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By N. R. Joshi, A. D. Agate

It is estimated that more than 80% of phosphate rock output in the world is used for fertilizer production. In India, there are only a few high-grade deposits of phosphate ores; therefore, most of the requirement for phosphatic fertilizers is satisfied with imported DAP (diamino phosphoric acid). Due to the drain on foreign exchange reserves, this import-dependent, essential commodity is in short supply in India and, therefore, is sparingly used by farmers. In addition, of the added phosphorus, normally 80% becomes unavailable to plants because phosphorus complexes are formed in soil, causing deleterious effects on plants. In our laboratory, this problem was tackled by using a bacterial consortium of phosphorus-solubilizing bacteria. It resulted in the speeding up of seed germination and increasing available phosphorus in the soil by 14%, over a period of 80 days. To use the low-grade deposits of phosphatic rocks available in India near Hirapur, Madhya Pradesh, India, which contain high amounts of iron, beneficiation through microbial means was used for phosphorus removal. Beneficiation was achieved partially through removal of extra iron by oxidizing ferrous iron from the ore by a Thiobacillus species after removal of impurities containing both silica and iron, instead of sieving and cleaning the ore using different techniques. This resulted in a cleaner ore, with nearly 70% of such impurities removed. The factors for beneficiation technique were standardized at the laboratory level and are being used for scaling up of the process. Thus, the beneficiation of phosphatic rock from Hirapur will be an important first step of phosphorus production in India.

Jan 1, 1999

By V. Badaker, R. J. Sweigard, C. D. Barton, J. W. Stringer, J. M. Ringe, A. D. True, D. H. Graves

Field studies have demonstrated the relationship between the growth of high-value trees on surface mined land and the physical conditions of the root growth medium. Specifically, the survival and height of hardwoods grown on less compacted material are far superior to those grown on compacted material. Furthermore, studies have demonstrated that the physical condition of the root growth medium can be characterized by dry bulk density and penetrometer resistance and that these parameters are also related to tree growth measurements. Site indices are useful for evaluating and predicting the productivity and timber yield for a specific location. A method has been proposed to estimate the site indices for various tree species on reclaimed surface mined land as a function of the physical properties of the root growth medium.

Jan 1, 2005

By G. W. Luxbacher

Acid rain legislation included in the Clean Air Act Amendments of 1990 caused a great deal of uncertainty regarding the price, source and production quantities of coal supplied to the eastern coal market. Powder River Basin and other western coals continue a rapidly accelerating migration eastward. South American coals move into the northern markets. States are proposing legislation to assist utilities in complying with the new regulations in hopes of maintaining their own coal industries. Some utilities question the long-term availability of eastern compliance coal. Major coal producers must make decisions now to assure their continuing presence in the market place. Several companies have adopted a strategy to acquire eastern compliance reserves, while others have invested in technology to compete as a low-cost producer. Legislation "Acid rain." This is a topic that was debated within the scientific, environmental and industrial communities for years. Those discussions resulted in a large outlay for the federal National Acid Precipitation Assessment Project (NAPAP), which was then ignored. Acid rain then became the subject of a "60 Minutes" broadcast that debunked the acid rain theory, supporting the NAPAP study conclusions. In the final outcome, however, acid rain was the driver for the Clean Air Act Amendments of 1990.

Jan 1, 1992

By Peter Sullivan, Johan van Heerden

Increased use of continuous miners and roadheaders in the underground coal mining industry in South Africa has led to improved productivity and efficiency of operations. Of major concern, however, is the increased amount of airborne dust generated during mining. Dust is a health hazard in terms of respiratory diseases, can impede productivity and is the major contributor to the potential of underground explosions. The concern of the South African coal mining industry with regard to the underground dust problem has led to the establishment of a Dust Control Section in the Coal Mining Division of COMRO. In the field of dust suppression system evaluation and design, collaborative work has been undertaken by COMRO and FLOSEP. This paper gives a review of the application of Computational Fluid Dynamics (CFD) in evaluating and improving environmental conditions in continuous miner and roadheader sections. A brief history of the development of the CFD model as well as a discussion of a typical application is included.

