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By Brian Ulrich

The majority of individuals involved in the mining industry can appreciate and under-stand that mining is an activity that is necessary to satisfy the very basic needs of society, and to assist in accommodating our ever-changing world. As the expression goes, ?if it can?t be grown, it has to be mined.? And at this point in time, society has granted the mining industry the right to go about the business of mining, with the general anticipation that the work will be carried out without causing undue harm to the environment or populations in and around the mining operation. The term ?sustainable development? is gaining momentum as a popular concept, and indeed it has become something of a catch-all phrase, but it is important that the idea behind the term is not cast aside as a nonsense buzz word, as it simply is an indication that development (e.g. mining) can be satisfactorily carried out with an eye toward stewardship of the environment and society. On Feb. 19, 2010, a round-table discussion (Roundtable 2010) on ?Strides Toward Sustainability in Mining? was hosted by Knight Piésold and Co. (Knight Piésold) at the Red Lion Inn and Casino in Elko, NV. Knight Piésold had local representatives (Bryan Ulrich and Steve Boyce), as well as representatives from other office locations (Cynthia Parnow and Rick Damiani from Denver, CO, and Rick Frechette from Tucson, AZ) to help facilitate the discussion. The meeting played host to 30 attendees from five states. Attendees included personnel from nine mining properties and various corporate offices. The majority of participants were people who are directly involved with environmental work on a day-to-day basis. Others were project managers whose jobs involve some level of environmental focus.

Jan 1, 2010

By Shiwei Wang, Ziwen Li, Chenhu Zhang, Peng Chen, Chengyong Wang

Accurate prediction of the partition coefficients in coal gravity separation is key to improving the preparation efficiency of coal and promoting its clean utilization. In China, the approximate formula method (AFM) has been applied to the calculation of coal gravity separation partition coefficients for decades, but its accuracy is limited. To improve the accuracy of the predicted partition coefficients, and thus the product yield of coal preparation plants, the present study proposes a modified hyperbolic tangent model to derive direct calculation formulas for the heavy medium and water medium separation partition coefficients. Four groups of coal samples were used to verify the accuracy of the direct formulas, and their predictions were compared with those of the AFM. The results showed that the partition coefficients and partition curves predicted by the direct formulas were closer to the actual values than those predicted by the AFM. Further, when the cleaned coal ash content was basically the same, the cleaned coal yield predicted by the direct formula was lower than that predicted by the AFM, and was also closer to the actual value. These results demonstrate that the direct formula produces more accurate results compared to the conventional AFM. As this formula has a reasonable theoretical basis, is simple to apply, and produces accurate results, it is expected to help improve the design and management level of coal preparation plants.

Oct 15, 2022

By William A. Gibson, Kenneth P. Neumann

In 1967, development of the Cyprus Thompson Creek molybdenum deposit began near Challis, ID. The first mining claims were staked on an intrusive rock out-crop. Exploration continued for 14 years. In 1978, the decision was made to develop the deposit. In Dec. 1980, approval was received for the environmental impact statement and facilities construction and waste rock removal began. By the middle of 1983, 126 Mt (139 million st) of rock had been removed and all facilities completed. Location The Thompson Creek project is located about 58 km (36 miles) southwest of Challis in Custer County, in south central Idaho. The mine and mill are situated between 2.2 and 2.6 km (7,217 and 8,530 ft) in elevation. The project is located in an isolated area. Surrounded by mountains, it is adjacent to the Sawtooth National Recreation Area. The Salmon river is 8 km (5 miles) south of the project. The project claim block is lo-

Jan 1, 1984

By Josh Swank

Albert Einstein once said, ?the important thing is not to stop questioning.? In the mining industry, a lack of inquisitiveness may lead to a blissful ignorance but it certainly will not increase efficiencies. While one may claim necessity is the mother of invention, questioning and analyzing how methods and systems can be improved is the catalyst to discovering necessities. Understandably, when working in the middle of Canada?s oil sands, where trucks operate around the clock every day of the year, it is nearly impossible to pull the nose from the grindstone long enough to provide thorough analysis. But, fortunately, some manufacturers/inventors have assisted by examining the process and the ensuing headaches within this application.

