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Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is in-tended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By R. B. Sudderth, A. Quiroz G., M. Torres M., C. Salgado Q., J. Fernández O., H. Bravo P., M. Torres B.

SNF FloMin, Inc. has introduced a complete line of extractants for recovery of various metals. Among them are the CuPRO MEX™ Brand of copper extractants that are based on the well- known 2- hydroxy 5-nonylsalicylaldoxime and 2-hydroxy acetophenoneoxime. This paper presents the laboratory and pilot plant trial results for SNF FloMin’s CuPRO MEX™ 3302 reagent, the equivalent to the wellknown ACORGA® M5640 extractant, and the composition of these reagents are described. Some examples of SNF FloMin’s CuPRO-Sim™ Advanced solvent extraction simulator are presented.

Jan 1, 2014

Surfaces forces have been measured between gold sphere and gold-coated glass plate in xanthate solutions using an atomic force microscope (AFM). The measurements conducted in potassium amyl xanthate (PAX) and potassium ethyl xanthate (KEX) solutions showed long-range hydrophobic forces, with the force curves showing no evidence for nanonubbles on the surface. The strongest hydrophobic force was measured at contact angle of 94° with a decay length of 23 nm. The hydrophobic force became weaker at higher concentrations and after a long immersion time, which may be attributed to the xanthate species adsorbed on top of the first mono layer. The hydrophobic force became stronger when the residual xanthate solution is displaced by pure water, indicating that hydrophobic force becomes the strongest in pure water.

Jan 1, 2009

By A. M. Nordale

Let us first trace a line, mentally, across Alaska and Yukon, starting at a point in the west slightly south of the delta of the Yukon river and from there continuing eastward, loosely following the 63rd parallel of latitude until we have passed beyond the eastern border of Yukon. We will make two pronounced digressions southward to include the greater parts of the Iditarod and Tanana River valleys. That visualized line roughly defines the southern boundary of permafrost. North of it lies a vast region, fully three-fourths of the area of the two territories, which includes Seward peninsula, the great Yukon River basin, and the tractless wastes of the Arctic. During some frigorific cycle in the distant geological past, the ground there was frozen to a depth of many hundreds of feet. How deep the frost actually penetrated is not known, but it has been found to exceed three hundred feet in many places. Nature afterwards provided a perfect insulating cover in the form of heavy moss and dense grass, which has protected the ground from the heat of the sun's rays during the intervening ages. This frozen condition has always been accepted as something indigenous to the North and little thought was given to -it until recently, when the United States Government and, I believe, the Canadian Government, began extensive studies of it, particularly in respect to its effect and bearing on the development of the great oilfields of the Arctic. Within this large region and but a short distance south of the Arctic circle are the three principal producing placer gold fields in the sub-arctic, whose hubs centre at Nome and Fairbanks in Alaska and at Dawson in Yukon Territory. The geological structure and history of the gold-bearing deposits of Dawson and Fairbanks are very similar and probably closely related. They are typical placer deposits produced by stream action during periods of erosion and inundation and subsequently covered with a thick layer of fine, powdery silt mixed with decayed vegetation which, locally, is termed 'muck'. The depth of muck varies from less than 10 to more than 250 feet, with the greater depth near the lateral edges of the valleys. The gravel underlying it is medium in size, well rounded, and composed mostly of quartz and schist. The proportion of sand or fines is approximately 40 per cent. No large boulders and little clay are found, for those districts, as well as that of Nome, have not been subjected to glaciation. The most common bed-rock found is either decomposed or hard schist, but infrequently it is slate, quartz, diorite, or a porphyry. The vertical concentration of the gold is invariably on bed-rock and in the lower few feet of gravel which overlie it. The horizontal concentration or paystreak is roughly parallel to the trend of the valley but does not ordinarily coincide with the course of the present stream. The width of the paystreak usually expands from a few feet at the head of a creek to several hundred feet near its mouth.

