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By Paul M. Tyler

The colony of French Guiana ( or Cayenne ) is administered by a governor , assisted by a privy council of five members . A council - general of 16 members is elected by French citizens resident in Guiana, and the colony is represented 3 in the French parliament by one deputy . The area is about 34,740 square miles . French Guiana is the largest gold producer of the French colonies , producing nearly $ 1,000,000 worth annually . Considerable prospecting has been done on the bauxite deposits , which are extensive . Copper , iron , lead , and 4 mercury deposits are also reported . In 1931 , 10,000 prospectors for gold were reported as working . The French Government is taking an active interest and has sent a committee of mining experts to explore the region ; no permits are to be issued to individual prospectors while the committee is in the colony . Plans for development of mining industry include consideration of 4,500 convicts and 2,500 natives already in the colony and available for labor .

Apr 1, 1933

By Robert L. Crosby

The Bureau of Mines investigated the substitution of cement copper powder for commercial copper powder in an Fe-7 pct Cu-l pct C powder metallurgy alloy. Copper powders from six different commercial cementation operations were separately upgraded by screening and hydrogen reduction. They were then mixed with commercial iron and graphite powders to form the Fe-7 pct Cu-l pct C alloy. Various chemical and physical properties were determined on the upgraded cement copper and the alloy powders. Mechanical, physical, and chemical properties were determined on green and sintered specimens made from the alloy powders. Mean tensile and bending strength of sintered specimens were significantly lower than the means from specimens made from commercial metal powders. The lower strengths are apparently related to poor sinterability.

Jan 1, 1970

By J. P. McGee

As part of a joint U.S. Atomic Energy Commission-Federal Bureau of Mines program for using nuclear energy to supply process heat, a simulated nuclear loop has been constructed to test components. This loop has been operated for more than 1,800 hours at 100 p.s.i.g. Of this period, 23 hours were at 2,500° F. and higher; 540 at 2,000° to 2,500° F.; 840 at 1,500° to 2,000° F.; 200 at 1,000° to 1,500° F.; and 260 below 1,000° F. Leakage at flanges and welds was not a serious problem. A helium-recycle system with gas temperatures of 2,300° to 2,500° F. and a static pressure of 250 p.s.i.g. appears feasible. Difficulties were encountered with the recycle compressor due to thermal distortion of the impeller and shaft. The use of sealed bearings limits compressor operation to the life of the bearings.

Jan 1, 1960

By W. P. Haynes

The Bureau of Mines has been studying a modified steam-iron process using coal-derived producer gas for making either hydrogen plus carbon monoxide or methane. To provide a guide for this experimental study, compositions of equilibrium product gases for the reaction of steam plus carbon dioxide with iron were calculated and are discussed in this report. The calculations, which are described in this report, are based on thermodynamic data in the literature and cover temperatures from 800° to 1,300° K., pressures from 1 to 30 atmospheres, and hydrogen-to-carbon atomic ratios in the gas of 4 to 12. The equilibrium gas compositions are discussed in regard to making hydro-gen, carbon monoxide, and methane in the oxidation step of the modified steam-iron process. From the viewpoint of thermodynamics alone, assuming the reactions reach equilibrium, the discussion considers the effects of temperature, pressure, and composition of feed gas upon the composition of the product gas, the degree of oxidation of the iron, and the possible deposition of carbon. The results indicated the following: (1) Nearly all the carbon can be converted to methane at low temperatures (800° to 900° K.) and high pressures (over 20 atmospheres); (2) to obtain high yields of synthesis gas, high temperatures are required. For example, at 30 atmospheres, a temperature over 1,200° K. is required to convert 60 percent of the steam plus carbon dioxide to hydrogen plus carbon monoxide. Lower temperatures may be used at lower pressures) (3) oxidation of the iron increases with increasing pressure and decreases with increasing temperature; and (4) process conditions favoring carbon deposition were found within the range of variables studied, but it is thermodynamically possible to operate the oxidation process with steam and carbon dioxide outside this range of carbon deposition.

Jan 1, 1961

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 R. S. DeCesare

Operation of the Bureau of Mines raw refuse continuous separation pilot plant is described, including modifications made to plant equipment for improved performance. Products recovered from refuse, many of which have been evaluated by other laboratories and private firms, are discussed. Sampling procedures used in the pilot plant and detailed data obtained from processing refuse from 13 municipalities are presented in appendixes. Fuel evaluations made on combustible fractions of refuse from the various municipalities are also presented. Information and data obtained at the pilot plant have been used to assist many municipalities in solving their urban refuse problems.

