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By Nathan Feldstein

The wetting of coal dust by aqueous solutions of surface active agents (surfactants) has been studied. Selected for study were thirty coals and typical surfactants selected from the typical classes of anionic, non ionic and cationics. Of these three classes the practical use of cationics in aqueous solutions has been eliminated due to the inherent negative Zeta potential charge of the representative coals studied. The wetting of the coals has been examined by column flow, contact angle, and settling rate measurements. Results indicated that both anionic and nonionic surfactants are to be considered viable for use; low critical micelle concentration values are also preferred for the surfactants. Study of native waters showed substantial variation in properties, i.e., pH, calcium ion concentration, and conductance. pH variations were also noted to affect the effectiveness of selected surfactants. Combinations of nonionic and anionic surfactants have, in certain instances, produced synergistic enhancement in the coal wetting superior to the effectiveness of each surfactant alone.

Jan 1, 1981

By B. J. Moore

This publication contains 14,242 analyses of gas samples from oil and gas wells and natural gas pipelines in 40 States and 24 foreign countries. These gas samples were collected in the period 1917-85 as part of the Bureau of Mines survey for helium occurrences. The gas analyses contained herein were made by several methods over the period covered. Analytical work on samples collected early in the period was done on the Orsat apparatus. The one-cut apparatus and four-cut fractional distillation equipment were added later. A mass spectrometer was acquired in 1949 and used for all gas analyses made after that time. From 1917 to 1978, helium analyses were made on special helium analytical equipment designed and built by the Bureau of Mines Helium Operations Laboratory. In 1978, this apparatus was replaced in the quantitative helium analysis work by a gas chromatograph.

Jan 1, 1987

By J. Douglas Causey

In 1987, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied a part of the 21,296-acre Million Hills Wilderness Study Area (NV-050-233) in order to evaluate its identified mineral resources. The study area is located in Clark County, NV, about 46 miles south of Mesquite, NV. The area is on the east edge of the Gold Butte mining district and has had minor production of copper and zinc from the Azure Ridge mine in the early 1900's. Assessment work was being done on the Esperanta claims, which covers the mine workings, in March 1987.

Jan 1, 1988

By J. Temporal

An introduction to the conference material in this issue is given together with the issue contents list, closing remarks by its chairman Dr. J. Temporal, the list of contributors and their companies, and the information that the 26th Sir Julius Wernher memorial lecture had had to be presented by the lecturer's wife, M. Biggart, in his absence due to site problems on the Storebaelt project

Jun 16, 1905

Grade control is a real challenge, and better sampling and modelling practices are among the tools that have proven efficient in improving it. Although based on rather trivial examples, this paper addresses the following important issues: How much of a challenge is it? How and to which degree can it be improved? And what kind of economic benefits should be expected in return for the corresponding efforts?

Jan 1, 1999

By D. Diering

Having agreed to perform this task, I naturally started to wonder what on earth I was going to talk about, and on reviewing the literature I was surprised at how little I knew and how much I?d forgotten about the origins of this industry. For example: ?I?d forgotten that the Chinese invented black powder at least 1 000 years ago, back in the 10th century (although some say this invention occurred 2 000years ago). ?I didn?t know that Roger Bacon was the first person in the Western World to give exact directions for the making of gunpowder in 1242 and to understand its potential. Pepper?s Playbook of Metals quotes:?...above all, he is named as the discoverer of gun-powder, a material which has brought more wonderful changes in the great family of man than the most potent elixir that could have been devised to prolong life?.

Jan 1, 2000

To provide an engineering solution to wood crib design and deployment strategies that will ensure safety for underground coal mine workers. This is accomplished by preserving necessary ground control requirements while minimizing support costs or by developing new support strategies to enhance ground support in difficult conditions. A secondary objective is to be able to quantify wood crib support performance to define support requirements for alternative support systems. These objectives have been achieved through a simple-to-use computer program called the wood crib performance model (wcpm).

Jan 1, 1997

By Karl E. Burgher

Since World War II, the need for the use of explosives with testing, construction, demolition, mining and quarrying near urban areas has increased dramatically. Once remote, testing areas have been encroached upon by commercial and residential areas. Evidence has been found that overpressure levels near these areas can be estimated using meteorological conditions. This paper reviews a study where 205 test shots were fired, meteorological conditions recorded, and over-pressure levels estimated using multiple regression techniques.

