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By E. P. Youngman

The basic mining law of Esthonia is the law that was passed by the Parliament (Riigikogu), or State Assembly, on March 17, 1927 (effective Avril 1, 1927), superseding the Russian Mining Law Book VII of the Code) issued in 1912. References in this digest are only to articles of the Law of Merch 17, 1927. However, the law concerning all industrial enterprises (Riigi Teataja No. 28, 1920, Law No. 106) governs not only mills and refineries but also mining operations themselves (arts. 2 and 3). No access was ad to that law. Esthonia is not well supplied with minerals; its industries are primari- ly agriculture and dairy farming. Natural gas, prites, lead, zinc, iron ore, salt, and mineral waters have been found but never as yet in deposits of commer cial size. The production of oil shale is of some importance; and peat, which covers as much as 5 per cent of the total area of the country, is mined in sub- stantial quantities. Cement rock, gypsum, fire clay, and phosphate rock likewise are produced, though only on a small scale.

May 1, 1930

By Ronald D. Hill, Elmore C. Grim

The removal of overburden often exposes pyritic materials (iron disulfide). As shown in equations 1 and 2, the oxidation of this material results in the production of ferrous iron and sulfuric acid. The reaction then proceeds to form ferric hydroxide and more acid, as shown in equations 2 and 4. [ ] Consequently a low pH water is produced (pH 2-4.5). At these pH levels, the heavy metals such as iron, manganese, copper, and zinc are more soluble and enter into the solution to further pollute the water. Water of this type supports only limited water flora, such as acid-tolerant molds and algae; it will not support fish life, destroys and corrodes metal piers, culverts, barges, etc., increases the cost of water treatment for power plants and municipal water supplies, and leaves the water unacceptable for recreational uses. The amount, and rate of acid formation, and the quality of water discharged are a function of the amount and type of pyrite in the overburden and coal, time of exposure, characteristics of the overburden, and amount of available water(l). Crystalline forms of pyritic material are less subject to weathering and oxidation than amorphic forms. Since oxidation by oxygen is the primary reaction during early acid formation, the less time pyritic material is exposed to air, the less acid is formed. Thus, a positive preventative method is to cover pyritic materials as soon as possible with earth, which serves as an oxygen barrier. In terms of mining, this step is accomplished by current reclamation techniques and small open pits.

Jan 1, 1974

By Foster Fraas

A comparison has been made between cubes and spheres in the matrix of the high-intensity wet magnetic separator. For two inclined plane surfaces, such as may occur with cubes, the maximum force value, H [dH-dx] is at the point of nearest approach and is much higher than the force resulting from adjacent spheres. Although the maximum force value for cubes is higher, it decreases more rapidly at increasing distances. The maximum force for spheres is at an appreciable distance from the point of nearest approach. At field intensities for magnetic saturation of the iron spheres, the force extends to further distances with greater uniformity approximating that of the constant force or isodynamic field. The force is also independent of the sphere diameter, which permits the scaling of the sphere diameter to provide changes in particle migration distances without changes in force gradient.

Jan 1, 1972

Develop a technology for producing high-quality hake graphite from the steelmaking waste known as kish. Approach Treat the waste kish as an ore and apply mineral processing techniques of physical beneficiation and chemical purification to produce a range of graphite products com¬petitive with the natural mineral. Background Graphite is a naturally occurring form of carbon with a unique combination of properties that make it indispensable in a very wide range of industrial and consumer applications. It has high electrical and thermal conductivity and remains stable to extremely high temperatures It has a low coefficient of friction and is nearly impervious to corrosion. The steel industry is dependent on graphite in clay-, magnesia-, and alumina-bonded refractories for crucibles, bricks, facings, and coatings. Electrical uses include graphite brushes in motors and generators, and electrodes in batteries. The transportation industry needs graphite for clutch and brake linings, and all industries depend on graphite in seals, gaskets, lubricants, and coatings. The consumer sees graphite in composite plastics and in the common pencil. As with all natural minerals, the availability of graphite is diminishing and costs are rising as quality decreases.

Jan 1, 1993

Develop a reliable, portable device for non-destructively testing the support integrity of a friction rock support (commonly referred to as a Split Set ). Approach The friction rock support, used to support mine roof and ribs, is a slotted tube driven into a drilled hole of smaller diameter. Upon installation, the tube is compressed radially. The amount of compression is a function of the hole diameter, the strength of the host rock, and the properties of the split set itself. A simple lightweight self-contained device was developed to determine the pull-out resistance of the friction rock supports in-situ, based on measurements of the tube's deformation. The tester measures the com-pressed internal volume of the slotted tube, which has been found to provide an estimate of the support's resistance to pull out. How It Works The tester consists of a pump and expander sections. The expander sections are made from an elastomer membrane which is stretched over two cores, each one inch in diameter and twelve inches long. The expanders are connected by a flexible coupler so that they can fit any alignment of the support.