Jan 1, 2013

By B. J. Schat, A. W. O. Bots, O. S. Langhorst

Amsterdam City Council is building a new metro line, the North–South Line. The line passes under Amsterdam Central Station (a listed building) about 18m below street level. The retaining wall that has to be built underneath the existing building is an innovative construction consisting of two rows of steel piles interspersed with a solid mass of overlapping jet grout columns: a composite ‘sandwich’ wall. This paper gives an overview of the approach taken to designing (computational models) and building the retaining wall. Special attention is paid to the observational method used for the construction of the jet grout columns.

Jan 1, 2007

By C. Roos, K. Jetmore

Developing a strategic underground mine plan is challenging and investigating multiple scenarios may take weeks. This process can be sped up using the Theory of Constraints to isolate the bottleneck mining activity and simplify the mine schedule process. This paper presents a technique to apply the Theory of Constraints to test multiple cutoff grade scenarios in Mineable Shape Optimiser and quickly produce many high-level production-based schedules that can be easily interpreted using stope-by-stope graphs, the Hill of Value, and through incremental return analysis.

Mar 2, 2022

By Wayne Trudel, Lloyd McEvers, Lori Clarke, Eric Saderholm, Charles Lynn Bolin, Leroy Schutz

Newmont mine geologists in Nevada are most proficient when applying technical expertise with multi-departmental teams in three main settings. The first is value creation through near-mine discovery, development and reserve conversion. Since 1986, geologists have created substantial net asset value in developing more than 1.35 kt (43 million oz) into quality Nevada surface and underground gold reserves. The second setting is value realization by supporting mine operations with ore control, selective mining, reconciliation investigations and strategic planning. The investment of technical research on reconciliation investigations led to new concepts and practices that highlighted opportunities for large revenue and reserve gains. In 2002, more than $65 million in projected revenue was added to the Gold Quarry south layback. Kriged mine polygon construction and controlled blast heave at the Lone Tree Mine provided millions of dollars in mining efficiencies. High-quality geologic advice in selective mining at the Twin Creeks Mine helped obtain $4.3 million revenue gains throughout 2002-2003.

Jan 1, 2004

By M. Misra

Improved liberation and flotation of kerogen from eastern oil shale were accomplished with high-temperature grinding and a1 so with the addition of fuel oil during the grinding stage. Liberation measurements indicated that possible coalescence and aggregation phenomenon of kerogen particles during grinding may reflect this behavior. Additionally, ultrasonic treatment of the rougher concentrate prior to cleaning improved the quality of separation.

Jan 1, 1984

A new analytical approach for characterizing and improving the performance of ball milling is presented. Individual ball mill circuit design and operating variables can be related to overall circuit performance through two distinct parameters for classification and breakage. The ball mill circuit functional performance equation is presented. Applications in the industrial plant and in the research field are discussed.

Jan 1, 1990

By David J. Lowell

The gold content of porphyry copper deposits ranges from less than 0.05 g/t to more than I g/t ((0.0017 to 0.035 oz per st) and the average is about 0.05 g/t (0.0017 oz per st) gold. Perhaps the highest grade mineralization found near a porphyry cop¬per deposit is the Ok Tedi Gold Cap ore body whose grade falls in the 2 to 3 g/t (0.07 to 0.1 oz per st) range. It is difficult to define a gold-rich por¬phyry copper deposit. All porphyry copper ore bodies contain some gold, but there seems to be a fairly sharp break in the gold content at about 0.1 g/t (0.003 oz per st) gold. There is also a problem in identifying dis¬seminated gold deposits that may have an indirect relationship to porphyry copper systems. This relationship is clear cut in deposits such as the Ok Tedi Gold Cap, the El Hueso deposit, the Fortitude and West de¬posits at Battle Mountain, NV, and the Sur¬prise deposit at Ely, NV. There are many other bulk disseminated, epithermal-type gold deposits - McCoy, NV, for example - that might be related to a porphyry system but where this relationship is remains very uncertain. In such places as the Goldfields and Tonapah district in Ne¬vada and in the El Indio, Chile district, there may be a vertically stacked ore deposit rela¬tionship between near surface epithermal deposits and disseminated molybdenite and chalcopyrite enargite mineralization at depth that may represent a deep porphyry system. This, however, has not been positively demonstrated. Most of the bulk epithermal gold deposits are probably not related to porphyry copper systems. Exceptions would probably be Ok Tedi, El Indio, El Hueso, Battle Mountain, and Lepanto where vertical or lateral zoning relationships are more apparent. This author believes that porphyry copper systems are related to a relatively unique type of intrusion that is probably distinct from, for example, the McCoy intrusivebody. For that reason, deposits such as McCoy, Chimney Creek, and the like will not be included in the definition of gold-rich por¬phyry copper deposits for this article. The interpretation of the origin of several of the deposits previously mentioned are subject to an unusual amount of contro¬versy. For example, geologists seem to be equally divided about the presence of a porphyry copper deposit below the El Indio deposit. Geologic setting Continental vs. island arc Several geologists have speculated that the gold-rich, moly-poor, porphyries are

