967). This paper was to revitalise interest in North America in one of the most fascinating, difficult and important problems in the field of theoretical mineral processing. Gaudin had many years previously (Gaudin, 1939) already presented a penetrating analysis of the problem and Wiegel and Li based their analysis very closely on the Gaudin model but they realised that the indeterminate geometrical structure of mineralogical materials demanded that only probabilistic models could provide the necessary quantitative information when working with real materials. They proposed and solved a randomised version of the Gaudin model but retained the essential geometrical simplicity of cubic mineral grains and a cubic fracture pattern. Although their model met with some limited success it was to be superseded in due course. During the 1940&apos;s and 1950&apos;s the classical field of geometrical probability spawned the mathematical discipline of integral geometry and as early as 1965, Bodziony (1965, a,b) showed that the techniques of integral geometry could accommodate the problems associated with the indeterminate nature of the geometrical mineralogical structure, provided that these were couched in probabilistic terms. In particular he showed that the quantitative description of the comminution process and that of liberation could be decoupled with the resulting economy of effort. This idea has profoundly influenced the course of research in liberation theory and has greatly facilitated its application and the measurement of liberation in a practical way. Bodziony demonstrated also that any theory that required the specification of the mineral "grain

Jan 1, 1989

By L. A. Puchkov

The paper presents the outline of the results in the algorithms and software of the microprocessor-based system for the powerful drugline bucket automatic motion, as well as the technological process control and functional diagnostics of the electrical equipment. The system is, aimed at the increasing both the draglines&apos; working efficiency and the professional, competence of the operators. The excavator-dragline, equipped by the automatized operation, diagnostic and information processing system, possesses considerable technological: flexibility, which can widen therefore its field of application. The tasks of the dragline bucket motion optimal operation, programming of the excavation and overburden dumping processes, as well as the tasks of the control and the analysis of the technological parameters and the diagnostics of electrical equipment conditions, are defined in the paper. In our paper we present the results of these tasks being solved, providing the algorithms of the main mechanisms for the automatic operation for the swinging bucket controlled motion, the algorithms of the statistical analysis of the working efficiency parameters the algorithms of the diagnostics for electrical driving systems. The algorithms of the motion operation are constructed using the predicting dynamic models. The diagnostic algorithms at the normal working conditions form a number of algebraic invariants always equal to Ø with the accuracy up to when the electrical equipment is parametrically adequate. The algorithms of evaluating and analysis of the excavation efficiency make use of the direct measurement and analytical identification. The working condition and quality of the operation and control algorithms are investigated by simulation and natural testing. The results of the mathematical simulation of the bucket motion (with the 20 m3 capacity) of the excavator-dragline with the boom of 90 m in length are given in the paper.

Jan 1, 1992