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By B. A. Comley

Over the past few decades a great deal of effort has gone into characterizing the effects of frother type and concentration in flotation using a variety of two-phase techniques. Whilst useful and informative, this research still does not assist in the selection of suitable frothers for three-phase industrial-scale froths. This paper investigates the effects of frother type and concentration in a three-phase industrial froth. The objective was to determine if progress could be made in terms of understanding the behavior of frothers in flotation and understanding how they affect the sub-processes occurring in the pulp and froth phases and, ultimately, the metallurgical performance of a flotation cell.

Jan 1, 2007

U.S. Borax’s mine in California’s Mojave Desert is the source of nearly half the world’s supply of refined borates. These minerals are used in hundreds of products, including essential plant nutrients that increase crop yield and quality, and safe building products that protect homes from insects and the elements. Borax’s workforce is also safe. In fact, it is among the safest in the nation. In 2003, the company was recognized by the U.S. Mine, Safety and Health Administration (MSHA) for achieving the best safety record among large U.S. mining operations. It was also recognized by its parent company, Rio Tinto, for achieving the best record among its nearly 80 worldwide mining operations. Borax’s safety performance is five times better than the national average. And its workforce recently achieved more than two million hours without a lost-time injury.

Jan 1, 2004

By T. Stauffer, B. McGunegle, A. Adu-Acheampong

The Fairmount Minerals, Inc., Maiden Rock underground sand mine historically delivered air to ventilate diesel-powered equipment at its working faces through high-resistance, 15-inch-diameter PVC distribution lines. In support of plans for expanded production, three new, low-resistance ventilation design alternatives were analyzed. The study determined that adequate ventilation for expanded production was possible with various commercially-available, high-volume/low-pressure fans combined with a systematic layout of control structures. The recommended re-design was implemented in 2001, resulting in a significant increase in flow volumes and a noticeable improvement in the mine environment.

Jan 1, 2007

By William Brundan

INTRODUCTION The Srisailam Left Bank Canal (SLBC) Tunnel Scheme is part of the Alimineti Madhava Reddy Project in Andhra Pradesh, South India. This scheme has been planned since 1983 and will provide irrigation facilities to drought-ridden areas in Andhra Pradesh. Water will be transferred from the Srisailam Reservoir during the monsoon months to 0.3 million acres of farmland and will also provide drinking water to villages en-route. The paper will address the design and onsite assembly of the Robbins Double Shield TBMs for Tunnel-1 of the SLBC tunnel scheme from planning to start-up of the machines. Also, it will provide a current status of the project and describe the advantages of a site assembly. Problems encountered to date and the solutions adopted will also be described. The project comprises over 50 km of tunnels and involves construction of the world?s longest tunnel without intermediate access. The TBM tunnels at 43.9 km in length and 10.0 m diameter will cross the Amrabad plateau, containing a wild life sanctuary and India?s largest tiger reserve, the Rajiv Gandhi. Jaiprakash elected to excavate the tunnel using two tunnel boring machines, rather than by drill and blast, in order to alleviate surface disturbances to environment and the tiger reserve, wild life sanctuary, and protected forestry areas. The Project was awarded to the Main Contractor Jaiprakash Associates Ltd with The Robbins Company as the Tunnel Boring Machine (TBM) supplier in August 2005. The Robbins Company supplied the TBMs along with two continuous conveyor systems and all spares and consumables to complete the tunnel excavation.

By Brendan Demich, Joseph McGuire, Emily J. Haas

Near misses recorded and reported by workers can provide awarenessto the potential causes of injury and prompt safety management initiatives. Although most companies require near-miss reporting, it is unclear what the value of these reports are, if any, and how they influence subsequent actions or controls to reduce on-the-job risks. Researchers at the National Institute for Occupational Safety and Health (NIOSH) conducted a case study with an aggregates company in which near-miss reports were analyzed at each of their locations over an entire quarter during the summer of 2018. Within that quarter, workers recorded 249 near misses. Of those, 167 were valid near misses that occurred at work. Researchers coded the reports using a qualitative 5 × 5 risk matrix. Of the 167 near misses, 19% were deemed low risk, 25% moderate risk, 30% high risk, and 26% critical risk. Several patterns in the near-miss incidents were documented, including classification of incidents and common corrective actions referenced (i.e., elimination/substitution, engineering control or redesign, work process/procedures, and personal protective equipment). The analysis provides insight into ways that risk communication and management programs can be improved to reengage workers and their situational awareness on the job.

