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By B. Jones, W. Zhang, Q. Li

Rare earth elements (REEs) are critical materials to the United States due to the imbalance between their supply and demand. Considerable research and development efforts have been devoted on REE recovery from coal refuse using inorganic acids as lixiviants, however, the cost of inorganic acids is normally high, and the environmental friendliness is low. As alternatives to inorganic acids, organic acids of small molecules such as lactic acid and succinic acid have been used as efficient and green lixiviants for metal extraction. In addition to the supply risk of REEs, food waste generation and disposal is another emerging and critical issue since nearly one-third of the edible food is lost or wasted each year. In this research, organic acids were microbially converted from food waste and used as lixiviants to leach REEs from density fractions of an Illinois Basin coal. Experimental results indicate that REE recovery increases of up to 15 absolute percentage points were obtained using organic acids relative to inorganic acids. The conversion of food waste into value-added, renewable, and environment-friendly chemicals promotes the economic viability of REE recovery from coal refuse.

Mar 2, 2022

By E. Giama, A. Macridis, A. M. Papadopoulos

ISO 14031 is an international standard that describes a process for measuring environmental performance evaluation by setting quantitative indicators and providing a structured approach for organizations to follow, independent of location, size, complexity and type of activity. It is not a standard for certification as ISO 14001 is, but it fits into the ISO 14000 series of standards and is intended to assist organizations to apply environmental management systems and obtain environmental evaluation. This case study’s main objective is to identify the interaction between ISO 14031 and ISO 14040-42. ISO 14040-42 is referring to Life Cycle Analysis (LCA) methodology. More specific, LCA is applied (based on the ISO 14040-42 standard) to stone wool’s production, the market dominating thermal insulation material, produced by bauxite and amphibolite. LCA is used as a decision making tool for the development of environmental indicators (based on ISO 14031 guidelines) and for environmental performance evaluation.

Jan 1, 2005

By CEM SENSOGUT, OZER OREN, YASAR KASAP

The mining sector, which is important in terms of raw-material and energy supply, is seen as a sector with high number of fatal accidents compared to other sectors. In this century of heightened occupational health and safety awareness, it is important to review past accident statistics and analyze current deficiencies using the information in inventory. Although there are many studies assessing occupational accidents occurring in the mining sector, there are few studies using the nonparametric linear programming method. There are many input and output parameters related to occupational health and safety. Nonparametric linear programming method has been found to be useful because it provides simultaneous evaluation of these input-output parameters, does not require functional form in the analyses and provides guidance on the improvement needed by the related parameter. However, this method analyzes data using a single period of time and does not take into account any changes in efficiency over time. In the literature, there is no study in which the change of occupational accidents occurring in mining and even other sectors over time is examined and the Malmquist total factor productivity index (MPI) is used. Within the scope of the present study, the aim was to examine the change of occupational accidents occurring in Western Lignite Corp. in Turkey, where underground and surface production methods are applied, between 2005 and 2018. It is the first time MPI is used to examine the change of occupational accidents over time. The DEAP 2.1 computer program written by Coelli [1] was used in the solution of the models [2].

In conjunction with steady increases in production levels, longwall operators have applied greater quantities of ventilating air and spray water in an effort to control respirable dust and/or methane. Air velocities greater than 7.6 m/s (1,500 )fpm) have been measured on longwall faces. Operators have expressed concern over the potential entrainment of respirable dust at these high velocities. The greatest likelihood for entraining dust into the high-velocity airstream may occur as shields are advanced, allowing relatively dry particles to fall from the shield canopy directly into the airstream. Laboratory tests to simulate dust liberation during shield movement were conducted at the Pittsburgh Research Laboratory of NIOSH at velocities ranging from 2.0 to 8.2 m/s (400 to 1,600 fpm). Airborne dust samples were obtained with personal impactors to quantify the size distribution and concentration of the dust entrained at the various air velocities. Statistically significant increases in both total and respirable dust concentrations were measured as test air velocities were increased.

