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By R. J. Sheets

"What is the primary responsibility of geo-engineers in mining? Early in my career, I was asked this question by an experienced engineer. After explaining some various tasks, I was informed that the main responsibility was to monitor. Although this proved true for many cases, I came to understand that monitoring is merely one means to achieve the primary responsibility of a geo-engineer — ensure the safety of all personnel. The potential for groundwater to impact stability allows this responsibility to be shared with hydrogeologists as well. Inherently, we monitor to identify risks; we analyze designs and develop models to mitigate risks; and we are provided opportunities to explain to supervisors the geo-risks to personnel and mine plans that will result from particular courses of action. A couple years ago, I took an opportunity to share experiences from the first several years of my career as a geotechnical engineer with junior geoengineering staff within my company. The intent was to share situations that were a part of my development, so they could learn and understand their responsibility to the safety of all personnel. Similarly, the purpose of this article will be to share these thoughts with new geo-engineers in the industry in order to help prepare them for the challenges they will face.What is our purpose?A senior hydrogeologist shared an experience that occurred in their career. The experienced hydrogeologist had spent some time with the hydrogeology staff, most of them relatively new to the mining industry, to understand how they viewed, and carried out, what they perceived as their responsibility at an active mining operation. After a couple months of observing and mentoring, the senior hydrogeologist met with everyone and posed the question “What is our purpose?” I am sure that most junior geo-engineers would start explaining different tasks or projects that they must complete. The list would include monitor ground water levels, track slope movement, evaluate designs, build models, oversee drilling programs, etc. These individuals did as well their supervisor. After going around the room allowing each individual to answer, the experienced hydrogeologist provided them the real answer to the question: Safety. If you examine the root intent of nearly every responsibility geotechnical engineers and hydrogeologists have, it is to apply our professional skills to ensure the safety of our workforce. When the objective of safety from the geotechnical and hydrogeology disciplines is achieved, inherently accomplishing the mine plan should follow suit, or it should significantly minimize the impact by gravity or ground water."

Jan 9, 2018

By Malcolm J. Robinson

Over 80% of Australia's population lives within 200 km of the coast, 70% in 10 major coastal cities. Potential cement raw materials are widely distributed but deposit size, quality, transport, market and environmental considerations are important in determining economic value. Major production locations are in a variety of geological environments ranging from Lower Paleozoic crystalline limestones to Tertiary and Recent polyzoal limestones and limesands, both onshore and offshore. Raw material transportation is by road, rail, sea, aerial ropeway and pipeline; road/rail transportation of the finished product is traditional but movement by sea of clinker and cement is increasingly a feature of the industry.

Jan 1, 1982

By Francois E. Heuze

This paper summarizes the geomechanics programs conducted in two hard rock underground mining operations in the Western United States, between 1966 and 1981. The two projects were directed towards understanding the behavior of the rock masses, at the scale of the caverns. To this end, the emphasis was put on large scale field measurements, complemented by limited laboratory testing. The results of these observations were used to build realistic finite element models of the underground chambers. In the marble mine, at Crestmore, California, the models were applied to the structural optimization of the room-and-pillar pattern. In the granite mining, at Climax, Nevada Test Site, the models explained some unusual stress changes observed during excavation. Based on the large number of geomechanical techniques employed, specific conclusions and recommendations are offered regarding the quality, applicability, and usefulness of the various methods. The two case histories clearly indicate chat numerical models are extremely useful for a detailed understanding of the structural behavior of mine openings. To be realistic, these models must be based first and foremost on large scale field observations. The lessons Learned on these two projects also are directly applicable to the design and analysis of nuclear waste repositories in hard rocks such as basalt, granite, and welded tuff.

