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In 1992, the United States economy grew at a rate of 2%. The Gross Domestic Product rose to $5,946 billion. With 257 million people - 635,000 in mining including petroleum - the United States has more than 100 million dwelling units and more than 190 million licensed motor vehicles. New private housing starts rose I 1 % to 1.2 million units. New car production rose 4% to 5.7 million units. Truck and bus production rose 20% to 4 million units. The rate of inflation was 3.5% and the prime rate of interest was 6.25%. The Producer Price Index (1982 =100) was relatively unchanged from 1991 as follows: fuels and related products and power 80, metals and metal products 119, chemicals and allied products 126 and nonmetallic mineral products 117. Energy Imports of crude and refined petroleum, costing $50 billion, rose 3% to 455 Mm3 (2.9 billion bbl). Domestic petroleum production fell 1 % to 582 Mm3 (3.5 billion bbl). Petroleum supplied about 41 % of US energy, natural gas 24% and coal 23%. Coal production, 60% from surface operations, rose 1 % to 914 Mt (1 billion st). About 78% was used to generate electricity and 3% was coked. Exports valued at $4 billion included 57 Mt (63 million st) of metallurgical coal and 39 Mt (43 million st) of steam coal. Ura¬nium mining, including recovery from phosphates, fell 18% to 3 kt (3300 st) U308.

Jan 1, 1993

By M. Javier

Defining the concept of sustainability is an important step for industry and society. It is necessary in order to clarify what it means when debunking the many misinterpretations pervasive in different levels of anthropogenic activities. Essentially, the extractive industry has a harvest of differences. Mining involves the extraction of natural resources which are finite, exhaustible, non-renewable, unsustainable, and pay only once. It is remarkable that the definition of sustainability that we will shortly arrive at has totally different characteristics from the definition accepted throughout society. We categorize nature as having its own destiny which is controlled by its own rules and principles and its own society, and is part of nature; therefore, society depends on nature and not vice versa as the initial focus. To society there are no conditions to humanize nature but only respect nature?s rules. It was a challenge to find simplicity for this task not only for the definition but also for the explanation of this concept specifically, to answer the question, ?what is the true meaning of sustainability?? Finally, we are also able through this definition to provide fuel for wide discussions and stimulate critical thinking to improve such a concept. As a result, we present this definition as the tool for society today and for future generations.

Jan 1, 2012

By D. C. Dahlin, W. K. O’Connor, G. E. Rush, C. A. Summers, S. J. Gerdemann

The Albany Research Center (ARC) conducted studies of mechanical activation by conventional and ultra-fine grinding techniques to enhance olivine reactivity in mineral carbonation reactions. Activated olivine is one of several solid feed materials used at ARC in reactions with carbon dioxide to form carbonate minerals. This paper compares grinding techniques via energy demand data and product characteristics, including particle size distributions, surface areas, full width at half maximum (FWHM) XRD analyses, and particle morphology by SEM analyses. Reactivity was gauged by percent conversion to carbonate in subsequent carbonation tests.

Jan 1, 2004

By B. Moore, Y. J. Zhang

In today’s competitive dimensional stone business environment, use of available technology is critical to achieve and maintain a competitive advantage. Awareness of improvements in diamond cutting technology, operation planning/scheduling, and geotechnical data manipulation/implementation are the keys to success. This paper presents the modern techniques of limestone sawing and quarrying developed and adopted by Indiana Limestone Company, Inc.(ILCI).To fulfill the growing market demands, ILCI’s quarries are committed to deliver planned quantities of all type of stone blocks in a variety of different colors, sizes, and textures. This involves scheduling which quarry ledges should be mined and when in order to minimize unnecessary inventory buildup. Challenges associated with ILCI’s operation are discussed and summarized in the closing of this paper.

Jan 1, 2004

By H. Do

In flotation, hydrophobic particles are selectively collected by air bubbles, and the bubble-particle aggregates enter the froth phase. However, less hydrophobic particles drop off from the froth phase, while more hydrophobic particles are recovered. Thus, the froth phase provides an important cleaning mechanism. In the present communication, the froth-phase recovery process has been modeled by considering particle retention times and the carrying capacities of bubbles. The model predictions are compared with the experimental data reported by Seaman et al. (2006). The results show that the froth-phase recovery varies with particle size, particle hydrophobicity, and bubble coarsening.

