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By M. Brnich, S. Kramer, B. McNamara, T. Hethmon, M. Pedersen-Howard, S. Rajapaske, D. Lingenfelder, B. Huber, D. Hebig

"The development of mining safety and health management as a recognized profession has been long in coming. Over the last 150 years, the mining industry has evolved from having individuals randomly involved in safety related work with no specific responsibilities or qualifications, on to the designation of individuals responsible for safety, regardless of knowledge, qualifications and experience and finally to today’s expectation that virtually every mine and mining company has designated individuals operating as safety and health professionals. Further, with the complexity, risk potential and moral expectations surrounding safety, people who address mine safety and health management are justifiably expected to function in a professional capacity including:1. Rendering a specialized service based on advanced knowledge and skill.2. Maintaining a high degree of obligation to those most affected by mine safety outcomes.3. Bound by an ethical code in working with the public, employers and miners.4. Maintaining confidentiality with an employer or client. This historical change parallels thedevelopment of other professions, e.g., attorneys, engineers, physicians, etc., with the exception that those professions require a license granted by a governmental agency, which is justified on the basis of public protection, in order to practice. Likewise, decisions made by today’s mine safety and health professionals, both directly and in association with other managers, clearly have a significant impact on the life and welfare of miners throughout the world.CertificationIn light of this, there is growing need to improve standards of competency and professionalism for those who work in mine safety and health management. An effective mechanism to accomplish this, other than licensure, is the use of accredited professional certification programs. There are many professional certification programs for safety and health throughout the world (Hale & Harvey, 2012). However, there is only one certification specific to mining —the Certified Mine Safety Professional (CMSP). The International Academy of Mine Safety and Health (ISMSH-SME) was formed with the purpose of developing and managing mining safety and health certification programs for the Society for Mining, Metallurgy and Exploration (SME). In 2016, following the discontinuation of the International Society of Mine Safety Professionals (ISMSP), which developed the Certified Mine Safety Professional (CMSP) credential in the 1990s, the IAMSH-SME began the process of updating and relaunching the CMSP program. Among other work required to gain third-party accreditation both domestically and internationally, the IAMSH-SME has developed a new Body of Knowledge associated with mine safety and health management (Table 1)."

Jan 6, 2018

By Chunbao Sun, Qi Liu, Chao Wang

Entrainment is a process by which fine and ultrafine particles are transferred to the flotation froth from the top of the flotation pulp, and eventually discharge to the concentrate product, evenwhen they are not attached to gas bubbles. Therefore, entrainment can be considered as a two-step process, one at the upper layer of the pulp to the flotation froth, and the other from froth to the concentrate. Entrainment is inevitable for both hydrophobic and hydrophilic minerals and is one of the significant factors affecting concentrate grade. This paper provides a comprehensive review of the entrainment mechanisms and entrainment models, as well as a summary of the main factors affecting entrainment and the techniques thatmay be used to lower or eliminate entrainment. Based on the review, we point out that selective aggregation of fine and ultrafine gangue minerals using appropriate process aids (polymeric depressants, inorganic salts, etc.) to increase their particle sizes appears to be a convenient and economical method. Directions of further research along this line are discussed.

Aug 31, 2020

By U. K. Custred

Who We Are Farmland Hydro (FHLP) is a Limited Partnership formed by Farmland Industries, the largest U.S. farmers’ cooperative, located in Kansas City, MO, and Norsk Hydro, a large Norwegian company engaged in fertilizer, petroleum and the specialty metals industry. Both of our parent companies have a long history of commitment to the fertilizer industry. This year, Farmland Industry celebrates its 71st year in the business, and Norsk Hydro celebrates its 100th operating year! We employ approximately 300 associates in Central Florida. What We Do Farmland has been active in Hardee County, FL since the 1970’s as a large landowner and citrus grower. We plan to expand this activity into phosphate rock mining. The phosphate rock produced here will be shipped to our nearby chemical fertilizer complex in Polk County, where we produce quality phosphate products - liquid and granular fertilizers. Of the phosphate rock mined, 90% is used to make fertilizer. Other uses include animal feed, vitamins, medicine, light bulbs, soft drinks, film, flame resistant fabric, optical glass, toothpaste, bone china and other consumer products.