Jan 1, 1980

By W. D. Dietzman

This Bureau of Mines report presents a continuation of statistics pertaining to distribution of petroleum reservoirs (or fields), wells, and production by depth and producing rate classification in the United States. These statistics show the change that has occurred since results of a similar study were published by the Bureau of Mines in 1967. Data are presented in tabular form by State for the 18 principal oil-producing States and by subdivision for the two larges t oil-producing States, Texas and Louisiana, Tabular summations and graphical illustrations are presented for the Nation. The data are classified by 4-barrel-of-oil-per-day rate increments up to 36 barrels and one increment of greater than 36 barrels of oil per day and by 2,000-foot depth increments up to 8,000 feet and one depth increment of greater than 8,000 feet. The overall average producing rates for States and the Nation have been published for many years; although such rates are useful, they are very general descriptions of producibility. A breakdown of production, wells, and reservoirs by various depths and rates and by State or by State subdivision provides a more detailed description of producibility.

Jan 1, 1976

By J. Burlin Johnson

In small-scale blasting experiments conducted in the Bureau of Mines laboratory, small charges were used to produce craters in blocks of concrete mortar. The results are compared with larger scale experiments of other research workers, and the comparison demonstrates the similarity of the results obtained and indicates that small-scale blasting should be a useful tool for predicting large-scale blasting effects. INTRODUCTION The purpose at this investigation was to conduct blasting experiments in mortar in the laboratory and then, by comparing the results with those from larger scale field blasts in rock to determine to what extent, if any, the laboratory results resemble those in the field. The work described herein was the initial phase of a project aimed at evaluating small-scale blasting as a tool for use in improving blasting techniques. It is evident from the stand-point of control and cost that small-scale blasting would be valuable in the study of rock fragmentation by blasting in mines and quarries, if the extrapolation is valid.

Jan 1, 1962

By F. S. Crawford

This study was made to find methods of preventing back strains, among workers in brick plants, however, the information should apply to other industries that employ hand labor too process materials. The report is based on information in letters from. Bureau of Mines engineers and other safety men in the United States who visited numerous brick plants. Back strains, as wall as hernias and other muscular strains, result when certain body structures are subjected to strains greater than, they can withstand. Such breakdowns may be prevented simply by not straining these body structures. This is simple in theory but complicated in practice. It requires primary education of new workers and reeducation of older workers in the best method of lifting, preemployment physical. examinations to select employees for the jobs that require constant lifting, all possible mechanization of material-handling operations, relocation of machinery, and elevation of working surfaces to reduce to a minimum the muscular effort the workers must exert to perform operations impossible to mechanize. Accidents of any kind are a total bee for the American economy and decrease productivity; whereas mechanization raises the level of productivity and constitutes progress toward total safety. Heavy lifting should be done mechanically whenever possible, saving the men to direct the machines. This is an essential step in preventing strain accidents.

Jan 1, 1953

By R. V. Ramani, C. B. Manula, A. Owili-Eger

• MINE VENTILATION NETWORK PROBLEM (NATURAL SPLITTING; FIXED • QUANTITY BRANCHES; METHANE SIMULATION; NETWORK TOPOLOGY REVISION; • ABSOLUTE PRESSURE) • NFIXB = NO. OF FIXED QUANTITY BRANCHES • DD(I) = AIR QUANTITY ASSIGNED TO FIXED QUANTITY BRANCH I, IN KCFP • NFBPF = NO. OF FIXED QUANTITY BRANCHES PLUS FAN • NFBPFG = NO. OF FIXED QUANTITY BRANCHES PLUS FAN PLUS METHANE • EMISSION BRANCHES • NBWNVP = NO. OF BRANCHES WITH NATURAL.VENTILATION PRESSURE • NVP(I) = NATURAL VENTILATION PRESSURE ASSOCIATED WITH • THE I-TH BRANCH • NF = NUMBER OF FANS • NB = NUMBER OF BRANCHES • MAXIT = MAXIMUM NUMBER OF ITERATIONS • MAXJ = MAXIMUM NUMBER OF JUNCTIONS • NJ = NUMBER OF JUNCTIONS INVOLVED IN THE SOLUTION * NM = NUMBER OF MESHES • NP = NO. OF POINTS TO DESIGNATE FAN CHARACTERISTIC * Q = QUANTITY OF AIR FLOW IN KCFM • R = RESISTANCE OF AN AIRWAY • WIDTH = AIRWAY DIMENSION • LENGTH = AIRWAY DIMENSION • HEIGHT = AIRWAY DIMENSION • SUMNVP = SUMMATION OF NATURAL VENTILATION PRESSURE FOR ANY MESH • X (I) = QUANTITY OF AIR, IN KCFM, ASSOCIATED WITH THE I-TB POINT • ON A FAN CHARACTERISTIC • E = ERROR FOR CONVERGENCE • FF = FRICTION FACTOR • FX(I) = FAN PRESSURE, INS INCHES OF WATER GAGE, CORRESPONDING • • TO A QUANTITY X(I) • H = HEAD LOSS IN INCHES OF WATER GAGE • I = BRANCH NUMBER • J, J1, J2 = JUNCTION, J1 AND J2 ARE TWO NODES WHICH DEFINE A • BRANCH • KEY = NO. WHICH SIGNALS THE TYPE OF FAN CHARACTERISTIC TO BE • EXPECTED