Jan 1, 1993

By Nicola Beltrandi, Andrea Pigorini, Holad Mohamed Dahir, Ezio Pedone

"Genoa is a very distinctive city located between mountains and the sea and infrastructural upgrading works often have to deal with the intersection of existing infrastructures. This is the case for the new railway tunnel construction between the stations of Brignole and Principe which under-cross two existing double-track tunnels in operation. The latter have been constructed with masonry bricks and the vertical distance between old and new tunnels is approximately 1m. Due to rock characteristics and the urban environment, stability and vibrations control are the main issues. Consolidation work with the fore-poling method and a specific sequence of excavation, primary lining and final lining support have been designed to assure stability and settlement control. A hard rock road-header has been used to assure vibration control. Finally, a real time monitoring has been implemented. The article presents monitoring and back-analysis results of the under-crossing of the existing tunnels. GENERAL LAYOUT OF WORKS The Genoa railway junction constitutes an integral part of the Ventimiglia-Genoa-Novara-Milan railway line route and it is included amongst the railway systems of the Tyrrhenian-Northern European multi-modal corridor (corridor of the two seas or corridor VII Genoa-Rotterdam). The main aims of the project concern the upgrading of the existing lines and the separation of the long-distance passenger and freight traffic flows from those of a regional and metropolitan type. The project includes: •,Completion of the connection with the port of Genoa Voltri and the Italy-France coastal route. •,Interconnection with the future Terzo Valico dei Giovi mountain pass route towards Milan. •,Upgrading of the Genoa Voltri – Genoa Brignole main line to four/six tracks. Rearrangement of the systems at the Genoa Voltri, Genoa Sampierdarena and Genoa Brignole Stations, reorganisation of the services in the Genoa Terralba area and interchangeability with the metropolitan system complete the design activities. The contract which includes civil and technology works is divided into four construction lots (ref. Figure 1):"

Jan 1, 2016

By M. Javier

"Mining makes civilization possible. It also creates socio-environmental liabilities forcing us to ask how much more of this mining can our planet support. It is clear that the future of mining differs from mining in the future. The laws of nature are being compromised by mining. This paper studies the problems at the core of the mining business which need to be addressed. What kind of mining will serve our existence with nature on this planet? What kind of mining perspectives are we able to formulate without having negative effects for future generations? Is mining technologically sustainable? The values of predictions, imagination, and creativity must be integrated to define what mining should be. Those values should be in the technologies necessary to restoring equilibrium of nature (Geomimic) as well as in complete extraction of metals, better utilization of the mineral reserves, and design the usage of metals to recycle. The purpose of this research is to examine many views and perspectives for future generations and to accelerate the pace of innovation of having mining without socio-environmental liabilities by design and by understanding nature. KEYWORDS: Geomimic, Sustainability, Waste mine Design, Management by Loss. INTRODUCTION The future of mining is being stifled by many antiquated and stagnant attitudes and policies by the industry and society as a whole. The time is now or never for real action and education against these attitudes and to upgrade them to meet the current needs of this planet if we are to survive. Doing this will prove that we understand and respect nature for us and our posterity. It will also show a positive assessment that the mining process can be reversed before the point of no return. And that is to say, only if reversibility is still an option. It may not be anymore but it’s worth a try. We need to use our imagination and engineering know-how to come up with new proposals to change the core of mining. It would entail re-engineering. There is a profound difference between the future of mining and mining in the future. The future of mining is the continuation and persistence of past practices in the industry and expecting new results. Mining in the future requires a paradigm shift for extraction through modern thinking about mining as it pertains nature. The new paradigm for mining in the future would restore equilibrium with nature. Always keep in mind the connection of mining to nature. What is the future of nature? To predict mining in the future we need to use past experiences in mining and our knowledge of modern science and engineering to formulate a prototype that will enhance mining while maintaining equilibrium with nature. Mining and protecting nature are not mutually exclusive. This new prototype has nothing to do with the level of bonding or insurance that the mining industry can legally provide. The goal of this paper is to contribute some new ideas to help transform the mining industry based on the laws of nature and its limitations. Using this new prototype we will develop the following 1. Extraction of minerals Reserves-Dimensions-Technologies 2. Usage of mineral resources-Manufacture’s products designed to be reused and recycled 3. Nature- Equilibrium (physical, chemical and biological)"

Jan 1, 2016

By Ernest K. Yanful, Paul H. Simms

The lysimeter is a useful tool for evaluating the performance of mine waste covers or liners. A major problem with its application is the possibility for preferential flow into or away from the lysimeter, if the lysimeter soil is finer or coarser than the barrier soil or sub-base soil. Analysis of a field lysimeter using a two-dimensional unsaturated-saturated liquid flow model suggested that preferential flow would occur and little or no water would be collected; however, in the field, the lysimeters collected significant amounts of water. A similar discrepancy was found between the observed and predicted water balance of a simple laboratory test simulating the lysimeter design. Vapour flow and partial flow, two phenomena not generally simulated in conventional flow models, are possible explanations for the difference between field and laboratory observations.

