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By H. V. Fairbanks

The following processes were investigated using ultrasonic treatment in mineral recovery: (1) cleaning coal from coal slurry ponds, and (2) extracting precious metals from tailings and other sources. The treatment entails the production of a water slurry of the material containing the mineral which is made to flow over the vibrating surface of the ultrasonic treatment unit. The vibrations transmitted into the slurry break up particle agglomerates and also produce a scrubbing action on the surfaces of the particles. The treated mineral particles were found to have increased settling rates, better compaction, and more rapid water drainage.

Jan 1, 1990

By K Louie

When BHP Copper's Lower Kalamazoo Project commenced production in January 1997, two of the four original hoists had been converted to hoist ore from the Lower K level. Conversions on these hoists not only allowed hoisting from a much deeper level, but also created a higher hoisting efficiency and higher capacity as well. Conversions included new drums, new cables, SCR drives and other solid state control technologies not available when the original hoists were installed. Two of the original hoists were installed in the 1950's and the other two were installed in the 1970's.

Jan 1, 1998

By M. R. Moon

The mine fire at Wilberg Mine in 1984 reached the surface resulting in the failure of the vertical ledge forming the roof and entrance for three main intake portals. The fallen material was covered with a concrete cap to seal the air from the mine. As the mine was recovered and ventilation pressure was placed on seals on the perimeter of the fire area, the concrete capped rubble proved ineffective. Due to the steep and rugged terrain and the inaccessibility to the portals from underground, horizontal holes were drilled into the portal entries and three seals were placed remotely. The seals in conjunction with pressure balancing the seals around the perimeter of the fire area resulted -in the control of the mine fire.

Jan 1, 1993

By Ossi V. I. Hintikka

There are several limestone deposits around the Lohja area in southern Finland. Raw material for cement rock is mined from some of them. The formations are geologically complicated, and therefore selective mining is used whenever possible. One of these mines is the Tytyri underground limestone mine, which is divided into two parts; Törmä and Solhem. In addition to the selective mining system hand sorting or picking must be used at the Tytyri mine to improve the overall grade of the blended limestone. Some means were needed in order to improve the quality and to increase the feed rate by the elimination of hand sorting. Sorting machines were considered and eventually a Sortex 811MW was pilot plant tested at the Ojamo mine near Tytyri. This machine now continues to be used on production.

Jan 1, 1971

By J. C. Mullen

Today, the coal mining industry is more knowledgeable on the potential negative economic consequences associated with improper management of hazardous substances and various types of solid waste. The practices evaluated during environ-mental audits are discussed and example situations are shared from previous audits of coal mines and analogous situations. The importance of assessing and understanding purchasing, warehousing, safety, maintenance, electrical, operations, and environmental management practices and procedures is highlighted as a key to a successful and practical program. A waste minimization approach is presented including strategies for screening product purchases, product substitutions, and testing and record keeping.

Jan 1, 1992

By R. E. Vivas, J. A. Villa

"INTRODUCTION Located in the state of Colima, Peña Colorada is one of the largest iron ore operations in Mexico. The project is owned in equal parts by ArcelorMittal and Ternium. Though boasting a production capacity of 4.5 million tons of concentrate per year, Peña Colorada is faced with declining ore grades. In order to respond to this situation, Peña Colorada had to expand production even further. This expansion created various challenges that were overcome by the adoption and application of new technology. Examples of these technological innovations are discussed in detail in this paper and include improvements in geo-modeling, mine planning and mine operations. The successful implementation of these technologies paid for itself many times over, and has led to significant improvements in production and performance, while lowering the operating costs and reducing the variance between planning and execution. PROJECT OVERVIEW Peña Colorada is a mining company which produces about 30% of the iron ore in Mexico. This project generates about 1,200 direct jobs and 3,000 indirect jobs, making a significant contribution to the local economy. Similarly, Peña Colorada invests in its local communities through numerous educational programs, scholarships, university agreements, social development, environmental agreements, etc. Peña Colorada’s operations consist of an open pit mine located in Minatitlán and a pellet plant located in the port city of Manzanillo, as shown in the location map below:TECHNOLOGICAL INNOVATIONS Most mining projects around the world typically follow the logic of “mining the next best ore”. Consequently, head grades tend to decline over the life of the mine. In the case of Peña Colorada, a decline in head grade combined with a decline in iron ore prices forced the operation to adapt to a new business environment and adopt new technologies to face these challenges. However, the first step along this process was to increase the confidence and reliability of the resource model. This task involved additional drillhole campaigns coupled with more detailed modeling techniques. Once the block model was completed, new optimization studies and production schedules were evaluated with new optimization tools that unlocked significant project value in many aspects of the mine plan. Similarly, new geotechnical studies were prepared, which provided new guidelines for pit slope design, and new technology was implemented to monitor ground movement and slope stability. The picture below shows two sectional block model views in MineSight 3D, along with the pit designs and geologic solids"