Jan 1, 2008

"The 34th International Conference on Ground Control in Mining (ICGCM) was held July 28–30 at the Lakeview Golf Resort and Spa in Morgantown, WV. Ground control experts have gathered at this location since 1981 to share ideas and successes for improving designs and technologies to enhance the stability of surface and underground mining operations. Ground control is important to all mining operations but is particularly crucial to underground mining to ensure miner safety and operational viability.The year’s event had 240 registered attendees with 20 pecent of that attendance being from the mining industry. A remarkable number of industry representatives attended given the challenges currently faced by the mining industry. A true testament to the value of the conference, the performance of Tom Barczak and Steve Tadolini as co-chairs and the drawing power of the many exceptional speakers that have attended the annual event for many years.The conference operates under the direction of a board of directors with the cooperation, wisdom and assistance of a large organizing committee. Visit the conference website, www.icgcm.conferenceacademy.com, to view the membership of the board and the committee and to access previously published papers."

Jan 1, 2015

By Ian Martin

A precious metals refinery’s switch to personal computer-based, three-dimensional piping design saved many hours in the design of a South African precious metals refinery. Bateman Minerals and Industrial provided engineering, procurement and construction management services for Impala Platinum Limited-Refineries’ new $60 million refinery in Springs, South Africa. This project is one of the largest platinum refineries in the world. Bateman evaluated a new design method during this project that involved developing a three-dimensional model for the project. The new method saved time by reducing the man-hours required to generate complete project documentation, including plans, sections, isometrics and material takeoffs. The new method also saved design and construction time by allowing designers to detect clashes before construction began.

Jan 1, 2000

By G. V. Krishnan, L. Adler

A rock classification for drilling and boring is presented covering most equipment types and providing an estimation of the key parameters for operation, such as thrust and speed, and of performance such as penetration rate and bit life. Drilling and boring are significant and integral aspects of both the mining and heavy construction industries. Together these constitute over 20% of the G.N.P. Drilling and boring represent the most arduous mechanical processes performed in industry. Their misapplication quickly leads to equipment destruction, hazards, and to major delays. The classification is unified in two ways: 1) for a particular rock class several parameters can be estimated, 2) the classification integrates most excavating activities (i.e. digging, ripping and even blasting), and is derived from ground control. The rock classification provides a job property, based on fundamental and index properties, which yields quick and rough estimates of vital information. However it does not obviate the need for a more thorough analysis, and maintaining field records. BACKGROUND In order to adequately describe a drilling operation the conditions, activity, and equipment must be characterized. Of these the major independent variables are the conditions. Conditions focus on the geologic mass and also consider whether the site is surface or underground. The primary component of the geologic mass is the rock type, detailed below in Rock Characteristics. The other components

Jan 1, 1983

Instabilities occurred as a result of climate changes caused to investigate the rock behavior dependency to temperature changes, in this paper. In the natural earth condition, the phase transition of pore water has known to be the most effective factor causing different rocks mechanical properties due to temperature changes. So, the temperature range of [-30, 30]°C is selected in laboratory tests of this study. P-wave velocity, unconfined compressive strength (UCS) and elasticity modulus of rocks at different temperatures are studied by developing a temperature adjusting apparatus. The tests were performed on three rock types. The results show that firstly, the temperature reduction and pore fluid freezing improves these rock?s mechanical properties. Secondly, the dependency of rock properties to climate changes depends on the type and shape of its porosity as well as porosity percent. The improvement of rock mechanical properties in jointed rocks exceeds rocks with spherical pores. Finally, maximum changes in rock?s properties occur at [-10, 0]°C, which includes the phase transition of pore fluid. Keywords: Temperature; Rock Mechanical Properties; Pore Fluid; Porosity.

Feb 27, 2013

By Steve Dubnewych

The Joint Water Pollution Control Plant, operated by the Sanitation Districts of Los Angeles County, treats wastewater generated by over three million people. A new tunnel and ocean outfall is being considered to meet future hydraulic demands and provide long-term redundancy for the Districts? existing tunnels, portions of which were constructed as early as the 1930s. The detailed process used to evaluate the feasibility of various tunnel and out-fall locations is described. Challenges include a geologic profile with mixed face and squeezing ground conditions; high water pressures; active fault crossings; gassy and contaminated ground conditions; and liquefaction, slope stability, and lateral spreading concerns in the area of the riser and diffusers.