Jan 1, 2000

By Ashish Ranjan Kumar, Steven Schafrik, Oscar Velasquez

Flooded-bed dust scrubbers installed on continuous miners use fibrous type multi-layered filters to capture dust from the airstream. Prolonged operations of the scrubber could lead to filter clogging due to dust accumulation. This results in reduced flow through the scrubber and elevated dust levels in the mine environment. This paper compares the performance of a conventional fibrous screen filter and a novel impingement type dust filter. The impingement filter is a self-cleaning system and was designed to have a resistance similar to the fibrous filter. The cleaning efficiencies for these filters were computed using iso-kinetic sampling and optical counting of coal dust particles in a clean unclogged state. The cleaning efficiency of the impingement filter also increased with an increase in particle size and was comparable with the conventional fibrous filter. The cleaning efficiency of the fibrous filter improved significantly with an increase in water flow. The non-clogging nature of the impingement filter and minimal maintenance requirement makes it an attractive alternative to the conventional fibrous type filter in mining applications. The research also proposes a term called ‘filter performance factor’ to compare the performance of different filters under similar operating conditions.

Sep 19, 2020

By Elimame Elaloui, Kais Elghniji, Constantin Virlan, Aurel Pui, Chaima Ouled Amor

Separation and identification of minerals composing the Tunisian silica sands have been conducted by acid etching and hot filtration/sedimentation (HFS) without affecting the quartz component. It was found that the hot acid etching process is an effective method to separate quartz and clay minerals in the silica sand. The SEM micrographs of the silica sand show rough surface and some cracks with irregular shapes. The surface becomes clean and smooth after acid etching process. After chemical dissolution, the clay minerals were recovered by hot filtration following by sedimentation at low temperature. FT-IR, EDS maps, and secondary electron (SE) analyses of separated clay minerals reveal the presence of Fe2O3, montmorillonite, and kaolinite minerals. The LIBS analysis of clay minerals shows the presence of Al, Fe, Ca, Al, and Mg. The sequential etching process can be introduced in the purification methods as an effective way to separate quartz from clay minerals.

Jul 29, 2020

By Christopher J. Bise

It is somewhat reassuring to note that the United States has an abundance of coal reserves which can be used to bridge the widening gap between the nation's energy production and consumption. The U. S. Bureau of Mines has recently established a demonstrated coal reserve base of 434 billion tons. (31)(Figure 1) As can be observed, the major percentage of the reserves is in the West. Although surface coal mining in the West has been gaining increased attention in recent years, western reserves that must be deep mined are significantly greater. Though deep mining activity in the west is very limited and accounts for less than 2% of the annual production, the primary reason, quite probably, is the greater thickness of the seams as compared to those found in the East. Forty-five billion tons of the western demonstrated coal reserve base for underground mining are in seams greater than 10 ft. in thickness. (37) Thick coal seams do not lend themselves readily to extraction with the underground mining methods practiced in the United States today. Experiences from the practices in other countries can serve only as guidelines. Consequently, a concerted effort is necessary to overcome the technical difficulties.

Jan 1, 1975

By J. P. Ulery

As a result of several recent methane/dust ignitions in surface auger and highwall mines, the U.S. Bureau of Mines investigated the occurrence of methane gas at these operations. Three mine sites were visited in western Kentucky and one in western Pennsylvania to collect run-of-mine coal samples for gas content determination using the modified-direct-method (MOM). Results indicate the samples emitted small quantities of methane, carbon dioxide, and nitrogen. Either methane or nitrogen was the predominant gas released. The same gases were released after crushing the samples for residual gas content; however, nitrogen was the primary component of this fraction. Total ~as contents ranged from less than 0.01 cm /g to 0.54 cm3/g. The hydrocarbon gases probably originated during coalification. Other gases may have originated partially as a byproduct of coalification and partially as a result of other, near-surface processes. The data suggest that although methane quantities are small, desorption could occur at near surface conditions prior to mining. The desorbed methane could accumulate as a free gas in fractures in the coal bed or roof rock. When these fractures are penetrated by the auger, methane could rapidly enter the whole atmosphere possibly creating explosive conditions.

