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By Lauri Gregg

How Can Man Meet the Carbon-Free Energy Challenge ? ? Increases in Energy Efficiency can displace 1/2 to 2/3 of the Carbon-Free Energy required to stabilize at 550 ppmv ? Renewable Energies require too much land and thus can displace 5 to 10 % of the energy requirement ? Large new sources of carbon free energy are needed ? Conservation is desirable but provides only a small and variable contribution ? People will have to adjust to higher levels of CO2 in the atmosphere as energy demand continues to grow

Nov 1, 2002

By Ludwig Schmidt

Steel tanks often corrode rapidly in oil fields where the gas produced with crude petroleum contains an appreciable quantity of hydrogen sulphide. In many instances working tanks have been discarded after only six months of service because of failure induced by corrosion. Aluminum has been used for some time in the fabrication of certain equipment incidental to the handling of oils containing hydrogen sulphide gas in solution, and has exhibited no serious corrosive action. These uses indicated that aluminum tanks might be equally effective in counteracting hydrogen sulphide corrosion. Consequently, in the spring of 1928, an all-aluminum stock tank of 500 barrels capacity and a "composite" tank of equal capacity, having a steel bottom and bottom ring and an aluminum top and top ring, were placed in service on the State-Lassiter lease of the Gulf Production Co. in Crane County, Tex. These tanks were under observation for one year, the test being sponsored by the Gulf Production Co., the Aluminum Co. of America, rind the Parkersburg Ric and Real Co. The results of this preliminary test sustained the belief that aluminum is highly resistant to hydrogen sulphide gas and likewise indicated the type or grade of aluminum which could be most economically used for lease tankage. However, in this preliminary test the Wake were not subjected to contact with the large quantities of highly concentrated brines such as often are associated and produced with crude oil. Therefore, it was suggested by representatives of .the Aluminum Co. that additional tests be made to include production conditions in which large quantities of brine would be handled, for past experience had shown that aluminum often is susceptible to the corrosive action of brines.

Jan 1, 1931

By C. R. van Staal, L. R. Fyffe, J. A. Winchester

"The geochemical characteristics of Early Paleozoic volcanic rocks are used to establish the following tectono-volcanic regimes in the northeastern mainland Appalachians: foreland continental rift volcanics; fore-arc ophiolites; island-arc volcanics; back-arc ophiolites; and back-arc ensialic volcanics. A Late Precambrian calc-alkaline magmatic arc bounds the Early Paleozoic volcanics to the southeast.The Precambrian calc-alkaline volcanics of the Caledonian Highlands, primitive Cambro-Ordovician oceanic-arc volcanics of the Eastern Townships, and within-plate Ordovician volcanics of the Miramichi Highlands can be related to a progressive change in mode of subduction from compressional Andean-type in the Late Proterozoic to extensional Western Pacific-type in the Early Paleozoic. The development of marginal oceanic basins in the Paleozoic created a more favourable environment for volcanogenic sulphide deposition, particularly in back-arc areas.The influence of tectonic setting is reflected in the distribution, size and metal ratios of the massive sulphide deposits associated with the volcanic rocks; deposits within intra-oceanic arcs in the Eastern Townships of Quebec average two million tonnes grading 2.2% Cu, 4.0% Zn, and 0.6% Pb, whereas those within a back-arc, ensialic rift near Bathurst, New Brunswick, average nine million tonnes grading 0.6% Cu, 5.4% Zn, and 2.2% Pb."

Jan 1, 1990

By Dennis N. Poffenroth

One concern of the Mine Safety and Health Administration is the structural integrity of steel wire ropes used on mine personnel hoists and elevators. Failure of such ropes has resulted in loss of life and property. Although thorough and regular visual examinations are performed, hoist ropes may still fail from undetected internal wear, corrosion, and broken wires. To complement visual examinations, nondestructive rope inspection techniques have been developed to determine deterioration and removal criteria. The techniques use electromagnetic and permanent-magnet test instruments designed by a Canadian firm. This paper describes the operating principles, field and laboratory testing of these nondestructive testing instruments, and discusses the feasibility of using this type of testing as a supplement to visual examination and destructive tests.