By Remo Grandori

The Umiray Angat 13,2 km long tunnel in Philippines have been bored through extremely variable and difficult ground conditions including a number of special events. In particular the following adverse conditions were found: faults in decomposed ground, high temperature rocks, extremely rapid and important convergence phenomena, water inflows up to 800 litres per second. The special El Nino climatic conditions caused a long dry season and lower the level of the lake that was granting the access by barge to the site under the minimum navigable level. Many equipment have had therefore to be transported to site by a 10 ton capacity helicopter, after having been partially dismounted. For the same reason most of the tunnel drive have been bored servicing the site by 1 ton capacity helicopters to transport materials, spares and personnel. In order to overcome the above geological and logistic problems several innovation were introduced and tested in this project. Despite all that difficulties the 13,2 km of tunnel were bored in about 24 months, with a global average of 500 m/month.

Jan 1, 2001

By K. V. Raj

In the mining industry, computational fluid dynamics (CFD) modeling is used extensively to simulate air flow in underground mines. CFD modeling of pollutant transport in open-pit mines is relatively new. Modeling the actual pit geometry of an open-pit mine and the open domain is complex. The complexity is primarily due to the faceted geometry of an open-pit mine with its numerous associated sharp features. Important issues that are not considered carefully at the geometry level are generally propagated to the subsequent processes. Several challenges and pitfalls are encountered in modeling pollutant transport in open-pit mines. These challenges and pitfalls are related to the geometry, meshing, boundary conditions, and turbulence modeling parameterization. An appropriate mesh selection is critical. A detail discussion of the meshing of the domain of an open-pit mine is presented in this paper. The selection of an appropriate turbulence model, such as kappa-epsilon (?-e), large eddy simulation (LES), Reynolds stress model (RSM), etc., to obtain the best possible solution is equally significant. This paper discusses the various challenges in modeling the pollutant transport process in an open pit and some of the approaches adopted to address these challenges.

Feb 27, 2013

By Qinghua Tian, Zhipeng Xu, Dong Li, Xueyi Guo, Liu Zhu

A possible process for extracting tellurium and antimony from a residue generated in alkaline sulfide leaching of telluriumbearing alkaline skimming slag was proposed. The central composite design was employed to define the optimal leaching conditions for tellurium and antimony extractions from the residue sample. Using a 23 factorial matrix, the best performance for tellurium and antimony extractions (96.36% and 99.64%) were obtained at 175 g L−1 Na2S concentration for 80 °C during 60 min. The notable degree for influencing tellurium and antimony extractions was leaching temperature, Na2S concentration, and leaching time. The analysis of variance results indicated that the regression model was significant and suitable to be used for the optimization of independent variables within the range. The model was validated under optimal operating conditions based on the experimental design results. Antimony and tellurium in the leach liquor were separated and recovered by H2O2 oxidation followed by Na2S-Na2SO3 reduction. 98.93% of antimony was precipitated selectively during H2O2 oxidation, while 95.06% of tellurium was precipitated during Na2S-Na2SO3 reduction. NaSb(OH)6 and elemental tellurium was obtained as the product.

The schlieren technique describes an optical analysis method designed to enhance light distortions caused by air movement. The ability to visualize air flow has significant implications for analyzing underground mine ventilation systems, including the enhancement of surveys and models. Currently, traditional schlieren methods are impractical underground. Background oriented schlieren (BOS) provides a solution to this problem. BOS requires two primary components, a professional quality digital camera and a schlieren background. A schlieren background is composed of a varying contrast repetitive pattern, such as black and white stripes. This background allows the camera?s sensor to capture minor light diffractions, such as those caused by air flow. Although BOS shows great potential for ventilation analysis, sensitivity is an issue. This paper seeks to validate the BOS technique for imaging flow through a regulator by comparing BOS images with traditional schlieren images. This paper also outlines initial experimental efforts used for the validation.

Jan 1, 2011

By Stephen Phillips, Luigi P. Gonano

Vertical circular shafts have been proposed for multiple access to high level nuclear waste deep geologic repositories. Shaft construction is a critical path item in the commissioning of a repository. Other constraints on the shaft design and construction criteria include the lack of design precedence for long term performance and the importance of minimizing rock and groundwater disturbance. A comparative evaluation of conventional and mechanized shaft sinking techniques is presented in the context of the particular geologic and design constraints. Technical and non-technical factors for blind drilling, blind boring, raise-reaming, drill-and-blast and ream-and slash methods are reviewed for typically "hard rock" and "salt" type repository sites. Appropriate shaft designs are developed, the suitability of each method to the particular requirements evaluated and construction costs and schedules determined. The explicit appraisal of the significant design factors for each method serves as a rational basis for the preliminary selection of the most suitable sinking technique for a particular set of site/design conditions.