By M. Slatter

The need for anti-corrosion coatings has existed for many years in the ground support industry, but the application requirements have made coating selection limited. Varying groundwater and chemical conditions continually challenge long term coating performance. Traditionally the industry coating preference has been hot-dip galvanizing due to its performance characteristics in highly corrosive environments and low cost nature. However, the galvanized coating has application limitations. This paper highlights some of these limitations and provides selection criteria for a new organic coating developed for one such difficult application, DSI?s Omega BoltPTM Pwhich is an expandable ground support. [ ]

Jan 1, 2009

By J. A. Mielczarski

Surface properties of minerals could be modified selectively and very specifically by adsorption -desorption (dissolution) processes. This requires a monitoring and control of the outermost surface layer at a molecular and atomic level. The nature and structure of self-assembled submonolayers and monolayers at the interface of minerals were studied by infrared reflection spectroscopy. The external reflection spectra of the adsorbed monolayers on any type of minerals: transparent, opaque or non-transparent, recorded at different angles of incidence and for two polarizations are an excellent source of information about the nature and surface distribution of the adsorbed species. The developed method allows to obtain detailed information at a molecular level about the adsorbed surface species. By combination of the simulated and experimental data, the qualitative description of the adsorbed species as well as quantitative evaluation of orientation and the thickness of the adsorption layers were obtained. This fundamental knowledge allows to determine the mechanisms of surface phenomena which govern selective separations. Examples of different surfactant - mineral systems and industrial applications will be discussed.

Jan 1, 2000

By J. P. Kennedy, O. A. Bascur

Large metallurgical complexes have more data than a small city and these data change as internal and external conditions evolve. Staffing turnover hinders experienced-based decisions especially with simple tools like spreadsheets. Lack of current information can contribute to decisions that result in significant deterioration in the quality of operation. Timely, unified information from sophisticated analyses presented to the broadest possible reach will improve operation. The major innovation is the addition of the web browser to the suite of software people will use with no training – the other two are spreadsheets and graphical presentations – and the consistent organization and transformation of the real time data to support broad access. This paper describes the data transformations and presentation methods necessary for a Web view, especially the special needs of real time data and analysis required for active operations decision-making. Many people inside and outside the complex, not just operators, need timely information that is abstracted, aggregated, organized and unified. Unification and aggregation of real time data presented via the Web opens a new paradigm for collaboration. The analysis tools are as important as the data. These rule-based tools add significantly to the operations database in the form of results stored for viewing with plant data. Mining and metallurgical plants already use many sophisticated analysis tools such as predictive maintenance policies based on statistical analysis vibration analysis, and oil and lube analysis for critical equipment. These add real time events, similar to an alarm package, and unified production information to the operational database. Simple models are used on line to create key indices that provide a real time indication of performance. Key indices include metrics for losses due to plant availability, performance efficiency, and overall process equipment effectiveness. These additional data in the operations database are used for early fault detection, increased production, better quality, higher availability of equipment and faster detection of process bottlenecks. An important feature is the ability for people to create their own key indices and store the results for use by anyone in the plant historian, but accessible by a browser. Keywords: plant information, principle components analysis, data reconciliation, gross error estimation, Internet, Word Wide Web

Jan 1, 2002

By R. Leithner

The need/wish to sequestrate CO2is based on the assumption of the International Panel of Climate Change (IPCC), that CO2 maybe the major driver in climatic changes, i.e. especially the anthropogenic CO2emissions due to the combustion of fossil fuels like coal, oil and natural gas will increase the atmospheric CO2-content, which will lead to higher temperatures in the atmosphere. The 0.03% CO2in the atmosphere have a 22% share of the natural greenhouse gas effect of 33 K necessary for life on earth. The main share of 62% has the water vapour in the atmosphere. Only if one concentrates on the greenhouse gas effect of the gases beside water vapour, CO2 becomes most important with 58% influence. In addition there are other influences on the climate like: • Eccentricity of earth’s orbit, precession of orbital plane, obliquity and precession of earth’s rotation axis (Milankovitch’s theory) • Sunspots and magnetic field of the sun • Changing streams in the ocean • Volcanic activities • Distribution of continents on the surface of the earth • Impact of meteorites • Change of insulation by interplanetary dust [Muller, R.A. 2000] etc. To answer the question, if the CO2-content in the atmosphere has an important or exclusive influence on the earth atmospheric mean surface temperature, one should look into history. Figure 1shows the mean temperature of the atmosphere and the atmospheric CO2-content time histories 1 billion years back; no correlation can be found between them. Nevertheless a lot of countries have committed themselves to reduce their CO2-emissions.