Jan 1, 1994

By J. A. Hartlage

Four years ago, Ashland Chemical Company introduced a new copper solvent extraction reagent for hydrometallurgical utilization. The reagent, an alkylated 8-hydroxyquinoline, is called Kelex 100 ®(1). Since the time of introduction, the reagent has been investigated by several workers for its solvent extraction utility in the separation and purification of transition metals (2-7). In the following text, those factors which are essential to the optimum performance of Kelex 100 on concentrated copper solutions will be discussed. To date, the reagent has been found useful in active concentrations of from 1 to 20% Kelex 100. In order to achieve the best performance for Kelex 100, it has been found that a phase modifier is essential. Various alcohols and phenols have been evaluated in order to improve phase performance and stripping characteristics of the solvent system. Modifiers and diluents are especially important when solvent activities between 3 and 20% Kelex 100 are employed. A 15% Kelex 100 solvent, for example, containing 15% nonyl phenol in Escaid 100 (Exxon) can be utilized to remove greater than 33 grams per liter of copper from an aqueous feed without interstage neutralization, and in the same process scheme the reagent can be stripped to less than 1 gram per liter barren organic producing a pregnant electrolyte containing greater than 40 grams per liter copper and less than 120 grams per liter sulphuric acid. The unusually efficient stripping of Kelex is accomplished by protenation of the extractive molecule during the stripping process.

Jan 1, 1974

By G. Bylapudi, A. Bhagwat, K. Mondal, A. J. S. (Sam) Spearing

Minimizing the effects of corrosion improves the long-term performance of the rock anchors and ground control systems in underground mines, which is fundamental for safe operation over the design period. The primary objective of this study is to explain the problems due to stress corrosion cracking (SCC), strain-induced corrosion cracking (SICC) and other forms of corrosion, and why the mining industry’s ground control professionals should take this into serious consideration. It is important to clearly determine the kind of SCC mechanisms that causes roof bolt failures in order to suggest the necessary action plan to mitigate or eliminate the possibility of the cause. Pertinent literature and studies around the globe on this complicated subject are reviewed. The secondary objective is to encourage the use of corrosion-resistant ground control products in the underground mining industry in areas of high corrosion potential. Characteristics of SCC on high strength steel are also reviewed. The literature and preliminary studies to date indicate that research work is necessary in United States.

Jan 1, 2015

By D. Anderson Willis, Alan A. Campoli, Douglas Mynear, Seth Mittle, J. Steven Gardner

