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By Casandra Gamez Gonzales, Angelina Anani

Copper, the newest addition to the critical mineral list, is an essential metal whose electrical and heat conductive properties label it as a vital mineral for the creation of renewable energy sources and the reduction of Greenhouse Gases (GHGs). However, despite copper’s leading role in the transition to sustainable energy and mining practices, the mining industry has faced various battles in the extraction of this valuable material. These challenges are based on mining’s negative reputation and extensive impact on the environment, nearby communities, and human rights. To ensure the survival of mining in the future and achieve mineral demands, an emerging topic that has initiated the revolution of the traditional sector into a more environment- friendly and transparent industry, is Environmental, Social, and corporate Governance (ESG). ESG has motivated companies to seek growth opportunities and standardize risk accountability and transparency based on its collective framework that creates, modifies, and implements local, national, and international standards. These standards focus on improving environmental, social, and governance issues faced by companies and their projects. ESG has served as a guideline that investors utilize to assess companies and promote sustainability, responsibility, and disclosure to create positive and balanced relationships with stakeholders and the environment. Nonetheless, concerns have been rising which state that ESG is negatively impacting the mining industry by targeting what fuels the industry and world: ore deposits and their resources. Therefore, this research focused on answering the following research questions: what are the impacts of ESG on the copper supply chain and how will stricter ESG standards affect future copper production?

Feb 1, 2024

By James Paone

Land utilized by the mining industry from 1930 through 1971 amounted to 3.65 million acres, or 0.16 percent of the land mass in the United States. Land reclaimed during the same period was 1.46 million acres, or 40 percent of the land utilized. This report includes data on land use for wastes from underground and surface mining, for wastes from mill operations, and on subsidence. Data on land use and reclamation were obtained from operating companies, mining organizations, appropriate State agencies, and others concerned with such activities. The 10 leading States in land used for mining in 1971 were, in decreasing order, Kentucky, Pennsylvania, Arizona, Ohio, California, Florida, West Virginia, Illinois, Minnesota, and Indiana. Mineral commodities accounting for a major portion of land use are, in decreasing order, bituminous coal, sand and gravel, stone, copper, phosphate rock, iron ore, and clay; for coal, these commodities are produced principally by surface mining operations. Reclamation over the 42-year period was largely on lands utilized for surface mining of bituminous coal. New surface mining methods, particularly for coal, incorporate some form of land restoration.

Jan 1, 1974

By P. Kawulka

An integrated pilot plant for the development of the S-C Copper Process was constructed at Fort Saskatchewan in 1975 and operated in 1976. The pilot plant was designed to treat 9 tonnes per day of a pyritic copper concentrate. A demonstration run conducted during the last quarter of 1976 averaged 90% on-stream time, and confirmed that the process is operable as a stable and integrated unit. The paper describes the parameters and equipment developed for thermal activation of chalcopyrite copper concentrates to make them amenable for the dissolution of iron and zinc, and their subsequent separation and recovery. The resulting high-grade copper sulphide was leached with return electrolyte and oxygen to extract 98.5% of the copper into solution. The copper was electrowon at 650 amps per square metre from purified solution, to produce cathodes analyzing 0.1 ppm Se, 0.1 ppm Bi, 4 ppm Pb and 10 ppm S. The electrical conductivity was >101% lACS and the spring elongation value [ ]350 mm. Elemental sulphur and gangue are removed from leach residues to make a concentrate containing over 95% of the silver and gold and most of the unleached copper. Conventional construction materials such as stainless steel, titanium, Hastelloy, acid brick, rubber and plastics performed well. The containment inherent in hydrometallurgy provided high standards of hygiene and safety.

