Search Documents

"For a good many years the Bureau of Mines and various state mining experi¬ment stations have endeavored to develop some method of utilizing the immense deposits of lignite in the United States. Work in relent year has indicated that the best method of this is to drive off the moisture and most of the volatile water from the lignite in some form of carbonizing apparatus leaving a residue high in fixed carbon and low in moisture and volatile matter, which by briquetting can be made into a high-grade fuel. The earlier forms of carbonizing equipment tried were complicated, costly to build and keep in repair, and could not be operated intermittently without being seriously damaged. During the year 1922, however the Bureau of Mines devised a very simple carbonizing oven which produces a uniformly well carbonized product. This oven is essentially a vertical shaft with means for supplying raw lignite at the top and discharging the carbonized limited at the lower end. Air in regulated amount is admitted to the shaft at two horizons, and a zone of combustion maintained through which the column of lignite passes. The lignite is thus carbonized by construction of its contained matter and a small proportion of its fixed carbon, leaving most of the fixed carbon in the carbonized product or ""char"". The degree of carbonization can be closely controlled by varying the volume of air supplied to the oven and the rate of travel of the charre down the shaft.The ""lignite char"" produced is a soft material resembling charcoal more than coal or coke, but somewhat harder than charcoal. A typical analysis is shown in the table headed ""Fuels,"" further on in this papers."

Feb 1, 1924

By David M. Hyman

The Bureau of Mines has developed two experimental designs for deter- mining the volumes and relative proportions of the various gas species, particularly methane (CH4), occluded in rock salt. To date, the rock salt samples analyzed have been relatively small (400- to 1,000-gram) grab samples from Louisiana Gulf Coast domal salt mines. The results obtained are comparable to results in Polish domal salt mines, in terms of occluded gas volumes per mass of rock salt. The notable difference between the Louisiana and Polish occluded gas mixtures is in the relative proportions of the individual gas species. The two methods used by the Bureau are ballmill crushing and dissolution. Of the two, the dissolution method appears to be more versatile because it can be performed in situ. The relevance and applicability of data on the occluded gas contents of rock salt are dependent on sample size, sample collection method, geologic context of the sample, and the correlation with gas emissions that occur as a result of mining-induced fractures and pressure differentials.

Jan 1, 1982

By J. F. Messerly

The purity of three specially prepared samples of benzene was determined with an adiabatic, low-temperature calorimeter with automatic control of shield temperature. Extensive measurements were made on each sample to determine how variations in operating procedures affect melting-point and freezing-point as well as purity data obtained by the calorimetric method. Detailed results of the investigations are presented, and effects of different operating procedures are discussed, together with problems encountered in interpretating experimental results.

Jan 1, 1963

By W. D. Riley

The U.S. Department of the Interior, Bureau of Mines, has been conducting minerals recovery research in support of the nation's geothermal program since 1974. The Bureau's program of laboratory and field studies has focused on determining the materials of construction for geothermal resource recovery plants and an the recovery of mineral values from the geobrines. An analytical program has been conducted at the Avondale Research Center to determine the chemical constituents of some high- and low-salinity geobrines found in the Imperial, Valley of California. Data are reported for the early stages of brine production of femur geothermal wells--the low-salinity, medium-enthalpy brines from the East Mesa Known Geothermal Resource Area (KGRA), Mesa 6-1 and 6-2, and the high-salinity, high-enthalpy brine from the Salton Sea KGRA, Magmamax 1 and Woolsey 1. The reported results indicate the importance of the operating and engineering history, the operating parameters during sampling, and the method of sampling in order to evaluate the chemical analyses.

