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By David Hatem, Paul Madsen, Daniel Adams, James Morrison, Randall Essex

Managing commercial risks associated with subsurface construction may be the greatest challenge the underground industry faces. The Geotechnical Baseline Report (GBR) was developed in the U.S. to help manage those commercial risks, and to stem increasing litigation in the industry. A guidelines document by the American Society of Civil Engineers was published in 1997 and was updated in 2007. This paper provides an historical perspective, overviews the main objectives of a GBR, presents issues and trends that instigated the need to update the 2007 publication, and describes the process that will lead to a new GBR guidelines publication in 2022

Dec 1, 2022

By Michael Schultz, Gregory Sanders

In 2017, the North Texas Municipal Water District (NTMWD) initiated the design of the Sister Grove Regional Water Resource Recovery Facility (SGRWRRF) to provide additional treatment capacity for future population growth within the Lavon Lake watershed. To provide a discharge location for SGRWRRF approximately 4.5 miles of 2.4- meter (96-inch) internal diameter pipeline will be constructed, including 2.3-kilometer (7,800) feet and 487-meter (1,600 foot) long tunnel segments. This paper will discuss the anticipated geology of the two tunnel segments, selection of the tunnel alignment, the anticipated initial tunnel support requirements and other aspects of the project design

Jun 13, 2021

By Bryan Ulrich

Knight Piésold?s annual roundtable discussion was held at the Red Lion Hotel and Casino in Elko, NV on March 14. This year the title was, ?Roundtable discussion on material co-disposal/ co-placement in the mining industry.? This topic was chosen because of the benefits that the mining industry could realize through the advancement of improved methods of storing tailings and mine waste and from reducing short-and long-term environmental hazards while reducing the footprint of these facilities and making strides toward attaining a walk-away solution. Knight Piésold had a local representative, Bryan Ulrich, as well as representatives from its Denver, CO office, including Tom Kerr, president of Knight Piésold?s U.S. practice, and Jeff Coffin, Ph.D., geotechnical engineer, to help facilitate the discussion. The event played host to about two dozen attendees from several western states. Attendees included personnel from more than 10 mining properties, various corporate offices and academia. The purpose of the roundtable was to exchange ideas and information pertaining to broad topics revolving around the subject of co-disposal/co-placement in the mining industry. Compared with traditional conferences and symposia, the roundtable forum tends to provide a less inhibited format for discussion. In the roundtable format, lively discussions and applicable tangential departures are encouraged. This was the seventh in the series of the Elko Roundtable events. Previous roundtables pertained to: ? Heap leach pad design, construction and operation. ? Design, construction and operation of tailings storage facilities. ? Site-wide water considerations. ? Mine closure and cover design. ? Strides toward sustainability in mining. ? High-density tailings, paste and filtered tailings. Acid rock drainage for engineers and environmental scientists.

Nov 1, 2013

By David J. Boron

The United States has the largest total (364 billion metric tons) and recoverable (182 billion metric tons) coal reserves in the world.1 However, progressive coal utilization in this country has been hampered by environmental constraints, such as restrictions on sulfur dioxide, nitrogen oxides, and particulate emissions. New technologies are being pursued both to appease these environmental concerns and improve economic performance and process efficiency. These technologies, however, have not reached the level of effectiveness required for optimum operation. If more stringent emission standards are imposed, it is likely that the coal industry, and the industrial and utility sectors will look increasingly toward the successful development of new and advanced coal cleaning technologies in order to continue and promote the use of coal in this country. The EPA New Source Performance Standards In 1979, the Environmental Protection Agency in response to the amendments to the Clean Air Act of 1977 issued new source performance standards (NSPS) for utility and industrial boilers. The NSPS set emission standards for sulfur dioxide, nitrogen oxides, and particulates affecting boilers of 250 MM Btu per hour heat input or 'greater that started construction after September 1978. Plants starting construction or in operation before September 1978 remained subject to the provisions of the regulations promulgated in 1971, i.e., SO2 emissions of 1.2 15/MM Btu. The NSPS for SO2 emissions provides a sliding scale for SO2 reduction depending on the sulfur content of the run-of-mine coal, with an upper limit of 1.2 lb of SO2 per million Btu and a minimum emission level based on 70% SO2 removal. Table 1 summarizes the EPA NSPS for SO2 emission standards.

