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By A. Anani

The goal of hot mix asphalt (HMA) design is optimal material blending to meet Superpave specifications. HMA cost minimization has being modeled as linear programing (LP) (Awuah-Offei et al 2011) and mixed integer LP problems (Brown et al, 2012) and solved with commercial software such as LINDO and CPLEX. Often these software, which are designed to solve general optimization problems, have licenses that cost thousands of dollars. The objective of this study is to develop a novel solution algorithm to the HMA optimization problem presented by Brown et al. (2012), which will negate the need for expensive commercial packages and is specific to this problem. This novel algorithm is based on the branch and bound algorithm for solving mixed integer problems. The algorithm is incorporated into a software package with an easy-to-use graphical user interface. The developed algorithm is validated using a real-life HMA problem. Using this solution algorithm will save companies thousands of dollars, otherwise used to purchase software licenses.

Feb 23, 2014

By Deborah A. Peacock

"Outer space technology and exploration have reached a tipping point, so that mining and mineral processing in outer space is now a certainty and not a dream. Several competing companies worldwide are on the way to building spaceships to land on the Moon and eventually mine the Moon and asteroids for volatiles, rare earth metals and Helium-3.The Google Lunar XPrize offers a $30 million prize1. China has recently landed a spacecraft on the Moon. The European Space Agency, with cooperation from the United States, has landed a spacecraft, Philae, on a comet. And, Mars One is planning a one-way trip to establish a settlement of humans on Mars.How and why are the Moon and asteroids and their resources of interest to private space industry companies? Why are the Moon and asteroids viewed as a potential business venue?Geology of the Moon and asteroids — Why do we want to mine there?Space enterprises are actively working toward establishing and operating lunar and asteroid mining locations for resource extraction, resource processing, conversion to salable products and distribution of the products and services in space and to Earth and beyond2.Forty-five years ago, the Apollo manned missions to the Moon returned rocks and regolith to Earth, which were studied and analyzed. What they found was that the Moon contains valuable minerals and resources. These minerals are largely due to meteor and asteroid impacts, which have, over eons, created this mineral-rich regolith. These impacts have occurred on Earth as well, for billions of years, particularly early on in the history of the solar system. However, on Earth, wind, water and vegetation have erased most of these impacts. On the Moon, in contrast, the only weathering is caused by subsequent impacts and the solar wind."

Jan 1, 2017

By Norman K. Olson

A geologic investigation of mineral resources in South Carolina first began in 1825 when the General Assembly authorized Lardner Vanuxen to conduct a "Geological and Mineralogical Survey of South Carolina." Vanuxen, South Carolina's first State Geologist, reported in 1826 on the limestones (marble) of the Piedmont which during those early years, were burned in many shall, scattered kilns in the region wherever suitable raw material was available. He also mentioned the possibility of using marl from the Atlantic Coastal Plain province for direct application and enrichment to the soil. Since before the year 1844 industrial minerals in South Carolina have been commercially produced literally from A to Z, asbestos to zircon. The first pub¬lished reports of actual commercial production, not just an occurrence, are referenced in Table 1 for 33 known industrial minerals and rocks in South Carolina. Known or suspected occurrences of undeveloped non-metallic mineral resources in South Carolina await future verification by geologic mapping, sampling (including coring), possible beneficiation, and market analysis. These industrial minerals and rocks include, but are not limited to, special, clay minerals (e.g. bentonitic clays, zeolites and others), sillimanite, argillite (lightweight aggregate), kaolin (alumina) and marl (underground storage and tunneling medium). In addition other non-metallic minerals, once mined but still worthy of reconsideration, include topaz (industrial), heavy minerals, barite, feldspar, and monazite. Finally, possibilities for new reserves, as an expansion of existing mine output, might develop for fuller's earth, limestone (lime), sericite (finely divided mica), vermiculite, kaolin (paper coating and filling, other filler), and metallurgical gravel. Official South Carolina data from the U. S. Bureau of Mines for 1974 indicated a total value of mineral production of $105.2 million. During 1974 production consisted of cam-on clays, (brick and tile), fuller's earth, kaolin and vermiculite

