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By E. A. Metz

Perfect combustion in an engine would produce only water vapor, carbon dioxide and nitrogen as by-products; however, complete combustion is never achieved. As a mobile power plant, the diesel engine is relatively inefficient in terms of energy produced from the energy potential of the fuel. The diesel is not a perfect engine. The fuel burned can undergo a very large number of reactions in the combustion chamber. It only stands to reason that a large number of compounds are contained in the exhaust, actually, thousands of chemicals. The exhaust can be broadly divided into a gaseous phase and a particulate phase. Each phase is made up of organic and inorganic compounds. The vapor phase contains carbon monoxide, sulfur dioxide, various oxides of nitrogen and many hydrocarbons. The particulate phase contains clusters of respirable inorganic particles made mostly of carbon. This paper will address the health hazards, as we know them today, of the major components of the particulate phase in the exhaust of diesel engines. It will briefly examine the operational factors of the diesel engine as it applies to particulate emissions. Longitudinal studies of occupationally exposed miners are needed with documentation of levels of exposure before a chronic effect of exposure can be determined. At this time, it is not possible to conclude from human studies the level of diesel exhaust exposure that results in the observed lung cancer risk.

Jan 1, 2001

By Scott G. Britton

This chapter discusses the necessary construction techniques for installing coal mine ventilation devices. Included in the discussion are the major air controlling devices called over- casts, regulators, stoppings, and doors. Under-casts, although a valid device, are used infrequently in coal mining and are not discussed here. Typically, coal mines require a great many ventilation devices to control the air movement. Post-I969 mines have had to design their air systems to comply with the Federal Coal Mine Health and Safety Act (CMHSA) as discussed in Chap. 1. Pre- 1969 mines have had to redesign major portions of their systems to comply with the basic components of the law such as separation of air courses, single unit split ventilation, and minimum air quantities. It is not uncommon, therefore, to find a large mine (2.0 Mt/a) requiring several hundred overcast installations (permanent, as well as repeat construction), plus doors and regulators placed among a thousand or more stoppings. When each of these devices is subject to leakage from installation and weathering defects, the importance of effective construction becomes evident. An historic rule of thumb for average mine ventilation says that about 70% of all the air pressure generated by the mine fan is lost between the portal and the working faces. Of course, this rule is subject to many factors, but the message is clear: there is a tremendous inefficiency in controlling leakage through common air devices. This chapter strives to present a standard approach and design alternatives which can go a long way in reducing this leakage, and hence, ventilation costs. Historically, mine ventilation has progressed from natural, or draft ventilation, to fire-induced ventilation (Fig. l), furnace-fired centrifugal fans and finally, to today's modem mine fans. Underground controlling devices have been in use in the coal mines since the late 1600s, but the CMHSA of 1969 was the real turning point for mine ventilation. Minimum quantities and velocities of fresh air were required for mining, forcing coal operators and engineers to reevaluate and improve their systems. As a consequence, the cost for ventilating air increased. Today, companies face a variety of choices among design alternatives, materials, labor, and costs of ventilating devices for their mines. The best approach for any individual company or mine is determined by (1) the needs of the mine, and (2) the local design parameters. In my discussions of ventilation construction I shall be fairly general in terms of device installation steps, where specifics are warranted for clarification, I will include this information.

Jan 1, 1983

By M. Rieber

Building on earlier work, an analysis relevant to international (Australasian) minerals trade is developed which accounts for both the impetus of globalization and national reaction or protection. At the firm level, integrated multinationals are contrasted with trade service providers. At the industry level tariff and, particularly, such barriers as quotas, standards, labor and environmental issues are explored. Specific areas examined include: location of both inventories and processing, sources of finance and currency risk, shipping availability and terms as related to processing level, residuals management or environmental controls, and “fair” labor standards. Intraregional rather than global trade is currently most likely.

Jan 1, 2002

By D. J. Shalanski

In 1962 a computerized data processing system was first installed and programmed for the grading of direct-shipping iron ore from the Sept-Iles terminal of the Iron Ore Company of Canada. Over the years several changes and improvements have been incorporated into this system. It is the purpose of this paper to describe its present operation and features. Sept-Iles is located on the north shore of the St. Lawrence River, 500 miles north east of Montreal. The direct-shipping ore is received by railroad from Schefferville, 320 miles to the north in the Knob Lake Iron Range of New Quebec and Labrador. The shipping season extends from mid-March to December. The maximum tonnage handled in this period being 13,045,000 long tons in 1959. Crude ore receipts for 1974 amounted to 6,568,000 tons of direct-shipping and 4,700,000 tons of plant feed material from Schefferville. This was augmented by 4,447,000 tons of concentrate and 7,572,000 tons of pellets from Labrador City 200 miles north of Sept-Iles. The direct-shipping ore has come from as many as ten mines, and grade variations, even-within the same mines, have been sufficient to require blending for uniform, acceptable cargos. Shipments of low phosphorous, non bessemer and manganiforous iron ore are made, to Canada, the United States, Europe and Japan with grade variations to meet customers requirements.

