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Caterpillar unveiled a new dozer, the new Cat D10T2 dozer, that builds on the success the company has had with its D10T model. The newest version of the dozer includes refinements to its power train, automated controls and structures. The result, the company said, is high productivity with superior fuel efficiency, reliable operation with long-lived structures, as well as enhanced access for service technicians and operators. The D10T2 uses the latest load-sensing hydraulics technology combined with Cat advanced engine controls to maximize the amount of material moved for every drop of fuel burned. Improved filtration protects the fuel system, hydraulic system and power train oil system to help ensure high reliability and minimal machine downtime. Refined large structures, such as redesigned track roller frames, deliver longer service before rebuilds. Improved access and egress features enhance safety and productivity of technicians and operators, and optional powered access systems and platforms enable configuring the D10T2 for the site. Caterpillar offers the D10T2 with two variations of the Cat C27 engine with ACERT Technology. One version is U.S. Environmental Protection Agency (EPA) Tier 4 Final certified, and the other is capable of achieving emission levels equivalent to EPA Tier 2 standards. Both engine configurations produce net power of 447 kW (600 hp) in forward gears and 538 kW (722 hp) in reverse gears. The engine controller automatically adjusts power output based on the direction of travel. With the new system, the D10T2 has about 20 percent more power in reverse compared to its predecessor model. The result is faster cycle times and greater productivity in certain applications. The D10T2 is suited for a variety of applications including mining, heavy construction and bulk materials handling.

Mar 1, 2014

By J. C. Johnson

The problem of estimating pillar capacity in coal mines has motivated development of a variety of empirical equations. Most of these equations have arisen from experience and a very limited set of measurements that have, necessarily, been focused on particular regions or coal fields. Their applicability is often limited to a specific range of pillar sizes. This is of particular concern in the design of large gateroad pillars and small barrier pillars between panels. The result has been a variety of equations and equation coefficients that can calculate load estimates to size pillars. Inclusion of these equations in more sophisticated loading models, such as boundary element methods (e.g. LaModel and MULSIM) has been hampered by absence of a function that describes specific variation of coal strength within the pillar. A singular exception, to our knowledge, is a function corresponding to the Bieniawski pillar strength equation. Because of this, it is the only coal strength criteria inherently available in most boundary element models. This paper presents a general method for deriving local coal strength, as a function of distance from the pillar rib, for an arbitrary pillar strength equation. Integration of this function provides the strength of pillar regions, or cells, needed for boundary element models. The method is demonstrated for the Bieniawski, Maleki and Holland-Gaddy equations. The Maleki and Holland-Gaddy equations contrast strongly with Bieniawski as strengths are extrapolated to large pillars and barriers. This development provides a tool for incorporating any of the proposed empirical equations into a boundary element model, thereby allowing the analyst to choose the most appropriate equation for a particular region, coal seam and/or pillar size.

Feb 23, 2014

By William Gleason

"Once the primary fuel source for the United States and the economic backbone for communities from Appalachia to Wyoming, coal has been on a steady decline since the mid 1990s, and is now at the center of political debate in the United States.The political spectrum of the United States is divided on the future of coal and its place in the energy sector. The coal mining industry and the communities that rely on coal have increasingly been pitted against forces that wish to regulate coal to the history books.In 2008, President Obama launched what many have called his war on coal, and during his eight years in office, he pushed through numerous pieces of regulations and legislation and that he said were aimed at reducing carbon emissions, but that others viewed as direct assaults on the domestic coal industry. Obama led the United States delegation to Paris to sign the Paris Accord in 2016, a 196-country agreement pledging that the United States would do its part to reduce carbon emissions. His administration also instituted clean air, power and water regulations that added extra environmental burdens to many industries, but perhaps none more so than the coal industry.In this month’s lead feature, “A study of U.S. coal mine closures since 1994” (page 18), the impact of the war on coal, and other factors, can be seen in text and figures. Author Jacob Brinkman and coauthors Jay Schafler and Catherine Johnson scoured the data of the U.S. Energy Information Administration (EIA) and the U.S. Mine Safety and Health Administration (MSHA) to show how coal production and mines have been impacted since 1994 and how the years 1994 to 2000 and 2008 to 2016 were particularly hard on the industry.For example, in 1994 there were 2,354 coal mines in the United States. Currently, there are 1,035 mines in operation.In 2016, then candidate Donald Trump promised to end the war on coal and to put coal miners back to work. In 2017, President Trump has followed up on those promises. He announced plans to withdraw the United States from the Paris Accord, signed an executive order designed to undo the Clean Power Plan put in place by President Obama, halted the research on the health effects of mountaintop removal coal mining, directed the U.S. Environmental Protection Agency (EPA) to revise the guidelines of waste water from power plants and has touted that more than 1,000 coal miners have returned to work since he was elected."