Jan 1, 2004

By Ken Mathers, Tom Conley, Jim Rozek

The Melbourne City Link Tunnels have been constructed through a BOOT process, the largest undertaking in Australia to date. Tolling commenced on the 1.6 kilometer Domain tunnel in April 2000, and the 3.4 kilometer Burnley tunnel December 2000. The project was delivered by design construct contracting and under ISO 9000. There were a number of major challenges in completing the tunnels, including much higher than expected groundwater infiltration, hydrostatic pressures greater than 6 bar, and unique design and construction applications required to prepare the tunnels for service. This paper covers the end play and final delivery of the tunnels.

Jan 1, 2001

By V. Kecojevic

The objective of this research was to establish the relationship between production, consumption and energy cost in the surface mining of bituminous coal. Specific energy sources such as diesel, gasoline, electricity, explosives and bituminous coal were considered in this study. Gain in net energy, proportion of the cost of energy consumption and total energy cost relative to total revenue of extracted coal were determined, and a new energy efficiency index and a new energy-cost ratio were established. A case study on an operating surface coal mine was carried out to demonstrate the application of the newly developed method. The results of this study can be used by the mine operators in establishing strategies for the optimization of energy production and consumption, and for reducing the cost of bituminous coal extraction.

Jan 1, 2014

By D. He

In China, the total reserves of vanadium, reported as V2O5, in stone coal is 118 Mt (130 million st). Recovering vanadium from such a large resource is very important to China?s vanadium industry. The technology now being used to recover vanadium from stone coal has the following two problems in the leaching process: a low recovery of vanadium and high acid consumption. To resolve these problems, a new leaching technology is proposed. The effects of factors such as H2SO4 concentration, liquid-solid ratio, temperature and time, and the types and additions of additives were studied. By adding 1.5% (by weight) CaF2 and leaching the roasted residue of stone coal with 5.4% (by weight) sulfuric acid at 90°C for 12 hours at a liquid-solid ratio of 2 mL/g, the leaching degree of vanadium reached 83.10%. This proposed leaching technology gives a feasible alternative for the processing of roasting residue of stone coal and can be applied in the comprehensive utilization of stone coal ores in China.

Jan 1, 2008

Narrow vein mining, with enough challenge and also where the cutting edge technology can be applied, is still a very important and exciting portion of the mining industry. Based on the deposit characteristics, the most flexible mining method, cut and fill, has been being tested mining this high grade Northern Nevada property, Hollister, since the year of 2008. In the last three years, 254,000 tons of ore were hauled out of the portal and 23,000 feet of development were excavated underground with the winning of several safety and environmental awards. Together with mine geology, the essential segments include mining cycle, ground control, ventilation, grade control and backfill method in cut and fill stopes were covered in this paper.

Jan 1, 2012

By Chris Tattersall, Tomyuki Kudo, Peter Raleigh, Nestor Garavelli, Steve Redmond, Michael J. Lehnen

Twin bore running tunnels driven approximately 4,500 route feet by a Mitsubishi Heavy Industries (MHI) EPB Tunnel Boring Machine link the West Portal and East Portal on this complex Light Rail Project. One third along the way, the TBM arrives at the Beacon Hill Station which is the deepest underground “binocular” station of its kind in North America and then “walks-across” the station to be re-launched on the other side to complete the drive. This paper discusses briefly the layout and design considerations but then focuses more deeply on the approach by the Contractor to drive and supply the tunnel. The paper addresses the approach used to launch, re-launch and recover the TBM and touches briefly on muck volume control and monitoring plus settlement monitoring and the performance achieved. Also of interest is a unique solution to a difficult launch situation involving a secant pile tieback wall designed with several rows of double I-beam steel walers spanning the eye at the West Portal under the I-5 freeway.

Jan 1, 2007

By Steven E. Mischler, Jay F. Colinet

The study analyzes the impact of the Continuous Personal Dust Monitor (CPDM) on reducing overexposures to coal mine dust. It compares compliance sampling data before and after the implementation of the CPDM and the 2014 MSHA dust rule. The results indicate a significant reduction in the percentage of samples exceeding the dust standard for various mining occupations, highlighting the effectiveness of the CPDM in improving miners’ health and safety.

Feb 22, 2022