Jan 1, 1989

By J. F. Brune

This is a shortened version of the paper ?The Methane-Air Explosion Hazard Within Coal Mine Gobs published in the 2013 volume of SME Transactions (Brune, 2013). This paper analyzes the explosion hazard resulting from the formation of methane-air mixtures in the mined-out gobs of underground longwall coal mines. Evidence from numerous mine explosions suggests that explosive methane zones can form within longwall gobs. Explosions and fires resulting from these methane accumulations have led to severe and fatal injuries to the miners, including the explosion of the Upper Big Branch mine in West Virginia, where 29 miners lost their lives. The paper also reviews current research on numerical modeling of gas flows in longwall gobs and outlines how targeted injection of nitrogen into gobs can effectively reduce the volume of such explosive methane zones. The paper concludes that comprehensive monitoring of gas compositions along the accessible fringes of the gobs along with inertization, improved ventilation schemes and further research are necessary to control this explosion hazard and make mining operations safe.

Feb 23, 2014

By B. A. Slaker

The ability to detect and quantify ground movements in underground mine workings is of the utmost importance to the safety of miners and continuity of operations. Rib sloughage is one of the most common forms of underground deformation. Remote sensing techniques, such as laser scanning, can be used to quantify this rib sloughage, by recording precise, timelapse point clouds of mine workings. In order to determine sloughage volumes and locations, two sets of laser scans were performed 42 days apart at a working section of an underground limestone mine. During this period, significant sloughing and scaling occurred, allowing for differentiation between the initial and final point clouds. Volumetric changes of 2.3-2.6 m3 were detected on rib faces during the time-lapse study. In addition, displacement in the mine roof was, as expected, not detected, suggesting well surveyed scans and an appropriate scan resolution.