"The diversification of energy sources in the United States has seen some major shifts during the past decade resulting from:• A sudden abundance of low-cost natural gas becoming available through advanced horizontal drilling and hydraulic fracturing techniques.• Incentive-driven policies leading to new development in alternative energy.• The emergence of alternative energy sources proliferated as a result of state and federal level incentives and falling capital costs.Coal was once recognized as the primary low-cost fuel source for the generation of electricity in the United States for most of the last century, providing upward of 50 percent of the total generation capacity during much of that period. However, within the past decade, lower-cost natural gas has overtaken coal as the primary source of fuel used in electricity generation, and alternative sources have steadily grown to now account for approximately 10 percent of the overall mix.West Virginia and Kentucky have not experienced the full breadth of the fuel shift, and, as of 2016, still obtained approximately 80-90 percent of electric power generation from coal. However, as coal plants are retired, there has been a shift toward natural gas for new power plants constructed in the region. The economics of power generation (i.e., lowcost fuel source) has typically been the major factor in determining shifts from one fuel source or technology to another. However, governmental energy policies and incentives have more recently been used to promote the development of new alternative technologies such as wind and solar energy growth to diversify the energy mix. The implementation of these incentives has provided some needed traction and resulted in driving the cost of manufacturing and installation of these new wind and solar systems downward to be more cost competitive with conventional fossil-fueled power sources. Future shifts in the generation capacity by fuel type will also be inevitable and impossible to project accurately as policies change and innovative technologies evolve. Determining factors may include the expiration of current incentives, decreasing capital costs, future environmental regulations, evolution of energy storage systems, technical challenges associated with increasing intermittent sources of generation and the development of unforeseen technologies. West Virginia and Kentucky have been among the least solar friendly states, ranking 44th and 48th of the 50 states (Fig. 1 for WV). The ranking of other coal producing states are similarly low:• Ohio 20• Pennsylvania 21• Virginia 38• West Virginia 44• Wyoming 45• Kentucky 48• Alabama 50"

Jun 1, 2019

By Hans Adden, Anne Lehan, Markus Thewes

"1. INTRODUCTION AND MOTIVATION Traditionally design processes are focussed at creating new tunnels for lowest building cost. But the trend towards sustainable constructions in tunnelling has greatly increased in recent years. A critical subtask of this approach is to realize the potential for optimizing and reducing the life-cycle costs (LCC) of tunnels and their components. To evaluate underground infrastructure projects from an economic point of view is therefore a highly topical subject of public authorities as well as private companies participating in Public Private Partnerships (PPP) projects. Nowadays, in the case of public works contracts, the contracting authorities shall draw up rules not only for the design but also for life-cycle costing. Within the scope of the decision-making process of building a new tunnel, planning the maintenance activities or the refurbishment of a tunnel in operation, the decision-makers need detailed knowledge about the current and future financial conditions of the planned projects and selected sub-measures. But in practice, the initial costs still represent the primary decision criterion in the planning phase, whereas the subsequent or follow-up costs, respectively, are only estimated roughly. Although tunnels are the key components and the most costly parts of the transport infrastructure, only a small number of scientific papers deal explicitly with the calculation of life-cycle costs for underground infrastructure. And in these cases, most authors use as the starting point only the basic form of the Net Present Value method which is known as the frequently applied life-cycle costing technique in building construction. The present study explains the strategic concept of life-cycle costing and its fundamental instruments for operational implementation. It shows the necessity to take into consideration that there are fundamental methodical problems when the life-cycle concept is transposed without modifications from building construction to civil engineering. The paper will discuss in detail some selected associated problems with the net present value method. On the basis of operational and safety related tunnel equipment it is shown, what impact this may have on principle determining the LCC of tunnels. Selected best-practices of maintenance planning for tunnels undertaken by the German Ministry of Transport fill the theoretical approach of the concept with life and give a practical orientation. In particular government authorities but also construction companies are interested parties in modern cost management considerations. The reason for this development is the replacement of aged excisting structures and the advancement of technical standards. The increase in the total numbers of tunnels (Fig. 1) as well as the need for future re-investments in existing tunnels show the overall economic impact and justify the change towards the life-cycle perspective."

Jan 1, 2016

By David A. Heitman

The Buick Concentrator is a highly automated operation which utilizes a process control system for continuous monitoring and control. The process control system development, installation, and application to the concentrator grinding and flotation circuits are presented in this paper. The design and implementation of analog field sensing instrumentation, a continuous on-stream X-ray analyzer, grinding and classfication circuit controls, and a recent digital process control system utilizing a centralized computer are discussed. Emphasis is placed on the project planning and installation of the digital control system including a presentation of future plans for continuing application of computer control.