Jan 1, 1947

By J. Racinais, P. Vincent

"In September 2011, Menard Oceania (MO) was engaged by Mac Mahon John Holland Joint Venture (MJHJV) to provide ground improvement solution for the $34bn Ichthys LNG development. With close to 400,000m2 of mangrove swampland set to be reclaimed and improved, this project was a great opportunity to showcase the technical, commercial and environmental benefits that Dynamic Replacement (DR) ground Improvement technique can provide. The ground improvement works involved complete design and construction for the Ichthys LNG site located at Blaydin Point on a low lying peninsula in Darwin Harbour. Dynamic replacement and stone columns technique were selected to treat intertidal mangrove mud to achieve required bearing strength, stability and limit settlement to an acceptable levels. The site is underlain by a 3m to 5m thick layer of highly organic mangrove muds with very soft shear strength ranging from 0kPa to 12kPa at depth. The site is exposed to daily sea water level tidal variations of up to 8m, which created significant constructability constraints and slope instability risks. This paper presents the design philosophy, the process involved in the selection of the construction methods, the site constraints encountered during the works and a review of the results achieved, quality control and post constructions performance.INTRODUCTIONInpex Browse, Ltd (Inpex) and its partner Total are developing the Ichthys gas field to pipe gas to onshore facilities at Blaydin Point on the south side of East Arm in Darwin Harbour. The proposed LNG plant consists of gas receiving facilities, 2 x 4.2Mtpa nominal capacity LNG trains, LPG and condensate production facilities, product storage and export facilities, a module offload facility (MOF), a flare pad (FP) and associated off plot facilities.The proposed on-shore facilities are located on extremely soft intertidal mangrove muds, therefore an appropriate ground improvement was required to achieve required strength and stability of site works and limit long term settlement to an acceptable level.Various ground improvement techniques were studied to select the most suitable for the ground conditions and site constraints encountered at the Blaydin point site. Dynamic replacement technique was selected for onshore section to improve soft mangrove mud to depths of 5.5m and Stone Columns (SC) technique was selected for MOF off-shore section to improve intertidal deposits to a depth of 2.5m.This paper presents DR design and construction works performed between December 2012 and August 2013 at Flare Pad Area."

Jan 1, 1900

By M. Perolo, A. Contini, E. Ramelli, G. Borgonovo, L. Locatelli

This paper presents the ground settlement monitoring system used during the construction of two tunnels bored by two EPB TBMs, beneath the existing and active railway embankment in Bologna (Italy). The tunnels run close to large buildings and beneath bridges and other infrastructure. Data are collected from remote total stations and from electro levels installed directly on the railway tracks. The automated monitoring system acquires and analyses data then sounds an alarm in the event that there is a problem. Alarms are sent out in case of excessive tilt or settlement. Data is provided through a dedicated web application for multiple-party access, to gather, manage and store monitoring data.

Jan 1, 2007

By S. Mudau, P. Mohasoa, M. J. Cole

Derelict and ownerless (D&O) mines in South Africa have been an ongoing concern for over a decade. While some progress has been made to rehabilitate D&O asbestos sites, significant work remains, exacerbated by the growth in illegal mining. There are concerns regarding the accuracy and transparency of the D&O database, lack of oversight, and constrained funding, and the government is increasingly looking to the private sector to fund rehabilitation. Given these challenges, a new, sustainable approach to D&O sites in South Africa is needed to bring clarity and transparency to the process, recognise responsibilities and promote partnerships, and explore economic opportunities at D&O sites to reduce the financial liability and respond to the growing demand for critical minerals. This article has three components: i) reviews of international D&O good practices; ii) it analyses South Africa’s current approach and the D&O sites; and iii) proposes a D&O framework that addresses data, risk ratings, responsibilities and rehabilitation, economic opportunities, and stakeholder engagement. The study finds that the majority of the 6,100 so-called abandoned D&O mines are quarries and mine site features, 16% are operational, at least 11% have owners, and only 752 (12%) require rehabilitation. The framework aims to bring clarity and fairness to decision-making and to assign risk and responsibility for rehabilitation and seeks to incorporate economic opportunities to reduce the financial burden of rehabilitation, create jobs for local communities, and respond to the growing demand for critical minerals for the clean energy transition.

