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By Michael V. Markel

This report summarizes work performed under USBM Contract No. J0100047 revealing the performance characteristics of a composite-type resilient screen deck. The ability of the composite to perform or compete with steel in noise attenuation and longevity was of interest. Tests were conducted at the River King Preparation Plant of Peabody Coal Company. This facility was chosen because it provided parallel process flow and met standard coal cleaning requirements. Comparisons could be made between the adjacent resilient and steel screen decks under similar operating conditions. Noise reductions of 1-6 dBA were realized in the near field. Although the test period did not determine resilient screen life, indications are favorable for their longevity.

Jan 1, 1981

The largest investment in mining equipment in Caterpillar?s history ? The F series mechanical and electrical drive trucks ? is rapidly advancing. Caterpillar showcased the 793F and 797F mechanical drive trucks and the 795F ac electric drive truck at MinExpo in 2008 and have continued testing since then. The 793F and the 797F have accumulated more than 75,000 hours of field testing and have proven their performance capabilities and their durability. The new Cat C175 engine that powers them has racked up 130,000 hours of field testing in mining trucks and more than 120,000 hours in power systems. Because of the success of these field-follow programs, the 793F is targeted to go into full production within a few months and the 797F late this year. Caterpillar engineers have been testing two 795F ac prototypes at the Tucson Proving Grounds in Arizona. The development program has provided input for the construction of a new 795F ac in Decatur, IL. The new truck recently shipped to a copper mine in North America where it will serve as the first field-follow 795F ac as it works at the mine. The 313-t- (345-st-) capacity 795F ac will enter a new size class for Caterpillar, and, as a result, the primary focus of the Caterpillar ac electric program has been on the 795F ac. The commercial launch date will be defined as the field-follow program progresses. ?It?s fitting that soon after producing the 50,000th Cat off-highway truck, we are now shipping our first ultra-class ac electric drive truck to a mine,? said Chris Curfman, president of Caterpillar Global Mining. ?Our new trucks further solidify our position as the one manufacturer to provide unparalleled options and unmatched customer support.?

Jan 1, 2009

By Oliver Bowles

The United States Bureau of Mines has within its ranks a group of engi- neers who are engaged in working out quarry problems, the solution of which will be of general benefit to the industries involved. The problems undertaken are approached in a systematic and thorough manner, all the evidence for and against any proposed change or new development being collected as carefully as an attor- ney would prepare his data on an important case. Unlike the attorney, however, the Bureau engineer does not take sides; his judgment is based entirely and in- partially on the array of facts presented. In order to gain the desired infor- mation he visits many plants, consults with the leaders in the industry, works out experiments in his laboratory, and supplements this information with a stu- dy of all available literature already published on the subject in any part of the world. As an engineer who has for eight years conducted such inquiries in the stone industry, I propose to discuss the Bureau of Mines viewpoint; and it may be of interest to consider with me in a brief and general way the engineer's method of looking at quarry problems, and some of the results attained through past and present labors. While the Bureau has conducted no investigation directly for the crushed- st one industries, two years of investigative work at cement-plant quarries, and work now being conducted at lire-plant quarries, has a very direct bearing on the problems of the crushed-stone industry, since stripping, drilling, blasting, loading, and transportation are similar in many respects in all stone quarries. The results of cement-plant quarry investigations are to be found in Bureau of Mines Bulletin #160. (b) Two short papers on lime-plant quarry problems have been issued in mimeographed form as Serial #01 (c) and Serial 3 (d).

Jan 1, 1923

Organization Place Date 1919 American Railway Engineering Association Chicago, 111. Mar. 18-20 Society of Industrial Engineers New York, N. Y. Mar. 18-21 American Electrochemical Society New York, N. Y. Apr. 3-5 National Foreign Trade Council Chicago, Ill. Apr. 24-26 American Iron and Steel Institute New York, N. Y. May American Institute of Electrical Engineers Lake Placid, N. Y. June