Jan 1, 1984

By M. J. Ankeny, J. J. Forbes

Several sets of questions and answers on the fundamentals of first aid to the injured, based on the Manual of First-Aid Instruction of the United States Bureau of Mines, are now in use in various parts of the United States. Persons experienced in first-aid instruction believe that a standardized set of questions and answers will assist materially in preparing men for examin- ations conducted by the Bureau for first-aid certificates. Inquiries as to whether a set of standardized questions and answers is available have been made frequently by those training men for the Bureau of Mines examination for certificates. It is believed that the following list of 171 questions and answers com- piled directly from the manual will be useful to company officials and em- ployees who are engaged in cooperative first-aid training to qualify for Bureau of Mines certificates. The list may also be used by field men of the Bureau in training instructors preparatory to a cooperative training campaign and in examining classes or individuals for first-aid certificates. The page references in parentheses refer to pages in the Manual of First-Aid Instruction.

Oct 1, 1935

By Jennifer S. Riefenberg

The U.S. Bureau of Mines conducts basic and applied research related to predicting, eliminating, and/or controlling rock bursts in underground hard-rock mines and coal bumps in underground coal mines. An important element in this research is the development of a reliable and efficient microseismic source location technique. This report presents the results of a Bureau study to develop and evaluate a new algorithm to locate microseismic events based on the Simplex method, a powerful linear programming technique. The technique was tested on both field data and simulated data. Microseismic event source locations obtained with this new Simplex-based algorithm were shown to have less error than those locations obtained using a least squares method. It was concluded that the Simplex approach to source location of microseismic events can be used effectively in microseismic monitoring.

Jan 1, 1989

By J. Sammarco

Proper illumination is critical to a miner?s ability to detect hazards in underground mines. Moving hazards are often located in the miner?s peripheral field-of-view, while slip/trip/ fall hazards are often located in the forward field-of-view. The objective of the research described in this paper was to determine if light-emitting diodes (LEDs) improve visual performance as compared to traditional incandescent (INC) cap lamps. The research presented focuses on comparative studies of a National Institute for Occupational Safety and Health (NIOSH) prototype LED, a commercial LED and an INC camp lamp. Thirty subjects participated in these studies, with ten subjects in each of the following age groups: 18 to 25 years, 40 to 50 years and 51+ years old. Visual per­formance was quantified by the subjects? speed and accuracy in detecting hazards, while visual performance for disability glare was quantified by the use of contrast sensitivity tests. Results suggest that LEDs with a visible spectrum containing a higher concentration of the shorter wavelengths can enable visual performance improvements with respect to disability glare, the detection of moving hazards in the peripheral field-of-view and the detection of floor hazards in the forward field-of-view. The NIOSH prototype LED cap lamp provided the best visual performance improvements for the older age groups in every test.

Jan 1, 2009

By J. F. Barkley

As part of the work of serving as Chairman of Subcommittee 3, Health and Industrial Requirements, of the American Society of Mechanical Engineers' Committee on Air-Pollution Controls, the author assembled the following information on accepted maximum permissible concentrations of air pollutants from the standpoints of health, damage to vegetation, damage to property, and requirements of industrial processes. A search in technical literature was made followed by direct inquiry to all State governments as to their regulations. The subcommittee membership - G. D. Clayton, senior sanitary engineer, Public Health Service, United States Department of Health, Education, and Welfare, Detroit, Mich., Dr. L. Greenburg, commissioner; Department of Air Pollution Control, New York, N.Y., Dr. M. Katz, Defence Research Chemical Laboratories, Ottawa, Ontario, Canada, and Dr. H. H. Schrenk, research director, Industrial Hygiene Foundation of America, Inc., Mellon Institute, Pittsburgh, Pa. - reviewed the information and made very helpful comments and corrections.

Jan 1, 1954

By Harley A. Coy

This paper, describing the mining methods and practice at No. 2 mine of the American Zino Co. of Tennessee at Mascot, Tenn., is one of a series of papers issued by the Bureau of Mines presenting the mining methods and costs in various districts throughout the United States. Its purpose is to summarize methods recently put into practice whereby increased efficiency has been effected. These improvements have to do principally with mill-hole mining, slushing, contract labor, and bonuses. In general, this paper supplements earlier articles and brings them up to date. ACKNOWLEDGMENTS The author acknowledges the assistance of M. H. Newman, geologist of the American Zinc, Lead & Smelting Co.; of William Black, assistant superintendent of mines; of P. M. Arthur, director of personnel; and of the engineering staff. The paper has been approved by H. I. Young, vice president and manager of operations.