Jan 1, 1983

By Harold E. Heide

Although the United States has been the largest consumer of tin, only a small quantity of tin was produced or. the North American Continent during peace times, and thy deficiency was made UP by foreign imports. Because the most important sources of tin wore cut off by the war with Japan, it became necessary to increase imports from South America and Africa and, if possible, develop domestic tin reserves. Most of the tin produced in North America has come from the Seward Peninsula, Alaska, and a substantial portion of this was produced from the Potato Mountain area. Tin was first identified as occurring in the Seward Peninsula by A. H. Brooks in 1900, when a part of heavy concentrates from Anikovik River and Buhna Creek, one of its tributaries, proved to be stream tin. 4/ His report was given considerable publicity by the daily press, and the first steamers north in 1901 carried a number of prospectors bound for the Seward Peninsula to search for tin. The deposits of stream tin on Buck Creek in the Potato Mountain area were discovered in the fall of 1901. 2/

Jan 1, 1949

By R. M. G. S. Berezowsky

An atmospheric ammoniacal thiosulphate leach system was developed to recover gold and silver from residues of the ammoniacal oxidation leaching of sulphidic copper concentrates. Extractions of 88 - 95% Au and 83 - 98% Ag were attained within 2 to 4 hours at 40 - 60°C in thiosulphate leaching of the oxidation leach residues of Manitoba chalcopyrite concentrates analyzing 24.6% Cu, 0.18 oz/ton Au and 4.26 oz/ton Ag and a complex British Columbia chalcopyrite/tetrahedrite concentrate analyzing 18.5% Cu, 0.27 oz/ton Au and 276 oz/ton Ag. Parameters affecting the Au and Ag solubilization included thiosulphate, ammonia, and cupric ion concentrations, temperature, retention time and the degree of Cu extraction and sulphide oxidation in the primary oxidation leach. The precious metals were recovered from the thiosulphate liquors by zinc dust cementation.

Jan 1, 1979

By Donald Markle

ANTHRACOAL is a mixture of small particles of anthracite coal and a matrix of practically pure carbon, formed from the distillation of coal-tar pitch or other suitable bitumen. It is a hard, dense, homogeneous mass, with a silvery luster and in color varies from silvery to grayish black. When pushed from the oven, it develops only partly the fingerlike structure of coke; but, unlike coke, it has a tendency to remain in blocky masses. When struck with a hammer or passed through crushing rolls, it breaks with an irregular fracture, similar to anthracite, but with very little fines. Due to its density, anthracoal is harder, tougher, and stronger than coke. The results of a test made by the blast-furnace department, of the Bethlehem Steel Co., on two barrels of anthracoal are given in Table 1. TABLE I.-Results of Shatter Tests on Anthracoal and Coke Anthracoal Test Good Blast-furnace Coke First Second Barrel Barrel Moisture, per cent 0.77 0.76 Under 5, variation not over 3 points Sieve test Through 2-in. screen, per cent 7.71 7.29 Under 40 Through 1-in. screen, per cent 1.37 1.56 Through ½ -in. screen, percent 0.93 1.08 Under 8 Over 2-in. screen, per cent 92.29 92.71 Over 60 Shatter test Through 2-in. screen, per cent 10.06 ' 12.40 1 Under 16 Through 1-in. screen, per cent 2.66 2.06 Through ½ -in. screen, per cent 1.80 1.26 Over 2-in. screen, per cent Hardness number 86.40 86.10 Over 81 Analysis Ash, percent 16.64 16.48 Under 11 Sulfur, per cent 1.17 1.10 Under 0.95 Volatile matter, per cent 0.77 0.27 Fixed carbon, percent 82.59 83.25 Over 87