Jan 1, 1983

By B. Cavender

Investments in new technology are often intended to improve the production or cost performance of existing operations. The economics used to justify these projects can be flawed, however, if they do not adequately consider the potential benefits of the alterative: the fully optimized use of the facility's present equipment and personnel. While new technology can be effective, dramatic improvements in production performance can also be achieved through the rigorous application of standard industrial engineering and operations management practices. An intermediate approach may also be effective: many basic improvements In the mine or plant necessary to support new technology will be equally effective when implemented for the facility's present operators. Firms who optimize their present operations are able to save the capital and avoid the risk associated with new technology. These firms will also be able to capitalize more quickly on new technology when it is implemented.

Jan 1, 1999

By Yu. A. Polozov, V. A. Lagunov, O. Yu. Lushinkova, Yu. I. Svirskiy, Eh. Ya. Kipko, Roy A. Williams

6.1 PRINCIPLES OF PLANNING GROUTING OPERATIONS FOR SHAFTS, DRIFTS AND TUNNELS The planning of integrated grouting of vertical, inclined or horizontal underground workings in saturated, fractured rock includes the following phases: 1. Planning for the collection and analysis of geological information concerning the characteristics of the struc¬tural deformation(s) that produced the details of the frac¬ture system being studied. 2. Planning for the acquisition of initial hydrogeological information produced by the flowmetric and hydrody¬namic investigations (described in Chapters 2 and 3). 3. Computing the initial engineering calculations of the ex¬pected or planned dimensions of the isolation curtains for each water-producing stratum (fracture zone) and the expected areal spreading pattern of the grout in each of these water-producing horizons. The selection of the lo¬cations, the initial optimal number of holes and the vol¬ume of grout needed to create each isolation curtain also are included in this phase. 4. The selection or development of a grout formula for the specific hydrogeological conditions that exist at the site. 5. Identification of a resource (deposit) required to produce the grouting clay. The planning of grouting operations must be supported by the acquisition of all necessary initial data, which in¬cludes: 1. The geographic location and administrative responsibil¬ity (ownership and regulatory constraints) of the mineral deposit and any peculiar features of the area where ex¬cavation of the underground workings is planned. The surface relief, the hydrographic network of the region, and the local climatic conditions must be evaluated prior to planning for buildings and waste discharges if any. 2. The economic status of the region, the available trans¬portation, the nature of the energy base, the water and heat supply sources, the location of construction mate¬rials suitable for making the grout all must be deter¬mined. 3. The geological and hydrogeological characterization of the work site must be accomplished. 4. The technical features of the shaft(s) and underground works must be characterized. 5. The organization's principal initial design plan features and the construction sequence of all buildings and struc¬tures must be developed. These must be correlated with the organization and schedule for excavating the under¬ground works. The technical characterization of a shaft or of other un¬derground workings must contain information about the purpose of the workings, the design depth, the planned excavation procedures along with cross-sections, and the parameters of the lining, if a lining is required. The geology of the section to be penetrated must include geological data obtained from existing exploration activities at the mineral deposit and conclusions about the shaft ex¬cavation conditions obtained from drilling technical moni¬toring holes and exploration drillholes. The interpreted stratigraphic regime, including the thickness, strike and dip of each stratum, must be shown in cross-section. The tec¬tonics, including all geologic structures, must be presented by cross-sections. The bedding orientations must be used to identify anticlines, synclines, monoclines and faults. The lithologic composition and the drillability of the rock com¬prising the section must be examined. The character of the rock's fracture pattern must be presented. Finally the per¬meability, porosity and storage characteristics of each aqui¬fer must be determined by in situ hydraulic property testing (injection tests or pumping tests, as described in Chapter 3). The fracture pattern of the indurated rock is presented in reports derived from geo-exploration borehole studies and from studies of outcrops on the surface and in all nearby underground workings. The extent of each fracture zone is mapped in three dimensions. The distribution of fracture apertures, the nature of the fractures according to each litho¬logic stratum, and the relationship of bedding planes to each fracture system are all determined. Acoustic logs, downhole cameras, caliper logs, oriented core, and any other appro¬priate geophysical tools available are used to construct the data base for this purpose. The hydrogeological characterization of the geologic section to be penetrated by the workings is based on the analysis of hydrogeological data collected during the drill¬ing and testing of technical monitoring holes and from in¬formation on ground water inflow collected during the ex¬cavation of nearby underground workings, if such workings exist. The hydrogeologic characterization must contain the following information: 1. The identification of all aquifers, their thicknesses and their locations in the section, 2. The distribution of hydrostatic head in the ground water in three dimensions, 3. The coefficient of saturated hydraulic conductivity (per¬ meability) of each aquifer, 4. The porosity and storativity of each aquifer, and 5. The projected rate of water inflow into the shaft, drift or tunnel for each aquifer prior to grouting. This step is used to identify the zones to be grouted.