Jan 1, 1982

By A. Ghosh

Commonly used predictors of ground vibration from blasting, being linear in log-log plot, do not model the underlying physics of wave attenuation. Amplitude of the wave decays with distance due to geometrical spreading and inelastic attenuation producing a nonlinear carve in log-log scale. The nolinear decay of seismic waves has also been observed from non-explosive sources, such as, pile driving, drop hammer, traffic, etc. The improved predictors, by explicitly taking these two mechanisms into consideration, model the data trend extremely well at all distance ranges. Actual field data from different studies have been used to validate the improved models.

Jan 1, 1991

Cement in 1975 indeed did operate in an unfriendly environment. World recession, escalating costs, fuel crises, reduced product demand . . . . all led to market conditions detrimental to industry profit margins and investment re turns. During the year plant utilizations fell, break-even points were raised, and competitive moves introduced to move built up inventory levels. A number of cement plants were temporarily taken out of production to help alleviate specific situations. Meanwhile, under resultant financial pressure, several companies omitted dividend payments, changed their top executives, and reorganized and reduced staff overheads. It was a difficult year for cement, yet a much more ominous note was sounded in permanent plant closings. Four more cement operations were shut down in 1975; to date in 1976 we know for sure of three additional plant closings, while rumour has it that at least one more may not be in production by year-end. The somber feature is found within the descriptions of the closed facilities, and in the stated reasons for their being taken out of cement manufacture.

Jan 1, 1976

By David W. Wisecarver

Kennecott Copper Corporation and the U. S. Bureau of Mines cooperated in a full-scale slope stability research project at the Kimbley Pit near Ely, Nevada. The west wall of the Kimbley Pit was mined from an over-all slope angle of 45° to an over-all slope angle of 57° and the pit was deepened nearly 50 feet. Mining was begun February 10, 1966, and completed October 30, 1966. Approximately 2.55 million tons of ore and waste were mined. The project was designed and carried out to learn more about the behavior of a pit wall as its slope angle is steepened and to obtain a possible insight into engineering parameters for use in design of future slopes. Data from this project are presented as obtained from (1) instruments installed in two adits for deformation and displacement measurements, (2) a subsidence network installed on the surface above the steepened wall, (3) pre- and post-mining observations of stress in rock, (4) sonic-velocity measurements, and (5) seismic and microseismic investigations. Changes occurred in measured quantities as the slope was steepened but stopped when mining was completed. Agreement was noted between the measured changes and predicted changes obtained from calculations using the finite element technique. Subsidence surveys and microseismic studies show the steepened pit wall to be stable.

Jan 1, 1968

By D. T. Jr. Tarr

History of Development The hydrocyclone, probably because of its basic simplicity, has been used for various classification applications since before 1890. A patent was granted in the United States in 1891 to Bretney on a device for separating sand from water, collecting the sand in a closed chamber for intermittent discharge, practically identical to some present-day water desanding cyclones. Between 1900 and 1937 there were 30 or more additional patents issued on liquid cyclone configurations or their use. About 1937 liquid cyclones began to be used commercially in the treatment of cellulose fiber in the pulp and paper industry separating contaminating particles from the fiber in water suspension used for making high grade paper products. Nichols Engineering & Research Corp. of New York was marketing a liquid cyclone for cleaning sand and din particles from fiber suspensions in the pulp and paper industry by 1937. The designs during this period were such that the cyclones discharged a small amount of relatively high density material into a chamber connected to the cyclone apex which in turn discharged the collected dirt material intermittently. By the early 1940s hydrocyclones as we know them today began to appear both in the pulp and paper industry and in coal prorzssing.18 Considerable experimental work was done on small, mostly 3-in.- diam, cyclones operating at relatively high pressure drops, in the range of 50 psi, to remove very small contaminating particles from cellulose fiber in the production of high-grade writing papers in the paper industry.18

