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By A. K. Bakshi

An on-line rheometer, suitable for use with slurries, has been developed at Michigan Technological University. This rheometer can be used with both Newtonian and non-Newtonian slurries, and produces complete shear-rate/shear stress curves which characterize the time-independent rheology of the slurry. The sensor utilizes the Hagen-Poiseuille equation and Boyle's Law to calculate the shear rate, slurry flowrate, and shear stress from a series of pressure measurements. The design of the unit allows the measurement sample to be continuously collected from operating process streams in the often-hostile on-line environment. The shear rate/shear stress curves can be used to conveniently calculate the apparent viscosity at any given shear rate, and also to measure any yield stress or other deviations from Newtonian behavior.

Jan 1, 1999

By J Liu

In situ coal gasification is a method of extracting a high proportion of the energy value from coal without the need for mining. In situ conversion of coal to combustible gases is achieved by drilling wells into the seam, injecting gasification agents and initiating combustion. The product gases are then extracted to surface using production wells. These gases are clean energy sources for power generation, heating or synthetic fuel production. In situ coal gasification is of particular interest with respect to its lower environmental impact, potential application to otherwise inaccessible energy resources (ie offshore, deep deposits or beneath protected lands) and low capital intensity. Practical application of this clean technology is restricted primarily by lack of satisfactory quantitative descriptions of the processes involved, in particular the hydromechanical processes.In this study, three characteristic physical zones of an in situ gasifier are identified as the rubble zone, combustion front and virgin coal zone. Coupled mechanical processes of coal consumption and overburden collapse are used to describe the permeability profile in the rubble zone. Additionally, the redistribution of overburden load associated with coal consumption is accounted for with the formulation of a stress (compressive) dependent permeability profile, which is applied to the virgin coal zone. The model was implemented into and solved by FEMLAB, an advanced computer simulation tool. The flow process, according to DarcyÆs Law, is subsequently described in terms of permeability dependent injectivity. Injectivity is an indicator of flow velocity, which has been identified as a crucial factor in determining the commercial value of product gases from in situ coal gasification. The stress alteration to coal permeability was found to have a dominating influence on the flow process. This finding implies that a greater understanding of the in situ coal burning induced deformation of surrounding rocks would be of significant value in assessing the economic viability of applying this clean technology to potential sites.

Jan 1, 2004

By L. X. Li

Coking coal producers often encounter variations in clean coal quality when mining multiseam deposits containing coals with different washability and coking properties. This paper describes how, for a single coal property, an initial clean coal specification with an ash content of 8.5% on an air-dried basis (ADB) and a free swelling index (FSI) of 5.5 can be improved to a specification with 7.5% ash content ADB and an FSI of 6. This is accomplished by sorting coal seams into two groups for processing and blending. A preliminary economic model demonstrates how this improvement enhances economic returns through a beneficial factor.

Jan 1, 2014

By Robert N. Roby

"The Moffet-Johnston property was investigated by the Bureau of Mines with the object of determining the presence of ore reserves that might be utilized during the war emergency. Preliminary examination was made during May and Juno 1943, as a result of which the Johnston 'tunnel was cleaned out and repaired, the .mime was surveyed, and a small program of exploration was undertaken. This report describes the work performed and presents the data obtained.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts prelimi¬nary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs benefication tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.The chemical and spectrographic analyses were made at Reno, Nov., under the direction of A. C. Rico, acting engineer in charge, Rare and Precious Metals Experiment Station, Bureau of Mines. The ore-dressing tests were under the direction of Rollien R. Wells, metallurgist, at the Salt Lake City laboratories of the Bureau of Mines.The author acknowledges the cooperation and assistance of the lessee of the property, H.R. Hakes, who furnished nine reports and other information.The Moffet-Johnston property is in secs. 2 and 3, T. 3 S., R. 5 W., in the Tidal Wave mining district of Madison County, Montana.The portal of the Johnston adit is near the mouth of Bear Gulch, 9 miles northeast of Twin Bridges, Mont. It is reached by an improved dirt road that serves mining properties farther up Bear Gulch. The Moffet mine and the Mountain View shaft are now accessible from the Bear Gulch road over an access road recently completed by the U. S. Grazing Service. The Grazing Service road has also been supplemented by bulldozer trails built by the Bureau of Mines.An electric-power line extends from the Montana Power Co's substation at Twin Bridges to mines at the head of Bear Gulch and passes within 200 feet of the Johnston portal.The claims of the Moffet-Johnston property were located about 1900. A report by H. V. Winchel, consulting geologist, in 1904 indicates that most of the development on the Johnston adit was completed by that date. At the time of the Winchel report, the Moffet workings had just penetrated the first ore shoot (fig. 4)."