Jan 1, 1993

By Ross W. Whipple

Applying geophysical techniques in potential geothermal areas has received: little attention in the United States, though it is widely used and accepted in New Zealand and Italy. In those countries it has been demonstrated that geophysical surveys can be useful in locating new geothermal areas and in directing test drilling programs. Geophysical studies in a thermal region can provide structural information and, if conditions are right directly; locate subsurface hot waters. They can give indications of sub-alluvial rock types and of the thickness of alluvial cover. In certain cases they can be used to estimate the power potential of a hydrothermal system.

Jan 1, 1963

By Chee Theng

"What would you do if you are an industry leader and disruptive technology threatens to overturn your business model? Although bearings and seals are in little danger of being displaced in the near future, one company is taking no chances in an age of digital disruption.“For SKF, digital transformation and the Industrial Internet of Things (IIoT) make this time right now arguably the most exciting time in our 100-plus years of history,” John Schmidt, president of SKF USA Inc., said during the SKF Technical Press Day in Philadelphia, PA.The company is not merely integrating digital technologies into its products and services but is taking a forward-looking, strategic approach. “To be successful, legacy companies have to undertake a process called digital transformation. It’s not just an IT initiative but is really about upgrading the strategic thinking,” explained Michael D’Argenio, vice president of digital transformation and customer experience at SKF Americas.Learning from those who went beforeD’Argenio cited the examples of two companies that saw entirely different outcomes in the face of digital disruption. The well-known case is that of Kodak, one of the storied brands in history, whose business was disrupted by the advent of digital photography. Although it invented digital photography, Kodak decided to box it up and put it on the shelf because it was scared of disrupting its business in photographic fim. Instead, it was disastrously disrupted from the outside.Less well known is the case of Encyclopedia Brittanica Inc., publisher of the longest-running English-language, general-knowledge encyclopedia in the world. Sales peaked at 120,000 sets in 1990, plunging to 8,000 sets in 2012. In 20 short years, it saw not one but two massive digital disruptions. The first was in 1993, when Microsoft published the first digital interactive encyclopedia on a CD-ROM, called Encarta, priced at just $99. The second was in 2001, when a communitycurated, free website called Wikipedia launched. Taking the opposite approach from Kodak, Encyclopedia Brittanica looked at its industry, its company and its customers through the lens of the new technologies, made a prediction about the future and, based on that prediction, took a bold move. Having identified its core value proposition as the delivery of reliable, high-value, verifiable knowledge, Encyclopedia Brittanica replanned, restructured and rebuilt its company from the ground up to deliver that same value proposition, only in a different way. It stopped producing the only product that it had known for 244 years and began producing digital products that it sold to educational institutions.“There is a lot to learn from the Encyclopedia Brittanica case,” said D’Argenio. “The company embraced its market change, it embraced its customer change, and it rethought what it needed to do to be successful. Because it owned that disruption internally, it was never disrupted from the outside. It continues to operate today and is as profitable as it has ever been.”"