Jan 1, 1988

By D. He

In China, the total reserves of vanadium, reported as V2O5, in stone coal is 118 Mt (130 million st). Recovering vanadium from such a large resource is very important to China?s vanadium industry. The technology now being used to recover vanadium from stone coal has the following two problems in the leaching process: a low recovery of vanadium and high acid consumption. To resolve these problems, a new leaching technology is proposed. The effects of factors such as H2SO4 concentration, liquid-solid ratio, temperature and time, and the types and additions of additives were studied. By adding 1.5% (by weight) CaF2 and leaching the roasted residue of stone coal with 5.4% (by weight) sulfuric acid at 90°C for 12 hours at a liquid-solid ratio of 2 mL/g, the leaching degree of vanadium reached 83.10%. This proposed leaching technology gives a feasible alternative for the processing of roasting residue of stone coal and can be applied in the comprehensive utilization of stone coal ores in China.

Jan 1, 2008

By Joseph Grumer

An instrumented spherical vessel has been used for many years to study laminar combustion waves. Concurrent measurements of flame speed and pressure-rise rates have led to evaluations of burning velocities, the pressure dependence of the burning velocity, and the expansion ratios of the gases passing through the combustion wave. For the most part, these studies have involved flames initially at atmospheric or subatmospheric pressure. The old spherical vessel used by the Bureau of Mines was not designed for use at elevated pressures. Moreover, being made of wrought iron, it was susceptible enough to corrosion to prohibit its use with many combustible mixtures that figure in industrial research. In mid-1956, under sponsorship of the Office of Naval Research, the Bureau undertook the development of a stainless steel spherical vessel capable of withstanding explosions of gaseous mixtures at initial pressures as high as 20 atm. and initial temperatures as high as 250° C. The design called for a double array (cross) of closely spaced small windows for observation of the flame as it traversed the vessel and a piezoelectric transducer to measure concurrently pressure-rise rates. Because no commercial contractor was willing to bid on the construction of such a vessel, it was built at the Bureau's Bruceton machine shop.7

Jan 1, 1961

By P. A. Lilly, W. Sarunic

In most cases, slope movement monitoring data are collected on a temporal basis and displacement or velocity is plotted against time in order to assist the engineer to make judgements about slope behaviour. Once an unusual behaviour pattern has been established, the data are then analysed to estimate when the key inflection points occur in the data, when the slope movements start to accelerate and, ultimately, when the slope is expected to collapse. The identification of these inflection points is sometimes difficult to achieve with the naked eye. This paper presents the application of a trend analysis technique, known as cusums, to assist in this process. The authors have presented a range of data from various real life examples which highlight the effectiveness of the cusums technique. A key aspect of the cusums technique is the use of a constant (K) against which data trends are assessed. This constant is best derived from slope performance data at each site, as each rock mass will behave in its own unique way. The authors have experienced slopes that have had threshold values ranging from 0.1mm/day through to 10mm/day, and therefore a conservative approach should be adopted when assessing the performance of slopes.

Jan 1, 2006

By Ren G. Dong, Dan E. Welcome

Instrumented handles or dynamometers are widely used to measure hand forces and/or the biodynamic response of hand-arm system. To study hand-transmitted vibration exposure, six generations of instrument handles were constructed or initially developed by researchers in ECTB/HELD/NIOSH. This presentation provided a summary of these handles. Their basic characteristics, limitations, and usefulness are described, which may help their appropriate applications and further improvements. Six Designs of Instrumented Handles Handle 1: The conceptual design is recommended in ISO 10819 (1996)1 for glove test. The grip force is measured by detecting bending strains on a measuring beam in the handle. A special handle fixture was designed to connect the handle to a shaker. Except the screws, the handle and fixture were made from aluminum. Handle 2: The design is based on the principle of shear strain measurement.2-3 Both grip and push forces can be measured simultaneously using this handle. This handle was directly designed for a simulated vibrating tool. Handle 3: This design is basically composed of a handle base, a measuring cap, and two charge-based sensors (Kistler 9212) sandwiched between the base and cap. The handle was also made from aluminum. The fixture for Handle 1 was also used with this handle. This generation of handle has three different handle diameters (30, 40, and 50mm).4 Handle 4: This design is an improvement from Handle 3. The handle fixture was totally redesigned and it was much stiffer than the previous one. The aluminum measuring cap was replaced with a magnesium cap. Handle 5: The basic structure of this handle is the same as that for Handle 3. However, the piezoelectric sensors were replaced with two strain gage based sensors (Interface SML-50). Handle 6: This handle includes two measuring caps, four piezoelectric sensors, and a handle centre base. The handle fixture was the same as that with Handle 4. Methods for Handle Examinations The static and dynamic characterizations were performed using the methods reported by Dong et al.5-6 Results and Discussion Handle 1: The static force measurement depended on the hand grip location on the handle. Its natural frequency was less than 200 Hz.5,6 Because the transmissibility of gloves may not vary significantly with the applied grip force, this handle may be acceptable for glove test. However, the force measurements with this handle may not be reliable. Handle 2: The static force measured with this handle was insensitive to the hand acting location. However, when the handle was vibrating, the force signals could be totally distorted. For this reason, it was not used for vibration studies.