Jan 3, 1919

By Floyd D. Varley, C. M. K. Boldt

Toolbox training is often described as short, informal training conducted at a worksite by technically competent persons for the benefit of a work team. The key feature of toolbox training is the focus on a work team and what is important to that group in its workplace. Toolbox training conducted by peers can connect miners and establish the feeling that the hazard is a real threat to them. This feeling can bridge the gap between delivery of a safety message and behavioral changes that can prevent an accident. Toolbox training is a popular form of "maintenance" training that should not be used to teach a new skill. The 10- or 15-minute toolbox session is simply too short a time to teach or learn a new skill and test for skill development. However, the toolbox format is an excellent way to inform workers of changes in workplace rules, conditions, or hazards by bringing the discussion of change to the level of the work group and suggesting how a change will affect the way workers perform their jobs. Toolbox training should be structured to address a very specific hazard. That is, the hazard source should be identified and the effect of the hazard on the worker described. The temptation to discuss a safety subject in broad terms will result in an equally vague result. For instance, discussing "equipment guards" is inappropriate for a 15-minute training session. There simply is not enough time to cover all the hazards and their remedies. A more appropriate topic would be "placing guards on a conveyor return roller" or "hazards of cleaning a conveyor return roller." Each topic is concise enough to allow the trainer time to define a particular threat to the safety of miners and discuss ways to defend against that threat. The clearest way to a safe workplace is to identify hazards methodically and eliminate them. This cannot be done with sweeping, generalized training. Some best practices that will protect a worker from the hazard should be presented, and the hazard should be located at the specific worksite. Toolbox training is an opportunity for the work team to participate in learning and share experiences and knowledge, often through storytelling. Storytelling is an ancient form of passing along information in an entertaining way. It is entertaining because it draws the listener in with imagination and creativity. Stories told within work groups are a way for miners to exchange experiences in which they made mistakes that resulted in an accident or a near-miss and learned a valuable lesson. Thus, co-workers can learn from others without the pain or fear that accompanied the storyteller's learning path. To encourage these shared experiences, the people in the group must be comfortable with one another. Participation doesn't stop with listening to a near-miss story or informing the group of an unsafe work practice. Participation by sharing experiences, knowledge, and skills should lead toward action in changing the unsafe tool, practice, or machine (Wallerstein, 1992). This power to change is called empowerment. Empowered workers use toolbox training sessions to discuss a problem; direct their own knowledge, experience, and talents in the context of their work environment to solve the problem; and put into practice what they have learned by sharing (Baker, 1992). A worker is much more likely to implement changes they have contributed to creating than changes forced upon them. Toolbox training functions best when the group size is small (under 20) and composed of workers with similar job functions. While combining all workers on a shift or multiple shifts may be convenient, the level of participation will drop dramatically as group size increases and participants are less connected. Similarly, when the work group participants are from different job functions, keeping the materials relevant to the individual becomes more difficult. The role of management in the toolbox training system is to communicate among various groups so that all groups at a mine site are hearing the same message. In very small operations, combining work groups can be productive if the trainer can promote open discussions and lead the group to solutions that address the needs of all and not let one group or individual dominate the discussion. WHY USE NARRATIVE METHODS An effective communications tool is to use stories as a means of describing a hazard and its consequences. Historically, using stories to transfer knowledge between individuals of the same and different generations is well established. All good stories share the same elements required to communicate safety principles. Stories require a setting (the part of the workplace), a plot (the circumstances that lead to a hazard), the solution (best practices), the lesson (what can happen), and the result (what will be done to prevent the hazard) (Dennehy, 1999).

Jan 1, 2002

By P. W. J. van Rensburg

Our mineral heritage - PRESIDENTIAL ADDRESS given by P. W. J. van Rensburg, Pr. Eng.. B.Sc. (Eng.)(Rand) INTRODUCTION Stone Age people were living in various parts of South Africa as recent,ly as a thousand years ago, when they were displaced by Iron Age people with a culture developed in the far north. These invaders brought farming, building, and the earliest mining developments to the Transvaal, thus ushering in the beginning of our great mineral heritage. It is of particular interest to record that, up to comparatively recent times, some of these people were excavating iron-bearing shale rocks for their smelting furnaces on the Melville Koppies in J ohannesburg. Although the most recent the iron-smelting furnaces discovered on these koppies is estimated to be some five-hundred years old, it believed that these Iron Age people were driven out, and their settlements destroyed, by Zulu impis only one-hundred-and-fifty years ago.

Jan 10, 1973

By M. Abdellatif

Keywords: Pyrometallurgy, furnace, DC arc furnace, smelting, silicon The technical feasibility of silicon smelting in a DC arc furnace was investigated. A graphite-lined furnace was operated at power levels of 150 to 160 kW, and 40 to 60 V. The average feed rate during the silicon production period was about 30 kg/h. The recipe consisted of pre-mixed batches of 28% petroleum coke and 72% lumpy silica. The target furnace operating temperature was set at 1600°C and then raised to 1700°C. In total, about 1.6 tons of premixed feed materials was processed over 16 feeding?tapping operations. The feed was manually charged into the furnace in sub-batches of 10 to 40 kg at a time. The total batch mass was set at 90 kg during the initial part of the testwork, and increased to about 120 kg for the rest of the campaign.