Jan 1, 1980

By Frank E. Cash

The Bureau of Mines in its safety work has for a number of years advocated and recommended the use of permissible portable electric cap lamps for use in all mines. In the course of time required for the evolution from an unsatisfactory to an efficient and safe light, but encouraging increase in their use has been experienced in Alabama. As early as 1916, small installations of these safer lamps were made or an experimental basis by several operating companies, and the first complete mine installation eras made at the Virginia mine of the Gulf States Steel Co., July 1, 1918. From the experiments in 1316 and the complete equipment of the first mine in 1918 gradual progress has been made until there are now 30 installations with 10 operating companies; as a result 20 mines have been put entirely and 5 partly on, closed lights, and 3 companies equip their engineering departments; two installations of closed lights are maintained by other companies for emergency use. One of the mines partly on the electric cap lamp is an ore mine - the only one in Alabama (and one of the very few in the United States) that uses closed lights. ACKNOWLEDGEMENTS The full cooperation of operating officials, lapmen, and lamp representatives was given in the collection of the data in this report, and is hereby acknowledged.

Jan 1, 1928

Reduce the potential of haulage related injuries in underground mines by providing a method for quickly assessing the state of repair of mine haulage track. The Problem Currently, there are no established standards or procedures for inspection or cleaning of underground mine haulage track. Many track defects are hidden from an inspector because of layers of dirt and debris on the ballast, spikes, fishplates, etc. When a visual inspection can be performed, it may be highly subjective, except for a few items that can be categorized or counted, such as missing bolts or spikes. Track inspectors may even become tolerant of defects that can gradually worsen. For these reasons, mechanical inspection methods are needed to supplement visual inspections. Approach The Bureau investigated this problem and designed a towed vehicle to both mechanically clean and inspect underground coal mine haulage track. The vehicle was developed using a systems approach, paying particular attention to human factors issues such as operator field of view, operator ingress-egress, control positioning, and seating design. The prototype was built using simple fabrication techniques and off-the-shelf components.

Jan 1, 1990

By Joseph M. Pugliese

The U.S. Bureau of Mines has produced a generic in situ copper mine design manual, which contains a computerized cost model for in situ copper oxide mining. The model specifies (1) site-specific parameters, which must be quantified for mine design, (2) a method for minesite design based on those parameters, and (3) a procedure for assessing economic viability for the mine design. The menu-driven computer program performs calculations for developing commercial mine design specifications, as well as capital and operating costs. The default values are based on 1986 dollars, and indices for updating costs are included. The program also provides discounted-cash-flow rate of return (DCFROR) and allows for sensitivity analyses for an in situ mining operation at any specific undisturbed copper oxide deposit. This report is to be used with the 1990 version of the computer program, which has been made user friendly. It describes the flies, tutorial, input phase, help function, and monitor display of all calculated values and of the DCFROR table. The monitor-displayed discounted initial value of investment and annual operating costs are defined. The dual rate-of-return situation and sensitivity analyses are also briefly discussed. Information is provided on obtaining the computer program on diskette.

Jan 1, 1991

By K. P. V. Lei

The Bureau of Mines as part of its research effort to minimize the generation of hydrometallurgical waste, investigated a sodium sulfide leaching-electrolysis procedure for treating hydrometallurgical residues for elemental sulfur and base-metals recovery. Research was conducted on a leaching residue from a lead concentrate. The following procedure was developed. 1. The elemental sulfur was dissolved as polysulfide with an Na2S solution. 2. The resultant metal sulfide bearing residue was oxidatively acid leached in a cationic membrane electrolysis cell; the metals were solu¬bilized at the anode, and a base was generated at the cathode. 3. The elemental sulfur was recovered from the polysulfide solution by neutralizing with the acid in the anolyte. Byproducts of the neutralization were H2S and a sodium salt solution. 4. Sodium sulfide was regenerated by reacting the H2S byproduct with the base in the catholyte. 5. Lead as PbCL2 was recovered from the anode residue by brine leaching, and the other metals were recovered from the sodium salt solution as metal sulfides. 6. The barren filtrate from the metal sulfide precipitation constituted the recycled electrolyte. Ninety-eight percent of the elemental sulfur, 98 pct of the lead, and up to 80 pct of other accessory metals were recovered from a residue obtained from the FeCl3-NaCl leaching of a lead concentrate.