Jan 1, 1977

By R. C. Kellner

Duval Sierrita Corporation, a wholly-owned subsidiary of Duval Corporation, operates an 86,000 STPD copper-molybdenum concentrator near Tucson, Arizona. Shortly after production commenced in February, 1970, it became apparent that the reduction crushing system represented a limitation to reaching the design capacity of 72,000 STPD. The development work performed on the reduction crushers in order to first meet design capacity, and to subsequently increase production to 86,000 STPD is described in this paper. The Sierrita plant is a conventional three stage crushing sys- tem. All crushers were supplied by the Allis-Chalmers Corporation and consist of two 58 x 89 Superior gyratories, four 138b EHD hydrocones, and ten 384 hydrocones. Screening is performed prior to and subsequent to secondary crushing and in closed circuit with the tertiary crushers. Typical throughput rates and equipment sizes are presented in Figure No. 1.

Jan 1, 1975

By Steve Kral

About 500 mineral-processing professionals from around the world gathered in San Francisco, CA in Oct. 22-27, 1995 for the XIX International Mineral Processing Congress (IMPC). Following the theme “Leading Mineral Processing into the 21st Century Through Advanced Technology,”186 speakers from 28 countries covered research and development activities and innovative processes. Subjects included comminution and simulation control, physical and chemical processing, flotation practices and fundamentals, precious metals processing and mineral waste and the environment.

Jan 1, 1996

By K. V. Raj, R. Jacksha

Conveyor systems persist in being a source of injuries and fatalities in the mining industry. To reduce these incidents, better methods are needed to enhance the monitoring of probable hazards and improve situational awareness during the normal operation and maintenance of conveyor systems. To address these issues, researchers from the National Institute for Occupational Safety and Health (NIOSH) continue to investigate emerging technologies that show the potential to improve miner safety around conveyors. This paper presents a feasibility assessment by NIOSH researchers of a fully integrated, commercially available wireless Internet of Things (IoT) system to improve situational awareness around conveyor systems. Included are discussions of a full-scale laboratory test bed that was designed to simulate a working conveyor system as well as the challenges and successes of integrating the IoT system with the test bed.

Oct 6, 2020

By C. H. Sheerin

Remotely located in the jungle near mount Puncak Jaya [16,500 ft (5,030 my), Irian Jaya, Indonesia rests Freeport's Indonesian copper mining operation. Shortly after start up of Freeport's copper concentrator in 1972, lower than estimated throughput was experienced within the crushing circuit. Within one year, Freeport had successfully engineered a solution, and was operating a 5,500 dmtpd wet screening circuit. Today, after 19 years of successful wet screening expansion and operation, the concentrator processes 57,000 dmtpd.

Jan 1, 1993

Mining is big business in Ontario. The province is Canada?s leading mining region. It consistently ranks among the top 10 jurisdictions worldwide for exploration spending, reaching about C$1 billion in 2011. More than 26 percent of all exploration and appraisal dollars spent in Canada are invested in Ontario. Minerals produced include nickel, copper, platinum group elements (PGE), cobalt, zinc, diamonds, gold and silver. It was reported that there are more than 600 mining exploration projects in the province. And, recent discoveries of chromite in northern Ontario?s Ring of Fire will add to the province?s mineral production in the coming years.

Jan 1, 2013

By J. A. MacLellan

It is the hope of the author that this paper, largely a compilation of observations and opinions built up over 20 years of experience in cold and remote areas may be of some help to others in designing better plants for the future in the north. The north is not as difficult to operate in as the better story tellers make it appear to be. ()n the other hand for 6 months of the year the cold is always there, and it seems to be waiting for someone to make a mistake. The simplest things can shut a multi-million dollar plant down at -4n' F with a 4n M.P.H, wind. It only takes one man door improperly latched to freeze up all the pumps on the bottom floor. Someone can poke a one inch hole in an outside wall in July and six months later while you are having Christmas dinner, a watchman will call up to report that the whole plant is flooded because the main water line just froze up and burst. Basic things to remember in plant design for cold and remote areas are: everything in these areas is more expensive due to long and difficult supply lines. Fuel is expensive and would be a major cost item even if it were not expensive, due to the extended periods of low temperatures. Building volumes should therefore he kept to an acceptable minimum. Service areas on the other hand must he adequate, because maintenance generally has to be conducted inside in a heated area. Supply vehicles for instance have to get completely inside the building to unload. If you try to unload a supply vehicle with the door open at -50° F, you won't be able to find the vehicle for fog and if you take more than 5 minutes half the water lines in the plant will freeze up. People in a remote area are expensive. The capital investment per employee may be as high as $30,000; with fringe benefits per annum costs of an employee will he as high as 812,000 per year regardless of basic wage rate. It