Jan 1, 1975

By A. D. German

This paper presents one of a series of digests of foreign mining legis- lation 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 tie laws of Ecuador 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..

May 1, 1930

By William Eathorne

"INTRODUCTION Retsof mine, adjoining the village of Retsof, Livingston County, New York, is about 5 miles northwest of Geneseo and 55 miles (air-line distance) due east of Buffalo. It is a single-bed rock-salt mine having extensive horizontal workings as much as 2-1/2 miles long and 1 mile wide and has been in continuous operation since 1885. Retsof tine is the largest producing salt mine in North America and is reputed to be the largest active salt mine in the world.Retsof is one of three large salt mines operated by the International Salt Co., Scranton, Pa.; T. Forster Courthope is general manager of Retsof and also of the company's Detroit salt mine in Michigan and has held that position for 27 years. He is assisted by Stanley Martin, general superintendent; R. Goetz, Maintenance superintendent; and John Riordan, mine superin¬tendent. All are old-timers at Retsof and, according to Courthope, contri¬buted the ""lion's share in bringing the mine to its present standard of safety.ACKNOWLEDGEMENTThis circular was made possible by the generous cooperation of T. Forster Courthope and his assistants, Stanley Martin, R. Goetz, and John Riordan. The information and time generously given are gratefully acknowledged.GENERAL INFORMATIONThe rock salt as mined contains about 99 percent sodium chloride and requires only crushing and screening to prepare it for the market. With the exception of a large jaw crusher underground, all crushing is done in a mill building attached to the headframe of the main hoisting shaft (fig. 1).Five sizes of salt are produced, ranging from about 1/2 inch diameter down to minus seven mesh."

Sep 1, 1949

By James E. Mauser

This report deals with the investigation of a continuous process for producing pure zirconium. It covers the construction, operation, and maintenance of the semicontinuous reactor. The report covers a study of test variables, such as reactor temperature and reluctant charge weights, and evaluates the results, such as billet metal hardness, residual billet salt content, and suitability of a purified billet as a consumable electrode for arc melting. The purpose of this project was to develop an inexpensive and continuous process for producing pure zirconium. The process developed, termed the semicontinuous reactor process, produced billets of compacted zirconium sponge. The metal was produced by reducing zirconium tetrachloride with sodium and magnesium beneath molten byproduct salt. Hydraulic rams at each end of a vertical reaction tube compacted the sponge and ejected it as a billet. These billets were purified by heat under vacuum to remove entrapped salt. The goal was to utilize the purified billet directly as a consumable electrode for arc melting.

Jan 1, 1961

The objectives of this research were to examine and to laboratory performance of several brands of rigid urethane een brands, produced by 13 manufacturers, were examined. was performed in a laboratory under controlled conditions. document the foam. Eight-All testing Preliminary laboratory tests included flame spread evaluations, flame penetration, ignition temperatures, air permeability, and adhesion. Having established arbitrary cutoff values, the original 18 candidates were narrowed to 8. More specialized tests followed. The effects of water immersion and dry aging on flame spread performance and other physical properties were then examined. This Bureau of Mines report was written to provide information for those concerned with using rigid urethane foam as a sealant. Its intent is to describe the various laboratory evaluations performed and to delineate the performance of each candidate. This report neither promotes nor discourages the use of rigid urethane foams. It presents results that will enable those responsible for using or enforcing the use of rigid urethane foams in underground mines to make informed decisions.

Jan 1, 1985

Enhance hydraulic fragmentation technology by developing alternative grout sealing methods. Traditional grout scaling methods rely on chemical adhesion and require large contact areas to restrict high-pressure fluids. Fluid injection into rock requires economical and effective seals. With economical and effective seals, rock is easily fractured in tension by high-pressure fluid injection (fig. 1). Approach An innovative grouting technique was developed and tested by the Bureau. Slowly hydrating expanding chemicals are placed within a borehole and around a section of high-pressure tubing. Testing was conducted using 9/16-inch-OD smooth-walled injection tubes in 1.5-inch-ID holes. Seal lengths weir less than 10 inches and curing times were less than 24 hours.