Jan 1, 2011

"The measurement of error in assays collected as part of a mineral exploration program or mining operation historically has been undertaken in a variety of ways. Different parameters have been used to describe the magnitude of relative error, and each of these parameters is related to the standard measure of relative error, the coefficient of variation. Calculation of the coefficient of variation can be undertaken in a variety of ways; however, only one produces unbiased estimates of measurement error: the root mean square coefficient of variation calculated from the individual coefficients of variation.Thompson and Howarth’s error analysis approach has also been used to describe measurement error. However, because this approach utilizes a regression line to describe error, it provides a substantially different measure of error than the root mean square coefficient of variation. Furthermore, because regression is used, Thompson and Howarth’s results should only be used for estimating error in individual samples, and not for describing the average error in a data set. As a result, Thompson and Howarth’s results should not be used to determine the magnitudes of component errors introduced during geochemical sampling, preparation, and analysis.Finally, the standard error on the coefficient of variation is derived, and it is shown that very poor estimates of relative error are obtained from duplicate data. As a result, geoscientists seeking to determine the average relative error in a data set should use a very large number of duplicate samples to make this estimate, particularly if the average relative error is large."

Jan 1, 2007

By Mark Sanders

This report compares a proposed 10/60 "piggyback" 02 generating self-rescue unit to the standard CO self-rescue unit with respect to work task interference. A simulated low seam coal mine was constructed and subjects performed locomotion, shoveling, cart pushing, and timbering tasks with the 10/60 or self-rescuer attached to their belts. Task completion time was longer on all tasks when wearing the 10/60 unit, although only locomotion was statistically significant. The 10/60 unit was bumped over 100% more often than the standard self-rescuer. Implications for design of the proposed 10/60 container are: 1) unit?s container must be extra durable to withstand the added abuse it is likely to receive by low coal miners; and 2) extra consideration must be given to preventing the device from slipping on the belt while working, especially in low coal.

Jan 1, 1980

By Bruce McDonald

This report contains the Phase I findings of a study to select and test devices for preventing lack of alertness in haulage truck drivers. The extent of the problem was determined by visiting surface metal and nonmetal mines, interviewing drivers and safety personnel and reviewing accident reports. A number of devices for detecting a lack of alertness were considered and three were recommended for testing in actual operation.

Jan 1, 1977

By Lester M. Adams

In 1980, the Bureau of Mines surveyed a group of mine seals in Randolph County, WV, to evaluate their effectiveness for reducing toxic pollutants in mine water discharges. The survey focused on 11 block wet mine seals, but mine seals of several other types were also examined. The seals were installed in 1966 and 1967 in abandoned drift portals by the Federal Water Quality Administration (FWQA), a predecessor of the Environmental Protection Agency (EPA), in cooperation with the Bureau of Mines and other Federal and State agencies, in a project known as Elkins Mine Drainage Pollution Control Demonstration Project. The seals were designed to prevent air from entering the mine portals while allowing mine water to flow out. It was believed that by preventing air from entering inactive or abandoned mines, the formation of toxic pollutants and acid mine drainage (AMD) could be reduced. Evaluation of the seals was based on water flow measurements, water analyses, and visual observations. The Bureau's 1980 data were compared with past data collected by the EPA. Several leaks and failures were observed in the clay seals, as evidenced by apparent blowouts and the absence of vegetation where the mine water surfaced. Analyses of the 1980 data indicated some improvement in the quality of water discharged from many of the wet air seals.

Jan 1, 1984

By Landy Stinnett

"When performing a valuation of a mineral property, a developing mine or perhaps an ongoing operation, the appraiser is typically provided with a range of information prepared by the property owner. This information can include ownership records, geological interpretation, assay data, an estimate of the reserves or resources believed to be on site (tons and grade), mine plans, production forecasts, capital and operating cost projections, and so forth.The appraiser familiarizes himself with the data, analyzes the various reports and then prepares the appraisal. There is usually a site visit, and there may be some effort at comparison of the particular mineral deposit with others in the region or with those of similar depositional characteristics, but for the most part, the appraiser is relying on the corporate documents, tempered by his/her experience in the field. Time is usually of the essence, the cost for the assignment has been trimmed, and therefore independent verification of the various components comprising the underlying data base (legal review, redrilling portions of the deposit, collection of new samples, re-assaying, etc.) is unlikely in most situations.In the case of high-value commodities — gold, silver, diamonds, perhaps the platinum-group elements — there have been numerous examples of the property owners attempting to increase the value of their holdings by nefarious methods. Most of these involve salting the deposit in some fashion; i.e., introducing small amounts of the commodity into samples being sent to a laboratory for analysis so that the resultant assay shows a higher grade (Donaldson, 2002; Greeley, 2001; Lechler et al., 2008 and Meech, 2001). Other schemes to enhance the apparent worth of a property include the use of nonstandard assay procedures, incorrect handling or withholding of the underlying information, and false reporting."