Jan 1, 1985

By William X. Chavez

The Mantos Blancos copper-silver district, a major copper-producing area since 1961, is located on the Tropic of Capricorn about 45 kilometers northeast of the northern Chile port city of Antofagasta, as shown in Figure 1. Copper oxide minerals occurring as atacamite (Cu C1(OH)3) and chrysocolla (copper silicate-hydrate) were discovered in the district in the early 1900's (Knobler and Joseph, 1962). The mine is situated in the northern Atacama Desert, one of the most arid regions on earth, and presently receives less than 1 cm per year of precipitation. The extreme aridity of the Atacama Desert is thought to have prevailed since at least Middle Miocene time (Mortimer et al., 1978) when development of important supervene copper enrichment was slowed in many areas of northern Chile (e.g., Chuquicamata, Exotica). Despite the paucity of precipitation, landform development is mature, with large alluvial fans and alluvial-filled valleys covering much of the region. In addition, the aridity and presence of salts have led to the formation of a sub-surface cementing of alluvium and colluvium by halite-rich caliche ranging from a few centimeters to over 3 meters in thickness. These factors, resulting in poor outcrop exposure, make even reconnaissance mapping difficult.

Jan 1, 1983

By Donald G. Rogich

The concept of initiating a large action-oriented contract, directed toward inherently safe mining systems, was conceived by the U. S. Bureau of Mines in January 1970. At that time we were in the process of establishing research contracts and grants, about 100 of which were let in FY 71 to deal individually with fairly specific technological areas. These projects in the aggregate covered a wide spectrum of health and safety problems. What appeared to be necessary was the creation of a project or program that would provide a focal point for the demonstration of many of the results of this research and also in the action sense culminate with working hardware and systems that could be tested and demonstrated over a fairly long teen. The concept of working demonstrable systems, rather than just a conceptual study, was, felt to be necessary for two significant reasons. In the development of any new system, the translation from concept to working hardware is usually a costly and time consuming process which acts as a deterrent to implementation. Secondly, many decisions in the mining community to change equipment or systems ,are based on first hand observation of the new system, in operational practice, an attitude which is certainly understandable in view of the high capital costs of equipment. The decision was made to procure a single R&D contract which would be aimed at developing underground coal mining systems which

Jan 1, 1972

By C. A. Young

Cyanide is a toxic species that is found predominantly in industrial effluents generated by metallurgical operations. Cyanide's strong affinity for metals makes it favorable as an agent for metal finishing and treatment and as a lixivant for metal leaching, particularly gold. These technologies are environmentally sound but require safeguards to prevent accidental spills. Various methods of cyanide remediation by separation and oxidation, including photolytic advanced-oxidation processes, are therefore reviewed. Reaction mechanisms are presented throughout the paper. The methods are compared in regards to their effectiveness in treating various cyanide species: free cyanide, thiocyanate, weak-acid dissociables, and strong-acid dissociables.

Jan 1, 1996

By Richard L. Gordon, William A. Vogely

ENERGY POI.ICY-PRINCIPLES AND THEIR PRACTICE Persistently, at least since the end of World War 11, governments have intervened broadly, deeply, and incoherently in major energy markets. If we take a broad definition of energy that encompasses gas distribution and electric power, we can observe regulations of even older vintage. This trend, of course, is not unique to energy. Expansion of government controls has occurred in many areas. The relevant basic question about energy regulation, therefore, is not why is energy special, but whether any general principles exist to explain the wisdom of existing regulations. This review takes place at a time, the middle 1980s, in which a massive onslaught is being undertaken against government regulation. However, the present chapter is influenced primarily by my observations of the failures of energy regulations and not by any inspiration from those ideologically opposed to government intervention. Several subquestions arise in policy appraisal. A primary need is to establish clear objectives and determine the consistency between these goals and the policies imposed. Thus, the first step is to set objectives. The next is to outline ways to attain these goals. However, it should be recognized that many apparently distinct options are economically equivalent. When the goal is to charge producers or consumers for something, it is possible to attain the same result through either government ownership or taxing private transactions. The tax can raise the price to the level the government would have charged if it were the owner. Creation of a Department of Energy is not necessarily any different from having separate energy agencies well coordinated by some small supervisory body. Thus, a distinction should be made between substance and form in policymaking. The critical substance concerns such matters as whether the government imposes financial penalties, incentives, or rules to attain a goal. Then, there can be many equivalent ways to implement the basic policy form. The second prior illustration suggests that one favorite question is how to attain proper integration of policy. At various times, voices on either (or even both) sides of the Atlantic have called for a coordinated energy policy. The U.S. Paley Commission made this a primary goal for future policy. The western European governments that were the founding members of the Coal and Steel, Economic, and Atomic Energy Communities spent much time in the middle fifties and much of the sixties trying futilely to agree on an energy policy. (See Gordon, 1970 for an annotated review). The energy price rises of the 1970s rekindled United States interest in coordination. However, astute observers of the problem such as O. C. Herfindahl of the United States and Maurice Allais (1 962) in France warned the discussions confused form with substance. The crucial issues were what were the goals and what were the best types of policies to attain such goals. Policy suffered, not from poor organization, but from discord about the goals and how to attain them. All this suggests that we need principles to guide policy appraisal. The branch of economic theory known as welfare economics concentrates on providing guidance about the problems of policymaking. The theory examines both what