Jan 1, 2000

By Sandy Clamage

"Seeing the elephant" was a term often heard from 1849 to 1859, the period of the great California Gold Rush. The phrase was used by those who dreamed of instant wealth that was believed could be found in California's virgin earth and mighty rivers. When news of fabulous gold strikes throughout the Mother Lode reached far away places, thousands of gold seekers left home and family to join in this incredible adventure. The barren, placid state of California soon became one of the most bustling, populous areas in the West. Before the Rush Before 1848, Mexico ruled California. It was then a remote region, isolated from the urbane world of the East by 2900 km (1800 miles) of scorching desert and impassible mountains. By sea, it was 29 000 km (18,000 miles) via Cape Horn. Spaniards and Mexicans settled the coastal lands on tracts donated to them by the Mexican government. The inland area was the domain of Indians and a few settlers who also had been granted estates by the government. Among those settlers was Captain John Sutter. He had been fortunate enough to obtain about 11 leagues of land (spanning 100 km or 60 miles in length) from Governor Alvarado of Mexico. Sutter was somewhat of a visionary and possessed a gifted tongue. He managed to receive most of what he desired with minimal trouble. Enchanted with Sutter's personality, Alvarado promised him Mexican citizenship. Alvarado also commissioned him to become "representative of the government and officer of justice on the Northern frontier." With uncanny foresight, Sutter began building a fortress on his land in the Sacramento Valley. It later became known as Sutter's Fort. It was more than just a fort, however. It also became a stopping place and home for many foreigners and Americans who traveled to California, and it eventually became the mecca for overland pilgrims. Sutter engaged in many projects. These included a cattle ranch, fur trade and trapping, and the construction of an irrigation system. With the influx of immigrants over the years, the community around the fort grew rapidly. Lumber was much in demand and Captain Sutter agreed to supply the necessary capital for a community sawmill. The site chosen was some 72 km (45 miles) northeast of the fort on the south fork of the American River in the town of Coloma. During the course of its construction, Sutter's carpenter, James Marshall, discovered a problem with the tailrace on the mill. First Strike Early in the morning on Jan. 24, 1848, Marshall was checking the tailrace. He noticed an object shining in a foot of water at the bottom of a ditch. He reached down and picked it up. His heart began to thump wildly as he realized he was holding a gold nugget. Sutter planned to keep the find a secret for as long as possible. He knew very well that he could become an extremely wealthy man. The ever loyal Marshall remained faithful to his employer and the pair did their best to obtain more

Jan 3, 1985

By Wojciech Klecan, John H. Raymer

Baseline quantities of difficult ground and support types were estimated for the Chattahoochee Tunnel using the Rock Mass Rating system. RMR classifies the ground into five categories, ranging from “very good” to “very poor,” based on five main parameters: intact rock strength, RQD, joint spacing, joint condition, and groundwater inflow. For the Chattahoochee Tunnel, these parameters were independently measured in the cores and shown graphically on the boring logs. A 55 matrix was calculated to obtain the statistical distribution of RMR for the project. Three baseline ground types were defined based on the RMR. Geologic mapping inside the tunnel during construction has verified the accuracy of this method.

Jan 1, 2003

By R. J. McGregor

The Internet has revolutionized worldwide communications. Any real or perceived mining incident or environmental spill, no matter how small or remote, can become a disaster of "biblical proportions" through the judicious use of the Internet by environmental and anti-mining groups. In addition, mining companies' own Web sites and unofficial message boards can provide plenty of additional ammunition to the anti-mining forces. This paper explores how the Internet and readily available information are used by anti-mining groups active on the Web.

Jan 1, 2001

By David J. Leeds

Increased interest in the utilization of the underground environment for water conveyance tunnels, vehicular tunnels, room and pillar type storage chambers, and military installations has focused attention on the possible effects of seismic activity on the stability of these types of structures. Earthquake experience has generally been related to the seismic stability on the surface of the earth. To establish aseismic design criteria, we attempt to predict the seismic exposure of a given site, both in terms of the spectrum of motion to which the structure must react favorably, and the recurrence rate of that motion. Experience gained from studying the effects of the Plowshare underground nuclear tests on existing tunnels and mines, coupled with the experience of the behavior of tunnels and mines in earthquake regions, provides us with an insight to predict the possible effects of earthquakes on underground openings and to establish design criteria. The type of damage ranges from minor fracturing and movements along pre-existing joints or faults through deformation of openings to collapse. The methods used to establish the seismic design criteria for an underground opening require modification of surface criteria to account for the difference in both amplitude and spectra underground. An aseismic evaluation should be performed on all important projects in areas exposed to possible earthquake motion. To perform this evaluation, information is required pertaining to the geometry and properties of structure and ground. Dynamic as well as static properties are required. A prediction of performance can be derived by exposing a model of the site, expressed in terms of its properties and geometry, to a design earthquake.

