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By Lawrence J. Froisland

To aid in minimizing adverse environmental impacts of mining and mineral processing, the Bureau of Mines studied changes in soil characteristics in topsoil stockpiled during mining operations. Topsoil stockpiles in arid areas of New Mexico, Utah, and Wyoming were sampled over a 1- to 8-yr period to determine any changes in physical, chemical, or biological parameters in the top 15 ft of soil. Parameters examined in this study included soil moisture, pH, electrical conductivity, and cation exchange capacity; total nitrogen, organic carbon, carbon to nitrogen ratio, extractable potassium, and soluble phosphorus levels in the soil; general levels of bacteria activity in the soil; and productivity of the soil as measured by shoot yield in growth tests. Data were analyzed by multiple linear regression to determine possible effects of stockpile age and depth. Bacteria population counts, used as an indicator of goner l bacterial activity, was the only parameter found to be significantly correlated with stockpile age and depth at more than one site. Bacterial activity increased with depth at the two sites where it was measured. Activity increased with age at one site and decreased with age at the second. Significant changes in soil pH, electrical conductivity, and moisture were significantly correlated with stockpile age and depth at single sites. This study did not show significant, consistent deterioration in soil characteristics or growth yield of topsoil stored in stockpiles.

Jan 1, 1987

Continued market pressure on the US coal industry was the overriding factor affecting developments in underground mining in 1986. An oversupply of coal in the spot market kept prices low throughout the year and caused a number of operations to close their doors. Operators stepped up their efforts to improve productivity at existing operations. They made technology advances and improved their relations with employees. A continuing market-related development during 1986 was the divesting of coal properties and operations by major oil companies, which were faced with economic pressures in both the oil and coal industries. Further increases in contract mining production resulted as some larger operators were unable to compete in a tough economic environment. Longwall mining is still seen by many as the technology that will provide the necessary productivity to remain cost-effective. But the number of active faces in the US declined in 1986, as reserves were depleted and economics forced some closures. At the first Longwall USA meeting in June, much attention was placed on improved technology, as electro-hydraulic controls for roof supports gained acceptance. Other recent developments include shearer initiation of roof supports, automatic horizon control for shearer drums, and collection and storage of machine data for predicting maintenance requirements. The government and academic communities continued their research on dust control at longwall faces. Jankowski, Kissel, and Daniel, (October 1986, Mining Engineering), gave an overview of progress in longwall dust control. And Mukherjee, Singh and Jayarman (November 1986, Mining Engineering), recommended design guidelines for improving water spray systems for dust control. Surface subsidence Increasing attention is being given to surface subsidence. This is primarily because of longwall mining and the Surface Mining Control and Reclamation Act. Improved methods of prediction of surface subsidence, especially computerized methods, are being continually developed. Mining engineering faculty at major universities such as Virginia are helping develop public policy and regulations concerning subsidence. As part of this effort, Unrug and Johnson identified major subsidence areas of Western Kentucky. Peng and Chen (February 1986, Mining Engineering), gave an overview of history and research of surface subsidence. And Elifrits and Aughenbaugh, (February 1986, Mining Engineering), discussed effects of moisture variations and overburden on subsidence. This research culminated in a Symposium on Surface Subsi¬dence at the SME 1986 Fall Meeting in St. Louis and the 2nd Workshop on Surface Subsidence at West Virginia University. Ground control in coal mining continued to be an item of major research interest. Some 30 papers were presented at the 5th International Conference on Ground Control in Mining at West Virginia University. And six sessions were related to coal mining at the 27th US Symposium on Rock Mechanics at the University of Alabama. At the 4th Annual Workshop, Generic Mineral Technology Center, Mine Systems Design and Ground Control emphasized efforts of the participating universities to improve ground control. Peng and Chiang summarized results of studying support capacity and roof behavior with longwall shield supports. And Unrug, Johnson, and Nandy analyzed the process of deterioration of shale roof in a case study of a room-and-pillar coal mine. The importance of geologic conditions in determining mining productivity is receiving increased attention in coal mine design in the US. Mullenex related, through case studies, the benefits to be derived through analyzing the depositional system of coalbeds as an integral part of mine design. Improved technology in this area was related by Lloyd, Semborski, and Stolarczyk. They discussed a case study of using radio imaging to indicate coal-seam discontinuities in advance of mining. Improved coal mining technology in general is being researched more heavily, to help improve US coal competitiveness. However, much of this research and development process has yet to be widely implemented. Equipment manufacturers are devoting more resources to development of continuous-haulage systems, mobile roof-supports, mine-monitoring systems, and predictive-maintenance systems using computers to extract machine data.