Jan 8, 1921

By William W. Adams

The quarrying and related industries of the United States made a large gain in employment (man-hours of work) in 1942 with a somewhat smaller number of men employed than in 1941. This was accomplished chiefly by increasing the number of workdays per man and also by increasing the length of the workday. In spite of the greater volume of work performed, the industry had a more favorable accident-frequency rate in 1942 than in the previous year. Accident and employment reports from operating companies showed that the industry employed 84,270 men for an average of 271 days per man in 1942, with a volume of work of almost 181 million man-hours. The average workshift comprised 7.93 hours, and the number of man-shifts worked totaled nearly 23 million. Injuries from accidents in and about the quarries and plants caused disability to 6,461 employees, 112 of whom died as a result of their injuries, including 28 employees whose lives were lost in a single disaster. The accident-frequency rate in the industry was 35.73 per million man-hours worked, comparing favorably with a rate of 40.11 for the previous year. However, the figure for 1942 included a death rate of 0.62 per million man-hours which, because of the disaster referred to, was considerably higher than the fatality rate of 0.44 for 1941. Had the disaster not occurred, the fatality rate for the industry for 1942 would have been 0.46. The major disaster in which 28 lives were lost occurred on March 26 at the Sandts Eddy quarry of the Lehigh Portland Cement Co. near Easton Pa.

Jan 1, 1944

By JESSICA W. A. AZURE, Samuel Frimpong, AZUPURI G. A. KABA, FORSYTH A. KADINGDI, PROSPER E. A. AYAWAH

This study developed machine learning (ML) models for predicting rock formation reactive forces experienced by a hydraulic shovel bucket during excavation. To do this, rock formation in the form of muckpile was modeled as granular ball elements in three-dimensional particle flow code (PFC) using linear bonding logic. A typical field-size hydraulic shovel bucket modelled in AutoCAD was used to excavate the rock formation and the three-dimensional shovel bucket resistive forces required to cut through the rock formation were measured and recorded. The experiments involved different muckpile height, bulk densities, repose angles, and average fragment size. Six ML algorithms, artificial neural network (ANN), K-nearest neighbor (KNN), linear, random forest (RF), regression tree (RT), and support vector machine (SVM), were evaluated on their ability to predict the shovel bucket resistive forces. The input variables used for the prediction of the resistive forces were the muckpile bulk density, angle of repose, height, and fragment size. The results showed that the ML techniques are useful and reliable methods of predicting rock formation resistive forces based on the rock formation properties. This research is a preliminary step towards developing reliable models for accurate prediction of excavation forces/torques which could potentially enhance hydraulic shovel process automation.

Sep 27, 2021

By H. L. Riley

This report describes the methods and equipment used by the Watauga Stone Co. to drill and blast limestone in a two-level quarry, and to crush, screen, blend, and load this stone. Power requirements per ton of stone produced are reported. The personnel requirements for individual phases of the operation are tabulated in man-hours per ton of stone produced.

Jan 1, 1963

By Arne Landsberg

A study of the chlorination kinetics of germanium, silicon, iron, tungsten, molybdenum, columbium, and tantalum has been made to determine the effects of temperature, chlorine concentration, geometric surface area and gamma radiation. The reaction products were volatile at the temperatures used this making it possible to follow the reaction rates by weight loss of the solid. Chlorination rates of germanium, silicon, and iron were found to be directly proportional to chlorine concentration while the rates for tungsten, molybdenum, columbium, and tantalum were proportional to the 0.5 to 0.6 power of chlorine concentration. A good correlation of reaction rate and geometric surface areas was not obtained because the true surface area of the samples could not be measured. Intense gamma radiation had no effect on reaction rates. The Arrhenius activation energies determined over the temperatures used are as follows: Germanium, 27 kcal/mole (233°-241° C); silicon 33 kcaL/mole (375°-517° C); iron, cold rolled, 20 kcal/mGle (259°-325° C) annealed, 21 kcal/mole (293°-337° C); tungsten, 43 kcal/mole (617-776° C); molybdenum, 37 kcal/mole (445°-4910 C); columbium) 34 kcal/mole (229°?255° C); and tantalum, 29 kcal/mole (370°-449° C).

Jan 1, 1965

By K. E. Stanfield

The oil yields of sections of Green River oil shale in Colorado, Utah, and Wyoming are presented as part of a continuing project to determine oil-shale reserves in the United States. Oil-yield logs, based upon analyses obtained from 1945 through 1952, are presented to show the thickness and richness of 202 sections of Green River oil shale. The logs are based on analyses of approximately 20,500 samples, representing 179,000 feet of shale, which were made by the Bureau of Mines, and upon analyses, representing approximately 26,000 feet of shale, which were made by other agencies. The samples consisted of cores from a Bureau of Mines coring program in U. S. Naval Oil-Shale Reserve 1, Garfield County, Colo., and cores, drill cuttings, and channel samples provided by other agencies, chiefly oil companies. Most of the samples of oil shale from Utah and Wyoming were derived from oil-well drilling operations. As a result, the oil-shale sections were widely scattered and were not extensive or reliable enough to be representative of the significant deposits of Green River oil shale in these States. The oil-shale sections for Colorado, however, were more comprehensive, and a number of the sections were used in a previous report as a basis for estimating oil-shale reserves in Colorado. The present report does not give estimates of oil-shale reserves but is limited to presentation of oil-shale analyses that may be used for future reserve estimates. Other sections of Green River oil shale are being analyzed, and the results will be published in subsequent reports.