Jan 9, 2017

By John C. Edwards, F. Friel, John J. Opferman, Robert A. Franks

A series of diesel fuel fire experiments were conducted in the Pittsburgh Research Center's Safety Research Coal Mine (SRCM) to determine products-of combustion (POC) spread rates along a single entry under zero imposed airflow conditions. Six experiments with an average fire intensity of 330 kW and three experiments with an average fire intensity of 30 kW were con- ducted in a 180 m long entry which had an average 2 m height and 4 m width. POC spread rates were measured by the response time of diffusion type CO detectors, positioned at 30 m intervals, to CO concentrations 5 ppm above ambient. For the 330 kW fires, average POC spread rates of 0.22, 0.1 3, and 0.06 m/s were determined at 30, 60, and 90 m distances from the fire. For the 30 kW fires these average spread rates were reduced to 0.08, 0.04, and 0.04 m/s. The measured maximum roof layer temperature 30 m from two of the 330 kW fire was 30 and 36"C, which is less than the 57°C alarm point of a typical mine thermal sensor. It was determined that smoke detectors can be more effective for mine fire detection than CO detectors. The experimentally determined POC spread rates can be used to provide guidance for specification of sensor spacing to improve early fire detection at zero or very low air flows.

Jan 1, 1997

By Regis F. Kopac

With the growing dependence on coal as an energy source, finding a means to prevent or reduce the freezing of coal during winter shipment has become increasingly important. Several chemical companies focused on this problem and applied chemical technology to develop suitable solutions. As a result, a number of freeze conditioning agents have been introduced in the past few years, several of which have been highly effective in controlling frozen coal. The efficacy of these chemicals has been well established, however many users have found that only a well defined program will produce acceptable results at a reasonable cost. Positive program results yielding recognizable benefits have caused many power generating and coking plants to consider freeze conditioning agents. A freeze conditioning agent (or FCA) has been defined as a multi-component organic liquid designed to be sprayed on coal particles at bulk shipping points to assure that receiving locations will be able to unload, store and use the treated coal with minimum delay or inconvenience. The chemicals are generally applied at rates of 1 to 2 pints (0.473 to 0.946 liters) per ton and normally function by changing the crystalline structure of water left on the coal during processing. The bond strength of the ice that may subsequently form is markedly reduced. Instead of freezing into solid, unmanageable masses, the coal can be easily unloaded by rotary dumping or the opening of hopper car doors.

Jan 1, 1980

By Jacob Petersen, Jon J. Kellar, Samuel Kessinger, Kiran Green

 The paper demonstrates that Belle Fourche Shale (BFS), an abundant shale, can be transformed into a ceramic through careful characterization and thermal processing. The study explores the potential of BFS ceramics for use as refractories and thermal energy-storage devices, highlighting their high thermal storage capacity, good thermal shock resistance, and cost-effectiveness.

Dec 1, 2023

By D. Akers

Many of the trace elements found in coal are associated with mineral matter, making it possible to remove them by physical coal cleaning. As part of work funded by the Electric Power Research Institute, both conventional and advanced coal cleaning processes were found to provide large reductions in the concentration of many trace elements that, if released into the atmosphere, are considered to be potentially toxic or environmentally harmful. Advanced physical cleaning technologies appear to provide greater reductions than conventional technologies. Chemical cleaning processes may also remove many trace elements, possibly including organically-bound elements such as beryllium. Care must be taken in the disposal of coal cleaning plant refuse because oxidation and leaching of this material can create highly acidic leachate and many trace elements are mobile in an acid environment. Laboratory leaching procedures are potentially useful in determining the degree of risk of water contamination by trace elements should an acid environment form.