Aug 1, 2019

By Lynn B. Hales, Randy A. Ynchausti

Introduction There continues to be a large economic opportunity associated with improving process performance through advanced process control systems within the minerals industry. The basis for this opportunity lies in the inherently low efficiencies of many of the unit operations found in mineral processing plants as well as the continual variation that is present in the ores being processed. The ageless target of such control systems is improved recoveries and concentrate grades, higher processing rates and lower unit costs. Many plants are enjoying the benefits of modem, well functioning process control systems but few if any have achieved plant-wide optimization in an economical sense. As new process modeling and control technologies, such as neural networks, continue to evolve and develop, the potential for plant- wide optimization is becoming a closer reality. Neural network technology appears to have a significant potential in the general field of process control and control of mineral processing operations. Neural networks are an emerging technology that have been evolving out of the study of biological systems since the early 1940's. The first software simulation of neural computing networks was reported in 1956 by Nathanial Rochester of IBM Research during the first conference on artificial intelligence which was sponsored by the Rockefeller Foundation. Neural Networks Neural networks can be considered to be a class of computer program that perform their problem solving functions based on a rudimentary model of the human brain and how it solves problems. Traditional computer programs and even computers themselves solve problems or process data sequentially and in a deterministic manner. The human brain, on the other hand, processes data and solves problems in a massively parallel fashion. We think of computers normally in terms of having a single processing unit, sometimes a co-processor to assist in certain activities such as mathematical functions or communications, bytes of memory, processing speed and program/data storage size.

Jan 1, 1992

By S. Tafazoli, N. Himmelman, D. Chan, E. Chow

"While Wearable Technology has been garnering attention in the consumer market, enterprise and industry have just begun exploring its potential applications. Since February 2014, Motion Metrics International has been working in collaboration with Vandrico Solutions Inc. to apply Wearable Technology to improve productivity and safety in the mining industry. This paper discusses the value proposition of using Wearable Technology to deliver critical notifications in mining. The advantages and disadvantages of various form factors are explored. The challenges, both specific to mining and in general to Wearable Technology, are defined. Finally, the concept of MetricsGear™, the first Wearable Technology platform developed for mining by Motion Metrics International in collaboration with Vandrico Solutions Inc., is described. MetricsGear™ is designed to notify the user with minimal distraction to keep the user focused on their primary task, and aware of mission-critical events. This focus and awareness allows the user to work more efficiently and safely. INTRODUCTION The mining process consists of a series of intricate stages, where certain events or conditions in one stage can have a huge impact on other stages. The notification of these critical events or conditions is vital for ensuring the overall efficiency of the mining process. Critical notifications can be classified as two types: time-critical events and contextual information. Time-critical events are situations where a timely response from a responder can have a significant impact on seizing an opportunity or mitigating cost. Some Human-Computer Interaction (HCI) experts classify notification types based on the Interruption, Reaction, and Comprehension (IRC) framework. Time-critical events are classified to have high interruption, high reaction, and low comprehension due to their urgency. The responder should have just enough information to identify the crisis and react as soon as possible (Chow, E. 2014). For example, when a tooth is lost during shovel operation, it is necessary to recover the missing tooth before it jams the primary crusher. The consequence of missing this critical time period is a jammed crusher that can cause the mine to be out of production until the jammed tooth is extracted (Baumann, M. 2013). In this case, the responder only needs to see an image to confirm if the tooth is missing, and information to identify which equipment and when the tooth went missing (see Figure 1). Contextual information is relevant information that is valuable for the receiver to be aware of as it can present an opportunity to improve efficiency or save cost. According to the IRC framework, contextual information is classified as low interruption, low reaction, and high comprehension. They are not as urgent as time-critical events, but provides more detailed and informative information to assist the receiver. For example, when a shovel’s worn tooth is predicted to require replacement soon, a notification to a GET technician can help him or her schedule a pre-emptive replacement of the tooth in an already planned maintenance to prevent having to reactively schedule another one when the tooth is critically worn. This helps reduce the amount of equipment downtime to maximize production (Baumann, M. 2013). In this case, the receiver will look at the information when he has a moment to spare to get a quick forecast, and make use of this information as needed (see Figure 2)."

Jan 1, 2015

By Juan Andres Jarufe, Carlos Cifuentes

Numerical modelling has been extensively used to estimate plastic displacement in faults and rock mass surrounding mine excavations. Particularly, for fault slip seismicity, modelled plastic displacement is usually utilized to estimate seismic potential, however these methods assume that all the displacement caused during an specific simulated excavation step, is released as a single event at each step. This representation corresponds to a conservative estimation since rock mass displacement does not occur as one single event but as an exponential distribution of many small displacements and a few large ones. When displacement is expressed as seismic magnitude, this exponential distribution is addressed as the Gutenberg Richter (GR) relationship. This paper present a method to decompose the results from numerical models into a distribution of seismic events The reconstruction of the GR relationship from modelling displacement permits not only a more realistic approximation of the expected maximum magnitudes but also provides a tool to develop a probabilistic estimation of the maximum possible magnitudes.