Sep 1, 1946

By Bernard Lewis

The ignition problem: for a layer of firedamp bordering on a cloud of detonation products is evidently considerably more complicated than in the usual laboratory ignition experiments, in which a well-defined volume of gas is heated and the occurrence of ignition is observed after an induction period. An atmosphere of firedamp exposed to the detonation of a high explosive is subjected to heating by shock-wave compression and thermal conduction and to intermixing at the interface of the firedamp atmosphere and the cloud of deto¬nation products. Although a reliable physical-chemical analysis of the problem is not yet possible, one may nevertheless form a general view of the role of compression waves and the processes of heat transfer and diffusion at the interface. Near the mouth of a shot hole, or near a freely suspended cartridge, the firedamp atmosphere attains very high temperatures by adiabatic compression, and it is certain that such temperatures are sufficient to initiate chemical reaction. The pressure wave pattern is reproducible from one test charge to another if the initial experimental conditions are held constant; on the other hand, experiments on firedamp ignition do not yield a reproducible threshold condition for ignition, but only an ignition probability. Thus, the induction periods are sufficiently long that there is time for the compressed', heated gas layers to undergo random changes that may quench or promote ignition. Therefore, the analysis of the ignition problem hinges primarily on the discovery of the random events that modify the chemical reaction in the activated gas layers.

Jan 1, 1948

By L Eriksson, D Penn, J Appelgren

Atlas Copco, a leading supplier of equipment and services to the mining and construction industries, is consistently pursuing its strategy to offer the most productive and economical solutions by continuously offering new innovative products. These are, in most cases, developed and tested in close cooperation with demanding end users before being officially launched on the international market. The demands for higher productivity and improved overall economy have resulted in systems for automation of the drilling cycle and also tools for integrating the drilling equipment to the production control system used by the customer. In terms of improving the blasted material quality, the company has placed emphasis on accuracy in the drilling process and documenting what has been drilled. By applying state of the art technology to the common automation platform, developed for the surface drilling market, major steps in improving overall drilling productivity and blasting performance have been achieved. This paper will give some examples derived from the latest development of solutions for the companyÆs surface drilling products.CITATION:Appelgren, J, Eriksson, E and Penn, D, 2012. Rotary drilling automation increasing operator productivity and drilling quality, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 13-18 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By W. H. Tomlinson

Although the thoughts and efforts of the great majority of people in many parts of the world are today directed toward killing each other, the purpose of this paper is to discuss means of conserving human life. In a world of turmoil and strife, we find time to discuss and make plans to achieve our objective -prevention of the "sacrifice" of life through avoidable accidents. The word" sacrifice" is used here advisedly, as one meaning of the word given in the 1942 edition of Funk and Wagnalls New Dictionary of the English Language is "the act of giving up some desired or valued object for the sake of *** future good." As everyone agrees that life is man's most priceless possession, one wonders if past sacrifices have been in vain. It appears that life is cheap in America; it is cheap because some of the industrialists are too much concerned with making a profit to devote much time and thought to conserving human life; it is cheap because some labor leaders apparently are interested solely in personal power and prestige; it is cheap because a great many workmen fail or refuse to cooperate energetically with the various organizations interested ill; their safety and welfare; it is of little value because, individually and collectively, we are indifferent to our responsibilities toward our fellow men.