Apr 25, 2025

By J. E. Gebhardt

Progress is reported on capturing the effects of gangue chemistry in the context of a comprehensive stockpile heap leach model for leaching copper sulfide ores, employing leading edge computational fluid dynamics (CFD) technology. The stockpile is a complex multi-phase process, comprising of a solid porous media, with complex fluid flow, gas and liquid phases, competing solid-liquid reactions, dissolution of minerals and transport through the heap. The model accounts for many of the challenging physical and chemical features of the heap, including transport and reactions kinetics for the important copper and iron sulfide minerals, ferrous oxidation, bacterial effects, thermal energy, acid and sulfate balances. In this contribution, the model has been extended to incorporate dissolution of various species from gangue reactions and precipitation of hydronium and potassium jarosite, ferric hydroxide, alunite, and gypsum. The effect of aeration on the simulation of a copper sulfide heap leach is provided as an example.

Sep 1, 2012

By Roberto Bria

El presente texto describe el módulo prefabricado para las salidas de emergencia. En este sentido, el sistema modular prefabricado busca facilitar y agilizar la instalación de salidas de emergencia desde el interior de mina hasta superficie mediante RB entubados con módulos armados fuera de la Unidad Minera, mejorando la seguridad mediante un sistema confiable de fácil colocación, reutilizable, y de gran robustez. De ese modo cumplir con el objetivo primordial de las salidas de emergencia de 200 m hasta la superficie, en terrenos de calidad de roca regular a mala.

Sep 21, 2013

By P. L. Weston

The Bureau of Mines used high-temperature reduction roasting, magnetic separation, acid-leaching, and autoclave precipitation processes to recover iron and manganese from brown Cuyana range ores of Minnesota. Wet magnetic separation concentrated over 90 percent of the iron in 3 of 4 ores as high grade products analyzing 74 to 85 percent iron, 2.5 to 6 percent manganese, and 3 to 10 percent SiO2. The nonmagnetic fractions were leached with dilute sulfuric acid extracting 83 to 93 percent of the contained manganese and small amounts of iron. The leach solutions contained Mn-to-Fe and Mn-to-SiO2 ratios favorable enough for possible consumption in metallurgical mane operations. Exceptionally pure Mn solutions were achieved by pressure precipitation of the remaining iron in an autoclave followed by lime precipitation of silica and alumina.

Jan 1, 1966

By M. Z. Emad, M. U. Khan, A. ur Rehman

The use of stemming plugs in surface blasting is gaining popularity because of the environmental, technical, and economic advantages. Although previous studies have established the operational effectiveness of different types of stemming plugs, evaluations of the economic and ergonomic impacts are lacking, thereby hindering their application in many mining operations. Consequently, a significant proportion of mining operations end up performing less efficient blasts. We evaluated the effectiveness of three types of stemming plugs by conducting multiple full-scale production blasts. The results show that stemming plugs reduce the need for secondary blasting and increase blast performance. An economicanalysis showed that the incorporation of stemming plugs can reduce blasting costs significantly.

Jul 1, 2021

By J. R. Ross

A reconnaissance for sources of scandium and a metallurgical investigation of recovery methods for byproduct scandium from uranium mill solutions were conducted by the Bureau of Mines. The work on scandium was undertaken to obtain information on domestic resources and to explore and develop recovery procedures in consonance with the Bureau's long-range program for conservation and wise utilization of mineral resources. The element scandium is widely distributed in the earth's crust in trace amounts, but it seldom occurs as an important constituent in any mineral. An exception is thortveitite, (Sc,Y)2 Si207) a rare mineral that contains various amounts of scandium and yttrium and may contain up to 42 percent scandium oxide (SC203). Knowledge of the chemistry of scandium has expanded rapidly in recent years (1, 4, 9)4 but only fragmentary information is available about the metal because it is still largely a laboratory curiosity without established uses (2, 3). A recent study shows some of the physical proper-ties of the metal are (1) density of 3.05 grams per cubic centimeter) (2) melting point of 1,540° C, (3) hexagonal close-packed structure) (4) hardness of about 50 Brinell (500-kilogram load), and (5) an alloy behavior similar to yttrium and rare-earth metals (2). The price of $2,850 a pound for scandium oxide of 99.9 percent purity and $2,700 a pound for oxide of 99 percent purity reflects the scarcity and complex chemistry of the element.

