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By A. D. Garman

This paper presents one of a series of digests of foreign mining legisla- tion and court, decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Latin America has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers, to whom it is being referred through the courtesy of the Department of State. Individual abstracts of the laws of each of the countries herein discussed have been prepared and published separately. This general summary is presented for the use of mining engineers and investors whose interests extend over the borders of a single country. It is also designed to bring out certain general principles of mining law and, so far as feasible, to indicate the trend of mining legislation in South and Central America. In order to gain perspective, the details of legislation are not com- pletely covered in this paper, but an effort has been made to bring out essential differences as well as points of similarity in the laws of the various countries. The course of legislation is first traced chronologically and the points discussed are then arranged in tables in somerhat greater detail. .Si. With a very few exceptions the existing mining legislation of Spanish America is a development, of the Spanish "Law Decree of Bases" (more briefly referr- ed to as the "Decree-Bases") of 1868. This in turn was influenced, particularly in its classification of minerals, by the French law of April 21, 1810.

Jul 1, 1930

By Jon C. Volkwein

Dust concentrations inside and outside enclosed cabs on several types of mining machinery were measured by the Bureau of Mines. Results indicated that properly enclosed cabs can offer significant dust protection for machine operators. Recommendations for improvements in cab technologies were discussed.

Jan 1, 1979

By d&apos, Dennis V. Andrea

The Bureau of Mines and El Paso Mining and Milling Co. conducted a cooperative in situ leaching research program at the Emerald Isle mine near Kingman, Ariz. The objective of this research was to develop in situ leaching methods for 200,000 tons of ore exposed in the pit bottom and also 3,000,000 tons of ore under 200 feet of overburden adjacent to the pit. The research included core drilling for fragmentation analysis, inplace permeability testing, seismic surveys, blasting tests, blast vibration measurements, inplace leaching, and ground water monitoring. A l5,000-ton test area in the pit bottom was blasted and leached inplace for 117 days. This successful test was followed by leaching 100,000 additional tons of unblasted pit bottom ore. Two test blasts, under 205 feet of overburden and extending to 290 feet, were detonated in an area near the open pit. The second blast was detonated because the first blast did not create adequate permeability for leaching. Pit bottom leaching was discontinued and the test area under 200 feet of overburden was not leached because the company terminated operations at the Emerald Isle mine. Based on the research completed, an expanded in situ leaching system was designed, but not implemented, to recover copper from a 1,500,000-ton area at the Emerald Isle mine.

Jan 1, 1977

By D. A. Rice

As part of a cooperative effort between the Bureau of Mines and the Florida Institute of Phosphate Research (FIPR), with input from the phosphate industry, the conversion of phosphogypsum to sulfur is being investigated. The proposed process incorporates the thermal reduction of phosphogypsum to calcium sulfide (CaS) and a hydrometallurgical treatment to convert calcium sulfide to sulfur (S°). The research described herein is focused on the latter half of the process. It was demonstrated that calcium sulfide could be converted to ammonium bisulfide (NH4SH), and that ammonium bisulfide could be oxidized by air in the presence of a catalyst, to elemental sulfur, which was adsorbed on the catalyst. Two methods for recovering sulfur from the catalyst were developed: (1) thermal treatment to volatilize sulfur, and (2) leaching the sulfur from the catalyst with liquid anhydrous ammonia. Over 90 pct of the sulfur adsorbed on activated carbon (the catalyst) was recovered by both methods. Based upon the encouraging laboratory investigations, a hydrometallurgical scheme was proposed for the overall conversion of calcium sulfide to elemental sulfur.

Jan 1, 1990

The Anaconda Copper Company reportedly reached an exclusive agreement with Cook Inlet Region, Inc., to explore 24 million acres in south-central Alaska and to share equally with Cook the proceeds of any mineral discovery. According to an Anaconda geologist, "the company is anticipating, based on geologic testing, that it will find significant deposits of copper, lead, and zinc. There is also evidence of the presence of precious metals such as silver and gold, and also strong evidence of strategic minerals such as chrome, platinum, tin, and nickel." Cook Inlet Region, Inc., is owned by 6,500 Alaskan natives. Chile, which has a growing, free-market economy under President Pinochet, reportedly will no longer require companies to obtain prior governmental approval for the exploration and development of new mines.