Jan 6, 2006

This report presents the results of studies of Kennecott Copper Corporation's tailings embankment at Magna, Utah. The stability studies described were performed on only one cross section of the embankment, utilizing; data obtained from drilling, sampling, and testing, which was limited in nature. The main objective of the data collection was to provide background information to support the overall research effort. Because of this limited scope, it is not possible to evaluate the degree of safety or adequacy of the embankment or disposal system, and the information and data contained in the body of this report must be judged in that light. The first part of this report contains discussion of site geology and seismicity, pertinent information on the refuge disposal system, a discussion of the tailings materials characteristics, a summary of the engineering analyses, and A bibliography. The second tart (appendices) contains basic geologic and engineering data supporting the discussions in the first part of the report.

Jan 1, 1974

By John Hoelle

Coal mines in southern West Virginia, south-western Virginia and eastern Kentucky have experienced coal bumps at least since 1933. Most of the bumps have occurred due to high cover, strong roof and floor strata and stress concentrations due to the mining sequence. A longwall mine in eastern Kentucky first experienced coal bumps on the tailgate side of the longwall face in 1989. The bumps continued until 1996. The bumps were the result of: Thick overburden up to 2200 feet Strong roof and floor (strata strengths up to 25,600 psi UCS and elasticity modulus up to 4,800,000 psi Previous over-mining in places Sandstone channels Not all characteristics occurred simultaneously. The bumps produced seismic events recorded up to 4.3 (Richter scale magnitude), and damaged pillars that were up to 147 by 152 feet in size.

Jan 1, 2008

By C. L. Brown

"INTRODUCTION The heavy loss of life from mine fires in some coal mines recently has focused attention on the importance of maintaining reliable communication systems between the active working sections of mines and the surface. A study of conditions following disasters in mines indicates that in several instances lives could have been saved if telephone communication had been available. Communication systems were not installed in some of these mines where disasters occurred, and in other mines they were installed in such a manner as to be rendered useless following a mine explosion or fire. Lives have been lost because of the inability of the rescue crews or persons di-recting the rescue to communicate with trapped men. Cases are known where many lives might have been saved had it been possible to give instructions for escaping or for location of barricades.More than 500 major disasters in which 5 or more lives have been lost have occurred in mines in the United States. The total number of lives lost in these disasters has exceeded 13,000. Some of the victims died instantly; but for many it was hours and in some instances days before death occurred. Evidence found in recovery operations following some of the disasters indi¬cates that many died needlessly because of the lack of suitable means of communication between the underground working areas and the surface.A localized gas and dust explosion in a coal mine in 1930 resulted in the death of 82 men; 2 were killed outright by the force of the explosion, 6 by a combination of burns and afterdamp, and 74 by afterdamp. About 140 men escaped or were rescued following the explosion, Of these, 119 escaped with little or no assistance, 2 were rescued promptly following the explosion, and 19 were rescued from behind a barricade. Seven bodies were re-covered from behind an ineffective barricade in another place; subsequent investigation proved that these men might have been guided to a safe location had an effective communication system been available."

Oct 1, 1946

By J. R. Yates, R. J. Young, G. E. Forward, J. B. Farrell, R. J. Milbourne

"Sustainable development in the mining and metallurgical industrial sectors can be implemented by two distinct groups: the managers and operators of existing facilities, working with industrial processes and systems that have been operating for many years, in some cases, several decades; and those who are engineering and building new facilities or upgrades of existing plants.The focus of this paper is to look at approaches and tools available to bring sustainable development thinking and action to these two distinct areas. The paper will discuss the concept of working with existing facilities and processes to minimize waste and maximize product from a regional raw material/resource consumption perspective using by-product synergy. The BPS concept has been carried out in Texas (e.g., TXI-Chaparral’s STAR), in Calgary, Alberta, with Suncor assistance, in Montreal, Quebec, with Noranda as project leader, and currently in Ontario with Dofasco as industry champion. Successful outcomes are presented. The paper will also discuss a new approach to designing greenfield facilities or upgrades to existing plants using a sustainable development review process. Undertaking the review early in every project can institutionalize the concept of discussing and implementing waste elimination, design for environment, ecoefficiency, risk minimization and community awareness and involvement in the future capital stock. The review process has been developed as an excellent tool for measuring and reporting on a corporation’s sustainable development progress. Examples of how this approach has been adopted in the mining and metallurgical industry, and the resultant outcomes are given."