Jan 1, 1982

By Jingcheng Li

Currently many underground coal mines worldwide have installed or been planning to install a tracking system to trace miners mainly for their safety. Although many systems have been reported functional, a lack of sophisticated and systematic error correction methods apparently is still an issue for them; often it results in a low system resolution. To improve the system resolutions, this paper introduces two position adjustment methods for mine tracking systems. The first is an entry-matching method that optimally adjusts an off-course tracking device to the closest tunnel (entry). The second is a distance measurement adjustment method that accurately adjusts the position of a tracking device along an entry according to a measured distance from the device to a reference point. The coplanar node-path network mine model is used as the foundation for the development of these two methods.

Jan 1, 2009

By Frank D. Lamb

Four samples of manganese-bearing material from the Aroostook County, Maine, deposits were tested at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., to determine their amenability to beneficiation by ore-dressing methods. The samples represented material from the Maple Mountain-Hovey Mountain deposit, the Dudley farm, and the Burnham farm and contained 11 to 14 percent manganese. None of the tests produced appreciably enriched concentrates suitable for further treatment for the production of ferromanganese. The intimate association of the manganese minerals with iron and siliceous minerals requires extremely fine grinding to liberate the manganese minerals in these ores and prevents efficient concentration by physical means.

Jan 1, 1953

By N. S. Dalal, X. Shi

"Electron spin resonance (ESR) measurements provide evidence for the formation of Cr(V) intermediates in the enzymatic reduction of Cr(VI) by glutathione reductase (GSSG-R) in the presence of NADPH, indicating an initial single-electron transfer step in the reduction mechanism. Depending on the pH, at least two different Cr(V) species are generated which are relatively long-lived. In addition, we have detected the hydroxyl (·OH) radical formation during the GSSG-R catalyzed reduction of Cr(VI) by spin trapping, employing 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and a-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) as spin traps. Superoxide dismutase (SOD) causes only a minor effect on the ·OH radical and Cr(V) formation, indicating that the ~ - is not significantly involved in the reaction mechanism. Catalase enhances the Cr(V) formation and substantially inhibits the ·OH radical formation, indicating the involvement of hydrogen peroxide (H20 2) in the reaction mechanism. Addition of H20i suppresses Cr(V) and enhances the ·OH radical fonnation. Measurements involving N-ethylmaleimide show that the Cr(V) species, produced enzymatically by the reduction of Cr(VI) by GSSG-R, react with H2O2 to generate ·OH radicals, which might participate in the initiation of Cr(VI) carcinogenicity.INTRODUCTIONC(VI) compounds have been found to exert serious toxic and carcinogenic effects on humans and animals [1-4) and to cause mutations in bacteria and transformation of mammalian cells [5-8). In contrast, most Cr(lll) compounds are relatively nontoxic, noncarcinogenic, and nonmutagenic [9, 10]. Cr(VI) and Cr(lll) oxidation states are different in their metabolic pathways: Cr(VI) ions are rapidly transported across cellular membranes [2, 11-13), while Cr(lll) moieties do not easily penetrate cells and are not oxidized by cellular constituents [3]. Since it is known that the reduction of Cr(Vl) is required for its reaction with DNA [2], the molecular mechanisms for the intracellular Cr(VI) reduction have been the focus of studies during the past decade but the details are still not understood."

Jan 1, 1990

By F. H. Nehl

Ion elutriation was used to extract silver cyanide complexes and free cyanide from aqueous streams containing up to 10 ppm silver and 5 ppm free cyanide. Screening tests selected nine of 350 different surfactants for further, larger scale experiments. The screening procedure used 0.1 g of each of the surfactants in 300 mL of synthetic wastewater. Air was sparged into the test cell at 50 cc/min. The foam was refluxed during the tests and was not sampled. Samples of the solution were taken at specified intervals and analyzed by wet chemical methods for free cyanide and by atomic absorption for silver content. The most effective surfactants lowered the silver and free cyanide concentrations to less than 0.5 ppm in 1 h or less. These surfactants were quaternary amine salts with one long chain (C12-C18) organic group and three methyl groups. Experiments using 3 L batches of wastewater or an ion elutriation cell continuously fed with solution draining from an inactive heap leach operation confirmed the results from the screening tests.