Jan 5, 1987

By L. Lehasa

The purpose of the project was to investigate the challenges faced by Khutala Colliery pertaining to underground road construction and maintenance. Furthermore the influence of these challenges on productivity and safety requirements were taken into consideration. The operating standards required for the construction and maintenance of the 2 seam road transport infrastructure was investigated, together with reasons why the standards of operating procedure are not met. The Code of Practice put in place by Khutala Colliery was used to view the standard operating procedures. Leading practices on underground road construction were researched. The project aims to discover the gaps that Khutala Colliery must bridge to implement enhanced practices with regards to underground road construction. During the period of study, observations were carried out to determine whether the road construction standards of operating procedure were being adhered to at all times for both road construction and road maintenance. Khutala Colliery has put in place a traffic management plan, which includes safety practices and work policies that must be adhered to while travelling on underground transport roads.

Jan 1, 2012

By M. G. Zabetakis

This publication describes an investigation conducted by the Federal Bureau of Mines regarding the cause of an explosion of a dephlegmator or fractionating column at the Cities Service Oil Company Refinery, Ponca City, Okla., January 22, 1959. The column was that used with the refinery's No.1 Dubbs Coker. The explosion caused the death of an employee of the refinery and resulted in extensive damage to the refinery and to nearby property. The Bureau's study of the explosion began January 26.

Jan 1, 1960

By Enrique Herrera, Manuel Munguía

La Fundición de cobre de Ilo de Southern Perú, arranco sus operaciones en 1960 con el proyecto Toquepala, en 1976 se expandió con el proyecto Cuajone, y en 1995 inició su proceso de modernización con la implementación de un convertidor Teniente y Plantas de Ácido Sulfúrico y de Oxígeno para reducir las emisiones gaseosas de dióxido de azufre al ambiente. En el 2007 se comisionó el proyecto de modernización de la Fundición de Ilo, con la implementación de un horno de fusión “Isasmelt” en reemplazo de los hornos reverbero y convertidor Teniente, y plantas adicionales de ácido sulfúrico y de oxígeno de mayor capacidad a fines de capturar el azufre de los concentrados por encima del 92%, y que se constituyó en el proyecto ambiental con la mayor inversión desarrollada en la historia del país.

Sep 30, 2022

By Jack Zhang, Chuck Edwards

"The versatility and specificity of rare earth elements (REEs) have led to their use in an ever increasing variety of applications in new technologies. Consequently, demand for REEs has increased significantly. However, to separate REEs safely and effectively is a complex and expensive process. While China has consistently invested in R&D of REE processing technologies, there have been only sporadic activities in REE mineral processing in North America in the past 20 years. This paper presents a review of REE mineral processing technology, providing an update on current capabilities in REE mineral processing. This paper reviews REE extraction from the major commercially valuable REE-bearing minerals such as bastnaesite, monazite, and xenotime, and also from the ion-absorption type of REE deposits. Currently, there are four major REE mining areas in China, one in the United Sates, and one in Australia. A review of the REE extraction processes in these major REE mining areas closes out the paper.INTRODUCTION The rare earth elements (REEs) include the 15 lanthanide elements, plus yttrium and scandium. The lanthanide elements are normally categorized in two groups: the light rare earth elements (LREEs), i.e. lanthanum through europium (atomic number (Z) = 57 through 63); and the heavy rare earth elements (HREEs), i.e. gadolinium through lutetium (Z = 64 through 71). Yttrium is usually grouped with the HREEs due to similarity in physical and chemical properties. Table 1 lists the REEs, atomic numbers, and abundances in earth’s crust (Taylor and McCleannan, 1985). Promethium is the rarest due to lack of stable isotopes. REEs with low atomic numbers are more abundant than those with high atomic numbers. More interesting is that the REEs with even atomic numbers are much more abundant than adjacent lanthanide elements with odd atomic numbers as shown in Table 1."