Jan 1, 1992

By P. Anciaux

The EUs? manufacturing and construction industries are vital to Europe?s economy. They rely heavily on a steady supply of materials which meet appropriate quality criteria and are available at a competitive price. The steadily rising global demand for (non-energy) raw materials due to increasing consumption in upcoming economies such as China, India and Brazil, is in some cases leading to rapid price increases, but also supply disruptions which affect the European industry chain. These considerations are at the basis of new policy initiatives that are being prepared by Enterprise and Industry Directorate-General in relation to the competitiveness of the European metals industry. Over the last year the raw materials supply issue has increasingly become the topic of de-bate among various stakeholders. In July 2006 the European Economic and Social Committee adopted an opinion on risks and problems associated with the supply of raw materials to European industry. It is therefore important to identify and analyse the future needs for European industry, the possible constraints and impacts on its competitiveness. The raw materials supply issue should also be looked at from the view-point of the EU extractive industry, which plays an important role in supplying raw materials to the downstream industries and which faces very specific challenges. Within the Enterprise and Industry Directorate-General the different factors that influence the competitiveness of the non-energy extractive industry are being assessed, in order to help identify policies and actions which could contribute to and enhance the competitiveness of the industry.

Jan 1, 2007

By Earl Parker

The mining/mineral processing industry constantly faces the challenges of handling tons of material in a variety of processes such as crushing, milling, drying, belt transfer and loadout. These processes result in the production of high volumes of dust. A variety of dust detection and collection equipment is needed to properly manage these emissions to remain compliant with stringent air quality and safety requirements. Dust monitoring and bag leak detection can provide ways to reduce air pollutants, make work environments safer and remain compliant with requirements from the U.S. Environmental Protection Agency (EPA), U.S. Mine Safety and Health Administration (MSHA) and U.S. Occupational Safety and Health Administration (OSHA). There are several approaches to monitoring particulate emissions from dust collection equipment. These can include visual inspections, differential pressure gauges or bag leak detection systems. Bag leak detection and monitoring systems can be optical, light based or electrostatic/triboelectric. Recent developments have advanced the efficiency and reliability of electrostatic/triboelectric style monitors. New technological improvements have been developed that are based upon the principal of unifying dc (impaction) and ac (induction) signals and incorporating other proprietary circuit innovations. This higher signal resolution technology results in a more robust and stable measurement for detecting the presence of particulate in a dust collector emission duct or a flow process pipe.

By J. Kretschmann

Southeast Asian countries cannot maintain their economic growth rate without the development of their mining industries. To make this development as sustainable as possible requires sound fundamentals securing not only economic progress and environment protection but also improvements in occupational safety and health (OSH) for the miners. Mining in South East Asia is still very labor intense and dangerous. Tremendous achievements from world class mining operations in advanced mining countries can be used as role models to improve the status quo of the Southeast Asian countries in OSH management. Know-how transfer, therefore, is a key factor for major improvements. Effects of this transfer based on a multi-level approach will be discussed based on a case study. It describes the transfer from German to Vietnamese hard coal mining industry. Crucial requisites for excellent achievements in OSH in Southeast Asian mining countries are also mentioned.

Feb 23, 2014

By W. F. Visser

The growing availability of information and data analysis capabilities provides new opportunities for improving the performance of operations. By using real-time measurements and artificial intelligence, it is possible to respond faster to changing conditions, while accurate and timely information permits the rapid evaluation of changes and fast business improvement decisions. This paper presents a blueprint for system alignment, organizational design and management practices to leverage these developments in performance-driven operations management in mining and mineral processing.

Asgco’s design of the Arrowhead Ceramic Lagging provides solutions to problems experienced with conveyor belt slippage around the drive pulley and severe wear problems on snub and bend pulleys. Asgco has developed a range of pulley lagging from ceramic, drive rubber and non-drive rubber lagging that is available in abrasion-resistant SBR and MSHA grade rubber for conveyor pulleys from slow belts all the way through to high-speed, high load belts. There is a growing need for a maintenance-free and reliable pulley lagging to ensure conveyor belts run to their highest efficiency.