Jan 1, 1985

By W. C. Morgan

Recently passed federal strip mining legislation officially emphasizes that the increased coal production required by this country through surface mining is going to be obtained only with stricter environmental standards. Dozing overburden down the hillside in Appalachian contour mining or leaving drag1ine spoils in area mining is now taboo and it is now or will soon be necessary to return the disturbed land to as good or better condition than before mining. These new restrictions will create a need for new and better ways to do the job. This paper describes one approach for utilizing scrapers and dozers to strip all of the overburden and to replace that overburden in an environmentally satisfactory fashion. The objective was to do this at a lower cost than that possible with the traditional dragline system using dozers and scrapers for reclamation and topsoil handling. In area stripping, the dragline has been able to move overburden at an extremely low cost. Operating costs of 8-13¢/bcy are typical in many operations where rehandling is not required. However, the cost of leveling the spoil piles and rehandling topsoil add considerably to the low basic cost of drag1ine stripping.

Jan 1, 1977

By M. S. Riyaz Ulla

The Hutti Greenstone belt, located in the northern side of Dharwar Craton, India, contains several promising gold fields. It is predominantly composed of meta-volcanics with minor intercalations of meta-sedimentaries. Alkali-SiO2 and Zr-P2O5 diagrams, immobile element trends, and an iron-rich trend on the AFM diagram indicate that the volcanic suite is low-potassium tholeiitic basalt. The lower Mg number, MgO-TiO2, MgO-Ni, and Ni-Zr plots reveal that the basalt was derived from a fractionated, highly evolved magma generated by 10-20% melting of the mantle at 1100°C and 5 kb pressure. The chemical variations suggest that the Hutti metabasalt represents volcanic arc rocks generated at a converging plate margin.