Jan 1, 1975

By K. H. McDaniel, D. M. Loring

The underground ventilation system at the Waste Isolation Pilot Plant (WIPP) provides for the unparalleled ability to ensure the safety of the workers, the public and the environment. Although small spatially, the system can vary the airflow from 31.2 to 217.1 m3/s (66,000 to 460,000 cfm). The system can automatically incorporate HEPA filtration in the event of radioactive contamination. Remote-capable regulators individually control the four main splits, and they can be adjusted from the surface if necessary. A ventilation remote-monitoring and control system provides real-time information. Future areas of concern include DPM compliance, system psychrometry, logic-based real-time mine-ventilation simulation and automation using PLC technology. This paper discusses the evolution of this system.

Jan 1, 2003

By Bruce Congleton

The Florida phosphate industry is a leader in environmental control, both in terms of dollars spent and significant achievements. For instance, since 1960 the phosphate industry has spent over $71 million for air pollution and control devices, including installation, research and development and maintenance. Water pollution control expenditures also total in the millions, with over $69 million spent in the same 10 year period. The industry also is a leader in water conservation measures, having spent nearly $ 18 million since 1966 for conservation devices. Since phosphate is mined by strip mining, land reclamation plays an important part in the environmental control picture. Here again, the phosphate industry has met the challenge with a voluntary program of reclamation which accounts for over 20,000 acres of land useable after mining has taken place. In terms of progress in environmental control, the industry has been able over the years to solve within the limits of technology the fluoride emission problems it once had, and is currently at work solving sulfur dioxide and particulate problems. In just the past year the industry also has been extremely successful in limiting phosphorus and nitrogen discharges into area streams. The industry continues to cooperate with state and local pollution control officials on matters of environmental control, and future plans include even closer cooperation and assistance, as well as increased expenditures.

Jan 1, 1972

By John A. L. Campbell

Surface dependent processes, such as froth flotation and flocculation, are important or potentially important techniques for combating some of the current major problems in coal preparation. In order to correctly apply or imporve a surface dependent process, it is of paramount importance to understand the interfacial phenomenon, especially the double layer properties, exhibited by the solid. The specific objective of this research was to determine the properties of the bituminous coal/liquid interface by an electrokinetic method, streaming potential, and to relate the findings, wherever possible, to the existing unit operations of froth flotation and flocculation. The electrokinetic properties of both the whole coal and its lithotypes were investigated. As part of the total investigation, the role played in the double layer by the reagents commonly employed in the surface dependent process was also established (1). These data will be presented at a latter date.

Jan 1, 1969

By J. Partyka

Adequate ventilation is a main concern if Lockerby Mine near Sudbury is to be expended. This study investigate a two-fold problem: (1) the new pressure and volume requirements of the main fans due to the theoretical. deepening of the mine, and (2) the effect of the natural ventilation pressure on the main fans. Field data was analyzed with the aid of a newly developed network simulation program, VNETPC Version 3. 0. The density change throughout the mine is accounted for by performing all computations at reference density. Results of the investigation indicate that the existing fan system must be supported by three to five additional underground fans as well, the density effect is significant. If neglected, it will greatly alter the simulation results

Jan 1, 1991

By K. Ohga

Japan has produced 14-16 million tons of coal per year in the past several years. About half of the production comes from eight coal mines in the Ishikari coal field, Hokkaido. Most of the gassy coal mines are in this field and the average mining depth of these coal mines has already attained about 700 m from the surface. Therefore, most of the coal mines have suffered from occurrences of coal and gas outbursts. To prevent outbursts and to reduce ventilation air, gas drainage has been carried out at all of these coal mines and these have had successful results. However, the methods of gas drainage differ from mine to mine. In this report, an outline of the main methods of gas drainage are described.

Jan 1, 1987

By Ratnakar Singh, Raj Kishore, Kisor Kumar Sahu, Ranjeet Kumar Singh, Ganesh Chalavadi

The Falcon concentrator is capable of separating minerals in fine size classes based on their differential density. Separation of mineral particles depends upon the fluid flow characteristics and relative movement of particles in a fluid. In the present study, a fluid flow characteristic inside the Falcon concentrator was established through experimentation and modeling. The Falcon concentrator has two fluid entry points: (a) Fluid entering through gravity assisted feeding system and (b) Fluid entering through the fluidized hole on the concentrator wall. In order to identify the role of fluid entering the concentrator, a tracer was injected into the system. As per the tracer based experimentation, it was established that fluid entering through the gravity based feeding system is responsible for thin flowing film formation in the stratification zone where particles are stratified based on their relative density. The momentum balance and continuity equations were simplified for a high centrifugal force field, and the fluid velocity profile was estimated inside the thin flowing film. Estimated fluid flow profiles will help to simulate the particle trajectories inside the Falcon concentrator. The influence of rotational speed, fluid flow rate, and cone angle on the fluid velocity profile were investigated. Fluid thickness over the concentrator wall is also estimated, and it is typically of the order of ~150–200 μm.