Jan 1, 2010

By Ernest L. Corp

Seepage forces computed by a finite-element flow program are combined with gravity forces in an elastic-plastic stress-analysis program to determine the stability of mine-waste slopes. Computer output provides a cross-sectional plot of the dam or embankment showing the safety factors for each element. The combined finite-element program called SEEP-SLOPE was used to analyze several trial embankments and the 1972 Buffalo Creek Dam failure Safety factors computed by the finite-element method (FEM) were compared with those computed by Bishop limiting-equilibrium method. For individual slip circles, there was little correlation between the factors of safety computed by the two methods. Both predict failure, but FEM shows a different mode of failure plus development of potential failure zones not indicated by conventional methods. Besides having a better theoretical basis than the Bishop method, FEM requires no assumptions regarding the location or geometry of the failure surface. As a result, the program will show progressive development of a failure zone, and areas can be pinpointed where remedial measures should be taken. In addition, nonhomogeneous cross sections can be analyzed, and zones of potential piping can be defined.

Jan 1, 1975

By Thomas A. Phillips

An economic evaluation of the Bureau of Mines process for the separation of raw urban refuse into its metal, mineral, and energy components is presented. The process recovers ferrous metal, mixed nonferrous metals, aluminum, mixed-color glass cullet, and refuse-derived fuel products from raw refuse. Data for this evaluation were obtained from selected runs at the Bureau's pilot plant in Edmonston, Md. A cost estimate was prepared for a plant capable of processing 1,000 tons per day of raw urban refuse operating two shifts, 6 days per week. The fixed capital cost, based on second quarter 1976 equipment costs, is approximately $14.5 million excluding land and shipping containers. The estimated operating cost is approximately $8 per ton of refuse processed. This does not include credit for the products, transportation of the products, a tipping fee, or a dumping fee for wastes produced. No finance charges or taxes are included in the operating costs.

Jan 1, 1977

By W. W. Graff

This paper describing the mining practice at Mine No. 5 of the Marquette range, Michigan, is one of a series being prepared by the Bureau of Mines on mining practices, methods, tend costs in the various mining districts of the United States. The top-slicing system of mining, has been used ever since the present operating company took control of the property in 1903, the main level and sublevel layout being chanced only as local conditions required and the use of mechanical equipment increased.

Jan 1, 1930

By B. J. Dalton

The Bureau of Mines Helium Research Center has as a long-range objective the development of an equation of state for helium that will allow all of the thermodynamic properties to be calculated within the accuracy with which they are known. If this objective is to be realized, a method of calculation must be known. This report gives the principles of the method we use in such problems. A computer program was developed for predicting these properties, including those at the critical point, that is perfectly general and applicable to any equation of state. To demonstrate the efficacy of our method, this computer program was used to evaluate thermodynamic properties of a Redlich-Kwong fluid in the two-phase region. Expressions for calculating various thermodynamic functions specific for this particular equation of state are derived. Numerical values are tabulated and graphs are presented for all functions calculated. It is shown that for a Redlich-Kwong fluid there are finite discontinuities in (1) the second temperature derivative of the Gibbs free energy or chemical potential at the critical point, (2) the second derivative of the vapor pressure curve with regard to the temperature on passing through the critical point, and (3) the measured heat capacity at constant volume on passing through the critical temperature when the calorimeter is filled to the critical density. It is also shown that the heat of vaporization is infinite for a Redlich-Kwong fluid at absolute zero.

Jan 1, 1969

By Townsend. James W.

"INTRODUCTION As a byproduct of its mineral investigation program, the Bureau of Mines has developed a number of operating devices and techniques worthy of note. This paper, prepared under the direct supervision of Paul T. Allsman, chief, Salt Lake City Division, Branch, and under the general supervision of Lowell B. Moon, chief, Mining Branch, reports upon one such device. A simple device has been developed for measuring angles of deviation from the horizontal as recorded on a glass tube by acid etching. The device has facilities, also, for measuring the angle between the long axis of the ellipse and the north-south reference points established by a Maas compass or from an established axial lamina, on the tube, which was ori¬ented to a specific direction in the hole by rod alinement.The device was found accurate within half a degree on repeated orientations of the same tube. However, the degree of accuracy is dependent on the accuracy of personal manipulation in orienting the tube to the correct plane."