Jan 1, 2002

By M. Moagabo

CO2 emissions from carbonate laden reclaimed mine spoil has been shown to pose a hazard to residents in homes built on or adjacent to such land. The objective of this project was to develop a soil CO2 flux survey protocol for assessing reclaimed mine land. The research involved CO2 chamber accumulation flux surveys; stable carbon isotope ratio analysis; statistical hypothesis testing to examine correlation between CO2 flux and soil temperature and moisture as well as spatial dependence; and geostatistics to map CO2 and delineate high flux zones. Soil temperature was observed to have a positive correlation with fluxes while soil moisture was observed to be negatively correlated. Spatial dependence of CO2 fluxes on reclaimed mine land was observed on one of the two study sites. The research suggests that macro-porosity and gas permeability may be important factors that explain CO2 migration in mine spoil. A flux survey protocol has been developed, based on these results, for reclaimed mine lands. The work demonstrates the capability of geostatistical methods to delineate high flux fields. Further research will be required to determine suitable thresholds for such analysis.

Jan 1, 2012

For the past two years, Cliffs Natural Resources in Minnesota has tried an experiment: it has staffed a booth at the Iron Range Earth Fest. ?It was a little unusual for a mining company to participate in an event that centers around preserving the Earth?s resources,? said Julie Lucas, environmental manager at Hibbing Taconite Company. ?But Cliffs is a sustainable company and we want to take every opportunity to share information about our practices. We found the response to be overwhelmingly positive.? Cliffs? outreach effort is just one of the surprising ways mining companies across Minnesota are reaching out to stakeholders and finding success. The 85th annual SME Minnesota Section Meeting (73rd Annual University of Minnesota Mining Symposium), held April 17-18 in Duluth, MN, demonstrated the Minnesota mining community?s commitment to connection and collaboration, and how that approach is bringing success.

Jan 1, 2012

By S. K. Kawatra, S. J. Ripke

During 1998, 62 million tons of iron ore pellets valued at $1.7 billion were shipped from U.S. mines. These pellets are the primary source for domestic iron and steel production. During pelletization, binders are required to improve the green strength of the pellets. Each year, bentonite binder costs a typical plant from $3 million to $5 million. Reducing the bentonite dosage has the advantages of significant cost savings while producing higher quality, lower silica pellets. The authors have recently identified a new and important bentonite binding mechanism, the fiber theory. During this study, procedures were developed that took advantage of the ability of bentonite to form fibers, and resulted in a dramatic decrease in the necessary bentonite dosage. Acceptable quality pellets were produced with the bentonite dosages reduced in half from 14 lb/lt (0.66%) to 7 lb/lt (0.33%).

Jan 1, 2001

By S. K. Mishra, S. B. Kanungo

Because conventional (physical) methods of ore dressing are not suitable for reducing the phosphorus contents of high-phosphorous manganese ores from Andhra Pradesh (AP) and the adjoining area in southern Orissa, India, the adoption of chemical methods becomes imperative. An attempt was therefore made to reduce the phosphorus content of partially beneficiated manganese ores from AP by roasting with sodium carbonate and then leaching with hot water. However, due to the higher phosphorus contents of the manganese ores from Nishikhal mines in southern Orissa, and because of their apparent resistance to dephosphorization by roasting with Na2CO3 alone, a mixture of Na2CO3 and NaCl was found to be necessary to reduce the phosphorus content to below 0.15%. Free-energy calculations at 700°C and above indicated that Na2CO3 (or Na2O as the active component) is a more active reagent than NaCl. Various process parameters, such as the temperature and time of roasting, the amount of sodium carbonate and the temperature and time of leaching, were studied to arrive at the optimum conditions for dephosphorization.