Jan 1, 1983

By Jack S. Watson, Rasika Nimkar, Robert M. Counce, Matthew Gordy, Patrick Zhang

Waste phosphatic clay presents a difficult disposal problem and a significant loss of P2O5. Recent developments make this study on the use of phosphatic clay as a feed material for H3PO4 production worthwhile. (a) New data from Florida Industrial and Phosphate Research Institute (FIPR) suggest that the Bclay^ waste can be effectively treated by improved solid separation coupled with flotation to produce feed material for recovering additional phosphate. (b) The use of BOLI Flowsheet^ provides capability to predict performance of aqueous-based processes for a range of possible operating conditions. Using the new FIPR data and BOLI Flowsheet^ enabled the design of a new process that can potentially extend the usefulness of current P2O5 ore deposits. Predictions using OLI Flowsheet were able to identify process conditions that effectively overcome the difficulty of high Mg content of phosphatic clay. Estimated manufacturing cost in the current study lead to valuation of the P2O5 content of the phosphatic clay recovered/utilized at 60 to 70% of that of the phosphate rock feed material currently used. Phosphatic clay should be considered as a valuable material that is currently given zero value. The new FIPR data and BOLI Flowsheet^ enables the design of a new process that can potentially extend the usefulness of current phosphate ore deposits by extending the fraction P2O5 of recovered

By A. Tobey Yu, W. Joseph Schlitt, Alfred Weiss, Frederic L. Kadey, Louis Kuchinic

Introduction The February and April 1984 issues of MINING ENGINEERING have already provided introduction to the long-range planning efforts of the Society of Mining Engineers (SME). These efforts are intended to provide the basis for effectively maintaining and improving the Society in the face of the changes that are besetting the mineral industry. This requires that SME recognize what changes are occurring and determine how these will impact the membership. Then a plan must be developed and implemented so that the Society successfully meets the challenges of the next decade. The Board of Directors has charged the Long Range Planning Commission with the responsibility for meeting these goals. This article provides a summary of the work done by the Management and Organization Committee of the Long-Range Planning Commission. This committee's task was to analyze the Society's current organizational structure and management process. Then a set of recommended improvements was to be developed. In doing this, the Committee has been careful to operate under that popular axiom, "If it ain't broke, don't fix it." Thus, changes were not proposed simply for the sake of change, but only where the present system appeared to be less effective than desired. Bases For Action The Committee began by establishing a set of premises about SME and its membership. These premises provided the bases for subsequent actions and recommendations by the Committee. Highlights from the premises included: • The Society should be run on a business-like basis. However, its "business" is that of a not-for-profit scientific, technical, and educational public institution. SME enables professionals involved in or associated with the mineral industry to serve the public purpose of benefitting mankind. • The Society operates as a national (US) organization with transnational (worldwide) interests. It recognizes its obligation to make its goods and services available to minerals professionals throughout the world. In addition, the Society recognizes its obligation to translate technology for the "lay" public, who then also become users of its goods and services. • The Society's Board of Directors is the policy-making body of SME and has final approval of all programs. These responsibilities will become greater when the Society becomes a separate corporation. • At present, the Society provides the following goods and services: publications, meetings/programming/short courses, academic education support, information dissemination - internal and external, and individual member services. • Planning is an ongoing process. It is best performed on a decentralized basis. That is, each major service category should have a responsible group authorized to conduct planning for that category, subject to the Society's master plan and the Board's approval. • The Society is privileged to have highly qualified and motivated members who volunteer their time and efforts on behalf of the Society. The best of these volunteers should rise to the highest positions of leadership - the Presidency of the Society and Institute (AIME). • The Sooiety is strongly committed to the protection and promotion of the history, traditions, and identity of AIME and the use of AIME as the unifying forum for the Constituent Societies. Identification of Potential Problems Once the premises about the Society and its membership were well in hand, the committee began examining the many facets of SME's organizational structure and management process. This was done in order to identify problems or potential problems in these areas. After considerable review and discussion, 10 areas of potential concern were called out for more detailed study and possible recommendations for improvement. These 10 areas include: • A lack of continuity at the Board level and among officers due to the established turnover policy. • A series of subboards that serve, by practice, to diffuse management authority and accountability, rather than enhance it. • A question as to whether the dissemination of information has been adequately planned, organized, and staffed. • An apparent illogical divisional organization. Two divisions are discipline oriented and two are commodity oriented. • A regional organization that does not adequately fulfill its purposes. • Uncertainties about the per-