Jan 1, 1982

By Norman R. Paterson

In November 1980 a combined airborne electro-magnetic (INPUT.) and magnetometer survey was conducted by Questor Surveys Limited in the State Line Area, Colorado-Wyoming. The survey was the result of discussions over a prolonged period between the authors and various investigators of the State kimberlite occurrences. As a result of these discussions and literature studies, it was decided that airborne geophysical methods would be potentially useful in the exploration for new kimberlite occurrences. The survey was designed by Paterson, Grant and Watson Limited and conducted by Questor Surveys Limited over an area in which more than 15 kimberlite bodies were known and on some of which ground geophysical surveys had been conducted. The survey was designed primarily to determine the airborne electromagnetic and magnetic responses of the known occurrences and to deter- mine whether these responses would be detectable under similar conditions in other parts of the State Line District and elsewhere.

Jan 1, 1984

By Yung Sam Kim

The study of ultrasonic-wave propagation in substances has been remarkably advanced in recent years in most engineering and science fields. The main object in studying the velocity of ultrasonic-wave propagation in solids, is to determine dynamic properties of these materials. The present paper, however, presents some other possible applications of ultrasonic-wave propagation in the study of rock mechanics as follows: Investigation of the mechanism of microseismic activites of geologic materials, (a) at initial or low stress level, (b) at final or fracture stress level, and (c) under fatigue loading condition. Also, correlations among stress level, density, and the velocity of ultrasonic-wave propagation in rocks are discussed in this paper.

Jan 1, 1973

By Thiemo Hagedorn, Gerhard Weissbach, Ralph Bergmann, Wilhelm J. Kogelmann

The objective of this unique method is to multiply the advance rate of conventional tunneling while improving both ground control and the safety of the crew. The high advance rate is achieved by concurrent rock excavation and installation of concrete lining at fully synchronized work phases. The novel TACHUSMATIC system consists of a high-production, robotic cutter boom, an automated slip form and continuous mucking and conveying. This novel system utilizes the inherent bearing capacity of the rock that is activated by a small, initial deformation. The supporting resistance is then provided both by the rock mass itself and the pumped in concrete lining. During the hardening of the concrete, the hydraulic cylinders of the TACHUSMATIC automatically apply the appropriate support resistance, thus providing safe ground control. This novel tunneling system is practically a fully automated, fail-safe NATM that does not require highly skilled engineers and crew. The TACHUSMATIC can be used for construction of circular, rectangular and horseshoe-shaped tunnels. When equipped with the Alpine Multi-Tool Miner (MTM) systems, the machine can work in a wide range of ground and rock conditions. The use of novel, diamond-tipped cutter bits (picks) will increase hard rock cutting capabilities and will significantly reduce pick consumption. Because of its moderate cost, the novel system is an economic alternative to conventional tunneling even at short drivages. A new installation is cost-effective for tunnels longer than 750 meters (2,500 ft.) At a typical tunneling project, the cost permeter is about 25% lower than with conventional methods.

Jan 1, 2003

By Minerals and Materials Analysis Section

During 1996, US mines produced 319 t (10.26 million or) of gold metal valued at $4 billion. At yearend, mine reserves were estimated to be 4.7 kt (151 million oz) of gold metal. Almost all of the production was from western states. Nevada accounted for about 68% of national production. Information for this article was obtained through annual reports of mining companies, US Geological Survey (USGS) databases and other public sources. Table 1 shows production and reserves by mine. It divides the mines into two categories. These are producing mines whose primary product is gold, and producing mines for which gold is a byproduct or coproduct. The mines listed in Table 1 accounted for more than 98% of US gold production during 1996. Except the Daisy Mine, the table does not include mines that produced less than 31 kg/a (1,000 oz/year). The Daisy Mine started production in December of 1996. Nor does it contain mines whose byproduct concentrate is

Jan 1, 1997

By David L. Kuck

Siderophyle platinum-group metals and sane gold are a thousand times more abundant in metal and chondritic meteorites than in terrestrial or lunar rocks. Type I and II carbonaceous chondrites contain granules of the high boiling point metals W, Re, Mo, Ir and Os. Metal meteorites and the metal fractions of other chondrites contain siderophyle Pt, Pd, Ru, Rh, Os, Ir and Au. Spectra of sunlight reflected from asteroids, when compared with those of meteorites and specific minerals, provide a rough classification and guide to sources of precious platin-group metals.