Nov 1, 2013

By W. G. Pariseau

Conventional barrier pillars in underground coal mines are intended to protect mains and sub-main entries for relatively long periods of time. Inter-panel barrier pillars that may be used in especially deep coal mines, say, below 800 m (2,400 ft), are intended to protect longwall panel faces and adjacent panel entries for the life of nearby panels. Barrier pillar failures have serious consequences, especially when failure is sudden and catastrophic. Design of barrier pillars is thus of considerable importance to safety and efficiency of operations. Locally, failure occurs at the limit to elasticity when stress tends to exceed strength. Strength of rock is stress dependent, so an analysis of stress is central to rational design of barrier pillars. There are several approaches to stress analysis for coal mine pillar design that range from the simplified but popular tributary area method including variations that use empirical definitions of the tributary area (volume) to more sophisticated numerical methods such as the boundary element method and the finite element method. Despite ease of use, empirical methods are limited and always suspect when applied to conditions beyond their scope of definition, while boundary element methods do not generally include pillars in the solution domain. The finite element method is not so restricted and thus is a natural choice for conventional and inter-panel barrier pillar safety analyses. Caving of roof strata certainly affects the distribution of stress about longwall faces and nearby barrier pillars. Conventional wisdom that considers roof strata to respond as cantilever beams indicates the longer the span the greater are loads on longwall faces and face supports. Failure of roof beams, caving, shortens spans and relieves face and support loads. The same view is applicable to barrier pillars in that long roof spans outside of barrier pillars leads to higher pillar loads than short spans. Hence, caving should be beneficial to barrier pillar safety. However, the benefit may be small depending on the extent of caving and only in the form of a slight reduction in overburden weight transmitted to the barrier pillar, especially in case of inter-panel barrier pillars. FINITE ELEMENT MODEL Finite element models for stress analysis in rock mechanics are formulated in consideration of physical laws, kinematics, and material laws. These models meet the essential requirements for equilibrium of stress, satisfy strain displacements relations, and in a general sense, relate stress to strain through material laws, often referred to as constitutive relations. The last may be complex and replete with nonlinearities. A de facto engineering material law is the elastic model in the form of Hooke?s law for linear, homogeneous materials that may be anisotropic. A limit to elasticity is imposed by strength in the form of a failure criterion or yield function that accommodates triaxial stress states. Examples used in rock mechanics are the well-known Mohr-Coulomb (MC)criterion, the popular Hoek-Brown (HB) criterion, and the Drucker-Prager (DP) criterion. The first is linear in stress, while the second is nonlinear. Both do not include any effect of the intermediate principal stress. The last is also linear in stress but includes the intermediate principal stress. All show an increase in the major principal stress at failure with confining pressure. In the UT2/3 finite element programs, the failure criterion Y is a nonlinear, anisotropic form and is also the plastic potential [1]: [YJI=+ 11NYJI=+- (1) ] where N is an exponent, usually 2, and J2 and I1 are nonlinear anisotropic forms of the second invariant of deviatoric stress and the first invariant of principal stress. The form (1) reduces to DP when N=1and isotropy prevails. When Y = 1, the limit to elasticity is reached and plastic deformation is possible. The material constants that enter (1) are all computed from unconfined compressive, tensile, and, in case of anisotropy, shear strengths. These latter strengths may be estimated from conventional laboratory test data. Of course, joints in field-scale rock masses induce different values. How different is often a matter of conjecture. For comparative studies, laboratory rock properties seem adequate. Inelastic, that is, plastic behavior occurs with strain beyond the elastic limit. Strain hardening, ideal plasticity, and strain softening are possibilities. Ideally brittle behavior with complete loss of strength is an extreme form of strain softening [2]. Caving may also be considered as strain softening with a less drastic reduction of material properties. As intact roof strata fail, fall, and form a rubble pile below, a new material is formed with greatly reduced elastic moduli and strengths, say, 1/100th of the original intact moduli and strengths. From another viewpoint, caving is simply a natural cut and fill process. Input for stress analysis by the finite element method includes: 1. Preexcavation stress state 2. Geology (stratigraphic column) 3. Structure (major faults, joint sets) 4. Elastic moduli 5. Strengths, and specific gravities of each rock type 6. Excavation sequence Output from an analysis includes distributions of: 1. Stress 2. Strain 3. Displacement 4. Local factor of safety (element fs) The last is defined as the ratio of strength to stress and in view of the failure criterion (1), is the ratio [fsJstrengthJstress=] where the numerator is the maximum possible value and the denominator is the actual value of the square root of the second invariant of deviatoric stress. This invariant is a measure of shear stress intensity but also reduces to uniaxial tensile and compressive strengths as the case may be. An fs greater than 1 indicates an elastic state of element stress; a value of 1 indicates the limit to

Jan 1, 2009

By V. Bush, T. G. Killingsworth, E. P. Ruffel

Effective and sustained corporate energy management programs are becoming a necessity for energy users as electricity deregulation laws are enacted on a state-by-state basis across the country and environmental regulations pertaining to emissions become more prevalent. The “Total Energy Asset Management” (TEAM) approach has been developed to assist energy end users with the development and implementation of corporate energy management programs designed to reduce energy risks and increase energy cost savings. This paper highlights the ways in which this approach can be applied to the mining industry while minimizing initial program implementation costs and increasing potential program benefits. Nearly the entire mining industry has become very focused on identifying opportunities to reduce costs per unit of yield. The industry as a whole has increasingly faced pricing pressures in large part due to the effects of global competition. The result of international marketplace participation and the emergence of higher efficiency recovery techniques have resulted in flat or even decreased prices for mining products. Thus, opportunities to reduce costs are actually opportunities to gain a competitive edge over similar mining operations. Due to the energy-intensive nature of many mining operations, the costs associated with energy are often a substantial percentage of operating costs. Therefore, it becomes very important to develop the corporate mentality that energy is an asset whose use should be optimized globally. In addition to the cost benefits of the TEAM approach, other benefits may occur such as reductions in facility greenhouse gas emissions.