Jan 1, 1971

By W. A. Wilkinson

Mining companies today are under increasing pressure to boost output from their existing mines and to bring new projects online quickly. Fundamental to the long-term performance of an operation is geologic modeling and mine planning. To maximize mine profitability, planners and schedulers must account for a staggering array of variables and create accurate mining plans that meet production and profit targets. Not surprisingly, this can be a difficult task, and getting it wrong can result in large unforeseen costs and significant lost revenue opportunities. This paper discusses the top five challenges geologists and engineers are facing in developing mining plans.

Jan 1, 2012

By Matthew Holden, Jason Emery, Matthew Benjamin, Peter Craig

Over the last 25 years, through adversity and a growing level of risk mitigation, Australian Longwall mines have been using higher and higher capacity cable bolts for secondary support. A recent survey revealed 85% of Australian longwall cable bolts are a 70 tonne capacity pre-tensioned hollow post groutable system. Mines avoiding pumping cementitious grouts are sometimes using pre-tensioned resin encapsulated solid cable bolts of over 90 tonne capacity. Results from various industry and University research has led to manufacturer's fine tuning the construction of their cable bolts. A review of this research explains how smooth wire construction is now dominant. Aggressive shear has also led to some mines using 8 tonnes pre-tension instead of the previous common 20 tonnes pre-tension. Lower pre-tension acceptance is now leading to a greater use of threaded cable bolt end fittings, these are tensioned to 8 tonne using the drill motor torque. A recent development is the TEX cable bolt, a slim line threaded end fitting that fits with the drill hole like a standard rock bolt. This cable is being installed at the coal face as primary support off bolter-miners. The laboratory and in-situ testing of the TEX cable is presented. In a bid to improve gateroad development rates and ground support in the last several years, a 100 tonne tensile capacity Goliath cable system was developed. The latest development in resin anchored solid cables is a 110 tonne capacity cable bolt, with laboratory and in-situ testing results presented.

Jun 25, 2024

By R. Addison, P. V. Avotins, E. Martinez, L. A. Haas, D. K. Mortenson, E. EI-Shall, R. D. Kulkarni, M. D. Flavel, S. Chong

Mineral processing activities in general reflected the economic ills of 1981 and early 1982, but in some areas the depressed state of the industry resulted in increased activity. As were all aspects of the minerals industry, processing plant operations were severely affected by the recession-prone economy, by sagging prices for primary metal products-copper, molybdenum, nickel, iron, manganese, and especially uranium-and numerous shutdowns and layoffs. Copper production by major producers in Arizona and Utah was severely curtailed; Amax, the major US molybdenum, producer did considerable belt-tightening; and the uranium industry was in a state of disaster. Even the precious metal superstars-gold and silver-were affected, with a steady decline throughout the year in world market prices. Perhaps hardest hit have been newly developed properties, particularly in the uranium industry, and old-line properties where historical development impacts today. No longer can such properties afford the luxuries, for example, of a long haul distance between mine and plant or continued use of antiquated facilities. Surprisingly enough, the very state of the economy has caused increased activity in some sectors of the mineral processing industry. In mill design, although large projects have been tabled, smaller projects have gone on, with innovations in design, often for cost-saving reasons, that will affect future designing approaches. Economic restrictions are impacting on mill flowsheets as researchers look for improvements and better, less expensive techniques. Other unit processes-hydrometallurgy, pyrometallurgy, concentration, materials handling-are impacted by the need for a better, less costly product. Although at the end of the first quarter of 1982, no major environmental legislation had been enacted, rumors persist that there will be a loosening of some of the stricter standards, both in the requirements themselves and in the time allowance for implementation. The year had seen some relaxation in how current legislation and standards are administered. For example, in OSHA (Occupational Safety and Health Administration) operations, there has been a shift toward voluntary checking of industry compliance with work rules, rather than emphasis on agency inspections. However, the industry continues to view environmental factors as having major influence on future operations and efforts to design for environmental safety are becoming almost as important as the processes themselves. Throughout the industry there has been a further focussing on project management, recognizing the necessity for tight control of budgets and schedules-and the systems used to effect them. Materials Handling Review prepared by A. T. Yu, ORBA Corp. The frenzy of coal export activities has continued into 1981. Many modern export terminals are now in construction while others have either been held up or cancelled. Economics and environmental permits have been some of the major problems. Currently under construction are terminals in Newport News, VA; Charleston, SC; and Baltimore, MD. Expansion of existing facilities at Mobile, AL, and New Orleans, LA, is also well under way. A wide variety of systems and components are being used. They include traveling shiploaders, tunnel and bucket wheel reclaim¬ers, stackers and high line trippers, and bottom and side dump-type car dumpers. Manufacturers from Japan and Europe have been participating along with domestic suppliers. As an attempt to avoid environmental problems, a system of loading and unloading coarse coal