Jan 1, 1981

By F. E. Brantley

Blister copper was successfully deoxidized with any of a variety of reducing gases; lancing techniques or a vertical-column furnace were used to contact the copper and gases. Of the gases tested, butane, when used to lance molten copper at about 1,200° C, reaction temperature, was slightly more effective than propane, natural gas, carbon monoxide, or reformed gas for deoxidizing copper from about 1.0 to less than 0.1 percent oxygen content, Laboratory-scale tests revealed that the vertical furnace, composed of a heated column packed with silicon carbide chips or hollow carbon cylinders, was significantly faster and more efficient than the lancing technique for deoxidizing molten copper with any of the gases tested. Comparison of the gaseous-reduction method with the conventional poling method suggests that the gaseous method has important technical and economic advantages for deoxidizing blister copper to any readily controlled amount of residual oxygen content.

Jan 1, 1962

By W. L. Hunter

This report describes results of beneficiation and smelting studies conducted by the Federal Bureau of Mines on chromite samples from the Emma Belle and Seiad Creek prospects in the Seiad Creek area, northern California. Samples were chosen from this area because the ore is typical of disseminated types that represent a sizable domestic reserve. The two samples were similar in composition, and both responded in like manner to gravity beneficiation. As the ore was banded, considerable coarse gangue was rejected in laboratory sink-float from a minus-3/4-inch, plus-6-mesh fraction without excessive chromium loss at a medium density of 3.32. An average of 85.6 percent of the chromium was recovered in the sink product, which analyzed 35 percent chromic oxide (Cr203). Tabling yielded concentrates containing 49 percent or more Cr203; however, recoveries, ranged from only 33 to 45 percent. A combination of tabling and electrostatic separation of the table middlings showed that the chromium recovery could be increased to about 73 percent; the composite concentrate averaged 53 percent Cr203.

Jan 1, 1960

By Margaret R. Egan

The Bureau of Mines experimentally burned Pittsburgh Seam coal and other combustible materials found in mines in order to obtain a better knowledge of their emission products. These experiments were conducted in the Bureau's intermediate-scale fire tunnel, which simulates environ-mental conditions in underground mines. Smoke characteristics, gas concentrations, mass loss, and ventilation were measured. From these values, heat-release rates, particle sizes, obscuration rates, combustion yields, and production constants were calculated. This information was sought as part of a comprehensive study of combustible materials that will ultimately advance the design of more efficient fire detection and suppression systems. The coal combustion measurements presented in this report, together with previous analyses of wood and transformer fluid fires form a data base by which future studies of other mine combustibles can be compared.

Jan 1, 1987

By L. G. Marshall

The geology, mining, beneficiating, types of products, and costs in terms of percent of total costs and of labor, power, and supplies of two crushed-limestone operations in Madison County, Iowa, are described in this paper. The operations are basically similar, differing in refinements in mining, product types, and markets. The operations are comparable as to personnel and as to weighted costs in terms of percent of total costs and in terms of man-hours, power, and sup-plies. The waste-to-stone stripping ratio is 1 to 0.8 at both operations, the powder factor is 0.29 pound of explosives per ton of stone, and daily production is 95 tons per man-shift. Both companies use crawler-mounted diesel shovels for loading, truck transportation, wagon drills, and dry screening.

Jan 1, 1963

By N. L. Wimmler

The Metaline mining district was examined in 1942 by Bureau of Mines engineers with the cooperation of geologists of the Federal Geological Survey. Because the demands of war production were rapidly depleting reserves in some of the older zinc-lead producing districts of the United States, it was decided that an attempt should be made to increase the proved or indicated ore reserves of the Metaline district. With this objective, certain areas to be explored by diamond drilling were selected. The Bureau of Mines began work on this program. January 15, 1943; work terminated September 8, 1945. Forty-five holes were drilled in seven areas, The holes ranged from 154 feet to 2,050 feet in length. Their combined length was 38,150 feet. Thirty-three of the holes were drilled in. the North Pend Oreille and the West Bella May areas.

Jan 1, 1949

The Department of Interior, U.S. Bureau of Mines performs the task of estimating the quantity of coal reserves existing in each state on a county by county basis. As a part of Information Circular 8655, the Bureau of Mines established the criteria for the uniform estimations of coal reserves and listed the most recent estimates of coal reserves by county and by seam. At the same time however, the Bureau recognized that these figures represented the upper bound with regard to the estimated actually usable or obtainable reserves. Recovery of these reserves are subject to the mining methods used and to the resolution of such problems as the use of poor quality coal and competition provided by conflicting land use. These problems, in practice restrict the recovery of the estimated quantities of coal reserves listed in IC 8655. Another impact, the subject of this manual, is the impact resulting from previous mining activities. In particular, many of the reserve seams included in the reserve estimates overlie or underlie mined-out coal beds. Portions of these reserve seams may therefore be unmineable or at best may have a reduced quantity of extractable coal. In order to improve the accuracy of the coal reserve base estimates, the Bureau of Mines funded an effort1 to develop a systematic methodology for estimating the coal loss associated with the impact of previous mining activity. The coal loss calculation model (CLCM) described in this manual is a result of that effort and addresses the percentage of coal loss in reserve seams due to previous overmining or undermining.