Jan 1, 2002

By Howard E. Kremers

Although more than 100 thorium-rare earth minerals are known, only a few have any commercial significance. Monazite, thorite, bastnasite, and some exotic thorium rare earth ores are reviewed Commercial interest is presently centered on monazite from the Union of South Africa, and thorite from this country. Thorium became commercially important with the development of the incandescent gas mantle about 75 years ago, Gas mantles consist of thorium oxide with small amounts of cerium oxide. The thorium nitrate used to make gas mantles was first obtained from rare thorium minerals, As a matter of fact, this use of thorium is still important and is one of the largest commercial uses for thorium materials. The discovery of monazite sand placer deposits along the coasts of Travancore, India, and in some Brazilian beach s .s, and the development of the old North and South Carolina monazite stream placers gave the mantle industry of 30 to 40 years ago a comfortable inventory of thorium ore. Even today, the thorium industry depends largely upon monazite ores for its source of thorium. This paper will briefly describe some of the major thorium ores and their principal deposits insofar as they relate to the thorium industry in this country. Because of similar chemical and physical properties, thorium always occurs with the rare earth elements and with varying amounts of yttrium. Thorium may predominate over rare earths, as in thorite-type minerals, or may represent only a fraction of the rare earth content. Typical ratios of thorium to rare earths in various minerals are given in Table 1, The average thorium content of the earth's crust is about 12 grams per ton, and in this respect thorium approximates lead, molybdenum, and some of the rare earths in abundance. The ore minerals of greatest importance to the-thorium-rare earth industry are monazite, thorite-type minerals, bastnasite-type- ores, and the family of minerals which is characterized by a preponderance of the heavy rare earths and yttrium. The latter classification includes xenotime, gadolinite, samarskite, euxenite, etc, The first two, monazite and thorite, are of greatest significance.

Jan 1, 1958

All aspects of precious metals processing were featured at a symposium held Oct. 3-6, 2007, at Loews Ventana Canyon Resort in Tucson, AZ. Although billed as "Precious Metals Processing: Advances in Primary and Secondary Operations," the symposium also looked at economic, regulatory and environmental issues affecting the precious metals industry. The symposium was sponsored by SME; The Minerals, Metals & Materials Society (TMS); and the International Precious Metals Institute (IPMI). It included workshops, technical presentations, guest speakers and social activities. Mining industry management, process engineers, equipment manufacturers, consultants, metals marketers, academics and others involved in the precious metals industry attended the conference. Needless to say, with gold nearing $25.721g ($800/oz) and platinum pushing $41.801g ($1,300/oz) at the time of the meeting, the mood among the attendees could not have been more positive. The symposium was privileged to have Father Ernest S. Sweeney, professor of Latin American History at Loyola Marymount University, as a guest speaker. Sweeney, a Jesuit priest, provided a colorful account of the history of mining in Arizona and the surrounding region of North America (Fig. 1). He described the importance of the mining industry and said, "To go down into the bowels of the earth to extract its riches for the benefit of all of us is an awesome task deserving our sincere respect and gratitude." However, he warned the industry that: "The ever increasing de¬mands on the mining community for the protection of the environment calls for endless efforts to maintain ethical standards in a business filled with risk, uncertainty and frustrations." Sweeney noted that the Spanish conquest of the Americas was driven by the three fundamental motives of "God, glory and gold." He noted that gold was the basic, most powerful driving force of the conquest and occupation of the Spanish empire. The first European to explore Arizona was the Franciscan missionary Marcos de Niza. He came to Arizona in 1539 in search of the fabled Seven Golden Cities of Cíbola. Sweeny noted that Spanish explorers were consumed, as Cortes himself described it, "with a burning fever that only gold could cure." Sweeney told the story of some of these early explorers, including Francisco Vázquez de Coronado who "mounted an expedition in pursuit of gold and rich empires to conquer." Coronado passed through Arizona and discovered the Grand Canyon. "Coronado returned to Mexico exhausted, bankrupt and disillusioned, but with a wealth of new knowledge of the borderlands of the Spanish empire," said Sweeney. He then described the colorful history of early gold, silver and copper exploration and mining in Arizona, including the famous tale of the Lost Dutchman's Mine. In a luncheon address, David Kanagy, SME's executive director, introduced the attendees to the upcoming OneMine. org Web site. Kanagy told the audience" One-Mine.org will be a collaborative digital library that will