Jan 5, 1982

By J. A. Marts

Reservoir properties including porosity and permeability distributions in longwall coal mine gobs have direct application to modeling the flow patterns and gas distributions in the gobs. Proper assessment of these distributions is required to assess gob gas hazards such as spontaneous combustion and explosive methane mixtures and to optimize gob gas venthole operation and nitrogen inertization. Determining the reservoir properties is difficult given that the gob is inaccessible and direct measurements cannot be easily taken. Several techniques had been used by previous researchers and will be discussed. This paper will present the methodology used to model the gob compaction by simulating the sequential extraction of coal. Two Western US coal mines were used for case studies. By determining volumetric strain, the porosity and permeability distributions in the gob can be calculated. The geo-mechanical model predicts an axisymmetric volumetric strain distribution with a steeper slope near the start-up room and a shallower slope near the active face.

By Qingwen Shi, Gang Xu, Shuwen Wang, Brijes Mishra

Pressure relief borehole is one of the most effective methods to treat coal burst in deep-buried coal seams. However, due to the large amount of randomly distributed fractures in the coal body and the varying stress environments in underground coal mines, there is no practical method to assess relief boreholes by far, which brings problems for borehole design and construction. This study focuses on the assessment of relief boreholes in a single driving entry wherein the impact of mining panels on relief boreholes is eliminated. A practical method, focusing on field monitoring of borehole deformation with a new device, is developed to evaluate the single driving entry’s relief boreholes. This method is applied to a Chinese coal mine. The application results showed that the convergence process of the boreholes showed a three-phase characteristic. Phase one involves the fastest deformation, reaching up to 8% in the first 3 to 4 days. Phase two lasts longer and converges more, reaching up to 30% in 4 months. Phase three stays balanced until the excavating face moves. The three-phase characteristic indicates that a large diameter of the borehole ensures relief efficiency because the borehole provides adequate space for deformation throughout its life span. In addition, it is verified that long boreholes and slow footage improve relief efficiency by providing adequate time for the boreholes to work. The application proposes that boreholes in the test coal mine need to be drilled larger and longer for optimization.

Oct 19, 2021

By F. Ansheng

Though it becomes increasingly important with the valuable minerals in their deposits tending to be fine and poor, the solid and liquid separation remains difficult especially when the particles are of micrometer size and of low density. Almost of all conventional thickeners result in that fine particles lose into overflows which often costitutes a loss of potentially valuable resources as well as an environmental hazard. The addition of flocculations may improve the settling of solids but may also not work well for the final removal of fine particles from the overflows (Ref.1).

Jan 1, 1990

By P. Guliov

In the first part of this paper the authors present an overview of industrial minerals produced in the Canadian provinces of British Columbia, Alberta and Saskatchewan, and supplied to the Pacific Rim countries. The second part outlines some of the unique opportunities for industrial minerals that exist in the three western Canadian provinces and those minerals we feel have development potential for overseas markets. Because of time constraints, it is not an exhaustive presentation on industrial minerals, but is focused on a few selected minerals that we believe have high potential.