Jan 1, 2012

By N. E. Mkadmi

Backfilling increases the stability of underground stopes and may help reduce the environmental footprint from the mining operation. The barricades holding the backfill in place must be designed to prevent failure based on the total and effective stress states, which depend on fill properties, stope geometry, and filling rate. This paper presents results from a numerical study aimed at analyzing the stress states associated with the response of paste backfill following stope filling, with an emphasis on the short term behavior. The simulations illustrate how stresses evolve with backfill drainage and filling rate in a vertical stope.

May 1, 2011

By Frank Hirthammer

Productivity, customer relations, and effectiveness of work depend to an ever-increasing extent on a functioning logistics system tailored to the needs of the user. Of course, it is not possible to cover and explain all aspects of the logistical requirements of even a small part of an industry, in a single article. The article speaks specifically about the particularities and differences in the logistical requirements in the explosives sector. Starting with questions of safety, handling and quality up to the legal basis, there are special requirements regarding the logistics in the explosives sector. The results of innovative logistics solutions are presented using three examples from daily work practice.

Jan 1, 2019

By T. Dlokweni

Several Rockmass classification systems have been developed and used in Civil Engineering design and for underground mining operations. Some of these rockmass classification systems have been modified and used in the South African coal mining industry to quantify descriptive geological information for use in coal mine design and roof support selection. The Coal Mine Roof Rating (CMRR) system developed in the USA has been investigated in detail as part of the study. Advantages and disadvantages of the system have been identified by means of underground and surface borehole testing. Investigations into the rating systems in South Africa found that most of the rating systems used in the South African coal mining industry are for planning purposes, and are conducted on borehole cores. This study also highlighted that the rating systems being used are based on geology, and that the human factor plays a major role in the rating systems. To overcome these problems, all the classification systems used in South African coal mines have been benchmarked against impact splitting technique and documented. The best elements of these systems are combined into a new standard system that will be easily used by all mine geologists and rock mechanics engineers. Plusieurs systèmes de classification de la masse rocheuse ont été développés et utilisés dans le Génie Civil et pour les opérations d'exploitation minière souterraine. Certains de ces systèmes de classification de la masse rocheuse ont été modifiés et utilisés dans l'industrie minière sud-africaine pour quantifier l'information géologique descriptive utilisée dans la conception de mines de charbon et la sélection de soutènement du toit. Le système d'Evaluation de Toit de Mine de Charbon (CMRR) développé aux USA a été examiné en détail, comme part de l'étude présente. Tests en surface de trous de mine ont permis d'identifier les avantages et inconvénients du système. Une étude des systèmes d'évaluation en Afrique du Sud a révélé que la plupart des systèmes d'évaluation utilisés dans l'industrie minière sud-africaine sont utilisés pour la planification, et sont menés sur les carottes de trous de mine. L'étude présente a aussi souligné que les systèmes d'évaluation utilisés sont basés sur la géologie, et que le facteur humain joue un rôle majeur dans les systèmes d'évaluation. Pour surmonter ces problèmes, tous les systèmes de classification utilisés en Afrique du Sud ont été référencés en termes de technique de fissuration sur choc, et documentés. Les meilleurs éléments de ces systèmes sont combinés dans un nouveau système standard qui sera utilisé aisément par tous les géologues de mine et les ingénieurs miniers. Verschiedene Gesteinsmassenklassifikationssysteme wurden entwickelt und kamen im Design für Hoch- und Tiefbau und Untertageabbau zum Einsatz. Einige dieser Gesteinsmassen-klassifikationssysteme wurden modifiziert und sind in der südafrikanischen Kohlebergbauindustrie in Verwendung, um beschreibende geologische Informationen für die Anwendung im Design von Kohlebergwerken und der Firstabstützungsauswahl quantitativ zu beschreiben. Das in den USA entwickelte Kohlengrubenfirstbewertungssystem (CMRR) wurde als Teil der Studie im Detail untersucht. Vorteile und Nachteile des Systems sind mittels der Untergrund- und Oberflächenbohrlochprüfung gekennzeichnet worden. Prüfungen der Bewertungssysteme in Südafrika ergaben, daß die meisten Bewertungssysteme die in der südafrikanischen Kohlebergbauindustrie benutzt werden, Planungszwecken dienen und werden anhand von Bohrlochkernen durchgeführt. Diese Studie hob auch hervor, daß die verwendeten Bewertungssysteme auf Geologie basieren und daß der menschliche Faktor eine Hauptrolle in den Bewertungssystemen spielt. Um diese Probleme zu überwinden, wurden alle in südafrikanischen Kohlengruben benutzte Klassifizierungssysteme vergleichsweise in Hinblick auf Spaltschlagtechnik überprüft und dokumentiert. Die besten Elemente dieser Systeme werden in ein neues Standardsystem kombiniert, das leicht von allen Grubengeologen und von Gebirgsmechanikingenieuren benutzt werden kann.