Jan 1, 1982

By Michel Dagbert

In the exploitation of porphyry-type deposits, the quality of the ore is mostly defined according to its grade. Besides the simplest distinction, ore-waste, several grade categories may exist and they correspond to the different ways in which the ore is further processed. At the time of mining the selection of the different categories is done from extensive information available from blast holes. But planning has to be done before this information is available and it is necessary for the geologist to forecast, from exploration and development data alone, the possible outcome of the selection done later on a block, a level, or the whole deposit and ultimately predict the ore reserves and value of the deposit. A good statement of this problem has been presented at the 1976 AIME annual meeting by Williamson and Hueller (1976). They have shown that, if the cut-off values are directly applied to the estimated grade of blocks, a gross overestimation of the recovered tonnage of ore (14%) will occur. This problem, now termed "the vanishing tons problem" (DaVid, 1977) seems to be common in many open-pit operations and it has been explained several times (DaVid, 1972; Huijbregts, 1975). In order to solve it l.Jilliamson and Mueller proposed a solution based on compiling masses and masses of blast hole data available from mined-out portions of the deposit. They derived empirical correction factors which provide for every block, given its estimated grade, the expected tonnage and average -grade of each category of material within that block. The purpose of our work is to repeat the same exercise but ignoring the blast holes data i.e. we want to derive the correction factors from the only DOH data. Doing this, we are more in the real conditions where the valuation of the mine and are reserve analysis has to be made before production actually starts. Two possible ways to achieve this goal will be investigated and the emphasis will be on recently

Jan 1, 1977

By A. E. J. Gallagher

There are many influences which have a bearing on the economics of industrial minerals production. The purpose of this paper is to discuss briefly three factors which have economic significance in the production of these mineral commodities. The three items of discussion include 1) the nature and relative value of the industrial minerals group, 2) project planning, and 3) market analyses. General aspects of these factors are familiar to most of us. However, an attempt will be made to give some current details regarding each. Also, in reality, project planning and market studies are usually so closely associated that they will be discussed jointly, rather than separately. This will be done by way of examples which show how these two activities actually evolved for two industrial minerals projects.

Jan 1, 1984

By C. L. Kosmoski

In recent years, coal mining safety has attained national attention due to several highly publicized disasters. Despite these threats to worker safety and health, the U.S. relies on the mining of coal to meet its need for electrical power, with 42% of electricity in the U.S. generated through the burning of coal (U.S. Energy Information Administration, 2012b; United Mine Workers of America, n.d.). Furthermore, the production of coal continues to increase and reach record levels every year (National Mining Association, 2012; U.S. Energy Information Administration, 2012a). For this reason, the coal mining industry must continue to find ways to protect its workers while maintaining productivity. One potential approach to protecting workers while maintaining productivity is through improving the safety culture at coal mines. In order to achieve this culture, operators, employees, the inspectorate, etc. must share a fundamental commitment to safety as a value. This type of culture is known in other industries as a ?safety culture,? and can be defined as the characteristics of the work environment (such as the norms, rules, and common understandings) that influence facility personnel?s perceptions of the importance that the organization places on safety. Fundamental to improving safety culture within an organization is understanding the existing safety culture; improvements cannot be made without first elucidating areas that require improvement. This manuscript details the process undertaken by researchers at the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) to assess the safety culture at five underground coal mines across the United States. The purpose of this manuscript is to present the aggregated results from those five safety culture assessments conducted at underground coal mines. Additionally, some general recommendations for areas where coal mines might focus their attention as part of their attempts to improve safety culture are offered.

Feb 23, 2014