Jan 1, 1997

By Thomas C. Anderson, Terry Weiss

The Mount Gunnison No. 1 Mine of the West Elk Coal Company (wholly owned subsidiary of ARCO Coal) had secured contracts to provide low sulfur, high Btu steam coal to various utility companies. This called for the development of the B-Seam at the Mount Gunnison Mine located some 400 feet below the operating F-Seam workings being mined with conventional room and pillar techniques. The B-Seam, to meet production goals, will be mined by a new 600-foot longwall machine making a 13-foot high cut. American Mine Services was awarded a competitively bid contract to drive two 2000-foot, 13-foot by 16-foot slopes at -15 percent, sink a 16-foot diameter ventilation shaft 400 feet between the F- and B-Seams, install a 60-inch conveyor in one of the slopes, remove 7000 feet of existing conveyor and rehabilitate 7000 feet in two entries to accommodate the placement of the longwall machinery. The slope portals were located 7000 feet in by the surface portal. Unique to the project was the placement of work shops and other infrastructure 7000 feet underground with an entry height of 6 feet. The $7 million contract was completed in less than one year using a mix of permissible (Schedule 31) and standard (Schedule 24) LHD equipment, all pneumatic jumbos and shaft sinking gear.

Jan 1, 1993

By R. E. Cook

"Mineral deposits require substantial amounts of energy to transport and be processed into useable form, and as such present a real processing challenge in that the deposits are never homogeneous and ore body compositional characteristics are all over the map! Extracting the desired mineral(s) from the deposit at sufficient profit margin, despite severe fluctuations in market price, requires process automation architecture capable of supporting an integrated enterprise solution. Such an architecture will encompasses the activities of individuals, process units, process areas, plant level activities, mine management and business planning and accounting systems. Key to the automation process is the aspect of value generation. This paper brings together the various requirements for the automation of a mining enterprise and presents the different aspects of how to obtain value across the entire mining operation.INTRODUCTIONMinerals’ processing sites are historically long lived, 20 year life of mine is not uncommon and 75 years is not unheard of. Considering that hardware technology advancements are introduced every six months, or less, it is prudent to select process automation systems that adhere to “open” industrial standards versus proprietary based systems. In the minerals processing industry, the key to survival is driving the cost of production per unit volume to the lowest possible level and provide enough profit to sustain operations. Control system architecture and Business information technology are rapidly becoming important tools in the quest for productivity. Getting key dynamic business performance information at the right time to the right person or process unit is crucial to successfully achieving corporate goals. The process automation architecture selected must therefore be able to integrate to the various networking enterprises and business systems.The mining industry is generally known as an “extractive” industry that is very physically-oriented with respect to operations and the activities in which workers engage. Large numbers of people performing manual tasks in difficult surroundings, produce very variable outputs. But, times are changing – and so are industry best practices. While the nature of work still consists of activities such as ore extraction, ore movement, ore concentration, refinement and logistics, automation innovations are starting to change the nature of many of the production steps. The industry has transitioned from requiring more physical activities by workers, to more information management, automated control and collaboration within the operation. Humans are good at situational intervention and non-linear reasoning and do best when empowered with an overall production perspective. Machines and automation are good at repetitive functions, steady state operation, and managing transitions. Thus, a combination of advanced technology solutions, reliable and useful information and full human contribution are necessary to mining operations for value generation."

Jan 1, 2015

By I. Sanchez

The development of the recent generation of large mining projects in South America has been challenging in many ways, but especially in the management of water in all its aspects. As a result, a number of projects have experienced difficulties and in some cases significant delays due to a lack of a clear and approved definition of the supply, use and discharge of water from mining and processing sites. The development of the recent generation of large mining projects in South America has been challenging in many ways, but especially in the management of water in all its aspects. As a result, a number of projects have experienced difficulties and in some cases significant delays due to a lack of a clear and approved definition of the supply, use and discharge of water from mining and processing sites.

Feb 23, 2014

By M. L. Clark

Advances in the recovery of gold from heap leaching are being made daily, but of all the systems vital to the maximum recovery of gold from a leach pile, none is more important than the methods used to construct the pile in preparation for the leaching operation. The technology described in this paper illustrates the latest systems developed to minimize compaction in the pile during its construction and reduce the cost of placement of ore on the pile. The Florida Canyon Mine of Pegasus is evaluated in detail to show reasons for its high degree of success to date.