Jan 1, 2017

By S. F. Diehl

Suites of monomineralic sulfide and carbonate minerals, as well as mine-waste composite samples, were analyzed using chemical and microanalytical techniques to understand behavior and bioavailability of mine waste elements such as Cu, Fe, Pb, or Zn. Petrographic, scanning electron microscopy (SEM), and laser-ablation inductively-coupled mass spectrometry (LA-ICP-MS) studies of mineralogical residence sites of trace elements are important because trace elements affect the chemical and physical behavior of minerals. Leachate solutions show that chalcopyrite, bornite, azurite, malachite, and galena are host to the trace elements Ag, Al, As, Cd, Co, Cr, Mn, Ni, Pb, and Zn. SEM studies reveal whether these trace elements occur within mineral inclusions or are substituted within lattice structures. SEM analysis reveals mineral phases not identified by X-ray diffraction (XRD), such as inclusions of sphalerite and cobaltite(?) within chalcopyrite.

Jan 1, 2010

By Hillary W. St. Clair

In a previous report 1/the author showed that the essential information from particle size analyses of grinding mill products can be represented by three or four parameters derived from the first four moments of the particle size data. These parameters may be used in gamma or beta distribution functions to estimate the weight fraction in any given size range. Moment analysis was used to study the progressive changes that take place in particle size distribution when a homogeneous isotropic mineral such as quartz is reduced in size by impact crushing. 2/ This report briefly reviews the essential features of moment analysis and describes extension of this method to size reduction by ball mill grinding.

Jan 1, 1972

By Fun-Den Wang

In underground coal mines, three types of roof failure (2)*, tensile, local, and shear, occur in the development entries and in room-and-pillar extraction areas. Most of the tensile failures in the roof at the center of the mine opening as well as those local failures due to fracture or jointing can be controlled by roof bolts, trusses, and timbering. However, control of the shear failure at the sides of the roof (or the cutter-roof caving) has not been successful with ordinary roof control methods. The only effective method, when there is an indication of cutter-roof caving, is to use cribs, which are costly and make transportation, ventilation, and production difficult. Frequently, the operator allows the cutter roof to cave and then cleans it up rather than trying to stop it. This shear type of roof failure is often associated with large areas which may progressively involve several hundred feet of roof caving at one occurrence. At times, this shear failure occurs suddenly with little or no warning. This can result in buried equipment and great danger to the safety of personnel. This shear failure may be due to one or more of the following: high stress concentrations at the corner of the roof from (1) high horizontal to vertical load ratio, (2) orthotropic elastic properties of rock and coal, (3) greater stiffness of the immediate roof layer than of the secondary roof layer, (4) viscoelastic behavior of rock and coal, and (5) geometry and material properties of the geologic setting. Removing or reducing the high stress concentration should improve the roof stability. The structural analyses of models of two typical

Jan 1, 1972

By S. J. Jung

The stability of underground openings for deep mines is critical, since incorrect orientation or geometry of shaft, stope, and accessways often results in the failure of openings due to high stress concentrations. Current state-of-the-art procedures for the design of underground openings are largely based on rules of thumb, experience, and trial and error. Rules of thumb are invariably based on the past experience of the designer and may not remain optimal as the depth and complexity of mine workings increase. Often, as conditions change, and as the interaction between geology, in-situ stress conditions, and mine openings grows more complex, the cost of maintaining structural integrity becomes prohibitive. Existing design procedures for deep mines are rapidly becoming inadequate as mines are worked at greater depths. For example, in the Coeur d' Alene Mining District, several million dollars are spent for inspection, repair, and maintenance on a regular schedule, largely as a result of inadequate design. In these types of situations, it is of critical importance that a new design methodology be developed for the layout and design of underground openings.

Jan 1, 1994

By F. J. Susko

The U.S. Bureau of Mines is using Fourier-transform infrared (FT-IR) analysis to investigate the bonding mechanism which occurs during the dewatering of clay slurries. High molecular weight polymers are used as flocculating agents in these processes. This investigation presents the results of an FT-IR study of calcium-exchanged montmorillonite treated with polyacrylamide (PAM) and polyethylene oxide (PEO). Both thin film and attenuated total reflectance (ATR) spectroscopic techniques were employed to study this clay-polymer system~ Results suggest PAM is adsorbed to the clay via the nitrogen atom of the polymer. A water bridge is involved in the bonding between the clay and PE~. Evidence also suggests that PEO may be adsorbed directly onto the surface of the clay.