Jan 1, 1962

Develop tools that mine personnel can use to comply with 30 CFR,Part 47. Background The new MSHA rule, 30 CFR, Part 47 (also known as the HazCom rule), requires all mines to develop a written program to track hazardous chemicals at their sites. More specifically, the rule requires that mines list all chemicals and determine which are hazardous; develop a written Hazard Communication Program; label all containers used to store hazardous chemicals; obtain or develop Material Safety Data Sheets (MSDS) for all chemicals stored or produced; provide miners with training in working around hazardous chemicals; and make information about hazardous chemicals available to all workers. All mines with six or more employees must have complied with the new rule by September 23, 2002, and mines with five or fewer employees will have to be in compliance by March 21, 2003.

Mar 1, 2003

By William H. Hamilton

This report describes the results and conclusions of the development and evaluation of a unique concept for a lightweight air powered drill tool for probe drilling in anthracite mines. A concept model of the lightweight air powered tool was constructed and evaluation testing conducted at the Kocher Coal Company Porter Tunnel Mine. The unique anchoring method proved to be extremely satisfactory and the overall light-weight air powered drill tool concept proved feasible. Based on the results of the concept model testing, two prototype production units were designed and manufactured. These prototype units proved to meet all of their design requirements of lightweight, portability, drilling controllability, structural integrity and miner acceptance. The need for a better bit and drill steel system, however, became evident during the testing program and recommendations are made for further investigation and development of a bit and drill steel system suitable for this application.

Jan 1, 1979

By Efrén Peña Pino

El presente texto señala la aplicación del sistema SAP en la minería subterránea de Minsur. Este sistema operativo maneja las propiedades y procesos de la Sociedad Minsur, el cual cuenta con tres Centros, dos de los cuales son operativos (San Rafael y Pisco) al margen de la central de administración (Lima) y permite la planificación de todos los recursos de la empresa de manera integral, evitando imprevistos y una mejora de decisiones.

Jul 31, 2003

By Gustavo Henrique Bolognesi Donato

Ensaios de curva R (J vs. ?a – crescimento dúctil de defeitos) e de propagação de trincas por fadiga (da/dN vs. ?K) são balizados por normas como a ASTM E1820, ISO 12135 e E647, as quais exigem dimensões mínimas para as amostras C(T) ou SE(B) a fim de garantir condições SSY e portanto a validade de K e J. Entretanto, tais exigências usualmente conduzem a dimensões expressivas que dificultam a retirada de amostras de chapas finas ou mesmo de muitas estruturas reais. Como alternativa, estudos de Koppenhoefer e Dodds (1998) e mais recentemente de Shin e Lin (2012) indicaram a possibilidade de uso de amostras em miniatura (inclusive Charpy contendo pré-trinca) para determinação de curvas R e da/dN vs. ?K. As grandes questões são a viabilidade de ensaio de amostras pequenas com repetibilidade e a adequada avaliação dos limites de validade das forças motrizes nestas geometrias, a fim de garantir condições de similitude. Como um passo nesta direção, este trabalho investiga o potencial de amostras Charpy pré-trincadas (10x10x70mm) na determinação de curvas R e da/dN vs. ?K. Inicialmente, ensaios de ambos os tipos foram realizados em amostras de um aço estrutural ferrítico empregando uma máquina universal MTS 810. Apesar das dimensões reduzidas dos espécimes, os ensaios se mostraram viáveis e apresentaram boa repetibilidade e estabilidade dos resultados experimentais. Ainda, boas práticas de ensaio puderam ser estabelecidas para suportar os trabalhos futuros com tais geometrias.