Jan 1, 1930

By S. R. B. Cooke

Certain saturated and unsaturated fatty acids and a variety of resin acids were used as collectors for specular hematite, magnetite, and goethite. Vacuum flotation tests were used with each collector and mineral to delimit the fields of flotation and nonflotation as functions of concentrations of collector and of hydrogen ion. The experimental results of these tests lead to the following conclusions. The respective fatty and resin acids exhibit characteristic fields of flotation and nonflotation for the three iron oxides. The fields are somewhat similar, and specular hematite apparently is the most floatable mineral. The insolubility of some of the organic acids may seriously restrict flotation at low pH, although the saturated fatty acids, caprylic and capric, collect minus-100, plus-150-mesh specular hematite only in acid pulp. The presence of a lower "critical pH" is explained on the basis of the dissociation and hydrolysis of dilute soap solutions.

Jan 1, 1959

By John D. Sullivan, Edward P. Barrett

The experimental work on the utilization of tin-plate scrap at the North- west experiment station of the U. S. Pireau of Mines in cooperation with College of Mines, University of Washington, necessitated the selection of a simple method for the determination of tin in the iron produced. Some of the standard methods for the determination of tin which were tried are given below: 1. Dissolving in acids and precipitating the tin as sulphide, igniting and weighing as Sn02. 2. Dissolving in aciis, reducing with nickel, cooling in an atmosphere of carbon dioxide, end titrating with standari iodine solution. 3. Dissolving in acids, precipitating the tin as sulphide, dissolving this sulphide in H3 and H2S04, heating until fumes of 503 are evolved, reducing with nickel or sheet lead, cooling in an atmosphere of carbon dioxide, ani titrating with a standard iodine solution.

Mar 1, 1923

By E. M. Frost

"Helium has great value to the oil and as industry as a tracer gas, according to tests just completed in the Elk Hills Field, Naval Petroleum Reserve No. 1, Kearn County, California. When used as .a tracer gas, small percentages of helium are mixed with natural gas pumped into a reservoir for conservation, repressuring, or cycling purposes. Because minute quantities of helium added to natural gases can be detected by analytical methods and accurately determined, the variations of the helium content of gas withdrawn from various parts of a field when helium has been added to the injected gas give interesting and long-sought data on the movement of injected gas through reservoirs.The Bureau of Mines engineers began their studies of the use of helium as a tracer material in gas-injection operations in the Elk Hills, California, oil field, Naval Petroleum Reserve No. 1, in response to a request by the Navy Department for assistance in connection with an expanded oil-production program instituted in that field. This report discusses the Bureau's work on the problem of determining the direction and extent of migration of injected gas in the Elk Hills reservoir by the use of helium as a tracer gas,The Bureau appreciates the cooperation and assistance of Commodore W. G. Greenman, U.S.N., director, and Commander R. Walling, U.S.N.R., Assistant director, Naval Petroleum .and Oil Shale Reserves, Washington, D. C., Captain H. P. Stolz, U.S.N.R., commanding officer, and Commander F. G. Taves, U.S.N.R.., of the Navy's Elk Hills staff. The Bureau also appreciates the cooperation and assistance given by V. O. Wankowski, F. C. Tratt, Marray Putnam, Dana Champion, and other personnel of the Standard Oil Co., of California, operators of the Elk Hills field.R. A, Cattell, chief, and C. C. Anderson, assistant chief, Petroleum and Natural Gas Division; C. W. Seibel, supervising engineer, Bureau of Mines Helium Plants; and H. H. Hinson, petroleum engineer - all of the Bureau's staff - furnished valuable advice and assistance during the course of the work. H. C. Miller and G. B. Shea of the Bureau's San Francisco Office contributed valuable liaison work. The writer wishes to express appreciation to all these people for their cooperation and assistance."

Jun 1, 1946

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigation beginning with No. 4251, of which this is the eleventh. The-data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each halt township is followed by a description of each deposit developed in that halt township. The 14 halt-township maps and 77 detail maps of the bauxite deposits in this series at reports give the locations and numbers of all the holes drilled on the project, except the deep holes drilled to test the geophysical anomalies. The locations of those holes show on figure 13 in volume 1. The descriptions of the deposits developed are followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained tram the widely spaced exploratory drill holes has been summarized and tabulated, and a table for each halt township is given with the discussion of that area.