Jan 1, 1990

By R. Pandey, G. Elie, E. Sarver

Respirable crystalline silica (RCS) is generally considered the most hazardous constituent of coal mine dust, and a new federal rule is expected to further limit exposures in U.S. mines. For regulatory purposes, RCS is monitored by collecting filter samples, which are analyzed for quartz (the predominant form of RCS in coal mines). The analysis is done using Fourier transform infrared spectroscopy (FTIR) in a centralized laboratory. To enable more timely results, National Institute for Occupational Safety and Health (NIOSH) mining researchers developed a directon- filter (DOF) FTIR analysis method and free FAST software that can be used in the field. For samples collected under specific conditions, FAST processes the FTIR spectral data to determine quartz mass. While the DOF FTIR method is not approved for regulatory RCS monitoring, it could be useful for engineering purposes, such as to evaluate mining parameters or new dust controls. This field study demonstrates how the method, including FAST, can be applied using low-cost, widely available sampling components. It further demonstrates how quartz percentage can be estimated in the field, by pairing a continuous personal dust monitor with a filter sampler.

Jun 1, 2025

By J. J. Carlson

An important factor in filtration is the zeta potential of the particles. Since zeta potential is a function of pH, it was hypothesized that adding CO would lower the pH and zeta potential. A reduction in zeta potential should enhance the flocculation and increase the filtration rate. This paper describes the effects CO on the zeta potential of both pure hematite and samples of hematite concentrate from an iron ore processing plant. A significant shift in the zeta potential, as a function of pH, curve was observed. These results point to an alteration of the particles mineralogy, not just a shift in pH.

Jan 1, 2010

By H. E. Rojas

The primary objective of most comminution operations is liberation; however, mill performance is generally quantified in terms of particle size. Only recently has the use of image analysis equipment made it possible to quantify mill performance on the basis of liberation. In this investigation, a series of tests were carried out to study the effect of mill operating parameters on the liberation of sphalerite from a sphalerite/dolomite ore. The parameters studied included mill rotational speed, mill loading and ball size. The results of this work appear to indicate that sphalerite liberation is improved under conditions that promote impact breakage, while dolomite breakage is enhanced under attrition conditions.

Jan 1, 1990

By Wilfred Walker

Much is known of the geography of the Alpine orogeny because it has now ended and all geosynclines are in their terminal, cordilleran form. The principle of sea floor spreading, continental drift, and mantle cells has gained general acceptance, but the number and position of the cells, even during the Alpine orogeny, is controversial. The oceanographers have demonstrated the uprises and in this paper it is suggested that downflows are marked by island arcs in the oceans and geosynclines (now cordillera) in the continents, for a total of about a dozen cells. Major mineral deposits associated-with the Alpine downflows are porphyry copper, molybdenum, nickel, chrome, lead-zinc-silver, gold, mercury, tungsten, and tin. Amore precise environment is known for some of these metals, for example, nickel, chrome, and mercury in flysch (which flanks mantle downturns), Ten major orogenies have taken place from 3500 m.y. to the present, Their re¬construction and metallogenesis is the subject of a continuing study.

Jan 1, 1971

By A. Bhagavatula, M. Rezaee, M. J. Kiser, R. Q. Honaker

"A field study of the coal preparation plant fleet in the eastern United States was undertaken to determine if quantify of rare earth elements (REEs) present in the product streams are large enough to justify further concentration. Representative composite samples were taken from the clean product, coarse refuse, and fine refuse streams from 20 coal preparation plants. Each stream was then separated into various size and density classes and analyzed for ash and REE contents. The large database showed that coarse refuse contained the largest amount of REEs, although the ratio of heavy to light REEs was greater for the clean coal products. The concentration of REEs was also compared to that typically seen in the earth’s crust. This enrichment ratio ranged from approximately 1.5 to more than 4.0 as the ash content varied. The database also showed that a linear correlation existed between La and Ce for many REEs of interest, although there were several notable exceptions for some of the high-value REEs. INTRODUCTION Worldwide energy demand is expected to grow by as much as 37% by 2040 according to the International Energy Agency (2014). This growth, coupled with a decrease of the reliance on coal to generate energy, means that it is more important than ever for countries to secure the materials necessary to meet its energy projections. For the United States, the U.S. Energy Information Administration (EIA) predicts that total domestic electricity use will increase roughly 25%, from 3,836x109 kWh in 2013 to 4,797x109 kWh in 2040 (EIA, 2015). In the EIA’s reference case, coal’s contribution to electricity generation drops from 39% in 2013 to 34% in 2040. On the other hand, renewables share of electricity generation grows from 13% to 18% for the reference case. Compared to its current state, renewable energy electricity production is predicted to grow as little as 50% to as much as 121% over this time period, depending on the economic case being examined. This growth will largely be seen in the wind and solar sectors (EIA, 2015). The focus on viable renewable energy resources will be crucial to the future of fueling American growth. Many of the renewable energy technologies, such as wind turbines and photovoltaic films, rely on materials and supply chains outside of the United States. The lack of a reliable and low-cost domestic supply could pose a threat to the growth of the renewable energy markets in the United States. This potential vulnerability recently led the United States Department of Energy (DOE) to create a Critical Materials Strategy Report. In this report, 15 elements were identified as critical for the continued growth of the renewable energy market. Eight of these elements were rare earth elements (REEs). Five REEs (dysprosium, neodymium, terbium, yttrium and europium) were identified as highly critical and vulnerable to shortages (Bauer et al., 2012)."