Jan 1, 1978

"INTRODUCTION AND ACKNOWLEDGMENTSAt the request of the lessees, the Pearl tract was examined in February 1946, by Otto Ruhl, an engineer of the Bureau of Mines. From the evidence of old drill logs and from the few available records of mining operations on the Pearl and the adjoining Trussel (Big Tom) tract, it appeared that a relatively small churn-drilling program might develop enough lead-since ore to justify resumption of mining. In March 1946, funds were allotted for churn drilling, and the work was begun the following month. Ten holes totaling 1,933 feet were completed before the close of the project in August 1946. The work was under the general supervision of C. H. Johnson, chief, Rolla Division, Mining Branch, and under the direct supervision of the Bureau project engineers. 3/In its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to our national security and economy, It is the,of the Bureau to publish the facts development by each project as soon as possible after its conclusion. The Mining Branch, Lowell B. Moon, chief, makes preliminary examinations and conducts investigation of mineral deposits. The Metallurgical Branch, O. C. Ralston, chief, participates in this program by making beneficiation tests and analyses. In the present project, no metallurgical tests were made, and for the sake of speed the samples taken were analyzed by a local commercial assayer. 4/"

Jul 1, 1947

By T. Matlou, S. Myendeki, V. Midzi, T. Zulu, H. Mabotja, T. Mulabisana, B. S. Zulu, L. Hlatshwayo, T. Makhateng

The Council for Geoscience (CGS) performed a macroseismic investigation following the occurrence of an earthquake in the Boksburg area on 11 June 2023. The event had a magnitude of ML 4.4 and a focal mechanism that showed the event as having strike-slip motion along a northwest-southeast oriented fault. The event resulted in aftershocks, some of which occurred away from the causative fault in the east in an area without a mapped fault. However, the cluster of past events in that area suggests that there is an active fault. Due to the size of the main earthquake, a macroseismic survey was conducted to determine its impact on the community in the region. Analysis of observed data obtained from questionnaires resulted in the creation of 153 intensity data points. Their distribution showed high intensity values close to the earthquake source area. However, the investigation highlighted a number of anomalies, such as the higher than expected intensity values observed far from the event epicentre. It could be that these anomalies are caused by site conditions, for example, amplification of ground motion due to thick soil layers.

Jan 12, 2025

A Joint Venture between Hope Bay Gold Corporation and Miramar Mining Corporation recently acquired the Hope Bay project in Nunavut, which represents the first discovery of a major new Archean greenstone gold belt in Canada since the discovery of Hemlo in 1982 and the Yellowknife belt in 1938. Located some 685 km North of Yellowknife, the Hope Bay Belt is geologically comparable to the other major gold producing regions of Canada. The initial discovery of gold mineralization in 1992 led BHP to acquire virtually all of the Hope Bay belt. Over the subsequent 6 years, BHP expended C$85 million on exploration, including 180,000 meters of drilling, 2.3km of underground workings and a 27,000 tonne bulk sample, as well as extensive environmental and economic studies. Hope Bay Gold and Miramar acquired the Hope Bay property in December 1999 for a cost of C$27 million, considerably less than the C$85 million spent by BHP in exploring the property. They both hold 50% of the project, and share expenses equally. Hope Bay Gold is the manager of all exploration phases and Miramar will manage feasibility, construction and operations. The Hope Bay Joint Venture controls 1,117 sq. km., covering virtually the entire 80 km long Hope Bay and adjacent Elu greenstone belts. We believe that Hope Bay is one of the best-undeveloped gold projects in Canada. Work to date has defined a global resource in excess of three million ounces of gold in three principal deposits, each of which is open to extension along strike and to depth. A C$17 million work program for year 2000 focused on advancing a significant portion of the gold resource to a measured and indicated category. This will provide the basis for initiation of a feasibility study in 2001. The 2000 drill program was one of the largest undertaken in Canada last year, and is a clear indication of our confidence that Hope Bay will develop into a major gold producing district. The majority of the potential mineable areas known to date lie within 350m of surface and would be accessed through a combination of open pit and declines. Currently, development of a 1,800 to 2,000 tpd gold mine producing in excess of 300,000 ounces of gold per year at cash costs below $US200 per ounce is envisioned. In addition, the exploration potential on the 80 km gold belt at Hope Bay is clearly tremendous.