Apr 26, 2022

By Ning Wang, Tengfei Guo, Wanyan Li, Hanjie Wen, Hannian Gu, Zehai Li

Red mud has been reported as a potential resource for lithium. To investigate the leaching behavior of lithium, a lithium-rich red mud was neutralized with hydrochloric or oxalic acid and then leached with acetic acid. When red mud was neutralized using dilute hydrochloric acid, about 58 to 60 percent of lithium was leached with 25 percent acetic acid at 95 °C for 60 min, while more than 95 percent of sodium and 85 percent of calcium were dissolved in the leachate solution. When oxalic acid was used to neutralize red mud prior to acetic acid leaching, lower lithium leaching efficiencies of about 42 to 47 percent were observed. Nevertheless, these leaching efficiencies of lithium were close to that of calcium and much higher than those of sodium under the same conditions. In this study, 25 percent (v/v) of acetic acid at 85 °C for 60 min was demonstrated to be the optimum conditions for lithium extraction from oxalic acid-neutralized red mud using acetic acid. The results are useful and of interest for lithium recovery and purification from red mud.

By J. Wyn Prior

The seismic refraction technique is probably the most popular geophysical method of bedrock profiling in geotechnical site investigations but is somewhat restricted by the inherent assumptions in the method. This paper describes how Hales' method of profile interpretation is modified to overcome the assumptions of increasing velocity and layer thickness with depth when only first arrival data is available. A further expansion of Hales method enables presentation of refraction data in a form whereby bedrock features, such as changes in velocity, relief and dip in particular, are more readily recognized. Characteristic curves of the more common bedrock features are presented as an aid to bedrock feature recognition.

Jan 1, 1976

By M. S. Moats, A. Luyima, W. Cui

"Organic smoothing additives are used to produce dense, thick, high-quality cathodes in copper electrowinning. Glue had been used traditionally and is still used in operations that do not employ solvent extraction to produce the electrowinning electrolyte. With the advent of solvent extraction–electrowinning, guar started to be used and remained in use for many years as it does not affect the phase disengagement in solvent extraction. Recently, however, guar has been replaced by less-expensive saccharide- and polyacrylamide-based additives. This paper is the first of a series of four papers that examine saccharides and polyacrylamides as new additives for copper electrowinning. A review of previous research related to copper electrowinning additives is presented here, along with a selected review of additives in other copper electrodeposition systems.IntroductionThe recovery of copper from solution by electrowinning was first practiced in the early 1900s, but it was the combination of solvent extraction with electrowinning (SX-EW) in March 1968 at the Ranchers Bluebird Mine (Kordosky, 1992) that changed the landscape for the electrowinning process. Most copper electrowinning capacity is now associated with solvent extraction, though some copper is still won directly from leach solutions (Robinson et al., 2013). The ability to produce high-purity copper cathodes from SX-EW has taken the continued improvement of SX-EW technology over the past more than 40 years.One of the technologies that has seen improvement is that of the organic smoothing agents used during the electrodeposition of copper in the tankhouse. These organic additives are added to the acidic copper sulfate electrolyte during electrowinning to improve the smoothness, brightness and density of the copper cathodes. The organic additives that are presently in use are different from those used in 1999 (Jenkins et al., 1999). Over the past decade, many tankhouses have replaced the use of guar-based organic additives with those derived from other saccharides. Until now, there has been no comprehensive publication in the open literature on the behavior of these additives during copper electrowinning."

Jan 1, 2016

By Sandip K. Mukherjee

In underground mining operations, ventilation and water sprays are the common methods of controlling dust. In recent years there has been a proliferation of technical literature dealing with water sprays for dust control. However, guidelines for the design of an effective water spray system have not been presented to the mining industry. This paper reviews developments in water spray dust control technology and recommends guidelines for water spray systems to control dust in under- ground coal and non-coal mining operations. These guidelines suggest type, number, location and orientation of nozzles, desirable operating water pressure, and associated filtration system.