Jan 1, 2003

By R. D. Begley

This paper will present detailed design drawings of a flexible single floor residential superstructure proposed for both longwall and room and pillar mining conditions. All efforts were made to provide an immediately available economical alter- native for future home builders on subsidence prone land. Based on this fact, a basement was not included in the design because additional costs and measures would be required to minimize cracking and leakage. A cost comparison with a traditional superstructure demonstrated that this would be a cost effective alternative. The criteria used to determine the design of the residential structure was as follows: 1. The appearance should not be different then a typical three bedroom residence; 2. Only commercially available devices and present architectural and engineering technology should be used to achieve the required "flexibility" of the super- structure; 3. The structure as completed would be capable of resisting a predetermined amount of vertical and horizontal movement; and 4. If the structure was to experience stresses beyond its capabilities, it could be easily removed from the foundation and releveled.

Jan 1, 1986

By J. J. Bouillon

"Located in the northwestern portion of the Abitibi greenstone belt, Les Mines Selbaie is a copper-zinc (silver and gold) producer. Felsic tuffs host three are zones. Composed of sulphide veins and breccias, they are not exhalative massive sulphide deposits, except, probably, for the massive pyrite (fragments and lenses) localized close to the top of the volcanic sequence.The total of all (mineable and mined) ore in the three zones presently outlined on the property, is of the order of 29.9 x 106 tonnes with average grade of 0.63 g/t Au, 37.02 g/t Ag, 1.21% Cu, 1.91% Zn.The ore reserve calculations and the daily production procedures are computerized to various degrees. The data handling process is highly computerized.Various geophysical methods are, and have in the past, been successfully used on the property. The ""mise-à-la-masse"" surveys were used to perform the geological interpretation of an underground deposit (A-2 zone). Presently the PULSE-EM surveys are performed in all surface and underground exploration drill holes."

Jan 1, 1990

By Abdurrahman Cetinbas

The effect of water infusion on the flow of methane and on the production of dust was investigated at an active face in the Pittsburgh coalbed. The average total flow of methane at the face decreased by approximately 79 percent, whereas the flow from the ribs increased about 24 percent after infusion. On the day after infusion, dust concentrations appear to have been reduced; however, the presence of large quantities of rock dust obscured the results on the following days.

Jan 1, 1972

By R. A. Welsh

The Bureau of Mines has developed a photoelectric concentrator apparatus which is capable of collecting incremental products from the discharge of wet concentrating tables. The instrument uses photoelectric cells as sensors to differentiate between two products which have differences in color or reflectivity. The photocells provide a signal that controls a mobile splitting device that separates the products. Tests conducted on a wet table demonstrated the ability of the apparatus to separate a product containing 81.5 percent pyrite from a lower-grade product containing only 68.8 percent pyrite. The photoelectric concentrator should have a broad application for collecting concentrates with visible color or reflectivity differences from wet concentrating tables.