Jan 1, 1988

By Y. J. Wang

The use of controlled recirculation began in the early 1930s. Although this method has been applied in many mines since then, a generalized comprehensive network analysis is still lacking. This paper presents a unique approach in which the ventilation network with a controlled district recirculation is divided into two subsystems: a main subsystem and a recirculation subsystem. The subsystems are analyzed individually, and the results and their relationships are then integrated into discussions of the total ventilation system. The analysis of the recirculation subsystem is facilitated by introducing a nondimensional parameter (A), which represents the ratio of the air quantity for the working face to that for the subsystem. As a result, far and regulator pressures and air power for various recirculation arrangements can be effectively expressed as a function of and the subsystem air quantity. Numerical examples are included.

Jan 1, 1997

By St. E. Deák

There is a large preoccupation concerning the development of expert tools (ET) in the mining industry, in order to minimize the impact from waste dumps and processing residues on the environment. In this paper, the authors present a new approach for the development of an expert tool for each area under study, in order to minimize production and disposal of mining wastes on the environment, by taking into account the DKRControl method as well as the Ecomining principles, regarding among others hazard identification, impacts and monitoring. Due to the complexity of this topic a reliable ET requires input from a number of interested stakeholders. The design and management of a mining waste disposal site over its entire life cycle is also considered very important.

Jan 1, 2008

By James P. Rider, Charles D. Taylor, Edward D. Thimons

Research was conducted to investigate how ventilation of a mining face is affected when scrubber flow is greater or less than intake flow. Tests were conducted in a full-scale surface test gallery built to simulate a mining entry with a continuous mining ma- chine at the face. Methane gas was released at constant flow at the mining face. Gas measurements taken at six locations near the face were used to evaluate how well the face was being ventilated. Increasing scrubber flow resulted in lower methane levels even when scrubber flow was much greater than intake flow.

Jan 1, 1997

By Z. C. Liu, F. F. Roxborough, Lin. B. B.

The size distribution of coal cut by a mining machine is an important performance factor. It is well established that the main machine system variable that affects product size is the depth of cut. In essence, the greater the amount of coal won by a machine cutting at shallow depths, the greater the proportion of dust and fines produced. Conversely, deep cuts produce less dust and a generally larger product size. When cutting with a rotating drum, as well as with a longwall shearer, the depth of cut always varies from zero in the vicinity of the roof and floor, where most of the dust and fines are produced, to a maximum at mid-drum level. In this paper, minimizing the amount of shallow cutting with a cutting drum is discussed, and the effects of the drum cutting and design parameters on cross-sectional cutting area per revolution are analyzed. This study shows the following: •more shallow cutting occurs during the entry quadrant of a cutting cycle than during pick exit; •the ratio of the projected area of shallow cutting to the total projected area of cutting by a single pick per drum revolution is virtually the same for drums of different radii (however, it decreases as the maximum depth of cut increases); and •for double drums, the use of unequal drum diameters can reduce the production of dust and fines, compared to using drums of the same diameter.

Jan 1, 1998

By W. A. Heitbrink, M. Schmitz, J. A. Organiscak, A. B. Cecala, E. Ahrenholtz

Mobile excavation equipment operators at surface mines generally have the highest exposure to airborne respirable silica dust. Operator cabs on newer equipment are usually enclosed and equipped with heating and air conditioning systems. Many newer cabs are also equipped with air filtration systems. However, some newer cabs and many older cabs have either inefficient or no air filtration systems. The U. S. surface mining industry is still populated with older equipment and many of these have cabs that provide little or no respirable silica dust protection. Collaborative field studies were conducted as part of a partnership involving NIOSH, Clean Air Filter®, Red Dot, MSHA, and several mine operators to demonstrate that effective dust protection can be provided by these cabs at a nominal cost to mine operators. This effort encompassed adding an external make-up air fan and filter system to a retrofitted roof-mounted heating and air conditioning system in three older equipment cabs, and attempting to seal the cab enclosures to achieve interior cab pressurization. Abetter than 90 percent dust reduction was measured inside two of the three enclosed equipment cabs. It was possible to achieve positive cab pressurization inside these two cabs. A less significant dust reduction was measured inside the third cab, where positive pressurization was not achieved. These field studies demonstrate the key elements needed to improve enclosed cab dust protection in a cost-effective manner.

Jan 1, 2003