Jan 1, 1954

By R. W. Van Dolah

The Bureau of Mines t.ced its investigations into sympathetic detonation of ammonium nitrate (AN) and ammonium nitrate-fuel oil (AN-FO) to define the scaling law for safe separation from detonating AN-FO. Both missile- and non-missile-producing AN-FO donors, weighing up to 5,400 pounds, were employed with acceptors of the same size. The usual cube-root scaling law was not confirmed; exponents for the relationship S = f(Wx) for AN were 0.51 with non¬missile-producing donors and 0.61 for missile-producing donors. For AN-FO an exponent of 0.80 was indicated in the missile-producing case. AN-F0 in polyethylene bags appeared somewhat more easily initiated than bulk AN-FO. The efficacy of barricades in protecting AN charges was investigated. detonation distances were reduced from one-third to one-seventh when filled barricades were employed. The investigation was extended to dynamite with both types of donors. With 1,600-pound missile-producing donors and an equivalent weight of dynamite, initiation would be expected in 50 percent of the trials at 167 feet. The corresponding value in the non-missile case was 67 feet. The data developed in this program of sympathetic detonation will allow the development of a rational set of safe separation distances for AN, AN-FO, and explosives.

Jan 1, 1966

By H. L. Riley

This report describes the methods and equipment used by the Watauga Stone Co. to drill und blast limestone in a two-level quarry, and to crush, screen, blend, and load this stone. Power requirements per ton of stone produced are reported. The personnel requirements for individual phases of the operation are tabulated in man-hours per ton of stone produced.

Jan 1, 1963

By A. K. Verma

Several longwall faces in India have collapsed due to adverse geological conditions and/or inadequate capacity of powered supports. Thus it is imperative to access the capacity of a powered support and its interaction at longwall faces of varying geomining conditions in advance with lots of confidence. To achieve this, an index has been developed to ascertain the front leg pressure (FLP) of chock-shield support and roof-to-floor convergence (RFC) at longwall faces. The index called ?Longwall Face Stability Index? (LFSI) has been developed using statistics and Finite Element Modelling (FEM). The front leg pressure (FLP) and roof-to-floor convergence (RFC) predicted from the LFSI are validated with the field monitored data from two longwall panels. In this study, an attempt is also made to incorporate various geomining conditions into the finite element models typical of longwall mining practice. The index has taken into account the wide variations of geomining parameters like thickness, young?s modulus and friction angle of main roof (small, large), coal type (soft, hard), powered support capacity, and depth of coal seam. Thus, LFSI can be thought of as an index representing combined effect of roof type, geomining conditions and powered support capacity.

Jan 1, 2008

By A. A. McDonald

Anode casting has been in operation for two years in Hudson Bay Mining and Smelting's Flin Flon smelter. The new plant allows all casting to be done on one shift and so achieves considerable labour savings. The equipment and operations are described. Some important features are as follows: very consistent anode weights by the use of the load-cell controlled casting ladle; excellent mould life ; very low reject rate; and trouble-free take -off tower. Some of the start-up problems are described and an outline is given of the main operator functions. Data on labour, propane and maintenance costs are presented.

Jan 1, 1977

By Cleo G. Rall

The method for determining the effective porosity of oil- and gas-bearing sands described in this report is a development of earlier methods (28)3/ devised by the Bureau of Mines. The apparatus bas been improved and made more convenient to use, but the procedure is essentially the same as that which has been in use for maw years. A tabulation at the end of the report gives the results of more than 4,800 porosity determinations for oil sands4/ in the fields of 13 States, A selected bibliography of references to articles containing descriptions and evaluations of various methods of' determining porosity is included in this report. The method was devised and developed at the Petroleum Experiment Station at Bartlesville, Okla., as part of the Bureau's research on fluid-energy relationships and on methods of improving the recovery of crude oil from underground reservoirs.