Jan 6, 1984

By Val E. Payne

Issues between resource utilization and resource preservation often develop in connection with coal mining. One such conflict exists in eastern Utah where PacifiCorp and Energy West Mining Company are working with State and Federal agencies to address the resource recovery/resource preservation dispute. The effects of underground longwall coal mining on golden eagle (Aquila chrysaetos) cliff nesting sites have been studied at the Cottonwood Mine since 1986. Subsidence, escarpment spalling, and the nesting activities of the local eagle population were monitored.

Jan 1, 1986

By T. Rasmussen, T. G. Jørgensen, T. Fischer, R. K. McLimans, C. Knudsen, D. Frei

Ilmenite-bearing paleo-beach deposits were discovered in Jylland, Denmark using a combination of Ground Penetrating Radar (GPR), portable X-ray fluorescence (XMET), bulk XRF analyses, Computer Controlled Scanning Electron Microscopy (CCSEM), and wire line logging. The Miocene-age paleo-beach deposits are located below a thin Quaternary cover in a region of very moderate relief and essentially no outcrop demanding unique approaches in exploration. Initially, an isopach map of the Quaternary is prepared from existing water well data. A geological model for likely occurrence of Miocene paleo-beach deposits is generated and the coincidence of thin Quaternary cover and potential paleo-beach deposits define targets for detailed exploration. The defined targets are traversed with GPR to identify paleo-beach structures which are then used to define a drilling program. This methodology located a paleo-barrier island at the Vorslunde location with more than 10% ilmenite in the sand. During the drilling process, the TiO2 and heavy mineral contents of the sand were logged every meter with a portable XRF unit (XMET) and subsequently calibrated more accurately by comparison to bulk XRF and CCSEM analyses for selected samples. The bulk XRF data also provided more complete compositional information. Insitu determination of geology, heavy mineral abundance, and corroboration of the XRF logging was done using wire line logs, a combination of spectral gamma and induction conductivity logs. Detailed characteristics (abundance, grain size, shape) and chemical composition of minerals was determined by the GEUS CCSEM methodology (Frei et al, this vol.). The average weight percent TiO2 for all Ti-minerals is 62%, 60% excluding rutile. That elevated TiO2 content (>> ilmenite stoichiometric value, ca. 50 %) indicates that ilmenite experienced an iron-leaching environment. The source of the sand deposit was investigated by dating contained zircon. The results show that the likely sources of zircon are in southern Norway and southwestern Sweden with common zircon ages of ca 1100 Ma. and 1500 Ma.

Jan 1, 2005

Where space is limited, as it is throughout most of the northeastern United States, new construction either takes place high above street level, or below it. In Lower Manhattan, NY both kinds of expansion can be found in abundance. That is good news for the nearly 200 attendees at the George A. Fox Conference, presented by the Underground Construction Association (UCA) of SME at the Graduate Center, City University of New York, on Jan. 30. Among the many projects taking place in Lower Manhattan?s massive trans-formation process, are expansions to the city?s vast underground network of subways and other tunnels. ?New Yorkers either live on the ground or below it,? said keynote speaker Charles J. Maikish while explaining how an attempt to build above street level walkways never caught on in the city. Maikish is the executive director of the Lower Manhattan Construction Command Center. His job is to oversee the $22 billion project that will transform the island by 2010. From the construction of Freedom Tower at the site of the fallen World Trade Center buildings, to the expansion of the Second Avenue Subway, the extension of the East Side Access, No. 7 line, the new trans-Hudson line and numerous waterway tunnel expansions, including City Water Tunnel No. 3, the task Maikish is charged with is a huge one. He is primarily responsible for coordinating the scheduling and staging of the overall rebuilding plan, along with the day-to-day coordination of construction work down-town. He places particular focus on mitigating impacts on the environment and mobility, maintaining and improving access and alleviating congestion of any kind related to construction. At the time of the Fox Conference, there were 59 projects under way in Manhattan. All of those projects need things like concrete and steel delivered to sites in very tight working environments. And some need the equipment in even tighter spaces. ?This is not just about the recovery of Lower Manhat-tan (from the 2001 terrorist attacks) but this is a plan to restore it and to maintain its integrity,? said Maikish. ?I think that is the appropriate response to the terrorist attacks.? When Freedom Tower is completed, it will stand 541 m (1,776 ft) about the skyline. That will be a strong statement to the world about America?s strength. But it is the work that takes place much lower that was of interest to the conference attendees. On this respect, Maikish said Manhattan?s efforts below ground aim to provide relief to the city?s street level congestion and to make sure Manhattan ? already essential to the economy of the United States and the world ? stays current by upgrading the existing telecommunications and technological network while also allowing room for growth in that area.