Jan 1, 1972

By D. E. Pollock, Andrew B. Cecala

It has long been known that ventilation is a cost-effective method to lower respirable dust concentrations in all types of mining applications. The National Institute for Occupational Safety and Health has been working on a number of different research techniques that use ventilation as a critical component to lower respirable dust levels at surface and metal/nonmetal operations in the United States. This article presents five such research efforts. The first research area discusses how improving the ventilation flow patterns in an iron ore mill facility lowered respirable dust concentrations by 31 pct throughout the primary grinding area. The second research area examines how respirable dust levels were lowered at a dimensional stone shop by using air cleaning units suspended from the ceiling. A third area discusses how improvements in ventilation at underground limestone mines lowered respirable dust concentrations. The fourth area examines how improvements in dust filtration and pressurization systems significantly impacted the air quality in enclosed cabs of surface mining equipment. The last area presents a newly developed clothes cleaning technique. This technique uses an air spray manifold to blow dust from a worker’s clothing in an enclosed booth, which confines the dust for capture and removal by a baghouse dust collector. These research areas represent an array of different control technologies to lower respirable dust concentrations. Ventilation is an integral part of these control technologies.

Constraints on the mineral industry are best treated as issues that have to be understood and managed in partnership rather than in conflict with communities. TheZapopan development at Mt Todd in Australia and the Martha Hill development at Waihi in New Zealand are but two of many recent successful examples at the local level.   However, at the national level, the issues are more complex and more difficult to resolve because the most influential stakeholders are now the urban electorates and governments defer to their perceptions when making decisions and policy. In the developed countries, government policies for the development of mineral resources have been progressively eroded since the early 1970s. At the same time policies for the environment and for native land rights have generally been carried out in a way that has reduced access to minerals and increased the cost and risks for prospectors and developers (Hancock, 1995). Since the end of the Cold War, the lesser developed countries (LDCs) have introduced policies to attract investment in their mineral resources that remained undeveloped under previous unstable or hostile regimes. The increased attraction of these LDCs and the decreased attraction of the developed countries has caused many Australian and North American companies to outlay increasing proportions of their budgets and capital investment in the LDCs.   Significantly, LDC policies for environment protection do not discourage exploration and mine development, Surveys of the relative appeal of the LDCs and the traditional mining countries of the developed world, rate Chile, Argentina and Indonesia ahead of Australia and Canada in terms of risk, delays and ease of doing business (Australian Mining Monthly, February 1994).

Jan 1, 1995

By David Bendersky

This report covers a technical and economic investigation of old electrical power systems, equipment and practices being used in the metal/non-metal raining industry. The principal sources of information were the MSHA District offices, visits to representa¬tive mines and mills, equipment manufacturers and the literature. A list of 85 mines and mills, submitted by the MSHA Districts as candidates for this study, is given and their characteristics are analysed. The electrical power systems and practices at the 10 mines and 9 mills which were visited are described. The principal areas which do not conform to standard electrical practices are discussed with emphasis on the safety aspects of these practices. The costs to update electrical power systems and practices in metal/non-metal mines and mills are given. The principal findings of the study are summarized and recommendations are submitted.

Jan 1, 1980

By J. B. Czirr

MESA Corporation has completed a four-year program for the Bureau of Mines to develop a technique for measuring roof competence in underground coal mines. The preferred technique employs a tracer gas that is injected into a roof borehole drilled near the working face. The tracer gas performs the dual purpose of determining the pressure loss rate from the borehole and of marking the diffusion pattern of the the escaping gas. The primary detection technique relies upon observation of the rate of pressure drop in a hole drilled in the roof strata under test. If this measurement indicates a significant probability of roof collapse, the gas diffusion pattern is outlined with the Leak-gun tracer-gas detector. These two techniques provide a comprehensive method for predicting the relative probability of roof collapse in operating coal mines.