May 1, 2001

By Gregory B. Beacher

Analyses have been performed on geotechnical properties of copper, uranium and phosphate (gypsum) tailings materials, with the intent of identifying typical measures of variability within and among sites, and of characterizing such variability for use in reliability modeling of tailings embankments. In all, data from approximately 41 sites were analysed. Fairly consistent results were obtained for within site variabilities. However no one probabilistic model was found to be applicable to all sites. The distributional forms for most of the data sets are regular, and tend toward Normality when spatial trends are removed. At many of the sites sufficient in situ data were available to allow estimates of vertical autocorrelation distances and measurement noise. Available data indicate that variability in pore pressures may have a more important effect than strength property variation. A major problem in interpreting available strength property data results from the unknown drainage conditions during testing.

Jan 1, 1983

By Mohan K. Wali

Soil and vegetation development were studied on abandoned mine sites near Velva in Ward County, North Dakota. The sites studied were 1, 7, 17, 30 and 45 years old since abandonment; unmined sites were also studied to provide measures of comparison. Species diversity was the highest at unmined sites (114) and lowest at the I year old site (26); sites 7, 17,30 and 45 years old had 37, 52, 43 and 68 species, respectively. Stand ordination revealed that site ages were the most important in influencing species diversity and composition. Stand-environ-mental complex ordinations encompassing 53 variables showed topographic variables to be the most important followed by site ages. Rates of nutrient accumulations were as follows: organic carbon 13.1 g m-2 yr-1; nitrogen 2.5 g m-2 yr-1; phosphorus 0.01 g m-2 yr-1; potassium 0.49 g m-2 yr-1. Carbon-nitrogen ratios showed the widest range for 1 year old sites (5-40) but 70 percent of the 45 year old sites showed values below 15 which were com-parable to the unmined mixed grass prairie sites. Species distributional diagrams are provided to show their habitat preferences which may be helpful in formulating species prescriptions for revegetation.

Jan 1, 1982

By B. J. Moore

This publication contains routine analyses and related source data for 278 natural gas samples from 14 States. All of the samples were collected during calendar year 1973 as part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 Fifteen previous publications have presented the results of 10,201 gas analyses prior to 1973. The first three, Bulletins 486,4 576,6 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960. The other 12 publications,7 which were issued as information circulars, supplement the three bulletins and contain 4,983 analyses of samples collected since 1960. This publication is the 13th publication supplementing the three bulletins.

Jan 1, 1974

By Sidney Katell

This report covers the period January 1963 through December 1963; it is a continuation of the series that began with the publication of Information Circular 7516 in October 1949. Also, it is the fifth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load involved in the preparation shared equally. The abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related subjects, are from the following sources:

Jan 1, 1964

By Sidney Katell

This report covers the period January 1963 through December 1963; it is a continuation of the series that began with the publication of Information Circular 7516 in October 1949. Also, it is the fifth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engineers. The agreement provides for the publication of an annual cost bibliography with the work load involved in the preparation shared equally. The abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related subjects, are from the following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal--Today and Tomorrow. 9. Coal Utilization. 3/ 10. Cost Engineering. 11. Hydrocarbon Processing and Petroleum Refiner. 12. Industrial and Engineering Chemistry. 13. Nucleonics. 14. Oil and Gas Journal. 15. Petroleum Management. 16. World Oil.

Jan 1, 1964

By Juan M. Pestana, Jeremy M. Gasser, Cuneyt Gokmen, Paul J. Sabatini, William Tanner, Daniel J. Woeste