Jan 1, 1976

By T. A. Henrie, D. C. Fleck, D. G. Kesterke

Uranium metal was electrowon from uranium dioxide dissolved in fluoride melts . The UO₂ was fed directly to the cell in a continuous manner . Electrolysis was performed at 1 , 200 ° to 1,300 ° C in electrolytes composed of UF4 , LiF , and BaFa . A single regulus of metal was collected in a confined area of the crucible . Product purity of 99.8 percent was attained . Carbon was the major contaminant . Compartmented cells were studied as a means of confining the oxide feed to the vicinity of the anodes .

Jan 1, 1964

By Mary F. Koehler

Interoxidic compounds, such as vanadates, have not been studied extensively in the field of thermodynamics. This is a report of three vanadates of sodium--metavanadate, pyrovanadate, and orthovanadate. Vanadates of other metals will be considered in future reports. The heats of formation at 298.15° K. of the three sodium vanadates (both from the oxides and from the elements) were derived from the results of sodium hydroxide solution calorimetry. Free energies of formation were obtained by combining heat and entropy values. The results support the conclusion that the three sodium vanadates were stable with respect to all possible decompositions in which vanadium retains its pentavalency.

Jan 1, 1960

By Yael Miron

The presence of pyrite (FeS2) in coal can cause or contribute to several problems for the coal mining industry. These problems, which include spontaneous combustion, roof falls, floor heave, and accidental explosions in coal surface mining when ammonium nitrate fuel oil (ANFO) explosives are used, result from pyrite oxidation. Pyrite oxidizes exothermically in the presence of air and moisture to form a large variety of products, including hydrated ferrous and ferric sulfates, and sulfuric acid. Some of the products are reactive chemicals and strong oxidants. The volume of many of these oxidation products exceeds the original volume of the pyrite; as a result, the adjacent coal disintegrates and its surface increases, rendering it more susceptible to oxidation. The heat from pyrite oxidation raises the temperature of the adjacent coal, accelerating the oxidation and self-heating rates of the coal. These combined chemical, physical, and thermal effects are the cause of the aforementioned problems. When ANFO is used in surface coal mines and contacts ferrous sulfate, a highly exothermic reaction ensiles. Additional hazards are fires or explosions caused by the frictional ignition of methane when the pyrite in the coal is struck by a cutting bit during mining.

Jan 1, 1994

By Ernest W. Johnson

Diamond, drilling of some blast holes in stoning operations is practised in at least two iron mines in the Lake Superior district - the Soudan mine of the Oliver Iron Mining Co., on the Vermilion range at Soudan, Minn., and the Anvil-Palms mine, operated by Pickands, Bather & Co., on the Gogebic range at Bessemer, Mich. Diamond drilling, at the Soudan nine has partly replaced percussion drilling because of the extreme hardness of the ore and of the lean formation. According to Wolff,4/ the jasper or lean formation in this mine is the hardest rock regularly drilled in any commercial operation.

Jan 1, 1945

By J. M. Stuve

Low temperature and high-temperature calorimetric measurements were made by the Federal Bureau of Mines on high-purity samples of Re02(s) and Re03(s) to determine heat capacities and enthalpies. The temperature range of heat capacity measurements was 5 to 310 K for Re02 and 8 to 309 K for Re03. High-temperature enthalpy measurements alone were determined for pure Re207(s,1). The derived standard entropies are S°298 = 11.43±0.01 cal/deg mole for Re02(s) and S298 = 16.55±0.02 cal/deg mole for Re03(s). High-temperature enthalpy equations expressed in calories per mole are as follows: Re02 (s) , H-H298.15 = 16.002T + 1.600 X 10-3T2 + 3.522 X 105T-1 - 6,095 (298 to 1,400 K); Re03 (s) , H-H298.15 = 20.293T + 3.238 X 10-3T2 + 3.950 X 105 T-1 - 7,664 (298 to 1,000 K); Re207 (s) , H-H298.15 = 38.437T + 10.309 X 10-3T2 + 4.315 X 105 T-1 - 13,824 (298 to 413 K); Re207 (s) , H-H298.15 = 30.181 + 17.713 X 10-3T2 - 10,612 (413 to 600 K) ; Re207 (1) , H-H298.19 = 66.101T - 10,092 (600 to 700 K). Gibbs energy of formation (?Gf°) data and related functions over the temperature ranges investigated are tabulated for the three oxides.