Jan 1, 2008

By Christy Z. Lueders

Introduction More and more women engineers are joining the traditionally male mining industry. Are they successful? Do they encounter special problems? How do men in mining respond? How can the mining industry effectively use its female resources? What contributes to the success of a woman in mining? What can male engineers do to ease the entry of female professionals into the workforce? An STM survey conducted last spring provided some answers to these questions. All BS graduates in mining, mineral engineering, and extractive metallurgy from 1960-1979 were surveyed. Nearly 60% of the female graduates, from 17 universities, completed questionnaires. The women were asked why they chose mining, how they relate to predominantly male co-workers, what job skills they have gained, and what areas of work they most enjoy. They were also asked how problems of a two-career family are solved. Data were gathered on salaries, titles, specialties, and products handled. Respondents, assured of confidentiality, are identified only by title. Many male mining executives were also questioned for their advice to women in mining. Profile of the Survey Participant The "typical" female mining engineer works with coal, is employed by an operating company, feels she works very hard to prove her abilities, does not want to be treated as an anomaly, and someday wants to be an independent consultant. Of the respondents, 44% listed coal as the most familiar product, 12% said copper, and the rest listed products from industrial chemicals to oil. Titles varied widely but women managers are rarely found. However, the majority of the survey population graduated after 1976 and thus lacks substantial experience. Of 102 female graduates, only 25 graduated before 1977. Since then, there has been a steady increase. The American Association of Engineering Societies reported that in 1980 more than 100 degrees were awarded to women in minerals engineering. Education Highly Valued Twenty-two percent of the women surveyed had graduate degrees, 38% planned further education, and 12% listed a PhD as their goal. The majority of graduate degrees are in technical fields. There were only two MBAs. Five women intended to pursue law degrees, and one woman, with a mining engineering degree and an MBA, is a part-time law student. Along with advanced education, the women agree that production experience is needed for career advancement. However, only 28% of the women have worked in production. Many women, especially younger grads, commented that these are the toughest jobs to get. This is a universal complaint, from males as well as females, though women seem to encounter more opposition. Several women mentioned they were small or slight of build and managers tended to shy away from hiring them for production jobs. Two-Career Marriages The most difficult problem for two-career couples is relocation. Whose career takes priority? Fifty percent of the women said transfers or offers would be examined on a case-by-case basis, weighing pros and cons for both parties. The husband's career took priority with 47% of the women; their own careers, with 3%. These statistics conflict with comments from two employee relations managers. Both said most female engineers they've encountered are married to men who follow their wives' careers. Seventy per cent of the married respondents said their husbands were also engineers. Four said their husbands were engineers at the same company. Some male and female engineers met on the job; others joined the company as a "package deal." Both partners being engineers can ease relocation problems, since an area or company offering one spouse a job can often provide a spot for the other. A company may benefit by getting two new hires for the relocation costs of one. Most companies contacted have policies that allow married couples to work at the same division, but discouraged them from working in the same department. With 40% of today's marriages ending in divorce, one risk is that one or both parties may quit. One personnel executive said there were several couples, each spouse in a different discipline, who were work¬ing out very well at his division. However, he recognized the potential for problems if, for instance, one gets promoted and the other doesn't, or salary increases are unequal. The personnel executive said he has actively recruited married couples, and would again, were each person competent.

Jan 10, 1981

The Functional Performance Equation for ball milling circuits allows us to isolate the circuit classification system efficiency (CSE) from the mill?s grinding performance. The factors which affect circuit CSE are reviewed, with emphasis on water usage at the classifiers. It is shown that manipulation of such water usage can be carried out to improve plant grinding circuit efficiency, at times by more than 30 percent.

Jan 1, 2009

The Department of Health and Human Services (HHS), National Institute for Occupational Safety and Health (NIOSH), Office of Mine Safety and Health Research (OMSHR), with the assistance of cooperating underground mining operations and state agencies, has conducted research exploring devices and technologies that could be used to assist miners navigating through smoke and dust resulting from a fire or explosion. Recent events in mines confirm that smoke and dust can enter and contaminate mine escapeways creating an atmosphere with severely reduced visibility. This reduced visibility results in substantially increased escape times, possible disorientation or confusion, and increased stress levels, and may prevent evacuation altogether. Tools or devices that assist miners in navigating through smoke-filled areas void of lifelines could make the difference in successful escape from the mine. This paper presents the results of OMSHR research to identify and evaluate tools and devices that could provide meaningful information to evacuating miners in areas with limited visibility and without the benefit of a lifeline.

Jan 1, 2011

By P. A. Dimas

A new family of sulfide flotation collectors has been developed in our laboratory. These formulations are comprised of novel renewable materials combined with conventional reagents. The resulting diversity permits tunability of collector chemistry to meet a range of flotation problems. Several attributes of the new collectors are presented.

Jan 1, 2012