Jan 1, 2007

By E. Sun

Tailings disposal is a significant consideration for the mining industry, with the majority of the ore processed in most mining operations ending up as tailings. Several tailings dam failure accidents have occurred during the past few years and mine tailings dam failures are occurring at relatively high rates. Tailings dam failure is disastrous with the serious damage and the loss of lives. To increase the tailings dam safety, a tailings dam monitoring and pre-alarm system (TDMPAS) based on the internet of things and cloud computing platform has been accomplished with the abilities of real-time monitoring of the saturated line, impounded water level, rain fall and the dam deformations etc. The TDMPAS has been applied in several mines in China and helped the mine engineers monitor the tailings dam safety and get warning information automatically and remotely in any kind of weather conditions. This work has been demonstrated the tailings dam monitoring and pre-alarm system (TDMPAS) is meaningful to monitor the tailings dam physical safety condition. The TDMPAS could be applied to monitor all the national tailings dams online in the future.

Jan 1, 2012

By L. E. Beverage, K. L. Johnston

This paper will address methods for minimizing liability and protecting materials from disclosure as result of self- evaluative audits and internal investigations. Specifically, the paper will cover the role of counsel in the investigative process and how best to design and conduct internal investigations to minimize the development of problematic material and disclosure of information. The paper will also address the extent of privileges that may be relied upon to protect materials and information from disclosure. These include the attorney-client privilege, the self-critical analysis privilege, and the attorney work product privilege. These privileges are qualified and understanding the limits of their coverage is essential to minimizing liability.

Jan 1, 2001

By M. T. Ansari

"This article explains the ways in which investment on mining infrastructure is a geopolitical issue. It discusses the effect of installing sufficient infra structure to get the product to the world market, and argues that there is a risk involved in depending on traditional suppliers who wish to invest in the infrastructure. It explains how to make a distinction between dedicated purpose infrastructure and general use infrastructure by examining the positions of the main actors in mining projects. It argues that these positions can not be understood as analogous to projects in developed countries. To conclude, infrastructure is a crucial link in the supply chain to market but the relative size of such projects in relation to the economy means that investors decisions in developing countries have quite different implications from those in developed countries."

Jan 1, 2011

By E. F. Schnitzer

During 1996 and 1997, Oregon experienced flooding on a scale not seen in many years. Some gravel pits located near rivers experienced erosion. In several cases, breaches occurred between the gravel pit and the river. Initial evaluation of several sites that experienced these breaches showed that impacts to the river system were complex and varied significantly from site to site. The impacts to the adjacent river system may be viewed as positive and negative. Several flood-plain-mining sites in Oregon located in areas of historic river flow reverted to active riverbeds. In many cases, state and federal fisheries biologists and university researchers saw the resulting increase in channel complexity and habitat as favorable. The Oregon Department of Geology and Mineral Industries —Mined Land Reclamation Program (DOGAMI-MLR) is studying the effects to the off-channel areas that resulted from the 1996 floods. More data is needed to make sound flood-plain decisions regarding mining.

Jan 1, 1999

By B. A. Ridolfi, S. M. Alvarez

The Moon Creek Reclamation Project provides a case study in the development of creative cleanup solutions for an abandoned lead and zinc mine and mill site located in northern Idaho. Innovative design features include construction of a 88,000cubic yard combined waste containment facility on soft in-situ tailings, water-balance cap, limestone gravel drains, a geocell mattress for stability, and a below-grade scour protection berm. The stream, including a wetlands buffer, will be relocated within an existing road alignment and rehabilitated to provide trout habitat. These elements allow for the integration of reclamation and stabilization measures into an effective site design.

Jan 1, 1999