Jan 1, 1944

By Ayman Tawadrous, Hendrik Botha, Simon St J Tose

The early miners and their mules always had the challenge of transporting unstable dynamite underground. The modern pumpable explosives, whilst far safer, still present a major logistics challenge for the mobile charging units (MCU). The challenge today is the efficient explosive delivery into declines, ramps, and vertical shafts, often requiring the MCUs to travel excess distances up and down to surface to re-load. Alternatively, the management of cassettes or ISO containers is utilized to deliver the pumpable base emulsion to the MCUs at the working face. Additionally, local laws and regulations regarding shaft clearance further compound the task and result in pausing other operations in the shaft or decline or ramp until the completion of the explosive transport. This paper examines the research & development challenges of dropping base emulsion down a vertical pipe to depths in excess of 1000 m (3280 ft.), either to an underground storage or directly into the MCU, depending on the depth. The boreholes (with pipes) are drilled in close proximity to the underground work areas. The paper also discusses the rheology of the emulsion within these vertical pipes as well as the economic benefits of such an innovative system. The learnings gained from this work, along with examples demonstrating the significant reduction in MCU travel and the safety benefits, are presented for the industry to consider moving forward.

Jan 21, 2025

By H. E. Peterson, W. L. Anderson

"INTRODUCTION The great demand for tungsten incident to the war has led to the exploration of a large number of low-grade tungsten deposits. To properly evaluate the low-grade deposits it is essential to have available a dependable method of analysis applicable to all types of low-grade tungsten ores. Results reported on the tungsten content of the ores have often varied quite widely and have led to confusion. The Bureau of Mines has been requested by Government lending agencies and by companies interested in the production of tungsten to publish a general method for the determination of tungsten in low-grade ores. To meet this need, the Bureau of Mines is herein submitting two methods for analysis that have been proved on a large number of tungsten-bearing ores various types in the Bureau of Mines laboratory in Salt Lake City. Also, a third method was developed that requires no cinchonine and has proved to be applicable on most tungsten ores. The cinchonine method is the generally accepted for analysis of tungsten ores. Very reliable results can be obtained by this method if certain precautions are taken, as outlined in this report."

May 1, 1943

By H. W. Wainwright

.1. The purification pilot plant and the equipment, solution, and gas cycle used for removing hydrogen sulfide and carbon dioxide are described. 2. As sulfur recovery is necessary in any large Fischer-Tropsch plant, pilot-plant runs were made at 300 p.s.i.g. to study the efficiency of tri-ethanolamine solutions in removing selectively hydrogen sulfide from gases containing varying amounts of carbon dioxide. 3. Aqueous solutions of TEA of 20, 30; 35, and 50 percent were investi¬gated. Data indicate that 30 to 35 percent is the optimum concentration if both selectivity and economy are considered. Slightly better selectivity is obtained with the.20 percent solution, but steam consumption is greater owing to the higher solution rates. Results from our pilot plant runs indicate that a 50 percent solution not only produces an acid gas of lower hydrogen sulfide content but also requires high solution rates to effect hydrogen sulfide purification. 4. Data from 37 runs using TEA are presented in tabular form. In addition, the data are correlated and presented in three sets of curves. By using these curves, it is possible to calculate the compositions of the purified and acid gases for various raw gas mixtures. 5. In cooperation with the Southern Natural Gas Co., investigations were carried out at 300 p.s.i.g. on the simultaneous removal of hydrogen sulfide and carbon dioxide, from gases using various concentrations of diethanolamine. 6. Data from 17 runs employing 20, 30, and 40 percent DEA are reported in both tabular and graphic form. 7. A comparison of the data from one DEA run made at 200 p.s.i.g. with those from the runs operating at 30O p.s.i.g. shows float the absorption capacity of the solution, and, hence, the steam requirements per gallon are about the sage for both pressures. .The only real advantage of the higher pressure is the additional volume of gas that can be treated. 8. The quantity of steam needed to reactivate fouled TEA and DEA solutions increased as the reactivator pressure was increased about 1,0 to 1.1 pounds of steam was required for each gallon of circulating solution when the reactivator was operated at 5 p.s.i.g. 9. A curve is included that shows the effect of the hydrogen sulfide con-centration in a lean 35 percent TEA solution on the hydrogen sulfide content of the purified gas and on steam consumption for reactivation. 10. Both TEA and DEA reduced the organic sulfur content of the raw synthesis gas considerably. Analyses of the lean amine solutions showed a gradual build up of sulfur compounds, indicating that the compounds formed by the amines and organic sulfur do not break down under the ordinary operating conditions of the reactivator. 11. Considerable operating difficulty was encountered in the pilot plant owing to foaming of the amine solutions. Laboratory experiments in which the effectiveness of certain antifoam agents was studied showed Alkaterge C to be most promising for the particular conditions studied.