Jan 1, 1993

With the advent of the environmental "green" movement of the 1960s, eventually leading to Earth Day 1970, Congress responded by passage of the National Environmental Policy Act (NEPA), 1970. NEPA gave impetus to a flood of federal acts and laws in the subsequent three decades. Many of those protecting man's environment, health, and well-being also affect mining. For purposes of this chapter, a current mineral law summarization lends itself to a division into two parts: viz., Part I, General Mining Law, and Part II, Enviromining Law. The word enviromining has been coined by the author and is defined and used herein as those federal and state statutes and regulations that were created to provide protection and preservation of man's environment, health, safety, and welfare, and they have particular application to and affect on mining activities. They are listed and treated under Enviromining Laws in Part II. Mining, as a basic industry to provide the essential minerals for mankind's necessities and well-being, truly reflects the mining industry's slogan, "If it can't be grown, it must be mined." Without the basic minerals and rocks won from the earth by mining and mineral processing for their valuable physical properties or chemical constituents, man would soon be forced to revert to the cave-dwelling age. Unfortunately, for man to survive in the "manner of life to which he has become accustomed," he is caught between the demands of cleaning up his deteriorating environment and a continued supply of his basic requirements and amenities for daily living supplied by mining of the earth's minerals. He must have "clean living" at the same time with "good living;" neither is expendable. A very high pricetag accompanies this essential and critical choice which must be paid by society. The United States is internationally recognized as the world leader in environmental matters. Many countries are following suit, principally the other Anglo nations. Because US law is founded and based on English law, on occasion, Anglo-American law is referred to and cited as authority in litigation anywhere in the Anglo-American world of jurisprudence. For this reason, and because mining and the industry is international in nature and operations, some British Commonwealth cases will appear in various topics. If the case is of interest to the reader, further inquiry at a law library may be made through use of the case's style and citation given. "Style" refers to the name of the litigating parties. "Citation" refers to the law publication in which the case and decision may be found, as well as the jurisdiction and court of decision. Citation of cases from the United States and British Commonwealth nations is explained under Case Citation Explanation. Space and time limit exhaustive treatment of subjects and covering all geographic and jurisdictional areas. This chapter is intended as a broad outline and is based on the author's master's thesis at the University of Missouri-Rolla, 1992. The following Case Citation Explanation provides guidance on formatting of citations.

Jan 1, 1994

By Manfred Jaeger, Klaus Ertmer, Walter Dietrich, Jochen Greinacher, Wilhelm J. Kogelmann

In Europe, novel low-cost excavator-mounted Multi Tool Miner (MTM) systems, consisting of cutter head, hammer, bucket and drill attachments permit one unit to perform multiple tasks replacing several purpose-built machines. At the Weser Tunnel in Germany, cross-passages between the twin tubes were excavated in frozen ground with a remote-controlled mini-excavator equipped with a quick-change cutter head, ripper tooth and bucket. In Switzerland at the N2 interstate near Basel, W. Dietrich AG enlarged a 2-lane tunnel to three lanes with a cutter head mounted on a special excavator. Blasting and heavy hammers were not permitted due to the closeness of the “live” twin tube. At the N20 Zurich bypass, the Joint Venture of Jaeger, Frutingerand AHB excavates highway tunnels, some with extremely large cross sections, conventionally. A cutter head mounted on an excavator removes the rock shattered by blasting precisely to the pay line, thus preserving the rock’s self-supporting capacity preventing subsidence and damages to water resources and buildings on the surface under low overburden.

Jan 1, 2003

By Dávila-Pulido. G., L. Magallanes-Hernández, F. López-Saucedo, J. Batista Rodríguez, A. Uribe-Salas

"This paper presents the results of tests performed to study the effect of slurry solids concentration on the behavior of gas dispersion in industrial-scale mechanical flotation cells. The experiments were conducted at five concentrator facilities run by a Mexican mining company, specifically in the rougher bank of the lead/zinc flotation circuits. Those mechanical cells having significant contribution to the performance of the circuit, that is, the cells that enable high recovery, were characterized. The measurement protocol enables measurement of the superficial gas velocity, gas holdup and bubble size, and sampling of the mineral slurry. The measured data indicate that bubble size and gas holdup decreases as the concentration of solids increases. IntroductionThe process of mineral concentration by flotation is based on contact between particles and air bubbles, the selective adhesion of hydrophobic particles onto the bubbles, and the rising of the bubble-particle aggregates to the surface of the flotation cell to overflow over the lip to form the concentrate. It is now accepted that the physical and chemical process variables that control the flotation of hydrophobic particles are closely related to gas dispersion (Schwarz and Alexander, 2005). Gas dispersion is defined by the superficial gas velocity, Jg (Torrealba-Vargas, Gomez and Finch, 2006), the gas holdup, eg (Tavera, Gomez and Finch, 1997), the bubble size, d32 (Dobby and Finch, 1986; Gorain et al., 1995; Hernandez-Aguilar et al., 2004) , and the bubble surface area flux, Sb (Manqiu and Finch, 1989; Manqiu, Finch and Uribe-Salas, 1991). In recent years, the advances that have been made in sensor technology have enabled the characterization of gas dispersion in industrial flotation cells with excellent results (Gomez and Finch, 2007). This technology advancement has allowed the gaining of a deeper understanding of such complex mechanisms as carrying capacity (Yianatos and Contreras, 2010), collection efficiency (Gorain, Franzidis and Manlapig, 1997; Massinaei et al., 2009) and bubble coalescence (Finch, Nesset and Acuña, 2008; Zangooi, Gomez and Finch, 2010)."