Jan 1, 2000

By F. C. Townsend

Centrifugal modeling was used to evaluate reclamation schemes of; (a) flocculants, (b) sand/clay mixes, (c) flocculants/sand addition and (d) capping with sand or sand/clay mix. Results suggest the hierarchy of effectiveness is: (d) capping, (b) s/c mixes, (c) flocculants/sand addition and (a) flocculants. Comparisions between currently used large strain consolidation computer programs reveal no difference between piecewise linear or finite strain calculations. Correlations between numerical and centrifugal model predictions reveal excellent agreement on magnitudes; however, rate predictions require improvement in laboratory input data and centrifugal scaling relationships.

Jan 1, 1987

By Guocheng Pan

This paper presents-:a new multivariate mineral resource estimation model, referred to as the Related. Information (RI). Instead of relating a mineral resource descriptor directly to a set of geological variables, the RI model relates the mineral resource descriptor to a synthesized information measure RI, which is created from a set of geological variables. All of the variables are transformed into binary characteristics. This model comprises two stages of estimation: estimation of a synthesized information measure and estimation of mineral resources. The information carried by a variable is classified into three types: mineralized-barren information, mineral resource variation information, and variable-controlling information. The synthesized information measure is defined as the product of the three types of information and the responses of binary geologic characteristics. The RI model is demonstrated on the pegmatitic Nb+Ta deposits in China.

Jan 1, 1992

By V. Dezelic, D. B. Apel

This paper describes the results of laboratory and field experiments conducted to determine the applicability of Ground Penetrating Radar (GPR) for the assessment of the strata thickness and for the identification of separation between bedding planes in stratified rocks. The knowledge about the extent of such separation in the roof layers and information about roof lithology can be used to determine the roof support requirements for underground mines where stratified rocks are present. The laboratory and field experiments were conducted at the Rock Mechanics Laboratory and the Experimental Mine at the University of Missouri-Rolla. The 1.5 GHz high resolution, shallow depth GPR antenna was used for all of the experiments.

Jan 1, 2004

By Nelson Alonso Portal Ravichaua, Melissa Esther Mendoza Tirado, Raúl Arévalo Saavedra

This study analyzes the implementation of an integrated strategy for environmental education and community awareness in Cajamarca, Peru—an Andean region affected by climate variability and the public perception of miningrelated water shortages. In collaboration with the Interactive Water and Earth Museum and the Newmont ALAC Foundation, three-month campaigns were conducted in schools and local communities. Key topics included the water cycle, climate change, and water availability, linked to urban infrastructure projects that improved flow rates through strategically located tubular wells tapping underground aquifers. The initiative addressed the challenge of communication in a context where mining is often blamed for scarcity, fostering scientific understanding of contributing factors. The study highlights how science-based outreach and institutional collaboration can strengthen resilience and promote sustainable water stewardship in mining-influenced regions.

Feb 22, 2026

The Canadian mining industry is one of the strongest in the world. Not only does the country produce a sizable amount of minerals and metals, Canada plays host to hundreds of global mining companies, large and small. The country, for the most part, recognizes the importance of natural resource development, particularly mining, to its economic well being. Like any country, though, there are federal and provincial regulations on the books that the industry takes issue with. But there are also certain economic incentive programs in place to encourage exploration and mine investment. And, unlike the industry and the United States government, the Canadian government and mining industry appear to have a reasonable working relationship.

Jan 4, 2010

By José Ricardo Lopes, Alaor Coelho, Marco Gomes, Alfredo Dacio Moraes Filho, Akira Koshima