By Alan Dahlstrand

The Jamestown Mine is a 6.3-kt/d (7000-stpd) open-pit gold mining operation located in the central portion of California's historic Mother Lode district. Most early production from the Jamestown area occurred in underground operations from 1906 through 1916. Pit production began at Jamestown in early 1987 and continued until July 1994. Although additional mineral resources existed, they were deemed to be uneconomic. About 23.3 t (750,000 oz) of gold were produced from pit operations, compared to 31 t (100,000 oz) from early underground mining. Recent operations at Jamestown included two open pits, a flotation mill and a flotation tailings facility. Flotation concentrates were produced in Jamestown and shipped to Yerington, NV for cyanide leaching in a carbon-in-pulp (CIP) circuit.

Jan 1, 1995

By O. Bernal, G. Velarde

Sociedad Minera Cerro Verde, majority owned by Phelps Dodge produces 200M lbs per year of LME Grade A copper from low cost leaching of secondary sulfides and SXEW processing. Central to the success of Cerro Verde has been the continuous improvement of leaching practices which currently yield over 80% recovery of the contained copper in the ore. This recovery has been achieved by careful attention to operational practices and leaching process fundamentals. This paper details the development of the concept of “Lixiviant Request Rate” where by solution is applied at an optimal rate for the grade, mineralogy, and the point in the leach cycle. Also paramount to the success of Request Rate technology has been the development of irrigation practices such as drip irrigation and irrigation grid design. These developments have ultimately resulted in improved copper production, decreased sulfuric acid and water consumption, decreased pumping cost, and more consistent PLS grades.

Jan 1, 2004

By E. Varouchakis

Spartan Spatial Random Fields (SSRF?s) provide a new geostatistical framework (Hristopulos, 2003) with applications targeting environmental risk assessment and natural resources estimation. SSRF?s have the ability to incorporate constraints based on physical laws in the statistical description and have proved to be computationally fast in the analysis of synthetic data sets. This paper presents an application of a specific SSRF model and a new local-error spatial estimator (Hristopulos, 2005) in the mapping of environmental pollutants using a real data set. A detailed comparison of the local SSRF estimator with a classical kriging method is presented. It is shown that the SSRF approach provides a competitive alternative for spatial estimation.

Jan 1, 2005

By Rafael C. Castro

As part of its risk management plan, the South Central Connecticut Regional Water Authority (RWA) is assessing the condition of its system of raw water conveyance tunnels and connecting pipelines. In 2006, the RWA inspected one of the system?s main tunnels, a 4-mi, 1950s-era tunnel that had not been inspected since its construction. The inspection team prepared extensively for the unknown conditions in the tunnel, and the inspection was completed safely and successfully. This paper describes the team?s pre-entry preparations, dewatering and ventilation efforts, surface-to-tunnel communication, access, physical inspection of the tunnel, and the lessons learned throughout the process. Additionally, this paper will preview planning for the subsequent inspections.

Jan 1, 2008

By Peter Amelunxen, Craig Lockhart

Significant effort was made in 2003 and 2004 to upgrade the existing instrumentation and process control infrastructure at the Phelps Dodge Bagdad copper concentrator. Specifically, • cameras were installed on the feed belt for online image analysis data, • ultrasonic level sensors were installed for froth height and sump level control, • a trial froth image system was installed on one of the rougher rows, and • a new expert system to tie everything together was integrated and tuned in-house. Control philosophy, observations, opinions, and general tips and tricks are discussed with the hope of assisting other plant personnel and expert system integrators.

Jan 1, 2005

By Joseph M. McCann

The Brightwater regional wastewater treatment facility, under construction in King County, WA, includes an extensive conveyance system that will feature deep, soft-ground tunnels and shafts. Excavation of the Ballinger Way Receiving Portal to 65.8 m (216 ft) below grade through challenging geology was accomplished by means of artificial ground freezing. This paper discusses freeze design development, system installation and monitoring, and the contractual and construction challenges that were overcome, including work sequencing and excavation means and methods, together with lessons learned.