Jan 1, 2017

By E. R. Dotson

Kaolin is an important industrial mineral. It has unique properties, which combined with its low cost, make it suitable for use in a wide variety of products. Kaolin is defined as "any of a group of clay minerals, including kaolinite, nacrite, dickite, and anauxite, with a two-layer crystal in which silicon-oxygen and aluminum-hydroxyl sheets alternate; approximate composition is AlZ03-ZSiOZ-1/ ZHZO".-The kaolin discussed here is composed chiefly of the mineral kaolinite. Kaolin is also commonly referred to as "china clay". Approximately 4.9 kkg (5.4 million short tons) of kaolin was sold or used in the United States, and .8 million kkg (.9 million short tons) was -exported in 1974. In domestic usage, paper coating and filling accounted for 43% of the total, fol-2/ lowed by refractories, rubber, and ceramics.-Figure 1 shows the amount of kaolin sold or used by domestic producers for specified uses for the years 1963-3/ 1973.- Kaolin was produced at mines in 14 states, but Georgia accounted for 75% of the 1974 domestic production. The average value for all grades was $36.00/kkg 4/ ($32. 67/ton) .-

Jan 1, 1977

By Manoj Kumar, Anil Kumar Singh, Prabal Patra, Ashish Agrawal, Souvik Ghosh, Subhashis Kundu, Kamma Ramakrishna Rao, Manish Kumar Gupta, Anindya Sarkar

The slag measurement systems in the cast house are very important. In the conventional method, the slag is granulated in a slag granulation system, and the slag flow rate is measured by the associated belt scale. However, in places where a slag granulation system is not available, the alternate approach is to deduce a theoretical calculation and develop the measurement because the commissioning of such slag granulation requires huge capital and has inherent geographical limitation. However, the theoretical approach suffers from several drifts and is far from the reality. In the present paper, we have innovatively engineered a sensor by designing the stellite-coated thermocouple that can measure the temperature of the slurry and placed it in such a way that the abrasive slag granules do not obstruct it, but we could measure the temperature of hot water, and further based on the thermodynamic approach, the slag flow rate is determined that can be compared with the theoretical approach. This approach of slag rate measurement is cost-effective and long-lasting.

Oct 2, 2023

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 Jr. Raleigh

As part vi the development of the Coal Quality Expert (CQRN) --a computer program capable of predicting the impacts of coal quality on power plant performance, costs, and emissions control--several nationally important coals are being characterized to augment the coal quality database associated with the software. The project is sponsored by the U.S. Department of Energy and the Electric Power Research Institute (EPRI) under the Clean coal Technology Program. Since 1989, CQ Inc. (a subsidiary of EPRI) has characterized seven bituminous coals from Alabama, Illinois, Kentucky and Oklahoma and six sub-bituminous coals from the Powder River Basin (PRB) in Montana and Wyoming. Coals from the PRB region--being burned more frequently in Midwestern and southern power plants to reduce emissions of sulfur oxide compounds--can sometimes contain significant concentrations of potentially toxic elements. Although no limits were imposed on air toxics emissions from fossil-fuel fired utilities by the Clean Air Act Amendments of 1990, future regulations may be implemented at the conclusion of Federally-mandated emissions studies. One possible result is that any increased utilization of coals, including those from the PRB, may depend on the potential for removing toxic trace elements prior to combustion.

Jan 1, 1993