Aug 8, 2018

By Grant R. Brown

The report provides guidance for determining those environmental impacts associated with the surface mining of steeply pitching coal seams. In addition to the environmental impacts, four additional issues are addressed, namely (1) Time and motion studies of those coal mining systems employed in mining seams which pitch in excess of 250, (2) Assessment of those mining techniques, (3) Development of rationale for the mining methods employed, (4) Identification of the reclamation practices and determine whether these practices were in compliance with appropriate Federal and State regulations. Five surface mines located in three geologically distinct basins of the United States were analyzed during the period of August through November 1979. The three basins include the Hanna Basin of Wyoming, the North Park Basin of Colorado and the Southern Anthracite Field of Pennsylvania.

Jan 1, 1980

By M. Magnelöv, Du Sichen, U. Sjöström

An experimental study has been performed to investigate the behaviour and separation of inclusions at the interface between steel and slag. The study has been limited to liquid inclusions because they can be a potential problem in transient situations such as ladle changes in continuous casting of steel. Model experiments with water and silicon oils have been carried out to study the kinetics of separation of simulated inclusions at an interface. The properties of the inclusions and the slags have been varied by using different oils with different viscosities, densities and surface tensions. The effect of temperature of the liquids has also been examined. Measurements of the terminal velocity, rest time and the behaviour of the liquid inclusions at the interface have been recorded using a video camera. It has been found that the inclusions reach their terminal velocity early in the vessel and the experimental velocities differ somewhat from the values evaluated using ?intermediate law?. The results from the experiments have shown that the size of the inclusions has no appreciable influence on the rest time. Droplets of AK50 oil have been found to have considerably long rest time. A water film surrounding the droplet has been expected to be the main reason for the long rest time. The present study has also shown that the viscosity of the oil has certain effect on the rest time, but only to some extent, since viscosity has double functions. A higher viscosity provides higher resistance to the droplet entering the oil phase leading to longer rest time and at the same time damps the lateral movement of the droplet along the interface, leading to easier stabilization and shorter rest time. On the other hand, a high viscosity of the oil phase results in slow dissolution process. It has been concluded that a meaningful model of inclusion separation at the metal-slag interface must take the interfacial phenomena into consideration. Keywords: Inclusions, terminal velocity, rest time, dissolution.

Jan 1, 2004

By Michael S. Moats, Scott C. Campin, J. Brent Hiskey

"Electrochemical techniques are a valuable means of analyzing the passivation of commercial copper anodes. Electrochemical impedance spectroscopy (EIS) provides information concerning transport and reaction phenomena occurring at an electrode surface. Commercial. copper anodes of varying compositions have been examined using EIS. Experiments were conducted in a flat cell with an electrolyte of 40 gil Cu2 + and 160 gil H2S04 maintained at 65 DC. Impedance spectra were obtained at the potentials characteristic of the open circuit voltage and passive region for each anode. The spectra of the passivating films exhibited a flattened resistive/capacitive loop at middle to high frequencies and an inductive loop at low frequencies. An equivalent· circuit utilizing an inductor-resistor series in parallel with the double layer capacitance and charge transfer resistance was adequate in modeling the impedance data. The influence of anodes impurities on the components of the equivalent circuit is discussed and correlated with a hi-layer passivation model.IntroductionPassivation of copper anodes during industrial electrorefining has received considerable attention in the past few decades. Great strides have been made in understanding the roles of anode impurities [1-25], electrolysis parameters [20,26], and electrolyte chemistries [20,26]. Even so, passivation still occurs even in the most modem of refineries. The exact cause of passivation is not fully understood. It is known that the anode surface becomes covered by a passivating film. This film has been proposed to be CuS04'&5H20, Cu20, or mixed oxides. The localized concentrations of Ft, Cu+, and Cu2+ ions determines which phase is more favorable. The presence of these ions is controlled by the reaction kinetics and diffusion of species through the slimes layer.Reaction kinetics between Cu, Cu +, and Cu2+ are based on the dissolution mechanism of copper. There exists four different models to describe the dissolution of pure copper. The classical model of Mattsson and Bockris [27] involves two single electron transfers with the cuprous-cupric reaction being the rate detennining step. More recently, Wong, Collier, and MacFarlane [28] used ac impedance to elucidate a more complex mechanism involving the affect of pH and anions. Their findings indicate that the formation of cuprous ions in solution, Cu(I)so~ is favored over Cu(1I) ions adsorbed to the electrode surface in the presence of sulfate and as pH increases from pH 1 to pH 5."