Jan 1, 2016

By G. F. Revey

Most commercial explosives contain 70 to 94% ammonium nitrate, by weight. When portions of these explosives end up in shot rock and ore, through spillage or incomplete detonation, ammonia and nitrates leach out of them and into ground water. In recent years, State and Federal regulators have been applying more stringent water quality standards, particularly at new mines and development projects. Bulk ANFO, a mixture of ammonium nitrate and fuel oil, is the explosive of choice at most mines, when mining conditions allow it. ANFO use is desired because it less costly than other explosives, but when spilled it dissolves readily in water. Several case histories in the United States and Canada show a clear connection between uncontrolled losses of bulk explosives and high nitrate levels in mine effluents. Mining companies have tried several approaches to reduce ammonia and nitrate levels in groundwater. They either control explosive losses, or they treat mine effluents at the end-of-pipe. This paper addresses the former solution --controlling explosive losses. For both packaged and bulk explosives, guidelines designed to limit losses during storage, handling and use, are described in detail.

Jan 1, 1995

By T. P. McNulty

During the last decade, many exhaustive studies have been made of process energy requirements for the production of various metals and materials. Some excellent technical papers and text books have resulted, and some of these are included in the bibliography of this paper. These studies were, of course, prompted by the economic pressures which resulted from the beginning of the "Energy Crisis" in 1973. Our intensified consciousness of the cost of energy led, then, to a greatly improved understanding of the energy consumption attributable to individual mining, processing, and refining steps. It is worth noting, however, that an awareness of the cost of energy is not new and that efforts to minimize this cost were an important part of sound mine and plant management practice throughout the earlier days of our industry. One only has to read a few accounts of mining operations around the beginning of this century to develop an appreciation for the cost of supplying wood, coal, fuel oil, or electric power to remote locations.

Jan 1, 1983

By Barbara J. Arnold

The Electric Power Research Institute (EPRI) and six EPRI-member utilities are sponsoring research to define relationships between coal properties and coal handling behavior. Deratings and outages caused by plugged chutes or bunkers or frozen coal can cost utilities millions of dollars annually in lost energy production as well as in manpower to restore coal flow. There is also the added expense of maintaining redundant equipment to assure a continuous coal feed to the boiler, a common practice for utilities. Over the past two years, researchers at CQ Inc. and Iowa state university have collected and analyzed coal samples to develop a coal handleability index for utilities to use when specifying coals for their power plants. These coal samples cover ranges in ash content, rank, grindability, size distribution, and moisture content--properties that affect the handling behavior of coals. Other properties, such as the washability and ash composition, are measured as well. Over the remaining two years of the project, all of these analyses will be correlated to handling behavior, measured using a triaxial shear tester that determines the strength of a coal under compression. An index will be developed and validated at host utility power plants.

Jan 1, 1991

By Q. Dai

In order to float coarse sylvite particles, Potash Corporation of Saskatchewan Inc. (PCS) uses amines and extender oil (Esso 904 oil). Since the content of polycyclic aromatic (PCA) compounds in Esso 904 oil is high, PCS has sought a suitable replacement. Various types of physicochemical tests, including measurements of the electrokinetic potential of emulsified oil droplets, oil/water interfacial tension and wetting of KCl plates by oil, did not provide conclusive results. However, captive bubble contact angle measurements on KCl plates in brine in the presence of flotation agents correlated reasonably with the flotation response. A few non-toxic oils were found to provide good results in the flotation experiments and are now tested under industrial conditions.

Jan 1, 1992