"Very low strength alluvial peat soil was found under two old drainage galleries with just 4.3m cover above a twin tunnel due to be excavated by a 10.6m diameter EPB Shield for São Paulo Metro’s Line 5. Alignment was required to strengthen soil and drive the TBM through safely without damaging the galleries. The design included six levels of self-drilling forepoling with lengths up to 15m, using 100 mm-diameter SCH160 metal tubing and injection bulbs with estimated 0.20m diameter. Two 6m-diameter circular shafts were excavated along the shield-tunnel axis, one each side of the galleries, and forepoling fanned out under gallery foundations. Given the peculiar soil and confined working space, more data were needed for correct drilling geometry. Ground mass treatment was successfully designed and executed and galleries were fitted with instruments to enable the shield’s advance. DESCRIPTION São Paulo Metro’s Line 5 (aka Lilas or purple line) is adding 11 stations along an 11.5km extension and three EPB TBMs are being used simultaneously (three EPBs on the same job for the first time in Brazil) with one of them excavating a large cross- section twin-track tunnel. Currently the largest work-in-progress for São Paulo Metro, this project has been divided into seven lots and 9km are already operational. This study refers to Lot 6 where the 10.6m - diameter EPB shield excavation is only 4.3m below two galleries running through a 10m layer of very soft peat soil in an old alluvial riverside region ringed by major roads. After recent filling, this area (Parque das Bicicletas) was used for recreation, although temporarily it has become a construction site. This paper will describe the original basic design; precautions in relation to the structural condition of the galleries after inspection; the problem of absence of data for their foundations; subsoil bore tests; evolution of the engineering design for the galleries and conditioning and reinforcing the soft soil below the galleries to ensure safe advance of the EPB shield, and finally the successful outcome of the solution used."

Jan 1, 2016

By Patrick G. Hill

This paper discusses safety protocols for Kiewit Construction’s Level (3) project. The Level (3) project will cover a majority of the United States, and literally thousands of site operations will be conducted over a wide geographic area under challenging conditions; rivers, roads and other features, both from the surface and often for great and from boring pits. Developing a progressive safety plan for fast-track linear projects using micro-trenching and directional boring techniques requires significant investigation, planning and evaluation. Safety protocols for inner duct installation, to be accomplished with extensive use of directional boring is an essential part of the safety plan for network construction. In light of the shear volume of work and the geographical extent of this project, in many different types of terrain, this paper will identify approaches to safety applicable to fast-track linear projects, whether surface or underground-based. Establishing a safety culture into all aspects of this operation will improve productivity and cut unnecessary expenses. This new approach involves continual improvement and evaluation of hazard analyses, inspection procedures and training.

Jan 1, 1999

By E. J. Wasp

The transportation of mine products incurs a cost which can have a significant bearing on the competitive position of the manufactured product. Clearly, the engineer who is responsible for selecting a mode of transport must base his decision, at least in large measure, on economic comparisons. And today, the engineer usually finds that he has to choose between several modes, including slurry pipelines. For the purpose of an initial economic screening, it is not necessary to go deeply into the technical details of a slurry system. What is usually needed, however, is a method with which the engineer can make a quick economic assessment to determine whether a slurry pipeline should be included in the detailed final analysis. This paper presents a rapid method for making such a preliminary appraisal. Experience with commercial slurry pipeline systems in several countries and with a variety of solid materials has shown that if several assumptions pertaining to critical design variables are made, it is possible to roughly estimate the transportation cost of a slurry system on the basis of only three factors: the specific gravity of the solid material, the length of the system, and the quantity of slurry to be pumped each year. It is assumed that conditions pertaining to field construction, corrosion inhibition, and the like, will be favorable. This assumption is critical because any factor which analysis shows to be particularly unfavorable will raise the total transportation cost estimate which this paper establishes. If the engineer employs this estimating procedure and decides that the use of a slurry pipeline is economically unattractive, his chances of being wrong are small. Conversely, if his quick appraisal indicates that the use of a slurry system is economically favorable, the engineer is justified in committing the time and money needed to make a more detailed investigation of the slurry pipeline potential.