Sep 1, 2016

By P. H. Derbyshire

The use of continuous flight auger piles has increased significantly in the U.K. to such an extent that it is now the most widely used method of constructing small diameter bored piles. This paper describes the improvements in equipment, techniques and particularly monitoring that have led to this growth. A review of the equipment in use describes how purpose built self erecting machines have been generally adopted. Improvements in ancilliary equipment are described. Concrete has almost completely replaced grout and techniques have been developed to extend the length of reinforcement that can be placed. Leading specialist contractors have developed instrumentation to monitor the construction of the pile (in terms of time, depth, torque, concrete pressure and flow) and keep a record for checking. A further significant development of this monitoring by means of sensors at various levels in the auger stem is described. The results obtained from this monitoring are reviewed and future developments discussed.

Jan 1, 1989

By K. Barbetti

"The carbon-in-pulp (CIP) process has been the dominant gold recovery process since the early 1980s. CIP has proven to be very adaptable for a wide range of ores and circuit configurations. The key performance indicator for CIP circuits is the minimisation of soluble gold losses to tailings, however, it is also important to operate the circuit efficiently (maximising gold loadings on carbon and minimising carbon inventory). Over the last 30 years the Curtin Gold Technology Group has studied CIP circuits as part of an on-going collaborative industry funded project (the AMIRA Gold Processing Technology Project). In the early years the project undertook basic research into understanding activated carbon, and its management in the circuit. More recently the development of process models and instrumentation has provided additional tools to assist operators. The results show that while most CIP circuits operate well, there are still significant opportunities for further cost savings, or additional revenue. This paper reviews the observations arising from this work, including key requirements for good carbon management, the results of benchmarking and industry surveys of carbon circuit over 20 years, the value of process modelling of CIP circuits to establish operating parameters, and the use of automated instrumentation to better optimise carbon control in the circuit.INTRODUCTION The introduction of activated carbon to recover gold from cyanide leach solutions in the last quarter of the 20th century was the most significant development in gold ore processing since the advent of cyanidation seventy years before. Replacing the Merrill–Crowe zinc cementation step with carbon-in-pulp (CIP) or carbon-in-leach (CIL) circuits provided a process that allowed the treatment of lower grade and problematic ores (e.g. high-clay ores), at lower capital and operating costs, and higher metal recoveries. The CIP circuit was first developed in the 1950s at the Carlton Mill, Cripple Creek, Colorado. All the components of the modern CIP process came to fruition at the Homestake Mine in South Dakota in 1973 (Fast, 1988). From the late 1970s onward a variation of CIP, carbon-in-leach (CIL) which combined the leach and adsorption stages, became the preferred circuit design in most parts of the word."

Jan 1, 2017

By Paul R. Terry

This paper presents a brief picture of the quality of coal produced in Eastern Canada for use in thermal generating stations. It describes, in particular, the characteristics of coals burned in six power plants -two in New Brunswick and four in Nova Scotia. Each station is dis-cussed in turn, and comments are made on the coals used therein with regards to origin and physical and chemical properties affecting station operation. A table of coal data shows, at a glance, the wide variation in the quality of coals received by these stations from producers in New Brunswick and Nova Scotia. "The promotion of improved coal quality for thermal generation can benefit our national economy." T HIS is the opening statement in a paper which was presented by Mr. D. A. Pirttinen at the Coal Division's Toronto meeting in April, 1960. In bringing the power engineer's viewpoint to the coal producers' attention, Mr. Pirttinen made a survey of utility steam plants operating in Canada, and the results of this survey formed the basis for his paper, which he titled: "Generating Station Coal Quality.