An access pathway and working platform were designed and constructed for equipment access for a Deep Soil Mixing (DSM) pilot study over a coal combustion residual (CCR) surface impoundment (SI). The DSM pilot study was conducted to evaluate slurry mix designs and construction techniques for installing DSM columns up to 95 feet deep. Two-dimensional (2-D) limit equilibrium and 2-D finite element analyses were used to evaluate multiple failure mechanisms including: (i) bearing capacity, (ii) punching shear of mixed ground and underlying CCR, (iii) effect of fluidized DSM columns on working platform stability, and (iv) liquefaction. The analysis results were used to design ground improvement required to increase bearing capacity and stability of the CCR under the proposed equipment access route. A long-reach excavator was used to perform shallow bucket mixing and walk onto the CCR SI atop previously mixed cells following a minimum cure time and acceptance of quality control test results. Prior to mobilizing the DSM rig, a static load test was conducted to evaluate performance of the working platform. Both the access pathway and working platform demonstrated acceptable performance under the design loads during the DSM pilot study. This case study emphasizes the economic and safety benefits that can be realized by appropriately designing critical temporary work items such as access pathways and working platforms in difficult ground conditions. INTRODUCTION A Deep Soil Mixing (DSM) pilot study was conducted at a coal combustion residual (CCR) surface impoundment (SI) to evaluate slurry mix designs and construction techniques for closure design of the SI (Site). Sluicing of CCR at the facility ceased and closure will be initiated based on requirements in the final United States Environmental Protection Agency (USEPA) Rule for Disposal of Coal Combustion Residuals from Electric Utilities, 40 CFR 257, effective October 19, 2015. The proposed closure approach involves constructing a DSM containment structure (DSM Wall) to separate the SI into two areas: (i) a closure by removal area; and (ii) a consolidate and cap-in-place area. The proposed DSM Wall would retain the CCR within the consolidated closure footprint and provide a barrier between the two areas of the SI. The predominant CCR in the SI where the pilot study was conducted were fly ash and bottom ash. CCR materials in surface impoundments are generally soft and saturated as a result of being sluiced into place and can present stability and safety challenges when performing earthwork activities.

Jan 1, 2019

By Thomas M. Barczak

Wood cribs are used extensively by the mining industry to stabilize mine openings. While the cost per crib is relatively low, their extensive use can result in annual mine costs of over $1 million. In an effort to improve the utilization of these supports and to reduce ground control hazards, the U.S. Bureau of Mines has developed engineering methods to assist mine operators in wood-crib design and employment. Design and employment criteria are established based on the strength, stiffness, and stability of the crib structure in relation to the load conditions imposed by the mine environment. Models have been developed based on full-scale tests in the USBM's Mine Roof Simulator that compute the capacity of wood cribs of various configurations and material constructions as a function of displacement of the crib structure due to roof-and-floor convergence. These models permit the comparison of the loading characteristics and costs of employment of different crib designs, and in conjunction with roof behavior models, provide a means to determine the optimum design and employment strategy.

Jan 1, 1993

By C. Steve Albrecht

The primary objective of this study is to "evaluate the influences of different equipment systems on prime farmland subsoil compaction due to surface mining in the Midwest." The study is centered on four mine sites each utilizing a different combination of equipment for soil removal and replacement. Subsoil compaction is the primary focus of this research effort. Primarily owing to physical location, it is difficult to alleviate the increased compaction directly below the topsoil in reclaimed soils. Different equipment combinations cause varied effects when soils are replaced during surface mining activities. By collecting field data within a statistical framework, the effects of different equipment combinations on subsoil compaction can be evaluated and conclusions drawn. This research effort evaluates a comparison of natural and replaced soils by moist bulk density data. This comparison centers on changes in bulk density and texture to a depth of 48 inches. For each study site a complete case study is provided for use in data correlation and interpretation. Basis for this research effort centers on four (4) major experiment designs: o Comparison of soil bulk density values for three distinct equipment systems evaluated on the same general soil types (i.e. scrapers, bucket-wheel excavators and end-dump haulback); o Evaluation of the effects of soil replacement in repeated lifts using scrapers; o Presentation of bulk density values representing soil compaction for four (4) equipment systems (i.e. bucket-wheel excavators, draglines, scrapers and end-dump haul back) on four separate mine sites in the midwest; o A prediction analysis model is developed for subsoil bulk density following reclamation based on equipment characteristics and a statistical evaluation of texture. The soil data base of information includes data from the 1982 Bureau of Mines study entitled, "Impact of Surface Mining on Soil Compaction in the Midwest" as well as data from this research project. The final report is synthesized through an analysis of field data, statistical analysis and literature review. The final report focuses on the interpretation of results for practical application by government and industry.