Jan 1, 1952

By F. H. Deily, D. S. Rowley, R. J. Howe

By L. Bloom

In 1996, lack of confidence in assaying methods and sample handling affected companies as diverse as Bre-X and Timbuktu. Both share prices and the ability to raise financing are impacted when the quality of assay data is suspect. Overseas projects are subject to enhanced scrutiny when local facilities are used that are unfamiliar to brokers, financing agencies and banks. Quality control systems can be -implemented but there are associated costs. These costs should reflect the risk to the mining company, investors and financiers and the size of the proposed investment. In this regard, assay control call is considered a form of insurance to enhance the value of an exploration or mining project.

Jan 1, 1997

By Cary Hirner, Sarah Lothman, Chris Mueller, Savita Schlesinger, Mike Hanna, Ian Fitz-James

Loudoun Water is currently implementing a quarry to reservoir conversion that will improve water supply reliability in periods of drought and flexibility in water supply operations when turbidity in its Potomac River supplies are high. The Milestone Reservoir Project consists of an inter-tie to the existing Potomac River Pipeline; new pipeline and tunnel; and a pumped intake and outlet works. Planned construction involves significant risks due to underground conditions which includes hard, igneous rock and high groundwater at the creek crossing. In addition, the site is constrained by Goose Creek, an adjacent residence, active mining in a quarry next to the new reservoir, public use of adjacent park space, and the Washington and Old Dominion Trail. Working with these constraints will require close coordination with active mining operations and public and private property owners. Safety of personnel involved with construction also represents a concern with quarry high walls over 30 meters in height near the planned construction. In consideration of key projects risks, Loudoun Water determined that an innovative CMAR delivery approach provided the best opportunity to achieve its goals in quality, innovation, front-end cost and schedule certainty, and operational flexibility and reliability. What matters most to Loudoun Water is the value in having a builder participate in the design process where key decisions can be made based on consideration of risks, cost, schedule, quality, and operability and maintainability of the system. While a progressive design-build delivery model may have produced similar outcomes, Loudoun Water had already invested in substantial development of the design for the work, and ultimately, CMAR provided Loudoun Water the opportunity to retain the partnership with the design team while gaining valuable input from a contractor. Among the challenges with CMAR in the Commonwealth of Virginia is a substantial limitation on self-performance corresponding to 10 percent of the construction value of the work. A significant industry outreach program was initiated by Loudoun Water to encourage participation with incentives in contract terms that allowed for the CMAR Contractor to make a reasonable profit. This paper reviews the CMAR procurement process and discusses contract incentives that were adopted to promote the work within the constraints of contract law in Virginia.

Jun 13, 2021

By John W. Moore

The discovery of porphyries in petroleum by Treibs (17-19) is one of the most significant achievements relating to the origin of petroleum. The presence of these remnants of chlorophyll and hematin in petroleum has immediate practical interest in several aspects of the petroleum industry. Because of their interfacial activities and film-forming tendencies, the metal-porphyrin complexes may be expected to affect the wettability of petroleum-reservoir rock surfaces and influence the flow of fluids in these reservoirs. Also, studies of the relationship of trace elements and porphyrins in petroleum may be expected to yield valuable information on source beds and petroleum migration. Finally, the extreme stability of several metal-porphyrin complexes complicates removal of these metals from some petroleum stocks where they exert deleterious effects on processing and utilization. Metal-porphyrin complexes are commonly associated with the asphaltic residues of crude oils in which they occur (8, 9, 15). However, investigations in this and another laboratory (15) show that small amounts of these complexes often remain in partly refined petroleum products, such as thermally cracked distillates and deasphalted stocks.