Jan 1, 1983

By E. C. Winegartner

In producing and selling coal, the coal company is faced with many different parameters by which the quality of its product is evaluated. One type, which we choose to call the economic parameters, includes moisture, ash, sulfur, and Btu's. These are reasonably well understood by both the coal supplier and the customer, and the dollar values can be placed on them. This is the group of parameters of primary interest to most purchasing agents buying coal. A second group of parameters governs how the coal will behave in the boiler itself and is of primary concern to the engineers designing the boiler and to the men who must operate and maintain it. Since we have not yet learned to put dollar values on these parameters, they generally show up in coal contracts simply as cutoff points, the purchaser simply saying that he will not accept coal outside of certain limits.

Jan 1, 1975

By William A. Wallace

Common mineral resources (sand, gravel, crushed stone, etc.), which are so necessary for the construction of metropolitan areas, are rapidly being depleted or otherwise rendered unavailable in the very areas that need them most. However, the problem of planning for these resources involves a number of independent and dependent variables that must first be defined and related. Finally, a dollar value must be assigned where possible. Complex interrelationships between the variables and their dependence on outside factors has made mathematical "solution" of the problem of planning for non-renewable mineral resources difficult at the present time. Therefore, the use of computer simulation is suggested as a means by which this complex problem can be investigated. The purpose of this paper is to report on a continuing research program whose objectives are: (1) to delineate the factors involved in planning for the utilization of common mineral resources in urban-suburban environs; (2) to construct a planning model for these materials amenable to computer analysis, (3) evaluate the model by using test cases, and (4) perform a sensitivity analysis to determine the initial parameters in future planning for these materials.

Jan 1, 1968

By D. Kang

The adsorption behavior of silver in ammoniacal solutions on to activated carbon has been studied. The parameters affecting the adsorption of silver on to activated carbon included temperature, agitation speed, concentration of cations and anions as well as that of ammonia. It was found that the adsorption of silver from ammoniacal solutions was dependent upon the initial silver concentration in the solution and other factors. The recovery of silver from ammoniacal solutions was found to be not so effective as the case with gold reported earlier. The adsorption rate was relatively slow overall, despite a rather fast initial adsorption. The apparent activation energy for the adsorption was measured to be 30.2 kJ/mol. It was believed that the kinetics of the silver adsorption on activated carbon was limited by a mixed control mechanism.

Jan 1, 1998

By William J. Robinson

What is the cummulative rate of recovery of copper from a sulfide leach dump? This is one of the most frequently asked questions today. We, in the industry, ask it of each other when we meet; however, the technical answers may vary from "I don't know" to 'quite good" from people within the same company. Management also poses this question because it plays a vital role in our planning for future production. The answer is difficult because of the many variables between different operations such as physical construction of the dump, topography of the original site, characteristics of dump material, mineralization, water application, etc. Each has a bearing on the rate of recovery. OPERATIONAL DATA Our method of water distribution is unique in that each dump is drilled to allow physical injection of water into the dump. The in¬jection holes are drilled vertically, on 251 centers, from the surface of the dump. Normally, the holes are drilled 40' deep and cased with 4" PVC perforated pipe.. The pipe is perforated at one-foot intervals with four V diameter holes at 901 spacing on the pipe circumference. We formerly alternated shallow holes (20'-40') with deep holes (80'-l80') in an effort to cover the entire dump and hasten oxidation. The shallow hole depth varied according to the compaction thickness. The deep hole depth varied according to the height of the dump and the original ground profile, We prefer to have the deep holes end 20'-30' above the original ground level. This generally allows us to penetrate the coarse material at the bottom of the dump. We had to discontinue the deep holes_ in order to cover more dump area in a shorter period of time to meet increased production requirements.

Jan 1, 1972

By William Gleason

With more than 20 major mines extracting copper, gold, coal, molybdenum and lime, Arizona is recognized as one of the better mining jurisdictions, not just in the United States, but in the world. However, that is not to say the road to production is always paved with gold, or in many cases, copper. Earning the license to mine in Arizona is a complex process with years of paperwork and permitting before the first tons of ore are ever processed. Now, get the federal government involved and the process becomes even more complex, and the path to production can become even longer.

Jan 1, 2013