Jan 1, 1990

By Staff

In 2012, the estimated value of mineral production increased in the United States for the third consecutive year. Production and prices increased for most industrial mineral commodities mined in the United States. While production for most metals remained relatively unchanged, with the notable exception of gold, the prices for most metals declined. Minerals remained fundamental to the U.S. economy, contributing to the real gross domestic product (GDP) at several levels, including mining, processing and manufacturing finished products. Minerals? contribution to the GDP increased for the second consecutive year. Trends in other sectors of the domestic economy were similar to those in mineral production and consumption rates (Table 1). After continued decline following the 2008-2009 recession, the construction industry began to show signs of improvement late in 2011 and throughout 2012, with increased production and consumption of cement, construction sand and gravel, crushed stone and gypsum, mineral commodities that are used almost exclusively in construction.

May 1, 2013

By R. A. Thomas, C. D. Litton

"The objective of this study was to develop a laboratory-scale method to rank the ignition and fire hazards of commonly used underground mine materials and to eliminate the need for the expensive large-scale tests that are currently being used. A radiant-panel apparatus was used to determine the materials’ relevant thermal characteristics: time to ignition, critical heat flux for ignition, heat of gasification, and mass-loss rate. Three thermal parameters, TRP, TP1 and TP4, were derived from the data, then developed and subsequently used to rank the combined ignition and fire hazards of the combustible materials from low hazard to high hazard. The results compared favorably with the thermal and ignition hazards of similar materials reported in the literature and support this approach as a simpler one for quantifying these combustible hazards. Resumen ¦ El objetivo de este estudio fue el desarrollo de un método a escala de laboratorio con el fin de clasificar los peligros de ignición y fuego de materiales comúnmente usados en minería subterránea y la eliminación las pruebas costosas y a gran escala que se realizan actualmente. Se usó un aparato de panel radiante con el fin de determinar las características térmicas relevantes de los materiales: tiempo de ignición, flujo de calor crítico para ignición, calor de gasificación y tasa de pérdida de masa. Se derivaron tres parámetros térmicos de los datos: TRP, TP1 y TP4, luego fueron desarrollados y subsecuentemente usados para clasificar los peligros combinados de ignición y fuego de materiales combustibles, de bajo riesgo a alto riesgo. Los resultados tuvieron una comparación favorable con los riesgo/peligro térmicos y de ignición de materiales similares reportados en la literatura y apoyan este enfoque como uno más simple para la cuantificación de estos riesgos combustibles"

Jan 1, 2015

By M. A. A. de Klaver

Functional Description Figure 1 is a typical flowsheet for a system for solid fuel addition to filter cake. Solid fuel, coal, coal breeze, or charcoal, is fed from a,stockpile to a surge hopper. The solid fuel is metered into a grinding mill. The fuel is dried and ground in a grinding mill. The on-size particles are removed from the mill by air sweeping. The ground solid fuel is separated from the air stream by a cyclone and stored in a surge hopper. The ground solid fuel is then pneumatically conveyed to a small hopper in the balling area. The fuel is proportioned into the filter cake just prior to mixing. An efficient mixer is very important to have a successful operation. The exact flowsheet would depend on a number of factors including what fuel is used, how the fuel is received, and the cnaracteristics of the fuel as received. Availability of floor space in the plant may also affect the flowsheet. For example, drying air may be supplied from the pellet furnace if the grinding mill can be located near the grate, or the pneumatic conveying system and a surge hopper may be eliminated by placing the grinding mill adjacent .to the mixing area. Also, for a multiple line plant, a ball mill rather than a roller mill may be more suitable.

Jan 1, 1980

By L. G. Hagenbuch

Several factors need to come together in creating an integrate mining equipment dispatching system. At the hub of these factors ace the central dispatching formulas. This paper details the development of these central dispatching formulas and explores the combining of these formulas with other elements to create an integrated dispatching decision. WHY DISPATCHING? Truck dispatching implies and in reality should equate to mine equipment efficiency. Good truck dispatching will yield good mine equipment efficiency while poor truck dispatching will yield the alternative. Truck dispatching can either be automated through a computerized, process or it can be manual. Every mine with haul trucks has a truck dispatching system whether it is recognized or not. Even a system wherein the hauler operators determine where they are going for their next load is a truck dispatching system.

Jan 1, 1987