Jan 1, 2003

Recovery of Pentlandite and Chalcopyrite from Tailings by Bi-Cyclone Powerful Flotation Column

Sep 13, 2010

By Danny A. Riley, James R. Sanger, Hani S. Matloub, Michael Agresti, David Rowe, Lin-Ling Zhang, Yuhui Yan, Paula Galaviz, Judith Marchant-Hanson, Ji-Geng Yan

Until now there has been controversy about which tests should be performed to diagnose early Hand-Arm Vibration Syndrome (HAVS). Initial screening questions, especially about tingling and numbness, routinely given to patients prior to examinations proved to be a very important tool in the diagnostic process1, 4. However, standardized tests that are simple, quick, valid and reliable are needed to support a diagnosis of HAVS. Purpose: To find the most valid and reliable tests to diagnose HAVS. Material and Methods Five major tests were performed on Group I and Group II. Group I: Control group of 12 volunteers including students, nurses, secretaries and physicians with no history of using vibrating tools (age 20 to 50y, mean age 38.5y; 5male, 5 female.) Group II: 12 workers (age 17 to 65y, mean age 39y; 9 male, 3 female) were sent by a local trade union with a history of using vibrating power tools on their jobs for varying amounts of time (mean 12.2y, from 0.5 to 35y.) Pre-enrollment survey showed that each had more than 4 complaints commonly associated with use of vibrating tools (including numbness, tingling, weakness, pain, finger color or nail changes, temperature change, and difficulty moving.) 1. Sensory nerve conductive tests: Amplitude and nerve conductive velocity (NCV) were evaluated. 2. Cold Stress-Temperature recovery time tests were done on the index finger of the dominant hand following these steps: Confirm water bath is within 4-5º C. Place the finger temperature probe on pad of the index finger of the dominant hand. Record temperature every 15 seconds. Place subject’s hand in the cold- water bath for exactly five minutes. Record temperature every 15 seconds for ten minutes. 3. Blood test: Venous blood was taken by a 21-gauge needle with the yellow collection tube adapter. S-ICAM, Sera Thrombomodulin, Norepinephrine levels were evaluated by Henderson Research Centre, Canada. 4. Finger Sensory Evaluation: Semmes-Weinstein monofilament test and 2-point discrimination tests were performed on bilateral fingers. 5. Digital blood pressure test: blood pressure was measured in bilateral index fingers. Results 1. Median nerve sensory conductive amplitude from palm to wrist : GI: mean 96 ± 31µm; GII: mean 43± 30µm; for dominant hands. GI vs GII: P<0.001

Jan 6, 2006

By Jim Nickerson, James McCleish, Tom Abkemeier, Nicholas Willig

The purpose of this project is to convey sanitary sewage from an existing pump station to a new waste water treatment plant. This paper will discuss the design and construction aspects of the project. The scope includes construction of three main shafts ranging from 34 to 100 feet in diameter at depths of 200 to 230 feet and 21,000feet of tunnel. Shaft construction consisted of slurry wall excavations keyed into claystone and limestone at depths ranging from 114 to 130 feet, followed by rock excavation utilizing drill and blast methods. The tunnel is being excavated in the Warsaw and Salem shale and limestone formations utilizing a 12&apos;-6" diameter Wirth hard rock TBM.

Jan 1, 2005

By Jack A. McQuiston, Thomas A. Cross

Corrosion of equipment and machinery in the coal industry is usually the result of three main agents: acids, chlorides, and abrasion. Acids and chlorides are especially troublesome in coal preparation plants where soluble salts and sulfur in the coal produce a highly corrosive wash solution. Abrasion is common in all operations where coal is handled or conveyed. Together, the acid-chloride-abrasion combination results in some of the worst corrosive conditions found in any industry. The variety of equipment and structures in the coal industry calls for different corrosion control techniques. Table 1 lists the areas of concern for a number of items. Just as there is a wide variety of corrosion problems, there is a wide array of coating materials available. Tables 2 and 3 are selection charts to provide guidance in narrowing down the choices. Experience has shown that a limited number of coating systems work best on coal equipment and structures. These systems are described in Table 4. The good-better-best designation in the table refers to coating system longevity. Good indicates the least costly and shortest service life. In nearly all cases the lowest annualized cost can be achieved by using the coating system rated best, due to the avoidance of costly repaints and unnecessary downtime. The most expensive coating system, though, is worthless unless the coating system is properly applied. Field inspection to insure compliance with specifications is an important aspect, and is a service available from many coating suppliers. Even the best coating systems require periodic maintenance to achieve satisfactory results. Spot rusting from mechanical damage should be repaired annually to maximize the coatingsystem&apos;s results.

Jan 2, 1980