May 1, 1947

By Paul W. Johnson, Ralph C. Kirby, Frank A. Peters

A series of economic evaluations of processes for producing metallurgicalgrade alumina from low- grade aluminous materials is being conducted by the Bureau of Mines to determine the relative processing costs . The two processes considered in this evaluation are concerned with the recovery of alumina from clay through the formation of ammonium alum . In the first process , dehydrated clay is leached with ammonium bisulfate solution ; in the second process , clay is baked with ammonium sulfate and then leached with water containing a small quantity of sulfuric acid . After the alumina is dissolved by either of these methods , the iron is reduced to the ferrous state to avoid crystallization of ferric sulfate with the alum . The recovery of pure alum requires two crystallization steps . The alum crystals are then redissolved and precipitated with ammonia to produce alumina hydrate , which is calcined to a - alumina . These evaluations are based on published work , and the proposed plants are designed for a capacity of 1,000 tons of alumina per day . The estimated operating cost per ton of alumina for the bisulfate leaching process is $ 117.06 , and for the sulfate baking process , $ 109.26 . Using a Marshall and Stevens chemical equipment index basis of 240.0 , the estimated fixed capital costs , in the same order , are $ 158 million and $ 146 million . Under current economic conditions , these two processes are not competitive with the Bayer process for the production of alumina from bauxite . Since small improvements will not reduce costs sufficiently to approach competitive costs , future research work with these processes should be confined to areas likely to result in major cost reductions .

Jan 1, 1965

By G. L. Neumann

"INTRODUCTION AND SUMMARYThe Guymard mine in Orange County, N. Y., is reported to have been discovered in 1862 and mined until 1876, producing 10,000 tons of lead and zinc ore. 2/The property was examined by an engineer of the Bureau of Mines 3/ in 1948. Development work was done by the Bureau in April and May 1949 and March 1950. During these two periods four drill holes totaling 2,090 feet were completed. The mineralized sections of the core were sampled and assayed.ACKNOWLEDGMENTSThe diamond drilling was conducted under the general supervision of McHenry Mosier, chief, Mining Development Branch, Minerals Technology Division, Region VIII, and the direct supervision of Kenneth M. Earl and the writer as project engineers. Drill cores were logged by Paul K. Sims of the Federal Geological Survey. Chemical analyses were made by the Bruce Williams laboratories, Joplin, Mo., and the Minerals Processing Branch, Minerals Technology Division, Region VIII, Bureau of Mines, under the general supervision of Paul M. Ambrose, chief, and the direct supervision of Howard F. Carl, chief, Physical and Chemical Section.LOCATION AND ACCESSIBILITYThe Guymard deposit (see fig. 1) is on the west slope of Mount Hope, Orange County, N. Y., 1,500 feet northeast of Lake Guymard.Graham station, near the deposit, is on the Erie Railroad about 8 miles north of Port Jervis and 4 miles south of Otisville."

Aug 1, 1952

By M. H. Kersten, G. A. Brady, Jerry W. Ramsey

Anthracite samples were oxidized with nitric acid to prepare products representing intermediate stages of oxidation . Similar oxidizing conditions affected different anthracites to varying degrees as characterized by peptization behavior with 0.1 N NaOH . Techniques used in attempts to separate and characterize the products included esterification , absorption spectrophotometry , sublimation , chromatography , electrophoresis , metal salt formation , and solvent extraction . Mellitic acid , either free or in the form of metallic salts , was identified in the acid- soluble products from 10 tests in which the anthracite was treated with nitric acid for periods varying from 24 to 1,000 hours . pentacarboxylic acid was also found in some products . Other benzene carboxylic acids were not present in amounts detectable by the methods used in this study . The acid- insoluble residue from nitric acid treatment varied significantly in solubility behavior toward different classes of solvents . The most effective ones tried included polar oxygenated solvents and pyridine . Infrared spectra of the extracted material indicated that similar compounds were extracted by the different solvents . Aliphatic amines and aniline peptized the residue and o- toluidine reacted with it . Organic material separated from the residue by peptization with dimethylformamide contained 1 percent ash , consisting of more than 50 percent zirconium .

Jan 1, 1964