Jan 1, 1948

By Ann G. Kim

The Bureau of Mines investigated factors that influence the formation of methane and other hydrocarbon gases in coal, which is an integral part of the coalification process. Coalification begins with a biogenetic stage in which plant debris decomposes and peat is formed; methane and CO2 are the predominant gases produced during this stage. During the diagenetic stage of coalification hydrogen and the hydrocarbon gases methane, ethane, ethylene, propane, propylene, butene, iso- and normal butane, and pentane are formed by dissociation of the organic material. Methane may also be produced by a secondary reaction of hydrogen with unsaturates or by the reduction of CO2. The gas contained in coalbeds is a mixture of methane, C2 through C5 alkanes, CO2, 02, N2, H2, and H2; its heating value is equivalent to that of natural gas. The gas content of coal depends on many variables, but an empirical relationship between adsorptive capacity, rank, and depth has been observed.

Jan 1, 1978

By BUREAU OF MINES

This paper is a revision of Reports of Investigations , Serial 2541 , which was published in November , 1923 , for the benefit of State mining inspectors , safety engineers of mining companies , and others interested in electrical safety inspection in mines . It presents the important points that should be watched by inspectors and briefly reviews the work of the Bureau of Mines in testing of electrical apparatus and equipment to determine their permissibility for use in gassy coal mines .

Jan 1, 1929

By P. L. Placek

Correlations were made on experimental data for four New Mexico ore series to determine relationships between ore grade and uranium extraction during leaching operations. Such relationships provide information needed to predict the long-range supply of minerals to meet national economic and strategic needs. Results show that other ore constituents and gangue materials in addition to uranium grade influence uranium extraction. In general, tailing grades decrease and uranium extraction increases as both H2S04 and NaCl03 concentrations increase. Terminal emf and terminal pH also were studied. Similar trends appeared for all ores; however, specific combinations of results also were observed for individual ores and ore series. Experimental results indicate that uranium extractions are higher for lower uranium feed grades than predicted by other estimates. Three factors--uranium feed grade, H2SO4 concentration, and NaC103 concentration--were used to design factorial experiments for each ore series. Four additional feed assay factors--V205, Fe, C02, and CaO--were included in regression equations to account for some of the variation in data. The three factorial factors are represented in the regression equations by linear and exponential terms of the form D i'1*G i + Di,2 *e Di, 3*Gi. The four additional assay factors are represented by linear and squared terms of the form Di,*Gi + Di,2*eDi3*Gi. where the Di, ,J are coefficients, the Gi are factors, and the symbol * represents multiplication in computer notation. The interactions of the factors are represented by products of the nonlinear terms for all pairs of the factors.

Jan 1, 1981

By C. C. Clark, R. R. Backer, J. D. Vickery

This report presents the results of tests conducted by the U.S. Bureau of Mines to determine the transport characteristics of highly concentrated paste backfill mixes made from dewatered total mine tailings. The slurry concentrations of the mixes were all above 78 pct by weight with slumps ranging from 6.4 to 16.5 cm (2.5 to 6.5in). Laboratory material property tests and full-scale pumping tests were conducted using pipe diameters of 102,128, and 154 mm (4, 5, and 6 in) and a positive-displacement pump. The results indicated that the tested backfill mixes can be successfully transported as a stiff paste and identified the influence of and the interaction among the various mix and system variables.

Jan 1, 1995

By R. B. Prater

Research by the Bureau of Mines includes efforts to devise means for maximum recovery of critical and strategic metals from primary and secondary domestic resources. As part of that effort, the Bureau developed a hydrometallurgical process to recover Co, Ni, and Cu from Missouri lead-smelter matte. The process includes leaching with H2S04 plus Mn02 as an oxidizing agent, liquor purification, selective precipitation of CuS, (Co,Ni)S, and MnC03, and crystallization of Na2S04&apos; This report is concerned primarily with liquor purification, in which As and Fe are removed from the leach liquor by pH adjustment and filtration. Two variations of the purification step are described. One variation provides liquor containing <1 mg/L As and Fe but requires two solid-liquid separations, The other is achieved with only one solid-liquid separation but leads to a lower degree of purification.

Jan 1, 1987

By P. D. Laverty

The U.S. Bureau of Mines treated mixed and contaminated super alloy scrap by pyrometallurgical and hydrometallurgical methods to separate and recover metal values. Best results were obtained by leaching Zn-treated or atomized scrap with HCI-02 at 9SO C and 50 psig 02&apos; This resulted in dissolving approxi-mately 98 pet of the AI, Co, Cr, Cu, Fe, Mn, Ni, and Zn while rejecting over 98 pct of the Mo, Nb, Ta, Ti, W, and Zr as an insoluble refractory residue. Chlorine was successfully substituted for HCI to leach Zn-treated scrap but was unsuccessful for leaching atomized scrap. The leaching solution was treated by pH adjustment and hydrothermal precipitation at 2000 C for 4 h to remove AI, Cr, Fe, and other contaminants as a filterable precipitate. Recovery of Co and Ni would be accomplished by solvent extraction and e1ectrowinning. Chromium recovery as a ferroalloy was demonstrated.

Jan 1, 1989