Jan 1, 1985

By Trevor Rangasamy

Technically based guidelines for managing rock related risks associated with strip mines in South African collieries are currently vague and are to a large extent based on experience and trial and error. To date, no mine specific or universal design charts exist within the South African industry. Quantification is done on a reactive basis i.e. following reported instabilities. The conditions under which, proactive tools to manage instabilities would be practically applicable are: The design of simple easy to use charts. Designing the charts for a target audience that is primarily production management. Well organized, logical set-up of the charts that will allow for easy future refinements. Allowing for variations in rock and soil properties within the charts that would account for colliery specific and region specific variability. The factors selected for in depth investigation that were deemed to have either individually or in combination, a primary influence on the stability of strip mines are (in no order of priority): Appropriate batter angles for ?soft? materials. Surcharge loading (spoils, dumps, topographical highs) on the highwall side. Influence of the thickness of stratification on stability. Influence of moisture content on stability. Influence of the changes to the coal seam dip angle on stability. Influence of persistent ?strip long axis? parallel faults/joints on stability. Spoil stability for variations in material type. This paper provides details of the work undertaken, using principally numerical modelling techniques, to produce design charts that will allow for proactive management of rock-related instabilities on strip mines.

Jan 1, 2008

By Paul Downing

Identity Theft Outline • What Are MY Chances??? • Types Of Thefts • Sources Of Theft Info • Stolen Identity vs. Background Checks • Information/Data Safeguards • Corporate Data Handling • Reclaiming Your Identity • Monitoring Your Identity

Jan 1, 2006

By L. F. Elkins

In 1946 Littlefield, Gray and Godbold published a thorough geologic description of the West Edmond Hunton Lime reservoir, located in Central Oklahoma, and discussion of its early performance.l They stressed implications of the nature of the reservoir rock on performance to be expected with production both by natural means and by pressure maintenance with gas injection. The essence of their analysis was that presence of an extensive interconnected system of fractures and solution channels constituting about 10 percent of the total reservoir void space in otherwise very low permeability reservoir rock would result in severe channeling of naturally encroaching water or injected gas through the fractures with little or no benefit to ultimate recovery of oil. Considerations were in progress to unitize the reservoir for pressure maintenance by gas injection. Some other engineers involved in the project had considerably different opinions at the time regarding continuity of fractures and regarding effects of such fractures on performance. The field was unitized Oct. 1, 1947. Subsequently, pilot gas injection tests were conducted in four areas of the field; large scale waterflooding was conducted in two parts of the field in the Bois d'Arc or Upper Hunton; and pilot waterflooding was conducted in the Chimney Hill or Lower Hunton. Full scale water-flooding is now in progress in the Chimney Hill section where it is oil productive. The primary purpose of this paper is to divine some of the secrets of this reservoir through analysis of all aspects of its performance, with the hope that it will be of help to engineers and operators in developing and operating other low permeability fractured reservoirs. In part, this considers variance of actual performance from some widely used conventional reservoir engineering assumptions. For brevity, other aspects of unit operation and its benefits to the owners are not discussed. Oil and Gas in Place For unit participation, net pay in the Bois #Arc defined by the gross SP anomaly on electric logs totalled 2,100,000 acre-ft in the 30,000-acre reservoir. Development of West Edmond predated modem logging techniques that now would be used to determine "net" or "productive" pay. In Fig. 1 this log pick is compared with detailed core analysis and core descripfion by Littlefield et a1.l for one well identified as A on the index map in Fig. 2. Not all of the gross Bois #Arc section had oil staining, but all cores with measureable intergranular permeability were stained. (The committee selection of the Bois d'Arc SP interval also includes the Frisco section as identified from cores by Littlefield.) The Bois d'Arc is oil productive throughout the entire 600-ft monoclinal accumulation from the eastern upstructure erosional pinchout to the west-side oil-water contact. (See Littlefield et al.l and McGee and Jenkins for geologic detail.)

Jan 1, 1970