Jan 1, 2006

By A. Cordonnier, Ch. Obry, R. Evrard

In spite of the large annual expenditures and the vast field of activity covered, it cannot be said that many new grinding machines have actually come to light and modified the existing market for more than half a century. Manufacturers have mainly made advances in increasing machine sizes, efficiency and reliability, and in machine automation. The relatively recent emergence of roller presses is the only exception to this homogenisation of machine ranges. The development of roller presses in pregrinding has shown the advantages of compression grinding over the ball mill from the power consumption point of view. But classical roller presses still have maintenance problems due to the high grinding pressure. The FCB Research Centre has carried out much work in this field and in particular has studied the advantages of this process in pregrinding and integral grinding. These researches lead to the development of two new compression grinding machines. The first one, HOROMILL®, presented for the first time on the 8th European symposium on comminution at Stockholm, finds its application in the field of fine to very fine grinding in dry process. The second one, RHODAX®, presented at INTERMAT in Paris, covers the field of secondary and tertiary crushing and the first stage of grinding for most of the minerals in dry or wet process. Its high reduction factor permits to do with only one machine the work realised today with two or three crushing/milling stages. These two complementary machines offer a wide range of combination summarised on [Figure 1].

Jan 1, 1995

By Biswajit Samanta, Pranjal Pathak

A multimine mineral value chain (MVC) consists of multiple mines in the upstream supplying raw materials to multiple destinations in the downstream. The short-term mine production scheduling problem of a multimine MVC aims to determine the optimal extraction sequence and destination allocation of blocks from all the mines collaboratively to meet the quality and quantity requirements of all the processing plants in each period, subject to all relevant technical and operational constraints of the mining system. It is carried out at shorter scales of days/weeks/months under the purview of long-term production scheduling. An optimal short-term production schedule for MVC involving multiple mines that share the same infrastructure (processing units, stockpiles and waste dumps) requires coordination across the network of mines. Optimizing the short-term production schedules independently at each mine fails to capture the benefit of collaboratively generating schedules for all the mines, resulting in suboptimal schedules. Additionally, in short-term production scheduling, the operations are modeled in greater detail with additional decision variables and constraints to model the more complex multimine MVC situations. This makes the large-scale instances of the problem computationally intractable for standard mixed-integer programming (MIP) solvers. This work presents a customized genetic algorithm (GA)-based heuristic approach to obtain near-optimal solutions to the industrial-scale instances of the short-term production scheduling problem of multimine MVC within a reasonable computation time.

Oct 1, 2022

By Brent A. Elliott, J. Richard Kyle

This article reviews the production trends of industrial minerals since 2000 for Texas, the leading U.S. producing state of industrial minerals with a total value of $5.2 billion in 2017, equivalent to 6.9 percent of all U.S. minerals value. Most current Texas industrial-mineral value comes from the production of cement, crushed stone, industrial sand, and construction sand and gravel. Construction material consumption is concentrated in the 25 metropolitan areas of the state, with production of industrial minerals in nearby counties. With Texas’ population projected to reach 50 million by 2050, continuing in-state development and production of industrial minerals will be required to meet in-state and regional demand. Texas’ most rapidly growing production of industrial minerals is industrial sand to supply proppants for multiple unconventional petroleum plays. Texas’ favorable geology and economic factors provide opportunities for the identification and development of new industrial-mineral production sites. Repurposing of former industrial-mineral production sites for post-production development likely will increase as efficient land use evolves. Understanding the geologic, economic and societal framework of industrial-mineral resources will facilitate more informed decisions about the complex issues that the region will face, including effects of sea-level rise on coastal infrastructure.