Jan 1, 1957

By M. S. Badollet

Introduction Very little fundamental research has been done on asbestos fibre to cake maximum advantage of its properties and to determine in what commercial products it can best be utilized. For the research chemist who is associated with asbestos development work, a thorough study of mineralogical information on asbestos deposits would furnish reliable information on the rock formations and the mineral impurities closely associated with the asbestos. Furthermore, ?he must have an intimate knowledge of the uses of the fibre in various products so that he can visualize the importance of the fibre and the role it plays in industry. Some of the properties of asbestos fibres such as strength, composition, length, harshness or softness, and mineral associates are of considerable importance to the manufacturer because they are responsible for many production difficulties. Fibre Strength It has been known for some time chat asbestos filaments have considerable tensile strength. These strengths have been referred to merely as 'weak' to 'very strong'. Not until recently have numerical values been applied to the strengths of asbestos fibres. But today we can take a thin fibre filament and mount it between two holders and apply a gradually increasing load or pull until the fibre breaks. By measuring the cross sectional area of the filament and the amount of load applied, we can calculate the tensile strength of the fibre in terms of pounds per square inch. This type of test is slow and rather difficult, but the fundamental data obtained furnish important basic information that can be applied to mechanical processing equipment and to certain asbestos products.

Jan 1, 1948

By Kevin L. Gering

A detection method and apparatus have been developed to perform real-time measurement of aqueous free cyanide, C-. A laboratory prototype can measure cyanide ranging from 5 micrograms ,per liter to 100 milligrams per ?liter for analysis times as short as 2 minutes per measurement. Sample size per measurement is typically only a few mI, thus? minimizing the waste volume produced from spent samples. The basis for this detection device is a quantifiable, stable affinity between the electrode material and free cyanide in the sample; The electrode exhibits piezoelectric behavior, allowing it to be used as a microbalance. This technology 'has experienced two generations of laboratory prototypes, and has been thoroughly tested to determine the operational sensitivity toward process variables such as pH, competing reactions, etc. The speed and ,accuracy of this method make it superior to conventional wet chemistry methods used for quantifying cyanide levels in water. A device based on this technology could be useful in areas involving process monitoring and environmental compliance, .particularly in the cyanide-based leach mining industry. Interest for this detector has been shown by the gold mining industry and others. Patent application is in progress.

Jan 1, 1998

By J. H. Rowland, A. C. Smith, K. A. Teacoach

Current regulations for fire suppression systems in underground coal mines to protect conveyor belt installations have been in place since the Coal Mine Health and Safety Act of 1969 was enacted. Over time, the coal conveyer equipment being used and ventilation conditions underground have changed significantly, particularly the width of the conveyor belts and the use of belt air at the face. The effect of these new conditions on the effectiveness of suppression systems during a fire is not known. The National Institute of Occupational Safety and Health (NIOSH) conducted a study to evaluate the effect of air velocity, water sprinkler activation temperature and a limited water application time on the effectiveness of water sprinkler fire suppression systems to extinguish large-scale conveyor belt fires. The fire tests were conducted using both new and used 1.8-m-wide, fire-resistant rubber belt that met the Mine Safety and Health Administration (MSHA) flame-resistant requirement specified in Title 30, Code of Federal Regulations, part 18, section 18.65 (also known as the 2G test). Tests were conducted using standard response sprinklers with activation temperatures of 68° C and 141° C at air velocities of 0.5 and 5.1 m/s. Two tests were conducted at both air velocities for each sprinkler activation temperature, one using a new belt and one with a used belt. The results showed that the suppression system was able to suppress the fires in ten minutes to the point that a miner could extinguish it with a fire hose. However, in several of the tests, the fire reestablished itself a few minutes after the sprinkler water supply was cut off and quickly grew out of control. This report discusses the large-scale experimental configuration, the installation specifications of the fire suppression system and the results and conclusions regarding the effect of air velocity, sprinkler activation temperature and limited water application on the suppression system performance.