Jan 1, 1984

By Rafael Lopes

Os aços utilizados na fabricação do vergalhão CA50 conforme norma NBR7480 são usados em todo o Brasil. A grande aplicação deste tipo de produto é na indústria de construção civil em função de sua excelente resistência mecânica e soldabilidade. Estas características permitem o avanço na construção de grandes empreendimentos. Em 2009, a Votorantim Siderurgia na sua Unidade de Resende, iniciou a produção do vergalhão CA50 em escala, procurando aumentar a sua participação no mercado de construção civil. Foi identificada uma grande variação nos resultados de limite de escoamento nos ensaios de liberação de produto realizados a partir de amostras coletadas no início das bobinas de vergalhão CA50. Em função disso, foi feita a caracterização do limite de escoamento e microestrutura ao longo da bobina onde foi identificado que esta grande variação do limite de escoamento estava presente em toda a bobina. Desta forma, foram definidos os principais parâmetros do processo de laminação que poderiam estar influenciando na variação do limite de escoamento e realizado um planejamento de experimentos (DOE) para o vergalhão CA50 16,0mm, aço 1030, onde foram identificadas que a combinação da melhor distribuição da vazão de água nas Caixas d’água utilizadas no tratamento térmico de têmpera e auto revenido, somada à maior distribuição das espiras no pelo Formador e à ventilação do Stelmor no mínimo apresentaram resultados de limite de escoamento acima do mínimo especificado pela norma NBR 7480 com menor desvio padrão quando comparado aos parâmetros de processo que eram utilizados na produção do vergalhão CA50.

Oct 30, 2017

By LeRoy D. Loy

The disposal of excess overburden from surface mining can be accomplished by use of a reclamation technique entitled head-of-hollow or valley fill. This report attempts to assess current valley fill regulations and practices, identifies inherent benefits and deficiencies, and develops concepts to enhance fill technology.

Jan 1, 1978

By E. Motica

Ores containing uranium and vanadium minerals have been mined from the Salt Wash Member of the Morrison Formation from many localities in the Colorado Plateau region since about 1900. The most productive deposits are in a relatively small area in Southwestern Colorado referred to as the Uravan mineral belt. The mineral belt is a narrow elongate area in which uranium-vanadium deposits in the Salt Wash have a closer spacing, larger size, and higher grade than those in adjoining areas. Pre- 1948 ore production from the mineral belt was 655,000 tons averaging 1.91 per cent V2O5 and 0.28 per cent U3O8. Production during the 1948 to 1964 period was 7,900,000 tons of ore averaging 1.46 per cent V2O5 and 0.27 per cent U3O8. The ore deposits occur principally in the uppermost sandstone unit of the Salt Wash. This unit consists of sandstone lenses formed by a system of aggrading braided streams flowing in an easterly direction generally normal to the mineral belt. These lenses, referred to as channels, are as much as one mile in width and average about 50 feet in thickness and can be traced for several miles along their courses. Areas favorable for one deposits are recognized principally by the following criteria: ( 1) a host sandstone thickness of over 30 feet, (2) the presence of carbonaceous material in the host sandstone, and ( 3) gray mudstones and clays associated with the ore-bearing sandstone. The ore minerals are believed to have been precipitated from laterally migrating solutions; there is no apparent genetic relationship between ore deposits and tectonic structural features. Exploratory and development drilling from the surface is conducted in three phases: first, wide-spaced drilling to find and outline favorable channels; second, moderate-spaced drilling in favorable ground to locate ore deposits; and third, close-spaced drilling to block-out ore. Long-hole drilling from underground stations is used to find and delineate extensions of ore bodies being mined. Due to intense production since 1948 from shallow deposits, best potential for new deposits exists in areas where the ore-bearing unit is 600 to 800 feet deep.