Jan 1, 1976

By J. Venter

The history of firedamp is the same as that of coal: The initial stage was the accumulation of vegetation, which was converted into peat under certain local conditions, then lignite, bituminous coal, and finally anthracite. These deposits ceased to increase owing to inundation that deposited earthy sediment, sometimes as much as several tens of meters (several tens of yards). The vegetable matter, whether it was covered with sediment or not, began to ferment. The basic organic components of the vegetable matter are: Cellulose, lignin, and wax and resin in varying proportions, according to the different kinds of vegetable matter. There are, in addition, some impurities, generally mineral.

Jan 1, 1953

By B. W. Madsen

Research by the Bureau of Mines has shown that treatment of open pit waste by crushing and sizing followed by flotation of the fines and leaching the coarse fraction results in greater metal recoveries than obtained by leaching only. Tests with a chalcocite-bearing quartz monzonite mine waste sample that had been crushed to minus 6 inches and screened on 1/2 inch yielded copper and silver recoveries of 71 and 22 percent, respectively, by the combined flotation-leaching process, compared with 48 percent of the copper and no silver recovered leaching the run-of-mine material. Copper was more readily leached from the coarse material with the minus 1/2-inch fines removed than from material with the fines included. The improved leaching was attributed to improved permeability and the associated improved circulation of air to the interior of the ore column. Cost estimates showed that the proposed intensive treatment of mine waste will require a greater capital investment and higher annual operating costs than conventional milling and dump leaching process. However, the income from the additional metal production offsets the increase in capital investment and operating costs, resulting in additional profit.

Jan 1, 1975

By Irving Hartmann, Edward Thomas

"INTRODUCTION Adoption of rubber-tire shuttle cars underground in conjunction with mobile coal-loading machines has introduced new problems in the control of dust on mine roadways. Where this type of loading and transportation is used, development and extraction are generally rapid, with the result that much coal is spilled from the shuttle cars during normal operation, Coal in the roadways from this source and from sloughing of the ribs is ground to fine dust by the wheels of the 'shuttle cars and by the treads of the loading and mining machines. The coal dust usually is somewhat contaminated by pulverized rock, and the mixture could not be loaded with the run-of-mine coal without undue contamination of the product even if it were cleaned up promptly.The presence of large quantities of fine, loose dust, which is constantly stirred up and kept in suspension in air by the traffic, constitutes a grave explosion hazard, reduces visibility along the roadways, and is physiologically harmful to the workmen who breathe the air. From the operating standpoint the loose material is undesirable along the roadways because it provides poor traction for the trucks and thereby increases wear and power consumption. The dust-explosion hazard could be eliminated or reduced by frequent application of sufficient rock dust on the roadbed; but this would not remedy the other difficulties, and in fact it might intensify them. Where practicable, the most direct and effective safety measure is to clean up and remove promptly all dust that forms and settles on the roadways. Unfortunately, in many cases this procedure is not feasible. A third Suggested remedy is to prevent dispersal of the dust into the air and to promote its consolidation on the floor by wetting the dust particles.During the past few years several mines have used calcium chloride on shuttle-car roadways to allay the dust thereon. When exposed to the' humid atmosphere of the mine this salt absorbs Moisture from the air and deliquesces, and in this way wets the dust on the floor of the roadway. In a survey conducted in coal mines in southern West Virginia and in eastern Kentucky where calcium chloride has been in use, somewhat conflicting re- ports were received regarding the merits of the application, and several operators have abandoned the practice either because of actual or assumed disadvantages. The purpose of the study described in this report was to collect and correlate evidence and, on the basis of experimental data obtained in the field and in laboratory tests, to present a clearer picture of the factors involved in the allaying of dust by use of salts."

Sep 1, 1945

By R. G. Travis

1. Reserve estimates have been made for eight coal beds in Monongalia County, W. Va., but only the Pittsburgh, Sewickley, and Upper Freeport beds are important at this time. The Pittsburgh, Sewickley, Waynesburg, and Upper Freeport beds contain the largest recoverable reserves. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 3,526 million tons as of January 1, 1954. Of this total, 3,294 mil-lion tons is in beds 28 inches and more thick. Areas in each bed except the Pittsburgh were omitted from the estimate because available data relative to the bed characteristics are too meager for making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956