Jan 1, 1989

By Lucien Eaton

This paper describing the mining practices at Mine No. 2 of the Marquette Range, Michigan is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various minim; districts of the United States. The publication, of this information should be of interest to the industry at large and the exchange of ideas thereby made possible should be of economic value to operators in all harts of the country. ACKNOWLEDGMENTS The author is indebted to the superintendent, engineer, and mining captain of the property discussed in this paper for much of the information presented. The geological classification is taken from publications of the U. S. Geological purvey.

Jan 1, 1929

By T. O. Llewellyn

The Bureau of Mines, as part of its goal to develop technology that can conserve domestic mineral resources investigated beneficiation methods for recovering phosphate minerals from two Southern Florida deposits with high magnesium content. Chemical analyses of sized fractions indicated that no coarse pebble concentrate could be produced from either deposit. Conventional fatty acid-fuel oil batch flotation tests on two phosphate samples, analyzing 6.8 and 8.5 pct P205, yielded concentrates containing 28.97 to 29.80 pct P20S at recoveries ranging from 72.4 to 76.9 pct of the flotation feed. The MgO content ranged from 1.20 to 1.36 pct. Bubbling S02 gas through an aqueous concentrate slurry, further reduced the MgO content of these phosphate concentrates to 0.5 and 0.8 pct, but with a concomitant loss in the phosphate recovery. Settling characteristics of slimes from both phosphate samples showed a slow settling rate, which is a typical characteristic of other slimes in the region.

Jan 1, 1981

By R. H. King

A very simple cold-bend test was devised and tested for evaluating thermoplastic jackets used on mine-power-feeder cables. A test sample is bent into a semi-circle whose radius is equal to the minimum bend radius recommended by IPCEA and then cooled to the, desired test temperature (-35°C). While at temperature, the sample is straightened by pulling the cable ends with a winch arrangement. The results show that of the jackets tested, those which cannot withstand the test literally burst when the sample is straightened.

Jan 1, 1978

By S. H. Ash

The United States Bureau of Mines has published relatively little on the flooding and unwatering of coal and metal mines. Bulletin 229, Fifty-Nine Coal-Mine Fires, published in 1927, contains several instances of the flooding of mines or sections thereof to extinguish fires but does not describe their unwatering. Report of Investigations 2649, Explosion Hazards Incidental to Unwatering Coal Mines, published in 1924, warned against the possibility of gas accumulations in flooded mines and indicated the precautions to be taken. Report of Investigations 2255, An Unusual Hazard in Reopening Long-Flooded Timbered Metal Mines, published in 1921, told of methane being pocketed and the danger thereof. The flooding of mines originates in many ways. At some mines flooding followed reopening after what was thought to be permanent abandonment; also, explosions have caused some mines to be flooded. Extinguishing fires, accidental encountering of underground streams or flooded old workings, and caves of strata admitting water from underground workings, water-bearing strata, or surface accumulations have also flooded all or parts of mines. Unfortunately, un watering often necessitates much study and causes apprehension largely because experiences in similar situations are not generally known, as few descriptions of successful or unsuccessful methods are available. The job has sometimes been contracted for outside the local management involved and has become a matter of record for the contractor only. As the cost-plus contract system often employed in the past is now known to be expensive, careful managements elect to handle the problem themselves, in line with the general policy of cutting expense where possible. This report describes specific in-stances of successful unwatering by operators.

Jan 1, 1933

By Allan F. Smith

The Bureau of Mines studied toxic products produced by burning eight fire-resistant mines conveyor belts, a brattice cloth, and an electrical cable insulation obtained from laboratory-scale burning experiments under various air-flow conditions. Generally, CO product concentrations for most materials were noticeably higher then the NO2 and HC1 levels that were measured; also, no phosgene was detected. However, several of the fire-resistant belt samples yielded HC1 concentrations that were above the reported lethal level for 1/2 to 1-hour exposures, although these data were limited to flow conditions where air dilution effects were small; the belt materials that showed this behavior included samples of polyvinyl chloride, styrene butadiene, styrene butadiene blends, and a British neoprene which yielded the greatest amount of toxic vapor. In addition, some results are presented on the phosphoric acid concentrations that may be produced from the decomposition of ammonium dihydrogen phosphate when dispersed on a burning coalbed.

Jan 1, 1973