Jan 1, 1968

By Isadora Almeida Rosa

Aços baixo-carbono com microestruturas ferrítico-bainíticos, bifásico, ou multifásicos têm características apreciáveis para a indústria automobilística, pois, combinam resistência, ductilidade e conformabilidade, permitindo produzir chapas mais finas resultando na redução do peso. Com o intuito de avaliar as características mecânicas e microestruturais obtidas através da variação da temperatura de bobinamento, desenvolveu-se um estudo a partir de um aço baixo carbono com microadição de molibdênio e nióbio, onde se verificou a possibilidade de produzir um aço dual phase na forma de chapas laminadas a quente, em escala industrial. Pode-se verificar que para menores temperaturas de bobinamento, obteve-se melhor desempenho quanto ao aumento da resistência mecânica e garantia de uma alta ductilidade vinculados a um refino expressivo no tamanho de grão da matriz ferrítica em conjunto com uma segunda fase com evidência de ilhas de martensita.

Aug 16, 2017

Real gross national product increased at a larger-than- expected annual rate of 8.3 percent in the first quarter of 1984, with both consumption and investment spending increasing significantly in real terms (table 1). Residential and nonresidential fixed investment increased at annual rates of 25.7 and 14.6 percent during the first quarter of 1984, and investment in nonresidential structures, which declined in 1983, also increased during the first quarter of 1984, nearly attaining its 1982 level. The annual level of personal savings increased $27.7 billion, while the personal savings rate (the ratio of personal savings to disposable income) increased to 5.8 percent during the first quarter. The increase in the personal savings rate comes as welcome news to analysts concerned over the flow of loanable funds to the private sector and the impact on interest rates in 1984 of increased private and Government demands. U.S. Minerals Industry Performance A major upswing in the performance of the metal mining sector occurred during the first quarter of 1984, with production increasing almost 11.2 percent from January to March, The recovery of the metal sector is also reflected in the performance of primary metal industry profits, which were positive during fourth quarter 1983 following seven consecutive quarterly losses (table 1). Two thousand nine hundred more metal mining production workers were employed in February 1984 than in February 1983.

Jan 1, 1984

By Joshua C. Adams, Les Chernauskas, Edward L. Hajduk

"Drilled shafts are increasingly being used to support bridge and building foundations. Because these foundations usually carry very high design loads and often serve as non-redundant, single load carrying units, these foundation systems need a high level of quality control (QC) and quality assurance (QA) during construction. One such method for providing QC/QA is crosshole sonic logging (CSL) testing, in which ultrasonic signals sent across the drilled shaft concrete assess concrete quality.CSL testing is an effective tool to evaluate the integrity of the in-place drilled shaft concrete. While typically used to evaluate drilled shaft concrete after construction, CSL testing can also be used to evaluate drilled shaft repairs. This application can be difficult, given the variability of repair methods and material properties. CSL testing can also be adversely affected by the condition of the concrete/access tube bond, leading to false anomaly detection and/or inability to evaluate concrete integrity effectively. This phenomenon, called access tube debonding, is often located in upper portions of the drilled shafts where large changes in groundwater occur, such as within tidal zones.Two case histories showcase innovative uses of CSL testing to deal with consistent access tube debonding and to evaluate drilled shaft repairs.CSL OverviewCSL testing involves placing ultrasonic transmitters and receivers in access tubes installed in the drilled shafts prior to concrete placement. Concrete quality is assessed by examining the First Arrival Time (FAT) and relative energy of the signal sent between the transducers. If the distance between the access tubes is known, an apparent signal velocity (i.e., wave speed of the ultrasonic signal through the concrete) can also be determined and used to assess concrete quality.Common CSL testing practice consists of simultaneously raising the ultrasonic transmitter and receiver and recording the ultrasonic signals with respect to depth. This results in a 2D examination of the"

Jan 1, 2009