Jan 1, 1969

By F. G. Crack

This paper is based on the philosophy that the management structure and strategy required for mine construction and development projects are different from that required for routine production and maintenance operations in a mine. The purpose of this paper is to present an integrated approach to the management of mine development projects. This paper highlights the four major aspects of the integrated approach. First, a brief review of the various types of contract documents is provided. Second, the management organization of a project is discussed. Third, the project manager's role and the field supervisor's responsibility are briefly outlined. Finally, the use of scientific techniques for planning, scheduling, executing, and controlling projects is presented. Each of these aspects is important; however, each by itself cannot be expected to bring order or unifying impact to the complexities involved in overall project management. When all these aspects are coordinated, the result will be a sore successful project from conception to completion.

Jan 1, 1982

By Robert Marks, Enrico Dal Negro, Richard Schulkins

"In July 2012 construction started on the Grosvenor project, a five million tonne per annum underground longwall mine planned for Moranbah in Central Queensland. Grosvenor is located immediately to the south of the existing Moranbah North mine which has been in operation since 1998. EPBM technology is being used for the first time in Australia for excavation of a coal drift. The TBM was used to build two drifts on the project, one for the coal conveyor which will transport to surface, and another for people and equipment to access the underground once the mine’s operational (as shown in figure 1). The TBM will pass beneath a steel archway roof that has been installed at the drift’s entrance and begin drilling into the ground to build the seven metre diameter tunnel, descending at an angle of one in eight until it reaches the depth of the coal seam approximately 160 metres below.INTRODUCTION AND BACKGROUND The first TBM used in a coal mine was in 1962, a Wohlmyer, in Westerholt, Germany. A further 75 km of tunnels were excavated in coalmines within Germany between 1971 to 1983. This paper will review the Grosvenor Mine project (Grosvenor) owned by Anglo American Metallurgical Coal (Met Coal) includes the construction of a new underground coal mine and surface facilities on the northern boundary of the town of Moranbah in the Central Queensland Bowen Basin coal precinct. The contract to undertake the underground development works was awarded to Redpath in 2012. The scope of the Grosvenor Project was to construct temporary office and workshop facilities, install 2 portal arches, backfill boxcuts and infrastructure, excavate by EPBM method 967 m of 1:6 gradient Conveyor Drift and 1,258 m of 1:8 gradient Transport Drift, development of 2,520 m of pit bottom area roadways and development of 10,550 m of the first longwall tailgate. In the following figures 2 and 3, is possible to see the aerial view of the job-site."

Jan 1, 2016

By C. P. Miller

In a study of the usefulness of geochemical and biogeochemical prospecting for nickel made about two years ago, approximately ten localities, representing several different types of nickel occurrences were sample, and about 1500 samples of plant and soil were collected. This report will briefly cover the data and results for two areas, and s summary of guides for prospecting.

Jan 1, 1959

By J. Loredo

Wastes related to abandoned mine sites can constitute important potential pollution sources, depending on their mineralogical and geochemical characteristics and volume. Mine waste disposal sites contain a diverse variety of wastes including overburden material and waste rocks, the ore which cannot be economically removed and wastes from the smelting processes when they are accomplished at the mine site. These materials are usually heterogeneous in size, mineralogy and metal concentrations. Asturias, in northern Spain, has an extensive mining history and, in consequence, there are abundant unreclaimed and derelict mine sites with abandoned mines and spoil heaps of different age, morphology, content and dimensions. In these spoil heaps, waste materials are subjected to the intense action of a humid environment, so the instability of sulphides and sulpharsenides results in the production of acid and metal-rich leachates, which are incorporated to surface water or infiltrated through the land reaching groundwater bodies. The mineralogical and geochemical characteristics of the stored materials are key data to evaluate if they represent an environmental risk. Mineralogy and geochemistry of wastes and the particular specific environmental conditions of each site affect the rate of weathering and therefore the metal release. The characterisation of mine wastes is a necessary step in order to establish suitable assessment strategies with the aim of reducing the leaching, transport and widespread of ecotoxic elements from mining wastes to the environment (surface water, sediments, soils and air). As a consequence of the weathering of As-rich mineral phases, high arsenic contents are commonly detected in effluents from mine voids and spoil heap leachates.

Jan 1, 2006