Jan 1, 1997

By M. Ghoreychi, X. Daupley

ABSTRACT: The paper is devoted to two major aspects related to the abandonment of salt mines: 1)- Long-term risk associated with the mechanical instability of surface and its consequences for public security and properties. 2)- Long term dissolution and transport of salt resulting from its communication with groundwater. Basic characteristic features of salt deposits and mining methods are presented through the studies already undertaken on French mines. This analysis allows to identify major hazards encountered in different traditional salt mines and solution-mining cavities. In particular, the role of overburden (presence and thickness of salt layer in exploitation roof, presence of clayey rocks or hard rocks e.g. dolomite or anhydrite), presence of water-bearing strata and possibly natural brine levels, discontinuities, etc. are discussed. In the second part, the main features of mechanical behaviour of salt (creep, damage) as well as transfer processes of this material are presented. The influence of these aspects on the long term evolution of abandoned salt mines is then analysed. KEY WORDS: exploitation, abandonment, salt, mechanical, stability, transport, solution, brine. ZUSAMMENFASSUNG: Der Artikel bezieht sich auf zwei bedeutende Aspekte beim Salzabbau: 1)-Das langsfristige Risiko zur Bodenoberflächeunbeständigkeit und sein Einfluss über Mensch= und Gütersicherheit. 2)-Die langsfristige Auflösung und Beförderung des Salz beruhen sich auf Studien über französiche Bergbauen. Diese Analyse emöglicht es, die bedeutendesten Risiken in verschiedenen Salzgruben zu identifizieren, bzw. Traditionellen oder durch Auflösung abgebauten. Insbesondere wird die Rolle des Deckgebirges (Vorhandensein und Dicke von Salzschicht am Dach des Grube, Beisein von Tanlager oder hartem Gestein wie Bitterkalk oder Anhydrid), Beisein von wasserhaltigem Boden und/oder gesalzenen Wasserflächen, Trennflächen, usw… erötert. Im zweiten Teil werden die haupsächlichen Eigenschaften des Salzverhaltens (Kriechen und Beschädigung) beschrieben. Ihr Einfluss über das Verhalten von stillgelegten Bergwerken lässt sich analysieren. SCHLÜSSELWÖRTER: Bergwerksbetrieb, Stilllegung, Mechanik, Beständigkeit, Ausbreitung, Aussolung, Solewasser. RESUME: L’article est consacré à deux aspects majeurs liés à l’abandon d’exploitations de sel : 1)- Le risque d’une instabilité à long terme de la surface du sol et son incidence sur la sécurité des personnes et des biens. 2)- La dissolution à long terme et le transport de sel sous l’effet d’une communication avec des eaux souterraines. Les principales caractéristiques de gisements et d’exploitations de sel sont présentées en s’appuyant sur les études antérieures réalisées sur les exploitations en France. Cette analyse permet d’identifier les risques majeurs rencontrés dans différentes mines de sel traditionnelles ou exploitées par dissolution. En particulier, le rôle du recouvrement (présence et épaisseur d’un banc de sel au toit de l’exploitation, présence de terrains argileux ou de roches dures telles que la dolomie ou de l’anhydrite), présence de terrains aquifères ou de nappes salées éventuelles, discontinuités, etc. sont discutées. Dans la deuxième partie, les principaux traits du comportement mécanique du sel (fluage, endommagement) ainsi que les processus de transport de ce matériau sont présentés. L’influence de ces aspects sur le comportement à long terme d’exploitations abandonnées de sel est ensuite analysée. MOTS CLES: exploitation, abandon, mécanique, sel, stabilité, transport, dissolution, saumure.

Jan 1, 2003