Jan 1, 2010

By Dongsheng Zhang, Xufeng Wang, Wei Zhang, Gangwei Fan

"Large-scale longwall mining of shallow coal seams could cause mining-induced fractures to communicate with the surface immediately in Northwest China, leading to a series of mine safety and environmental issues, including crack formation, water loss, vegetation deterioration, land desertification, and spontaneous coal combustion. Therefore, an accurate and effective understanding of the spatiotemporal evolution law of mining-induced fractures in overlying strata and its relationship to upper aquifers is critical. In this paper, the application of the geophysical-chemical properties of radon in mining engineering is explored as a potential solution to the shortcomings of existing surveying methods. A radioactive measurement method is proposed for the detection of the development of mining-induced fractures in overlying strata in the Baoshan Coal Mine (BCM). The on-site trial indicated that the first weighting step is approximately 60 m, the average periodic weighting step is approximately 20 m, and the influence coverage of the advanced abutment pressure is approximately 30 m. The presented method could be used as an indirect technical support to increase the safety of coal mining by acting as a simple, fast, and reliable method of detecting mining-induced fractures in overlying strata.INTRODUCTIONAccording to the latest coalfield prediction results provided by China’s National Administration of Coal Geology (CNACG) (Zhou et al., 2013), China’s coal resources are mainly distributed throughout the West, e.g., Inner Mongolia, Xinjiang, Shaanxi, Shanxi, Ningxia, and Guizhou. Two major coal mining areas have been established in the Northwest and the Southwest, and are typically represented by Inner Mongolia and Guizhou (Zhang et al., 2010). Northwest China is an arid to semi-arid area, where the coal seams are typically shallow and covered by a thin layer of bedrock. In its natural state, the surface’s ecological environment is fragile. Large-scale longwall mining of shallow coal seams could cause mining-induced fractures to communicate with the surface immediately, leading to a series of mine safety and environmental issues, including crack formation, water loss, vegetation deterioration, land desertification, and spontaneous coal combustion. This can propel any potential ecological fragility into a state of actual destruction (Zhang et al., 2011). Therefore, an accurate and effective understanding of the spatiotemporal evolution law of mininginduced fractures in overlying strata has become the theoretical basis of solving the above issues."

Jan 1, 2015

By M. P. Dalton

This paper which describes the milling practice at the Morning concentrator of the Federal Mining and Smelting Co., Mullan, Idaho, is one of a series being prepared by the Bureau of Mines. ACKNOWLEDGMENT The author wishes to acknowledge the assistance given by H. G. Washburn, general manager of the Federal Mining and Smelting Co., and by C. S. Price, assistant mill superintendent, in the preparation of this paper.

Jan 1, 1932

By B. F. Bush

THE coal-fields of Missouri, situated hi the northern and western portion of the State, are distributed, in whole or in part, over 57 counties, embracing an area estimated by Mr. Broad-head to be practically 23,000 sq. miles, including small detached beds and outliers in St. Louis, St. Charles, Lincoln and Warren counties in the eastern part of the State. This area includes about 8,000 sq. miles of Upper or Barren Measures, 2,000 sq. miles of exposed Middle, and 12,420 sq. miles of exposed Lower Measures. In a general way, the Missouri coal-field is bounded on the east by an imaginary line entering the northern part of the State just east of the 92c1 Meridian and passing across the State in a southwesterly direction to a point on the Kansas-Missouri line a little below the southern boundary of Barton county. An important part of the field overlaps this line and extends down the northern side of the Missouri river, under¬lying the greater part of Randolph, Howard, Boone and Audrain counties. In all, 34 counties produced coal during the year 1903. Fig. 1 shows the position of the coal-fields in Missouri. GEOLOGICAL FEATURES. The Coal Measure formations, all of the Carboniferous age, rest unconformably upon the rocks of the sub-Carboniferous or Mississippian series, and, in some cases, upon the rocks of the Devonian and Silurian ages. From their outcrop on the eastern and southeastern borders of the field, the Measures dip west to northwest at the rate of 10 ft. per mile, reaching a maximum thickness estimated by

Jan 1, 1905