Jan 1, 1954

By P. H. Jennings

Commercial tellurium commonly contains heavy basemetal impurities such as lead, copper, iron, etc., as well as selenium and oxygen. The base metals may be removed by vacuum distillation or by zone melting. Vacuum distillation is a convenient method for treating moderate quantities (~ 100 kg.) for the production of a material having a total content of heavy metals in the 10-30 ppm range. By zone melting, it is possible to lower all the heavy metal impurities tm below the limits of spectrographie detection. Neither vacuum distillation nor zone melting is effective for the removal of selenium, but treatment of molten tellurium with hydrogen converts selenium to hydrogen selenide. This procedure is too s low to be considered except as an adjunct to zone melting. In the course of air-melting, many of the more easily oxidized impurities form a dross and may thus be readily removed. Substantial refinement with respect to iron, tin, chromium, aluminum, sodium, silicon, magnesium, calcium and manganese can be achieved in this way. Although tellurium can be electrodeposited from either acid or alkaline solutions of the dioxide, various factors militate against successful electro-refining, amongst which may be mentioned the brittleness of cast tellurium anodes and the tendency for the metal to be deposited in dendritic form, even at low current densities.

Feb 1, 1966

By P. H. Jennings, J. C. T. Farge

Commercial tellurium commonly contains heavy base-metal impurities such as lead, copper, iron, etc., as well as selenium and oxygen. The base metals may be removed by vacuum distillation or by zone melting. Vacuum distillation is a convenient method for treating moderate quantities ( 100 kg.) for the production of a material having a total content of heavy metals in the 10-30 ppm range. By zone melting, it is possible to lower all the heavy metal impurities tm below the limits of spectrographie detection. Neither vacuum distillation nor zone melting is effective for the removal of selenium, but treatment of molten tellurium with hydrogen converts selenium to hydrogen selenide. This procedure is too slow to be considered except as an adjunct to zone melting. In the course of air-melting, many of the more easily oxidized impurities form a dross and may thus be readily removed. Substantial refinement with respect to iron, tin, chromium, aluminum, sodium, silicon, magnesium, calcium and manganese can be achieved in this way. Although tellurium can be electrodeposited from either acid or alkaline solutions of the dioxide, various factors militate against successful electro-refining, amongst which may be mentioned the brittleness of cast tellurium anodes and the tendency for the metal to be deposited in dendritic form, even at low current densities.

Jan 1, 1966

By D. Harrington

Before the present century there existed a fairly persistent demand for the establishment of a Federal Department of Mines, but relatively little was done about it until a considerable number of very serious coal-mine disasters in 1906, 1907, 1908, and 1909 created what might almost be termed a national scandal and virtually forces the Federal. Government to take action to try to solve the problem of the cruse and prevention of such disastrous occurrences. Instead of a Department of Mines, the mining people had to accept a bureau, which was created on July l, 1910; and while the Bureau of Mines was given numerous functions, unquestionably the promotion of safety in the mineral industries was and continues to be one of its main "jobs." The Bureau's organic act was approved in 1910 and amended in 1913. Both the original and amended acts indicated that promoting; the health and safety of the mine workers constituted the chief function of the Bureau, and that this was the construction placed on its activities by those put in charge in 1910 is shown very definitely by the fact that as soon as the Bureau came into existence on July 1, 1910, both health end safety activities were started in its Mine Accidents Division. Before the end of the first fiscal year (June 30, 1911) 6 mine safety stations had been established in various parts of the United States, add 6 nine safety cars had been put into the field; by October 1910 first-aid-training work was being done in mining regions. The Bureau eras able to function so promptly in its safety work largely because sections of the Geological Survey, which had been doing some coal-mine safety work since 1907 or 1905, were transferred into the Bureau when it began to operate in July 1910. On October 30, 1911, a national First-Aid Meet was held at Pittsburgh, Pa., at which first aid and mine rescue were demonstrated. During the fiscal year 1910-11, the first year of the Bureau's existence, 509 persons were given certificates indicating completion of the Bureau's training course in first aid.

Jan 1, 1939