By Herbert H. Einstein, Edward C. Tse, David B. Ashley

INTRODUCTION Decision-making in the design and construction of underground facilities must be made under conditions of varying geologic uncertainty, uncertainty which can have a major cost impact if not properly regarded. Of the two approaches for dealing with this variability, preparing for the "worst" anticipated conditions and optimizing design and construction in-situ, preparing for the "worst" conditions is the more if not solely conventionally practiced method in the United States. While the conventional approach is recognized at times to be extremely overconservative, it will remain preferred until a more adaptable method is shown to be economically superior. This paper presents research aimed at providing just such answers as to when and if an adaptable tunnel design and construction approach is more cost effective than a non-adaptable one. To fully understand the characteristics of this choice between adaptable and conventional tunneling alternatives a summary discussion of adaptable methods is presented. An acknowledgement of the importance of geologic and other factor uncertainties in making this decision leads to the adoption of decision analysis as a quantitative methodology for formalizing the problem. Exercising this methodology on three prototypical tunneling scenarios--urban deep, urban shallow, and transmountain--allows an isolation and ranking of the most crucial factors in making the basic approach decision. One scenario, a transmountain highway tunnel, is carried further through a detailed probabilistic analysis to show under what conditions of varying uncertainty adaptable approaches possess economic advantages.

Jan 1, 1979

By M. M. Nash

Since the late 19th Century, scholars have been concerned about finding proper methods of managing business. The search seems to be taking us full-circle to the time and motion studies of Taylor (Horn, 1987). It wasn't until the late 1970's, however, that systematic investigations were made in the mining industry. One of the first was a study by Sanders, Patterson, and Peay (1976). That project explored the relationship of attitudes and safety. Peay, Atkin, and Goodman (1977, then reviewed the whole area of Organizational Development, including the so-called Rushton experiment.

Jan 1, 1988

By A. Noble

The design of separation circuits can be a complex, labor-intensive and costly process. While the engineer?s experience along with extensive data sets and simulation are crucial tools for determining the final solution, a more fundamental approach is suitable to compare preliminary options and reduce the number of potential alternatives. In light of this need, the authors have developed the Circuit Analysis Reduction Tool (CART?). This software package relies on the fundamental principles of linear circuit analysis; however, the solution methodology has been streamlined to automatically incorporate stream splitting and unique separation performance for each unit. The resulting tool allows preliminary analysis of circuit designs without the need of detailed feed characterization. In addition to the basic analytical approach, this paper supports the veracity of the methodology with several simulated examples for various separation models.

Feb 27, 2013

By Carolina Bruecker, Axel Preusse

"The topic of ground movements in Germany has been studied extensively in the past, especially in the field of active mines. The active hard coal mines were finally shut down in 2018 in Germany and lignite mining is expected to take place only until 2038. The so-called long-term liabilities of the mine operators in Germany include, among other things, the long-term guarantee of stability and thus the monitoring of ground motion.So far, the economic use of underground mining in Germany was mainly the supply of raw materials. In the future, the underground storage of compressed air, methane, or hydrogen will play an important role in renewable energy supply and climate change. Therefore, underground storage space will become more important and spatial planning is essential to ensure availability of safe underground openings for the various options of environmentally friendly energy storage.However, this renewed usage of underground openings may also bring new and sometimes unknown challenges of geomechanical influence. On the one hand, the aftermath of hard coal and lignite mining will be an increasing challenge in mining subsidence engineering. On the other hand, new possibilities due to underground spatial planning may lead to subsidence and/or heaving of the upper surface.INTRODUCTIONBoth hard coal and lignite have a long tradition in Germany. The Prosper Haniel mine in the Ruhr area was closed at the end of 2018 after 150 years, which signalled the end of hard coal production in Germany. Lignite mining still takes place in the Central German, Lausitz, and Rhineland districts. However, lignite mining in Germany is expected to be phased out gradually by 2038 (MDR, 2019). With the closure of these mines, however, mining damage is not over. The long-term consequences of mining, which extend far beyond the closure of the mines, are associated with the liability and responsibility of the individual mining companies. The so-called eternity burdens on the mining company continue to apply. In the field of lignite production, the discontinuation of dewatering and the resulting possible elevations of the surface will be a relevant topic for the future of mine surveying. The same applies to the hard coal mines, which are partially flooded in Germany and therefore require extensive monitoring of soil movements in the future.The discontinuation of energy from hard coal and lignite calls for a change in the energy mix. With the renewable energy revolution in Germany, the focus is on a sustainable and environmentally compatible climate and energy policy based on renewable energies. Sustainable use of the subsoil, both natural and anthropogenically produced cavities, will play an essential role in the objectives of this policy. For example, disused mine cavities can be used to store electricity from renewable energy sources. (Umwelt Bundesamt, 2018) These functions will again cause classical ground movements such as subsidence and uplift, but will also bring new challenges for the mine surveyor. Challenges can be underground cavity exploration in inaccessible areas or legal aspects of underground competition."

Jan 1, 2019