By A. D. Hammond

Vanadium is a transition metal, ductile, silver-gray metal. It is harder than most metals and steels and it has a good resistance to corrosion, it is stable against alkalis, sulfuric and hydrochloric acids. Vanadium is oxidized in air about 660 °C, although an oxide layer forms even at room temperature. The chemistry of vanadium is noteworthy for the accessibility of the four adjacent oxidation states 2-5. In aqueous solution the colors are lilac V2+, green V3+, blue VO2+ and, at high pH, yellow VO42-. Considered to be as abundant as zinc, metallic vanadium is not found in nature, but it is known to exist in about 65 different minerals. Economically significant examples include patronite (VS4), vanadinite (Pb5(VO4)3Cl), associated to the uranium mineral carnotite (K2(UO2)2(VO4)2?3H2O) and in a vanadium mica called, roscoelite K(V3+,Al,Mg)[(Si,Al)4O10](OH)2. Other important vanadium ore oxides are montroseite (V,Fe)O(OH) and corvusite (Na,Ca,K)V8O2.4H2O. Much of the world's vanadium mine production comes from magnetite-hosted deposit and to a lesser extent, in sedimentary-hosted sandstone. Vanadium is also present in bauxite and in fossil fuel deposits such as crude oil, coal, oil shale and tar sands. In crude oil, concentrations up to 1,200 ppm have been reported. A significant vanadium production comes from the processing of petroleum residues, fly ash and recycling spent catalysts. In 2011, metallurgical applications accounted for 93% of the use of vanadium. Here, an alloy called ferrovanadium is utilized to strengthen steel to be used as rebar in the construction industry, in the manufacturing of axles, crankshafts, gears and chassis in the automotive and transportation industries and in the manufacturing of high-speed tools. In the aerospace industry, vanadium is utilized as a titanium alloy in the manufacturing of airframes and jet engines. The reason for the wide use of vanadium as alloy is its high strength-to-weight ratio, the highest of any engineered material on earth. The major non-metallurgical use of vanadium is in the production of catalysts for the chemical industry. The most commercially important compound is vanadium pentoxide (V2O5), which is used as catalyst in the production of sulfuric acid.

Feb 23, 2014

By K. Galos

The paper presents increasing importance of mineral secondary and waste raw materials in the minerals management in Poland. Definition of mineral secondary and waste raw materials is proposed, according to current Polish law. On this basis, sources of various types of mineral waste raw materials are analysed. The special attention is paid to the wastes from mining and processing, wastes from power plants, and wastes from steelworks and other smelters. Other types of waste and secondary materials, such as metallic containers, glass containers, batteries, metallic wastes and scraps, are also taken into account. Analysis of sources of such materials is shown together with the main directions of their economic use. Available sources of information on manufacture and use of the mentioned secondary and waste raw materials are also analysed. Finally, for a wide range of waste materials, their current and expected significance as substitutes for some industrial and construction minerals in Poland is given.

Jan 1, 2011

By MEHMET ALI RECAI ONAL, MAHMUT CAMALAN

The key motivation of this study is to evaluate the potential of well-known hazardous gases—carbon dioxide (CO2), hydrogen (H2) and oxygen (O2)—as grinding aids for mineral liberation in ball milling. The results show that exposure of chromite ore particles to CO2 flow will promote chromite liberation at breakage and, therefore, using CO2 as a grinding aid may partially reduce the carbon footprint of the mining industry. For that purpose, the use of two-phase (gas–solid) or three-phase (gas–solid–water) moving-bed mixers are recommended for the pretreatment of mill feed before ball milling.

By Keith Wallace

Although systematic control of ventilating air currents in underground mines dates back to the Greek and Roman empires, quantified analysis dealing with the cost of providing airflow did not appear until about 1860 when the first fans with acceptable efficiencies became available. Initially, these were introduced to avert methane explosions initiated by shaft bottom furnaces. However, discussions arose on how much coal the steam driven fans consumed in comparison with shaft furnaces in order to produce the sane amount of airflow. Ventilation economics had arrived. In 1981/82 a project was funded by the Department of Energy and carried out at the University of California, Berkeley in order to analyze and compare alternative ventilation designs from the viewpoint of economics and systems efficiency1. This paper highlights some of the results of that study.

Jan 1, 1983

By Yuting Xue, Danqing Gao, Brijes Mishra

Heterogeneity and discontinuity significantly affect rockmass strength. Past studies have largely used arbitrary scaling approaches to produce rockmass strength from laboratory rock tests. This paper proposes a stochastic approach to produce rockmass strength from laboratory rock tests. Based on the laboratory data, MATLAB with an extreme value stochastic model generated a database for each physico-mechanical property of the rock. Then finite-difference software FLAC2D simulated laboratory-sized rock specimens. Random material properties in MATLAB were generated using the grids developed in the numerical model. The random properties were then applied to the final FLAC2D model. Model runs simulated the approach performed in the laboratory. The results from the model indicate that a stochastic approach produced compressive strengths that were lower than those from the deterministic approach. Failure modes for each specimen were different from those observed in the laboratory. In addition, random density also influenced the failure mode, highlighting the importance of stochastic analysis in rocks.