Jan 1, 1965

Develop tools that mine personnel can use to comply with 30 CFR,Part 47. Background The new MSHA rule, 30 CFR, Part 47 (also known as the HazCom rule), requires all mines to develop a written program to track hazardous chemicals at their sites. More specifically, the rule requires that mines list all chemicals and determine which are hazardous; develop a written Hazard Communication Program; label all containers used to store hazardous chemicals; obtain or develop Material Safety Data Sheets (MSDS) for all chemicals stored or produced; provide miners with training in working around hazardous chemicals; and make information about hazardous chemicals available to all workers. All mines with six or more employees must have complied with the new rule by September 23, 2002, and mines with five or fewer employees will have to be in compliance by March 21, 2003.

Mar 1, 2003

By E. D. Gardner

From the standpoint of tonnage and dollar value copper is the most important nonferrous metal mined in North America. The opening of copper mines has had an important bearing on the development and settlement of many sections of the continent. The prosperity of many of the mining States or provinces depends directly upon the copper-mining industry. Normally, about 35,000 men are employed in the copper mines, mills, and smelters of the United States. The United States is the most important producer of copper among the nations; more copper is mined in North America than in any other continent, and for many years the United States alone produced about half of the copper of the world. During the last 10 years increasing production in South America and Africa has reduced the relative importance of North America and the United States.

Jan 1, 1938

By Paul F. Ziemkiewicz, Aaron Noble, Christopher R. Vass

The conventional rare earth element (REE) industry has historically sought to develop ore deposits where geologic processes have produced mineralized zones with commercially attractive REE concentrations. These deposits are extremely uncommon, particularly in the USA. Given the criticality of these materials and the need for sustainable domestic supply, the current research seeks to leverage other autogenous processes that lead to concentrated REE resources. One such process is the generation of acid mine drainage (AMD). AMD is very common in many coal mining districts and results from the exposure and oxidation of pyrite during mining. During the generation and migration of AMD, liberated sulfuric acid mobilizes several metal ions including REEs. Treatment of AMD is required under U.S.C §1251, the Clean Water Act, and often consists of neutralization, oxidation, and metal hydroxide precipitation. To investigate the deportment of REEs during this process, a field sampling campaign was undertaken, whereby the concentration of REEs in AMD and AMD precipitates was measured directly. In the nine sites evaluated in this study, the REE concentrations of the precipitates varied from 29 to 1286 ppm with an average of 517 ppm among the sampled sites. The individual elements were enriched compared with the associated bulk Northern Appalachian (NAPP) coal material by factors ranging from 3 to 15. Furthermore, the distribution of REEs in all precipitate samples favored the heavy REEs (HREEs) when compared with traditional REE ores. This research represents the first part of multi-part research endeavor to characterize, classify, and determine the practicality of refining REEs from AMD and its by-products.

By Paul F. Ziemkiewicz, Aaron Noble, Christopher R. Vass

The conventional rare earth element (REE) industry has historically sought to develop ore deposits where geologic processes have produced mineralized zones with commercially attractive REE concentrations. These deposits are extremely uncommon, particularly in the USA. Given the criticality of these materials and the need for sustainable domestic supply, the current research seeks to leverage other autogenous processes that lead to concentrated REE resources. One such process is the generation of acid mine drainage (AMD). AMD is very common in many coal mining districts and results from the exposure and oxidation of pyrite during mining. During the generation and migration of AMD, liberated sulfuric acid mobilizes several metal ions including REEs. Treatment of AMD is required under U.S.C §1251, the Clean Water Act, and often consists of neutralization, oxidation, and metal hydroxide precipitation. To investigate the deportment of REEs during this process, a field sampling campaign was undertaken, whereby the concentration of REEs in AMD and AMD precipitates was measured directly. In the nine sites evaluated in this study, the REE concentrations of the precipitates varied from 29 to 1286 ppm with an average of 517 ppm among the sampled sites. The individual elements were enriched compared with the associated bulk Northern Appalachian (NAPP) coal material by factors ranging from 3 to 15. Furthermore, the distribution of REEs in all precipitate samples favored the heavy REEs (HREEs) when compared with traditional REE ores. This research represents the first part of multi-part research endeavor to characterize, classify, and determine the practicality of refining REEs from AMD and its by-products.

By L. E. Cardwell

This publication contains routine analyses and related source data for 377 natural gas samples from 19 States and two foreign countries. Of this total, 373 samples were collected during calendar year 1970. The remaining four samples were collected during previous years, but releases granting per-mission to publish the analyses were not received until 1970. All samples were collected as part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863 and 576.4 Twelve previous publications have presented the results of 9,050 gas analyses prior to 1970. The first three, Bulletins 486,6 576,8 and 617,7 contain analyses and related source data on 5,218 gas samples collected from

Jan 1, 1971